158 results on '"Philip E. Lapinski"'
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2. Deletion of SHP-2 in mesenchymal stem cells causes growth retardation, limb and chest deformity, and calvarial defects in mice
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Philip E. Lapinski, Melissa F. Meyer, Gen-Sheng Feng, Nobuhiro Kamiya, and Philip D. King
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Medicine ,Pathology ,RB1-214 - Abstract
SUMMARY In mice, induced global disruption of the Ptpn11 gene, which encodes the SHP-2 tyrosine phosphatase, results in severe skeletal abnormalities. To understand the extent to which skeletal abnormalities can be attributed to perturbation of SHP-2 function in bone-forming osteoblasts and chondrocytes, we generated mice in which disruption of Ptpn11 is restricted to mesenchymal stem cells (MSCs) and their progeny, which include both cell types. MSC-lineage-specific SHP-2 knockout (MSC SHP-2 KO) mice exhibited postnatal growth retardation, limb and chest deformity, and calvarial defects. These skeletal abnormalities were associated with an absence of mature osteoblasts and massive chondrodysplasia with a vast increase in the number of terminally differentiated hypertrophic chondrocytes in affected bones. Activation of mitogen activated protein kinases (MAPKs) and protein kinase B (PKB; also known as AKT) was impaired in bone-forming cells of MSC SHP-2 KO mice, which provides an explanation for the skeletal defects that developed. These findings reveal a cell-autonomous role for SHP-2 in bone-forming cells in mice in the regulation of skeletal development. The results add to our understanding of the pathophysiology of skeletal abnormalities observed in humans with germline mutations in the PTPN11 gene (e.g. Noonan syndrome and LEOPARD syndrome).
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- 2013
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3. Development of severe skeletal defects in induced SHP-2-deficient adult mice: a model of skeletal malformation in humans with SHP-2 mutations
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Timothy J. Bauler, Nobuhiro Kamiya, Philip E. Lapinski, Eric Langewisch, Yuji Mishina, John E. Wilkinson, Gen-Sheng Feng, and Philip D. King
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Medicine ,Pathology ,RB1-214 - Abstract
SUMMARY SHP-2 (encoded by PTPN11) is a ubiquitously expressed protein tyrosine phosphatase required for signal transduction by multiple different cell surface receptors. Humans with germline SHP-2 mutations develop Noonan syndrome or LEOPARD syndrome, which are characterized by cardiovascular, neurological and skeletal abnormalities. To study how SHP-2 regulates tissue homeostasis in normal adults, we used a conditional SHP-2 mouse mutant in which loss of expression of SHP-2 was induced in multiple tissues in response to drug administration. Induced deletion of SHP-2 resulted in impaired hematopoiesis, weight loss and lethality. Most strikingly, induced SHP-2-deficient mice developed severe skeletal abnormalities, including kyphoses and scolioses of the spine. Skeletal malformations were associated with alterations in cartilage and a marked increase in trabecular bone mass. Osteoclasts were essentially absent from the bones of SHP-2-deficient mice, thus accounting for the osteopetrotic phenotype. Studies in vitro revealed that osteoclastogenesis that was stimulated by macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor kappa B ligand (RANKL) was defective in SHP-2-deficient mice. At least in part, this was explained by a requirement for SHP-2 in M-CSF-induced activation of the pro-survival protein kinase AKT in hematopoietic precursor cells. These findings illustrate an essential role for SHP-2 in skeletal growth and remodeling in adults, and reveal some of the cellular and molecular mechanisms involved. The model is predicted to be of further use in understanding how SHP-2 regulates skeletal morphogenesis, which could lead to the development of novel therapies for the treatment of skeletal malformations in human patients with SHP-2 mutations.
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- 2011
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4. Isolation and Culture of Mouse Lymphatic Endothelial Cells from Lung Tissue
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Philip E, Lapinski and Philip D, King
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Mice ,Cell Survival ,Immunomagnetic Separation ,Cell Culture Techniques ,Animals ,Endothelial Cells ,Cell Separation ,In Vitro Techniques ,Lung ,Cell Proliferation ,Culture Media - Abstract
There is increasing interest in the study of the mammalian lymphatic system, including the lymphatic endothelial cells (LECs) that make up lymphatic vessels. The ability to isolate primary LECs from tissue of normal and genetically modified mice permits detailed analysis of this unique cell type. Here, we describe a robust protocol for the isolation and in vitro expansion of LECs from mouse lung by antibody-based magnetic separation.
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- 2021
5. Abstract 1633: Comprehensive cell- and gene-based tumor profiling using flow cytometry and Nanostring in a murine bladder cancer model
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Philip E. Lapinski, David W. Draper, and Scott Wise
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Cancer Research ,Oncology - Abstract
Background: Five checkpoint immunotherapies that target the PD-1/PD-L1 axis are currently FDA approved. Novel approaches are helping to identify new combination treatment strategies for therapeutic intervention of bladder cancer, which is the thirteenth leading cause of cancer-related deaths. Using anti-mPD-1 treatment in a murine bladder cancer model MB49, we show that non-targeted immune gene expression profiling combined with flow cytometry provides a gene and cell-specific signature for the tumor microenvironment, which aids in the identification of targets for novel treatment approaches. Methods: C57BL/6 mice with established MB49 tumors were treated with anti-mPD-1 or isotype control antibodies. Tumors were collected 3 days after the last treatment. Treatment-induced immunophenotypic changes were examined in tumor-infiltrating immune subsets using T cell- and myeloid-focused flow cytometry panels. We used the mouse PanCancer IO 360™ Nanostring panel for transcriptomic analysis of 770 genes and the ROSALIND™ platform (OnRamp BioInformatics) to identify differentially regulated genes between treatment groups. Results: Treatment of tumors with anti-mPD-1 showed moderate anti-tumor activity, with a 58% tumor growth inhibition at day 18 post-implant. Immunophenotyping by flow cytometry revealed that anti-mPD-1 triggered an increase in tumor-infiltrating CD8+ T cells compared to control animals. Additionally, the CD8+ T cell phenotype was altered by treatment, with increased frequency of ICOS and LAG-3 in CD8+ T cells in tumors from treated animals. Changes in the T cell compartment also included reduction in the proportion of central memory CD8+ and CD4+ T cells compared to controls. In the myeloid compartment, iNOS expression increased in tumor-associated macrophages from treated animals. NanoString analysis revealed 62 genes were differentially regulated in tumors from treated animals compared to controls. ROSALIND analysis classified 30 of the genes as regulators of interferon, cytotoxicity, antigen presentation, and cytokine signaling. Among the genes upregulated by anti-mPD-1 were IDO, TIM-3, and CSFR1, which can promote tumor growth and are clinical targets being investigated for new immunotherapies. Conclusions: NanoString analysis complemented immunophenotyping to provide a comprehensive profile of the MB49 tumor model. Together, these data demonstrate that anti-mPD1 increases T cell recruitment into the tumor and upregulates the expression of genes known to enhance T cell recruitment and anti-tumor activity. iNOS protein upregulation suggests that anti-mPD-1 treatment may also exert effects by driving M2 macrophages towards an M1 phenotype. Further investigation may elucidate clinical implications for inhibitors of these gene products as treatment options in combination with anti-mPD-1. Citation Format: Philip E. Lapinski, David W. Draper, Scott Wise. Comprehensive cell- and gene-based tumor profiling using flow cytometry and Nanostring in a murine bladder cancer model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1633.
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- 2022
6. Isolation and Culture of Mouse Lymphatic Endothelial Cells from Lung Tissue
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Philip E. Lapinski and Philip D. King
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Cell type ,government.form_of_government ,fungi ,Biology ,Isolation (microbiology) ,In vitro ,Cell biology ,Genetically modified organism ,Lymphatic Endothelium ,Lymphatic system ,Cell culture ,biology.protein ,government ,sense organs ,Antibody - Abstract
There is increasing interest in the study of the mammalian lymphatic system, including the lymphatic endothelial cells (LECs) that make up lymphatic vessels. The ability to isolate primary LECs from tissue of normal and genetically modified mice permits detailed analysis of this unique cell type. Here, we describe a robust protocol for the isolation and in vitro expansion of LECs from mouse lung by antibody-based magnetic separation.
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- 2021
7. Macropinocytosis drives T cell growth by sustaining the activation of mTORC1
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Philip E. Lapinski, Jackson S. Turner, Irina L. Grigorova, John C. Charpentier, Joel A. Swanson, Philip D. King, and Di Chen
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CD4-Positive T-Lymphocytes ,0301 basic medicine ,T-Lymphocytes ,Science ,T cell ,Antigen presentation ,T cells ,General Physics and Astronomy ,Endosomes ,mTORC1 ,Mechanistic Target of Rapamycin Complex 1 ,Endocytosis ,Article ,General Biochemistry, Genetics and Molecular Biology ,Mice ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Extracellular ,Animals ,Guanine Nucleotide Exchange Factors ,Humans ,Compartment (development) ,Amino Acids ,lcsh:Science ,Receptor ,Multidisciplinary ,Chemistry ,Pinocytosis ,General Chemistry ,Cellular immunity ,Cell biology ,Mice, Inbred C57BL ,030104 developmental biology ,medicine.anatomical_structure ,TOR signalling ,030220 oncology & carcinogenesis ,lcsh:Q ,Lysosomes ,Signal Transduction - Abstract
Macropinocytosis is an evolutionarily-conserved, large-scale, fluid-phase form of endocytosis that has been ascribed different functions including antigen presentation in macrophages and dendritic cells, regulation of receptor density in neurons, and regulation of tumor growth under nutrient-limiting conditions. However, whether macropinocytosis regulates the expansion of non-transformed mammalian cells is unknown. Here we show that primary mouse and human T cells engage in macropinocytosis that increases in magnitude upon T cell activation to support T cell growth even under amino acid (AA) replete conditions. Mechanistically, macropinocytosis in T cells provides access of extracellular AA to an endolysosomal compartment to sustain activation of the mechanistic target of rapamycin complex 1 (mTORC1) that promotes T cell growth. Our results thus implicate a function of macropinocytosis in mammalian cell growth beyond Ras-transformed tumor cells via sustained mTORC1 activation., Macropinocytosis has been implicated in the expansion of transformed cells when nutrient-depleted. Here the authors show that macropinocytosis also contributes to the expansion of primary T cells even under nutrient-replete conditions, potentially by providing access of extracellular amino acids to an endolysosomal compartment to sustain mTORC1 activation.
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- 2020
8. RASA1-driven cellular export of collagen IV is required for the development of lymphovenous and venous valves in mice
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Xin Geng, Philip E. Lapinski, Philip D. King, R. Sathish Srinivasan, Di Chen, and Michael J. Davis
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MAPK/ERK pathway ,Collagen Type IV ,Organogenesis ,Embryonic Development ,030204 cardiovascular system & hematology ,Biology ,Basement Membrane ,Negative regulator ,Mice ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Lymphatic vessel ,Animals ,Protein kinase A ,Molecular Biology ,Lymphatic Vessels ,030304 developmental biology ,Basement membrane ,0303 health sciences ,Chemistry ,030302 biochemistry & molecular biology ,Endothelial Cells ,p120 GTPase Activating Protein ,Embryo ,Embryo, Mammalian ,Venous Valves ,Cell biology ,Endothelial stem cell ,medicine.anatomical_structure ,MAPK Inhibitors ,Signal transduction ,Developmental biology ,Research Article ,Developmental Biology - Abstract
RASA1, a negative regulator of the Ras-mitogen-activated protein kinase (MAPK) signaling pathway, is essential for the development and maintenance of lymphatic vessel (LV) valves. However, whether RASA1 is required for the development and maintenance of lymphovenous valves (LVV) and venous valves (VV) is unknown. In this study we show that induced endothelial cell (EC)-specific disruption of Rasa1 in mid-gestation mouse embryos did not affect initial specification of LVV or central VV but did affect their continued development. Similarly, switch to expression of a catalytically inactive form of RASA1 resulted in impaired LVV and VV development. Blocked development of LVV in RASA1-deficient embryos was associated with accumulation of the basement membrane protein, collagen IV, in LVV-forming EC and could be partially or completely rescued by MAPK inhibitors and drugs that promote collagen IV folding. Disruption of Rasa1 in adult mice resulted in venous hypertension and impaired VV function that was associated with loss of EC from VV leaflets. In conclusion, RASA1 functions as a negative regulator of Ras signaling in EC that is necessary for EC export of collagen IV, thus permitting the development of LVV and the development and maintenance of VV.
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- 2020
9. RASA1-dependent cellular export of collagen IV controls blood and lymphatic vascular development
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Philip E. Lapinski, Joyce M.C. Teng, Philip D. King, Di Chen, and Paula E. North
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0301 basic medicine ,MAPK/ERK pathway ,Collagen Type IV ,Angiogenesis ,MAP Kinase Signaling System ,Heart Ventricles ,Apoptosis ,Hemorrhage ,Endoplasmic Reticulum ,Arteriovenous Malformations ,03 medical and health sciences ,Mice ,0302 clinical medicine ,Pregnancy ,Cell Line, Tumor ,Animals ,Edema ,Transgenes ,Protein kinase A ,Lymphatic Vessels ,Neovascularization, Pathologic ,Chemistry ,Endoplasmic reticulum ,ER retention ,p120 GTPase Activating Protein ,General Medicine ,Heart Valves ,Phenylbutyrates ,Cell biology ,Mice, Inbred C57BL ,030104 developmental biology ,Phenotype ,Ras Signaling Pathway ,Animals, Newborn ,030220 oncology & carcinogenesis ,Vascular Disorder ,Female ,Signal transduction ,Neoplasm Transplantation ,Signal Transduction ,Research Article - Abstract
Combined germline and somatic second hit inactivating mutations of the RASA1 gene, which encodes a negative regulator of the Ras signaling pathway, cause blood and lymphatic vascular lesions in the human autosomal dominant vascular disorder capillary malformation-arteriovenous malformation (CM-AVM). How RASA1 mutations in endothelial cells (EC) result in vascular lesions in CM-AVM is unknown. Here, using different murine models of RASA1-deficiency, we found that RASA1 was essential for the survival of EC during developmental angiogenesis in which primitive vascular plexuses are remodeled into hierarchical vascular networks. RASA1 was required for EC survival during developmental angiogenesis because it was necessary for export of collagen IV from EC and deposition in vascular basement membranes. In the absence of RASA1, dysregulated Ras mitogen-activated protein kinase (MAPK) signal transduction in EC resulted in impaired folding of collagen IV and its retention in the endoplasmic reticulum (ER) leading to EC death. Remarkably, the chemical chaperone, 4-phenylbutyric acid, and small molecule inhibitors of MAPK and 2-oxoglutarate dependent collagen IV modifying enzymes rescued ER retention of collagen IV and EC apoptosis and resulted in normal developmental angiogenesis. These findings have important implications with regards an understanding of the molecular pathogenesis of CM-AVM and possible means of treatment.
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- 2019
10. RASA1
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Philip E. Lapinski and Philip D. King
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- 2018
11. Blood Vascular Abnormalities in Rasa1 Knockin Mice
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Timothy J. Bauler, Philip E. Lapinski, Elizabeth D. Hughes, Thomas L. Saunders, Jennifer A. Oliver, Philip D. King, and Beth A. Lubeck
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Mutation ,Pathology ,medicine.medical_specialty ,Transgene ,Point mutation ,P120 GTPase Activating Protein ,Biology ,medicine.disease_cause ,Pathology and Forensic Medicine ,Intracellular signal transduction ,Pathogenesis ,medicine ,Allele ,Signal transduction - Abstract
Capillary malformation–arteriovenous malformation (CM-AVM) is an autosomal dominant blood vascular (BV) disorder characterized by CM and fast flow BV lesions. Inactivating mutations of the RASA1 gene are the cause of CM-AVM in most cases. RASA1 is a GTPase-activating protein that acts as a negative regulator of the Ras small GTP-binding protein. In addition, RASA1 performs Ras-independent functions in intracellular signal transduction. Whether CM-AVM results from loss of an ability of RASA1 to regulate Ras or loss of a Ras-independent function of RASA1 is unknown. To address this, we generated Rasa1 knockin mice with an R780Q point mutation that abrogates RASA1 catalytic activity specifically. Homozygous Rasa1 R780Q/R780Q mice showed the same severe BV abnormalities as Rasa1 -null mice and died midgestation. This finding indicates that BV abnormalities in CM-AVM develop as a result of loss of an ability of RASA1 to control Ras activation and not loss of a Ras-independent function of this molecule. More important, findings indicate that inhibition of Ras signaling is likely to represent an effective means of therapy for this disease.
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- 2014
12. Somatic Second Hit Mutation of RASA1 in Vascular Endothelial Cells in Capillary Malformation-Arteriovenous Malformation
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Paula E. North, Patricia E. Burrows, Philip E. Lapinski, Philip D. King, Valerie K. Salato, and Abbas Doosti
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0301 basic medicine ,Adult ,Male ,Pathology ,medicine.medical_specialty ,Capillary malformation ,Adolescent ,Somatic cell ,Port-Wine Stain ,Biology ,medicine.disease_cause ,Germline ,Article ,Lesion ,Pathogenesis ,Arteriovenous Malformations ,03 medical and health sciences ,0302 clinical medicine ,Germline mutation ,Genetics ,medicine ,Humans ,Child ,Genetics (clinical) ,Germ-Line Mutation ,Mutation ,Endothelial Cells ,Arteriovenous malformation ,p120 GTPase Activating Protein ,General Medicine ,medicine.disease ,Molecular biology ,Capillaries ,030104 developmental biology ,Female ,Endothelium, Vascular ,medicine.symptom ,030217 neurology & neurosurgery - Abstract
Capillary malformation-arteriovenous malformation (CM-AVM) is an autosomal dominant vascular disorder that is associated with inherited inactivating mutations of the RASA1 gene in the majority of cases. Characteristically, patients exhibit one or more focal cutaneous CM that may occur alone or together with AVM, arteriovenous fistulas or lymphatic vessel abnormalities. The focal nature and varying presentation of lesions has led to the hypothesis that somatic “second hit” inactivating mutations of RASA1 are necessary for disease development. In this study, we examined CM from four different CM-AVM patients for the presence of somatically acquired RASA1 mutations. All four patients were shown to possess inactivating heterozygous germline RASA1 mutations. In one of the patients, a somatic inactivating RASA1 mutation (c.1534C > T, p.Arg512*) was additionally identified in CM lesion tissue. The somatic RASA1 mutation was detected within endothelial cells specifically and was in trans with the germline RASA1 mutation. Together with the germline RASA1 mutation (c.2125C > T, p.Arg709*) in the same patient, the endothelial cell somatic RASA1 mutation likely contributed to lesion development. These studies provide the first clear evidence of the second hit model of CM-AVM pathogenesis.
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- 2017
13. Unbiased RNAi screen for hepcidin regulators links hepcidin suppression to proliferative Ras/RAF and nutrient-dependent mTOR signaling
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Flavia D’Alessio, Christopher C. Oakes, Matthias W. Hentze, Lorenza A. D'Alessandro, Philip D. King, Martina U. Muckenthaler, Anan Ragab, Franziska Roche, Katarzyna Mleczko-Sanecka, Georg Damm, Ramesh Ummanni, Debora Call, Philip E. Lapinski, Michael Boutros, Ana Rita da Silva, Ursula Klingmüller, and Ulrike Korf
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inorganic chemicals ,Male ,MAPK/ERK pathway ,congenital, hereditary, and neonatal diseases and abnormalities ,Transcription, Genetic ,Immunology ,Response Elements ,Bone morphogenetic protein ,Biochemistry ,Cell Line ,Proto-Oncogene Proteins p21(ras) ,Mice ,Red Cells, Iron, and Erythropoiesis ,Hepcidins ,Hepcidin ,RNA interference ,hemic and lymphatic diseases ,Transcriptional regulation ,Animals ,Humans ,Mice, Knockout ,Regulation of gene expression ,Gene knockdown ,biology ,Gene Expression Profiling ,TOR Serine-Threonine Kinases ,Reproducibility of Results ,nutritional and metabolic diseases ,Cell Biology ,Hematology ,Proto-Oncogene Proteins c-raf ,Gene Expression Regulation ,Bone Morphogenetic Proteins ,Cancer research ,biology.protein ,RNA Interference ,Mitogen-Activated Protein Kinases ,Signal transduction ,Protein Binding ,Signal Transduction - Abstract
The hepatic hormone hepcidin is a key regulator of systemic iron metabolism. Its expression is largely regulated by 2 signaling pathways: the "iron-regulated" bone morphogenetic protein (BMP) and the inflammatory JAK-STAT pathways. To obtain broader insights into cellular processes that modulate hepcidin transcription and to provide a resource to identify novel genetic modifiers of systemic iron homeostasis, we designed an RNA interference (RNAi) screen that monitors hepcidin promoter activity after the knockdown of 19 599 genes in hepatocarcinoma cells. Interestingly, many of the putative hepcidin activators play roles in signal transduction, inflammation, or transcription, and affect hepcidin transcription through BMP-responsive elements. Furthermore, our work sheds light on new components of the transcriptional machinery that maintain steady-state levels of hepcidin expression and its responses to the BMP- and interleukin-6-triggered signals. Notably, we discover hepcidin suppression mediated via components of Ras/RAF MAPK and mTOR signaling, linking hepcidin transcriptional control to the pathways that respond to mitogen stimulation and nutrient status. Thus using a combination of RNAi screening, reverse phase protein arrays, and small molecules testing, we identify links between the control of systemic iron homeostasis and critical liver processes such as regeneration, response to injury, carcinogenesis, and nutrient metabolism.
- Published
- 2014
14. The Transition from Stem Cell to Progenitor Spermatogonia and Male Fertility Requires the SHP2 Protein Tyrosine Phosphatase
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Philip E. Lapinski, Kyle E. Orwig, Gen-Sheng Feng, William H. Walker, Aleksandar Rajkovic, Bart T. Phillips, Philip D. King, Pawan Puri, and Hitomi Suzuki
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Male ,Aging ,endocrine system ,Cell Survival ,Cell Count ,Protein Tyrosine Phosphatase, Non-Receptor Type 11 ,Protein tyrosine phosphatase ,Biology ,Cell fate determination ,Mice ,Cell surface receptor ,Cell Adhesion ,medicine ,Animals ,Humans ,Spermatogenesis ,Cells, Cultured ,Cell Proliferation ,Mice, Knockout ,Stem Cells ,Gene targeting ,Cell Differentiation ,Cell Biology ,Sertoli cell ,Spermatogonia ,Cell biology ,Fertility ,medicine.anatomical_structure ,Immunology ,Intercellular Signaling Peptides and Proteins ,Molecular Medicine ,Stem cell ,Gene Deletion ,Germ cell ,Signal Transduction ,Developmental Biology - Abstract
SHP2 is a widely expressed protein tyrosine phosphatase required for signal transduction from multiple cell surface receptors. Gain and loss of function SHP2 mutations in humans are known to cause Noonan and LEOPARD syndromes, respectively, that are characterized by numerous pathological conditions including male infertility. Using conditional gene targeting in the mouse, we found that SHP2 is required for maintaining spermatogonial stem cells (SSCs) and the production of germ cells required for male fertility. After deleting SHP2, spermatogenesis was halted at the initial step during which transit-amplifying undifferentiated spermatogonia are produced from SSCs. In the absence of SHP2, proliferation of SSCs and undifferentiated spermatogonia was inhibited, thus germ cells cannot be replenished and SSCs cannot undergo renewal. However, germ cells beyond the undifferentiated spermatogonia stage of development at the time of SHP2 knockout were able to complete their maturation to become sperm. In cultures of SSCs and their progeny, inhibition of SHP2 activity reduced growth factor-mediated intracellular signaling that regulates SSC proliferation and cell fate. Inhibition of SHP2 also decreased the number of SSCs present in culture and caused SSCs to detach from supporting cells. Injection of mice with an SHP2 inhibitor blocked the production of germ cells from SSCs. Together, our studies show that SHP2 is essential for SSCs to maintain fertility and indicates that the pathogenesis of infertility in humans with SHP2 mutations is due to compromised SSC functions that block spermatogenesis. Stem Cells 2014;32:741–753
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- 2014
15. Macropinocytosis of amino acids regulates T cell growth by promoting the sustained activation of mTORC1
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John Charpentier, Philip E. Lapinski, Jackson Turner, Irina Grigorova, Joel A. Swanson, and Philip D King
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Immunology ,Immunology and Allergy - Abstract
Macropinocytosis, a non-selective form of bulk endocytosis, has been associated with diverse processes in mammalian cells, including antigen presentation and regulation of receptor density. In Ras-transformed tumor cells, macropinocytosis of protein regulates growth when amino acids are limiting in the extracellular space. A requirement of macropinocytosis for the growth of non-transformed cells has not been described previously. Here we show that primary mouse and human T cells engage in constitutive macropinocytosis that is enhanced approximately three-fold in response to CD3/CD28 antibody stimulation. We further show that macropinocytosis is essential for the growth of CD3/CD28 antibody-stimulated T cells during the G1 phase of the cell cycle, even under amino acid-replete conditions. Macropinocytosis in activated T cells provides a means of access of extracellular amino acids to an endolysosomal compartment necessary for sustained activation of the mechanistic target of rapamycin complex 1 (mTORC1), which in part explains its function in G1 growth. In addition, macropinocytosis promotes activated T cell growth by means other than activation of mTORC1, possibly by furnishing bulk substrates for anabolism and anaplerosis. Regulation of mammalian cell growth by macropinocytosis, therefore, is not limited to Ras-transformed tumor cells but may instead represent a more general means of promoting sustained mTORC1 activation in highly proliferative cells. These findings provide important new information upon the mechanisms by which T cells acquire nutrients for growth and suggest means by which T cell growth might be manipulated for therapeutic benefit.
- Published
- 2019
16. Deletion of SHP-2 in mesenchymal stem cells causes growth retardation, limb and chest deformity, and calvarial defects in mice
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Melissa F. Meyer, Philip D. King, Gen-Sheng Feng, Philip E. Lapinski, and Nobuhiro Kamiya
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medicine.medical_specialty ,Cell type ,Neuroscience (miscellaneous) ,Limb Deformities, Congenital ,Medicine (miscellaneous) ,lcsh:Medicine ,Protein Tyrosine Phosphatase, Non-Receptor Type 11 ,Protein tyrosine phosphatase ,Biology ,LEOPARD Syndrome ,General Biochemistry, Genetics and Molecular Biology ,Bone and Bones ,03 medical and health sciences ,Mice ,0302 clinical medicine ,Germline mutation ,Immunology and Microbiology (miscellaneous) ,Internal medicine ,medicine ,lcsh:Pathology ,Animals ,Protein kinase B ,030304 developmental biology ,Mice, Knockout ,0303 health sciences ,Fetal Growth Retardation ,Mesenchymal stem cell ,lcsh:R ,Mesenchymal Stem Cells ,Thorax ,medicine.disease ,PTPN11 ,Endocrinology ,030220 oncology & carcinogenesis ,Noonan syndrome ,Research Article ,lcsh:RB1-214 - Abstract
Summary In mice, induced global disruption of the Ptpn11 gene, which encodes the SHP-2 tyrosine phosphatase, results in severe skeletal abnormalities. To understand the extent to which skeletal abnormalities can be attributed to perturbation of SHP-2 function in bone-forming osteoblasts and chondrocytes, we generated mice in which disruption of Ptpn11 is restricted to mesenchymal stem cells (MSCs) and their progeny, which include both cell types. MSC-lineage-specific SHP-2 knockout (MSC SHP-2 KO) mice exhibited postnatal growth retardation, limb and chest deformity, and calvarial defects. These skeletal abnormalities were associated with an absence of mature osteoblasts and massive chondrodysplasia with a vast increase in the number of terminally differentiated hypertrophic chondrocytes in affected bones. Activation of mitogen activated protein kinases (MAPKs) and protein kinase B (PKB; also known as AKT) was impaired in bone-forming cells of MSC SHP-2 KO mice, which provides an explanation for the skeletal defects that developed. These findings reveal a cell-autonomous role for SHP-2 in bone-forming cells in mice in the regulation of skeletal development. The results add to our understanding of the pathophysiology of skeletal abnormalities observed in humans with germline mutations in the PTPN11 gene (e.g. Noonan syndrome and LEOPARD syndrome).
- Published
- 2013
17. The Ras GTPase-activating protein neurofibromin 1 promotes the positive selection of thymocytes
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Philip E. Lapinski, Luis F. Parada, Beth A. Lubeck, Philip D. King, Jennifer A. Oliver, Yuan Zhu, and Jackson S. Turner
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congenital, hereditary, and neonatal diseases and abnormalities ,Mice, 129 Strain ,GTPase-activating protein ,T cell ,Cellular differentiation ,Immunology ,Receptors, Antigen, T-Cell ,Mice, Transgenic ,Biology ,Lymphocyte Activation ,Article ,Mice ,T-Lymphocyte Subsets ,medicine ,Animals ,Cytotoxic T cell ,Clonal Selection, Antigen-Mediated ,Molecular Biology ,Mice, Knockout ,Neurofibromin 1 ,Cell Differentiation ,nervous system diseases ,Cell biology ,Mice, Inbred C57BL ,Thymocyte ,medicine.anatomical_structure ,Ras Signaling Pathway ,ras Proteins ,biology.protein ,Female ,CD8 - Abstract
TCR-mediated activation of the Ras signaling pathway is critical for T cell development in the thymus and function in the periphery. However, which members of a family of Ras GTPase-activating proteins (RasGAPs) negatively regulate Ras activation in T cells is unknown. In this study we examined a potential function for the neurofibromin 1 (NF1) RasGAP in the T cell lineage with the use of T cell-specific NF1-deficient mice. Surprisingly, on an MHC class I-restricted TCR transgenic background, NF1 was found to promote thymocyte positive selection. By contrast, NF1 neither promoted nor inhibited the negative selection of thymocytes. In the periphery, NF1 was found to be necessary for the maintenance of normal numbers of naive CD4+ and CD8+ T cells but was dispensable as a regulator of TCR-induced Ras activation, cytokine synthesis, proliferation and differentiation and death. These findings point to a novel unexpected role for NF1 in T cell development as well as a regulator of T cell homeostasis.
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- 2013
18. RASA1 regulates the function of lymphatic vessel valves in mice
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Philip E. Lapinski, Philip D. King, Scott D. Zawieja, Beth A. Lubeck, Di Chen, Abbas Doosti, and Michael J. Davis
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0301 basic medicine ,Mutation, Missense ,Apoptosis ,Negative regulator ,03 medical and health sciences ,Mice ,0302 clinical medicine ,Lymphatic vessel ,Medicine ,Missense mutation ,Animals ,Lymphatic Vessels ,business.industry ,RASA1 Gene ,Endothelial Cells ,Embryo ,p120 GTPase Activating Protein ,General Medicine ,Phenotype ,Mice, Mutant Strains ,Cell biology ,030104 developmental biology ,medicine.anatomical_structure ,business ,030217 neurology & neurosurgery ,Research Article - Abstract
Capillary malformation-arteriovenous malformation (CM-AVM) is a blood and lymphatic vessel (LV) disorder that is caused by inherited inactivating mutations of the RASA1 gene, which encodes p120 RasGAP (RASA1), a negative regulator of the Ras small GTP-binding protein. How RASA1 mutations lead to the LV leakage defects that occur in CM-AVM is not understood. Here, we report that disruption of the Rasa1 gene in adult mice resulted in loss of LV endothelial cells (LECs) specifically from the leaflets of intraluminal valves in collecting LVs. As a result, valves were unable to prevent fluid backflow and the vessels were ineffective pumps. Furthermore, disruption of Rasa1 in midgestation resulted in LEC apoptosis in developing LV valves and consequently failed LV valvulogenesis. Similar phenotypes were observed in induced RASA1-deficient adult mice and embryos expressing a catalytically inactive RASA1R780Q mutation. Thus, RASA1 catalytic activity is essential for the function and development of LV valves. These data provide a partial explanation for LV leakage defects and potentially other LV abnormalities observed in CM-AVM.
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- 2016
19. RASA1
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Philip E. Lapinski and Philip D. King
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0301 basic medicine ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,030215 immunology - Published
- 2016
20. A Role for p120 RasGAP in Thymocyte Positive Selection and Survival of Naive T Cells
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Philip E. Lapinski, Yu Qiao, Cheong Hee Chang, and Philip D. King
- Subjects
CD4-Positive T-Lymphocytes ,Male ,Naive T cell ,Cell Survival ,T cell ,Immunology ,Mice, Transgenic ,Thymus Gland ,CD8-Positive T-Lymphocytes ,Biology ,Resting Phase, Cell Cycle ,Article ,Mice ,Interleukin 21 ,T-Lymphocyte Subsets ,medicine ,Animals ,Immunology and Allergy ,Cytotoxic T cell ,IL-2 receptor ,Mice, Knockout ,CD28 ,Cell Differentiation ,p120 GTPase Activating Protein ,Cell biology ,Mice, Inbred C57BL ,Thymocyte ,medicine.anatomical_structure ,ras GTPase-Activating Proteins ,Female ,CD8 - Abstract
Activation of the Ras small GTP-binding protein is necessary for normal T cell development and function. However, it is unknown which Ras GTPase-activating proteins (RasGAPs) inactivate Ras in T cells. We used a T cell-specific RASA1-deficient mouse model to investigate the role of the p120 RasGAP (RASA1) in T cells. Death of CD4+CD8+ double-positive thymocytes was increased in RASA1-deficient mice. Despite this finding, on an MHC class II-restricted TCR transgenic background, evidence was obtained for increased positive selection of thymocytes associated with augmented activation of the Ras–MAPK pathway. In the periphery, RASA1 was found to be dispensable as a regulator of Ras–MAPK activation and T cell functional responses induced by full agonist peptides. However, numbers of naive T cells were substantially reduced in RASA1-deficient mice. Loss of naive T cells in the absence of RASA1 could be attributed in part to impaired responsiveness to the IL-7 prosurvival cytokine. These findings reveal an important role for RASA1 as a regulator of double-positive survival and positive selection in the thymus as well as naive T cell survival in the periphery.
- Published
- 2011
21. Development of severe skeletal defects in induced SHP-2-deficient adult mice: a model of skeletal malformation in humans with SHP-2 mutations
- Author
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John E. Wilkinson, Timothy J. Bauler, Philip E. Lapinski, Yuji Mishina, Gen-Sheng Feng, Philip D. King, Nobuhiro Kamiya, and Eric Langewisch
- Subjects
Aging ,Medicine (miscellaneous) ,Osteoclasts ,lcsh:Medicine ,Protein Tyrosine Phosphatase, Non-Receptor Type 11 ,Protein tyrosine phosphatase ,LEOPARD Syndrome ,Mice ,0302 clinical medicine ,Immunology and Microbiology (miscellaneous) ,Osteogenesis ,Tissue homeostasis ,0303 health sciences ,hemic and immune systems ,Cell biology ,RANKL ,030220 oncology & carcinogenesis ,embryonic structures ,Signal transduction ,biological phenomena, cell phenomena, and immunity ,Signal Transduction ,Research Article ,lcsh:RB1-214 ,Macrophage colony-stimulating factor ,medicine.medical_specialty ,animal structures ,Neuroscience (miscellaneous) ,chemical and pharmacologic phenomena ,Biology ,General Biochemistry, Genetics and Molecular Biology ,Bone and Bones ,Spinal Curvatures ,03 medical and health sciences ,Calcification, Physiologic ,Internal medicine ,Weight Loss ,medicine ,lcsh:Pathology ,Animals ,Humans ,Protein kinase B ,030304 developmental biology ,Macrophage Colony-Stimulating Factor ,lcsh:R ,Survival Analysis ,Hematopoiesis ,PTPN11 ,Disease Models, Animal ,Endocrinology ,Cartilage ,Mutation ,biology.protein ,Biomarkers ,Gene Deletion - Abstract
SUMMARY SHP-2 (encoded by PTPN11) is a ubiquitously expressed protein tyrosine phosphatase required for signal transduction by multiple different cell surface receptors. Humans with germline SHP-2 mutations develop Noonan syndrome or LEOPARD syndrome, which are characterized by cardiovascular, neurological and skeletal abnormalities. To study how SHP-2 regulates tissue homeostasis in normal adults, we used a conditional SHP-2 mouse mutant in which loss of expression of SHP-2 was induced in multiple tissues in response to drug administration. Induced deletion of SHP-2 resulted in impaired hematopoiesis, weight loss and lethality. Most strikingly, induced SHP-2-deficient mice developed severe skeletal abnormalities, including kyphoses and scolioses of the spine. Skeletal malformations were associated with alterations in cartilage and a marked increase in trabecular bone mass. Osteoclasts were essentially absent from the bones of SHP-2-deficient mice, thus accounting for the osteopetrotic phenotype. Studies in vitro revealed that osteoclastogenesis that was stimulated by macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor kappa B ligand (RANKL) was defective in SHP-2-deficient mice. At least in part, this was explained by a requirement for SHP-2 in M-CSF-induced activation of the pro-survival protein kinase AKT in hematopoietic precursor cells. These findings illustrate an essential role for SHP-2 in skeletal growth and remodeling in adults, and reveal some of the cellular and molecular mechanisms involved. The model is predicted to be of further use in understanding how SHP-2 regulates skeletal morphogenesis, which could lead to the development of novel therapies for the treatment of skeletal malformations in human patients with SHP-2 mutations.
- Published
- 2011
22. MicroRNA-132–mediated loss of p120RasGAP activates the endothelium to facilitate pathological angiogenesis
- Author
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Sudarshan Anand, Eric A. Murphy, Sara M. Weis, Philip E. Lapinski, Miller Huang, David J. Shields, David A. Cheresh, Philip D. King, Rajesh Mukthavaram, Lisette M. Acevedo, Lea Scheppke, Bharat Majeti, and Jeffrey N. Lindquist
- Subjects
Pathology ,medicine.medical_specialty ,Endothelium ,Angiogenic Switch ,Retinal Artery ,Angiogenesis ,Drug Evaluation, Preclinical ,P120 GTPase Activating Protein ,Biology ,Article ,General Biochemistry, Genetics and Molecular Biology ,Neovascularization ,Mice ,miR-132 ,Vasculogenesis ,medicine ,Animals ,Humans ,RNA, Small Interfering ,Cells, Cultured ,Cell Proliferation ,Neovascularization, Pathologic ,Antibodies, Monoclonal ,Endothelial Cells ,p120 GTPase Activating Protein ,General Medicine ,Up-Regulation ,Mice, Inbred C57BL ,MicroRNAs ,medicine.anatomical_structure ,Cancer research ,RNA Interference ,Ectopic expression ,Endothelium, Vascular ,medicine.symptom - Abstract
Although it is well established that tumors initiate an angiogenic switch, the molecular basis of this process remains incompletely understood. Here we show that the miRNA miR-132 acts as an angiogenic switch by targeting p120RasGAP in the endothelium and thereby inducing neovascularization. We identified miR-132 as a highly upregulated miRNA in a human embryonic stem cell model of vasculogenesis and found that miR-132 was highly expressed in the endothelium of human tumors and hemangiomas but was undetectable in normal endothelium. Ectopic expression of miR-132 in endothelial cells in vitro increased their proliferation and tube-forming capacity, whereas intraocular injection of an antagomir targeting miR-132, anti–miR-132, reduced postnatal retinal vascular development in mice. Among the top-ranking predicted targets of miR-132 was p120RasGAP, which we found to be expressed in normal but not tumor endothelium. Endothelial expression of miR-132 suppressed p120RasGAP expression and increased Ras activity, whereas a miRNA-resistant version of p120RasGAP reversed the vascular response induced by miR-132. Notably, administration of anti–miR-132 inhibited angiogenesis in wild-type mice but not in mice with an inducible deletion of Rasa1 (encoding p120RasGAP). Finally, vessel-targeted nanoparticle delivery1 of anti–miR-132 restored p120RasGAP expression in the tumor endothelium, suppressed angiogenesis and decreased tumor burden in an orthotopic xenograft mouse model of human breast carcinoma. We conclude that miR-132 acts as an angiogenic switch by suppressing endothelial p120RasGAP expression, leading to Ras activation and the induction of neovascularization, whereas the application of anti–miR-132 inhibits neovascularization by maintaining vessels in the resting state.
- Published
- 2010
23. Cutting Edge: Codeletion of the Ras GTPase-Activating Proteins (RasGAPs) Neurofibromin 1 and p120 RasGAP in T Cells Results in the Development of T Cell Acute Lymphoblastic Leukemia
- Author
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Philip E. Lapinski, Olga Ksionda, Beth A. Lubeck, Jennifer A. Oliver, Jeroen P. Roose, Yuan Zhu, Luis F. Parada, Ivan Maillard, Mark Y. Chiang, and Philip D. King
- Subjects
Time Factors ,T-Lymphocytes ,medicine.disease_cause ,law.invention ,Mice ,law ,Immunology and Allergy ,2.1 Biological and endogenous factors ,Receptor, Notch1 ,Aetiology ,Receptor ,Cancer ,Mice, Knockout ,Regulation of gene expression ,Pediatric ,Mutation ,Neurofibromin 1 ,p120 GTPase Activating Protein ,Hematology ,Precursor Cell Lymphoblastic Leukemia-Lymphoma ,medicine.anatomical_structure ,Signal transduction ,Signal Transduction ,congenital, hereditary, and neonatal diseases and abnormalities ,Pediatric Research Initiative ,Childhood Leukemia ,Pediatric Cancer ,T cell ,Knockout ,Immunology ,Thymus Gland ,Biology ,Article ,Neurofibromatosis ,Rare Diseases ,medicine ,Animals ,Notch1 ,Neurosciences ,medicine.disease ,Survival Analysis ,Lymphoma ,Gene Expression Regulation ,Cancer research ,biology.protein ,Suppressor ,Spleen ,Gene Deletion - Abstract
Ras GTPase-activating proteins (RasGAPs) inhibit signal transduction initiated through the Ras small GTP-binding protein. However, which members of the RasGAP family act as negative regulators of T cell responses is not completely understood. In this study, we investigated potential roles for the RasGAPs RASA1 and neurofibromin 1 (NF1) in T cells through the generation and analysis of T cell–specific RASA1 and NF1 double-deficient mice. In contrast to mice lacking either RasGAP alone in T cells, double-deficient mice developed T cell acute lymphoblastic leukemia/lymphoma, which originated at an early point in T cell development and was dependent on activating mutations in the Notch1 gene. These findings highlight RASA1 and NF1 as cotumor suppressors in the T cell lineage.
- Published
- 2015
24. Essential role of the T cell–specific adapter protein in the activation of LCK in peripheral T cells
- Author
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Philip E. Lapinski, Gonzalo G. Garcia, Philip D. King, Jennifer N. MacGregor, and Francesc Marti
- Subjects
T cell ,Immunology ,Receptors, Antigen, T-Cell ,chemical and pharmacologic phenomena ,Biology ,SH2 domain ,Mice ,T-Lymphocyte Subsets ,medicine ,Animals ,Immunology and Allergy ,Cells, Cultured ,Adaptor Proteins, Signal Transducing ,Mice, Knockout ,T-cell receptor ,Brief Definitive Report ,CD28 ,Signal transducing adaptor protein ,hemic and immune systems ,Cell biology ,Enzyme Activation ,Mice, Inbred C57BL ,medicine.anatomical_structure ,Lymphocyte Specific Protein Tyrosine Kinase p56(lck) ,Cytoplasm ,Brief Definitive Reports ,Signal transduction ,Tyrosine kinase ,Signal Transduction - Abstract
T cell–specific adapter protein (TSAd) is a SRC-homology-2 (SH2) domain–containing intracellular signaling molecule that is required for T cell antigen receptor (TCR)–induced cytokine synthesis in T cells. How TSAd functions in TCR signal transduction is not clear. Previous work has suggested a nuclear role for this adapter. However, other evidence suggests that TSAd also functions in the cytoplasm. Using T cells from TSAd-deficient mice, we now show that the major role of TSAd in the cytoplasm is in activation of the LCK protein tyrosine kinase at the outset of TCR signal transduction. Consequently, TSAd regulates several downstream signaling events, including intracellular calcium mobilization and activation of the Ras–extracellular signal–regulated kinase signaling pathway. TSAd regulates LCK activity directly through physical interaction with LCK SH3 and SH2 domains. These studies reveal TSAd as a positive regulator of proximal TCR signal transduction and provide important new information on the mechanism of TCR-induced LCK activation.
- Published
- 2006
25. A Rare Transporter Associated with Antigen Processing Polymorphism Overpresented in HLAlow Colon Cancer Reveals the Functional Significance of the Signature Domain in Antigen Processing
- Author
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Huiming Zhang, Philip E. Lapinski, Haotian Zhao, Pan Zheng, Qunmin Zhou, Malini Raghavan, Yang Liu, and Tianyu Yang
- Subjects
Cancer Research ,DNA Repair ,Base Pair Mismatch ,Molecular Sequence Data ,Down-Regulation ,Genes, MHC Class I ,ATP-binding cassette transporter ,Major histocompatibility complex ,HLA Antigens ,MHC class I ,Humans ,Amino Acid Sequence ,ATP Binding Cassette Transporter, Subfamily B, Member 2 ,Integral membrane protein ,Peptide sequence ,Alleles ,Genetics ,Antigen Presentation ,Polymorphism, Genetic ,biology ,Antigen processing ,Endoplasmic reticulum ,Histocompatibility Antigens Class I ,Transporter associated with antigen processing ,Molecular biology ,Oncology ,Colonic Neoplasms ,biology.protein ,ATP-Binding Cassette Transporters - Abstract
Transporter associated with antigen processing (TAP), a member of the ATP-binding cassette transporter superfamily, is composed of two integral membrane proteins, TAP-1 and TAP-2. Each subunit has a C-terminal nucleotide-binding domain that binds and hydrolyzes ATP to energize peptide translocation across the endoplasmic reticulum membrane. A motif comprising the sequence LSGGQ (called the signature motif) and the amino acid that is immediately C-terminal to this motif are highly conserved in the nucleotide-binding domains of ATP-binding cassette transporters. To search for natural variants of TAP-1 with alterations in or near the signature motif, we sequenced the TAP-1 exon 10 amplified from 103 human colon cancer samples. We found a rare TAP-1 allele with an R>Q alteration at a residue immediately C-terminal to the signature motif (R648) that occurred 17.5 times more frequently in colon cancers with down-regulated surface class I MHC than those with normal MHC levels (P = 0.01). Functional analysis revealed that the Q648 variant had significantly reduced peptide translocation activity compared with TAP-1(R648). In addition, we found that mutations S644R, G645R, G646S, and G646D interfered with TAP-1 activity. TAP-1 G646D, which showed the most severe defect, resided normally in the endoplasmic reticulum and associated with the peptide loading complex, but failed to transport peptide across the endoplasmic reticulum membrane. Thus, a TAP-1 polymorphism adjacent to the signature motif may be a contributing factor for MHC class I down-regulation in colon cancer. Given the widespread defects in DNA mismatch repair in colon cancer, mutations at or near the signature domain can potentially modulate antigen processing.
- Published
- 2005
26. Tapasin Interacts with the Membrane-spanning Domains of Both TAP Subunits and Enhances the Structural Stability of TAP1·TAP2 Complexes
- Author
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Philip E. Lapinski, Malini Raghavan, and Gayatri Raghuraman
- Subjects
Immunoglobulins ,Peptide ,Peptide binding ,Biochemistry ,Antiporters ,Adenosine Triphosphate ,Tapasin ,ATP Binding Cassette Transporter, Subfamily B, Member 3 ,Humans ,Nucleotide ,ATP Binding Cassette Transporter, Subfamily B, Member 2 ,Molecular Biology ,chemistry.chemical_classification ,Endoplasmic reticulum ,Cell Membrane ,Membrane Transport Proteins ,Cell Biology ,Transporter associated with antigen processing ,Precipitin Tests ,Adenosine Diphosphate ,Protein Subunits ,chemistry ,Cyclic nucleotide-binding domain ,Biophysics ,ATP-Binding Cassette Transporters ,Tapasin binding - Abstract
The transporter associated with antigen processing (TAP) proteins are involved in transport of peptides from the cytosol into the endoplasmic reticulum. Two subunits, TAP1 and TAP2, are necessary and sufficient for peptide binding and peptide translocation across the endoplasmic reticulum membrane. TAP1 and TAP2 contain an N-terminal hydrophobic membrane-spanning region and a C-terminal nucleotide binding domain. Tapasin is an endoplasmic reticulum resident protein that has been found associated with the TAP subunits and shown to increase expression levels of TAP. Here we investigated TAP-tapasin interactions and their effects on TAP function in insect cells. We show tapasin binding to both TAP1 and TAP2 and to the corresponding nucleotide binding domain-exchanged chimeras as well as to a truncated TAP1.TAP2 complex containing just the membrane-spanning regions of TAP1 and TAP2. However, tapasin interactions with either the truncated TAP construct containing just the nucleotide binding domain are not observed. Tapasin is not required for high affinity peptide binding to TAP1.TAP2 complexes, and in fact, the presence of tapasin slightly reduces the affinity of TAP complexes for peptides. However, at near physiological temperatures, both tapasin and nucleotides stabilize the peptide binding site of TAP1.TAP2 complexes against inactivation, and enhanced thermostability of both TAP subunits is observed in the presence of tapasin. The enhanced structural stability of TAP1.TAP2 complexes in the presence of tapasin might explain the observations that tapasin increases TAP protein expression levels in mammalian cells.
- Published
- 2002
27. Calreticulin recognizes misfolded HLA-A2 heavy chains
- Author
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Philip E. Lapinski, Malini Raghavan, Syed Monem Rizvi, and Laura Mancino
- Subjects
Protein Folding ,Insecta ,Time Factors ,Pan troglodytes ,Peptide ,Peptide binding ,Plasma protein binding ,Endoplasmic Reticulum ,Cell Line ,HLA-A2 Antigen ,MHC class I ,Animals ,Humans ,chemistry.chemical_classification ,Multidisciplinary ,biology ,Endoplasmic reticulum ,Calcium-Binding Proteins ,Temperature ,Biological Sciences ,Precipitin Tests ,Ribonucleoproteins ,Biochemistry ,chemistry ,Chaperone (protein) ,biology.protein ,Protein folding ,Calreticulin ,Peptides ,Protein Binding - Abstract
Our studies investigated functional interactions between calreticulin, an endoplasmic reticulum chaperone, and major histocompatibility complex (MHC) class I molecules. Usingin vitrothermal aggregation assays, we established that calreticulin can inhibit heat-induced aggregation of soluble, peptide-deficient HLA-A2 purified from supernatants of insect cells. The presence of HLA-A2-specific peptides also inhibits heat-induced aggregation. Inhibition of heat-induced aggregation of peptide-deficient HLA-A2 by calreticulin correlates with a rescue of the HLA-A2 heavy chain from precipitation, by forming high-molecular-weight complexes with calreticulin. Complex formation between HLA-A2 heavy chains and calreticulin occurs at 50°C but not 37°C, suggesting polypeptide-based interactions between the HLA-A2 heavy chain and calreticulin. Once complexes are formed, the addition of peptide is not sufficient to trigger efficient assembly of heavy chain/β2m/peptide complexes. Using a fluorescent peptide-based binding assay, we show that calreticulin does not enhance peptide binding by HLA-A2 at 37°C. We also show that calreticulin itself is converted to oligomeric species on exposure to 37°C or higher temperatures, and that oligomeric forms of calreticulin are active in inhibiting thermal aggregation of peptide-deficient HLA-A2. Taken together, these results suggest that calreticulin functions in the recognition of misfolded MHC class I heavy chains in the endoplasmic reticulum. However, in the absence of other endoplasmic reticulum components, calreticulin by itself does not enhance the assembly of misfolded MHC class I heavy chains with β2m and peptides.
- Published
- 2002
28. The histone methyltransferase Ezh2 is a crucial epigenetic regulator of allogeneic T-cell responses mediating graft-versus-host disease
- Author
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Shin Mineishi, Arul M. Chinnaiyan, Yi Zhang, Izumi Mochizuki, Philip E. Lapinski, Fang Xie, Qing Tong, Shan He, Yongnian Liu, Ram Shankar Mani, Pavan Reddy, Kazuhiro Mochizuki, and Philip D. King
- Subjects
T cell ,T-Lymphocytes ,Immunology ,Priming (immunology) ,Graft vs Host Disease ,chemical and pharmacologic phenomena ,macromolecular substances ,Biology ,Biochemistry ,Methylation ,Epigenesis, Genetic ,Histone H3 ,Mice ,immune system diseases ,Proto-Oncogene Proteins ,medicine ,Animals ,Enhancer of Zeste Homolog 2 Protein ,Epigenetics ,STAT4 ,Bone Marrow Transplantation ,Mice, Knockout ,Mice, Inbred BALB C ,Transplantation ,Bcl-2-Like Protein 11 ,EZH2 ,Polycomb Repressive Complex 2 ,Membrane Proteins ,hemic and immune systems ,Cell Biology ,Hematology ,STAT4 Transcription Factor ,medicine.disease ,Allografts ,medicine.anatomical_structure ,Graft-versus-host disease ,surgical procedures, operative ,Histone methyltransferase ,Cancer research ,Apoptosis Regulatory Proteins ,T-Box Domain Proteins - Abstract
Posttranscriptional modification of histones by methylation plays an important role in regulating Ag-driven T-cell responses. We have recently drawn correlations between allogeneic T-cell responses and the histone methyltransferase Ezh2, which catalyzes histone H3 lysine 27 trimethylation. The functional relevance of Ezh2 in T-cell alloimmunity remains unclear. Here, we identify a central role of Ezh2 in regulating allogeneic T-cell proliferation, differentiation, and function. Conditional loss of Ezh2 in donor T cells inhibited graft-versus-host disease (GVHD) in mice after allogeneic bone marrow (BM) transplantation. Although Ezh2-deficient T cells were initially activated to proliferate upon alloantigenic priming, their ability to undergo continual proliferation and expansion was defective during late stages of GVHD induction. This effect of Ezh2 ablation was largely independent of the proapoptotic molecule Bim. Unexpectedly, as a gene silencer, Ezh2 was required to promote the expression of transcription factors Tbx21 and Stat4. Loss of Ezh2 in T cells specifically impaired their differentiation into interferon (IFN)-γ–producing effector cells. However, Ezh2 ablation retained antileukemia activity in alloreactive T cells, leading to improved overall survival of the recipients. Our findings justify investigation of modulating Ezh2 as a therapeutic strategy for the treatment of GVHD and other T cell–mediated inflammatory disorders.
- Published
- 2013
29. Lymphatic abnormalities are associated with RASA1 gene mutations in mouse and man
- Author
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Sunkuk Kwon, Caroline E. Fife, Philip E. Lapinski, Erik A. Maus, Renie Guilliod, Melissa B. Aldrich, John C. Rasmussen, Manuel L. Gonzalez-Garay, Eva M. Sevick-Muraca, Philip D. King, and Patricia E. Burrows
- Subjects
Indocyanine Green ,Male ,Pathology ,medicine.medical_specialty ,P120 GTPase Activating Protein ,Biology ,medicine.disease_cause ,Frameshift mutation ,symbols.namesake ,Mice ,Sturge-Weber Syndrome ,medicine ,Animals ,Humans ,Exome ,Coloring Agents ,Frameshift Mutation ,Sanger sequencing ,Mice, Knockout ,Mutation ,Multidisciplinary ,Hyperplasia ,Lymphatic Abnormalities ,p120 GTPase Activating Protein ,Biological Sciences ,Penetrance ,Disease Models, Animal ,Lymphatic system ,Knockout mouse ,symbols ,Female - Abstract
Mutations in gene RASA1 have been historically associated with capillary malformation–arteriovenous malformation, but sporadic reports of lymphatic involvement have yet to be investigated in detail. To investigate the impact of RASA1 mutations in the lymphatic system, we performed investigational near-infrared fluorescence lymphatic imaging and confirmatory radiographic lymphangiography in a Parkes–Weber syndrome (PKWS) patient with suspected RASA1 mutations and correlated the lymphatic abnormalities against that imaged in an inducible Rasa1 knockout mouse. Whole-exome sequencing (WES) analysis and validation by Sanger sequencing of DNA from the patient and unaffected biological parents enabled us to identify an early-frameshift deletion in RASA1 that was shared with the father, who possessed a capillary stain but otherwise no overt disease phenotype. Abnormal lymphatic vasculature was imaged in both affected and unaffected legs of the PKWS subject that transported injected indocyanine green dye to the inguinal lymph node and drained atypically into the abdomen and into dermal lymphocele-like vesicles on the groin. Dermal lymphatic hyperplasia and dilated vessels were observed in Rasa1-deficient mice, with subsequent development of chylous ascites. WES analyses did not identify potential gene modifiers that could explain the variability of penetrance between father and son. Nonetheless, we conclude that the RASA1 mutation is responsible for the aberrant lymphatic architecture and functional abnormalities, as visualized in the PKWS subject and in the animal model. Our unique method to combine investigatory near-infrared fluorescence lymphatic imaging and WES for accurate phenoptyping and unbiased genotyping allows the study of molecular mechanisms of lymphatic involvement of hemovascular disorders.
- Published
- 2013
30. Nonredundant Functions for Ras GTPase-Activating Proteins in Tissue Homeostasis
- Author
-
Philip E. Lapinski, Beth A. Lubeck, and Philip D. King
- Subjects
Guanosine ,GTPase ,Biology ,Models, Biological ,Biochemistry ,Article ,Mice ,chemistry.chemical_compound ,Anti-apoptotic Ras signalling cascade ,Animals ,Homeostasis ,Humans ,HRAS ,Receptor ,Molecular Biology ,Tissue homeostasis ,Neurofibromin 1 ,Cell Membrane ,p120 GTPase Activating Protein ,Cell Biology ,Protein Structure, Tertiary ,Cell biology ,chemistry ,ras GTPase-Activating Proteins ,ras Proteins ,Triphosphatase ,Signal transduction ,Signal Transduction - Abstract
Inactivation of the small guanosine triphosphate–binding protein Ras during receptor signal transduction is mediated by Ras guanosine triphosphatase (GTPase)–activating proteins (RasGAPs). Ten different RasGAPs have been identified and have overlapping patterns of tissue distribution. However, genetic analyses are revealing critical nonredundant functions for each RasGAP in tissue homeostasis and as regulators of disease processes in mouse and man. Here, we discuss advances in understanding the role of RasGAPs in the maintenance of tissue integrity.
- Published
- 2013
31. Regulation of Ras signal transduction during T cell development and activation
- Author
-
Philip E, Lapinski and Philip D, King
- Subjects
Review Article - Abstract
T cell receptor-induced activation of the Ras signaling pathway is essential for T cell development, proliferation and differentiation. Given the central role of Ras in T cell biology its activation must be tightly regulated. However, precisely how Ras activation is controlled in T cells is not completely understood. In this review, we provide a summary of the known factors and mechanisms involved in positive and negative regulation of Ras activation in the T cell lineage.
- Published
- 2012
32. Development of promyelocytic leukemia zinc finger-expressing innate CD4 T cells requires stronger T-cell receptor signals than conventional CD4 T cells
- Author
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Pamela L. Schwartzberg, Dietmar J. Kappes, Philip E. Lapinski, Hanief Sofi, David L. Wiest, Gretta L. Stritesky, Lingqiao Zhu, Kristin A. Hogquist, Hung Sia Teh, Yu Qiao, Reiko Horai, Cheong Hee Chang, Derek B. Sant'Angelo, Kristen L. Mueller, Xi He, and Philip D. King
- Subjects
CD4-Positive T-Lymphocytes ,CD3 ,Green Fluorescent Proteins ,Kruppel-Like Transcription Factors ,Receptors, Antigen, T-Cell ,T-Cell Antigen Receptor Specificity ,Biology ,Jurkat cells ,Epithelium ,Interleukin 21 ,Mice ,T-Lymphocyte Subsets ,Cytotoxic T cell ,Animals ,Guanine Nucleotide Exchange Factors ,Promyelocytic Leukemia Zinc Finger Protein ,IL-2 receptor ,Bone Marrow Transplantation ,Mice, Knockout ,Multidisciplinary ,Thymocytes ,ZAP70 ,Cell Differentiation ,Biological Sciences ,Protein-Tyrosine Kinases ,Natural killer T cell ,Flow Cytometry ,Molecular biology ,biology.protein ,CD8 ,Signal Transduction - Abstract
MHC class II-expressing thymocytes and thymic epithelial cells can mediate CD4 T-cell selection resulting in functionally distinct thymocyte-selected CD4 (T-CD4) and epithelial-selected CD4 (E-CD4) T cells, respectively. However, little is known about how T-cell receptor (TCR) signaling influences the development of these two CD4 T-cell subsets. To study TCR signaling for T-CD4 T-cell development, we used a GFP reporter system of Nur77 in which GFP intensity directly correlates with TCR signaling strength. T-CD4 T cells expressed higher levels of GFP than E-CD4 T cells, suggesting that T-CD4 T cells received stronger TCR signaling than E-CD4 T cells during selection. Elimination of Ras GTPase-activating protein enhanced E-CD4 but decreased T-CD4 T-cell selection efficiency, suggesting a shift to negative selection. Conversely, the absence of IL-2–inducible T-cell kinase that causes poor E-CD4 T-cell selection due to insufficient TCR signaling improved T-CD4 T-cell generation, consistent with rescue from negative selection. Strong TCR signaling during T-CD4 T-cell development correlates with the expression of the transcription factor promyelocytic leukemia zinc finger protein. However, although modulation of the signaling strength affected the efficiency of T-CD4 T-cell development during positive and negative selection, the signaling strength is not as important for the effector function of T-CD4 T cells. These findings indicate that innate T-CD4 T cells, together with invariant natural killer T cells and γδ T cells, receive strong TCR signals during their development and that signaling requirements for the development and the effector functions are distinct.
- Published
- 2012
33. RASA1 maintains the lymphatic vasculature in a quiescent functional state in mice
- Author
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Beth A. Lubeck, Philip E. Lapinski, R. Sathish Srinivasan, Eva M. Sevick-Muraca, Sunkuk Kwon, Philip D. King, and John E. Wilkinson
- Subjects
government.form_of_government ,P120 GTPase Activating Protein ,Mice, Transgenic ,Biology ,Mice ,Growth factor receptor ,Lymphatic vessel ,medicine ,Animals ,Humans ,Lymphangiogenesis ,Extracellular Signal-Regulated MAP Kinases ,Lymphatic Diseases ,Cell Proliferation ,Lymphatic Vessels ,Hyperplasia ,Endothelial Cells ,p120 GTPase Activating Protein ,General Medicine ,medicine.disease ,Vascular Endothelial Growth Factor Receptor-3 ,Lymphatic disease ,Mice, Inbred C57BL ,Lymphatic Endothelium ,Lymphatic system ,medicine.anatomical_structure ,Ras Signaling Pathway ,ras GTPase-Activating Proteins ,Cancer research ,government ,Female ,Proto-Oncogene Proteins c-akt ,Research Article ,Signal Transduction - Abstract
RASA1 (also known as p120 RasGAP) is a Ras GTPase-activating protein that functions as a regulator of blood vessel growth in adult mice and humans. In humans, RASA1 mutations cause capillary malformation-arteriovenous malformation (CM-AVM); whether it also functions as a regulator of the lymphatic vasculature is unknown. We investigated this issue using mice in which Rasa1 could be inducibly deleted by administration of tamoxifen. Systemic loss of RASA1 resulted in a lymphatic vessel disorder characterized by extensive lymphatic vessel hyperplasia and leakage and early lethality caused by chylothorax (lymphatic fluid accumulation in the pleural cavity). Lymphatic vessel hyperplasia was a consequence of increased proliferation of lymphatic endothelial cells (LECs) and was also observed in mice in which induced deletion of Rasa1 was restricted to LECs. RASA1-deficient LECs showed evidence of constitutive activation of Ras in situ. Furthermore, in isolated RASA1-deficient LECs, activation of the Ras signaling pathway was prolonged and cellular proliferation was enhanced after ligand binding to different growth factor receptors, including VEGFR-3. Blockade of VEGFR-3 was sufficient to inhibit the development of lymphatic vessel hyperplasia after loss of RASA1 in vivo. These findings reveal a role for RASA1 as a physiological negative regulator of LEC growth that maintains the lymphatic vasculature in a quiescent functional state through its ability to inhibit Ras signal transduction initiated through LEC-expressed growth factor receptors such as VEGFR-3.
- Published
- 2012
34. RANTES
- Author
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Kirill A. Martemyanov, Pooja Parameswaran, Irene Aligianis, Mark Handley, Marga Gual-Soler, Tomohiko Taguchi, Jennifer L. Stow, Carol Wicking, Soumik BasuRay, Jacob O. Agola, Patricia A. Jim, Matthew N. Seaman, Angela Wandinger-Ness, Heather H. Ward, Diamantis Konstantinidis, Theodosia A. Kalfa, Andrea Varga, Manuela Baccarini, Debbie L. Hay, Patrick M. Sexton, David R. Poyner, Carlo Petosa, Tomoki Nakashima, Hiroshi Takayanagi, Hoa B. Nguyen, Lawrence A. Quilliam, Michael S. Samuel, Philip E. Lapinski, Philip D. King, Eugenio Santos, Alberto Fernández-Medarde, John J. Priatel, Kevin Tsai, Kenneth W. Harder, Jose-Luis González de Aguilar, Pavel P. Philippov, Evgeni Yu Zernii, Masakazu Fujiwara, Mohammad Ghazizadeh, Roger J. Summers, Michelle L. Halls, Emma T. Westhuizen, Scott A. Busby, Thomas P. Burris, David P. Siderovski, Adam J. Kimple, Zhihui Xie, Kirk M. Druey, Nicolas Reymond, Francisco M. Vega, Anne J. Ridley, Gregory G. Tall, Weikang Cai, Jennifer L. Rudolph, Douglas A. Andres, John Colicelli, Pamela Y. Ting, Christine Janson, Michael F. Olson, James P. Brody, Julie A. Maupin-Furlow, Hugo V. Miranda, Philippe P. Roux, Filip Van Petegem, and Kelvin Lau
- Published
- 2012
35. ROCK I
- Author
-
Kirill A. Martemyanov, Pooja Parameswaran, Irene Aligianis, Mark Handley, Marga Gual-Soler, Tomohiko Taguchi, Jennifer L. Stow, Carol Wicking, Soumik BasuRay, Jacob O. Agola, Patricia A. Jim, Matthew N. Seaman, Angela Wandinger-Ness, Heather H. Ward, Diamantis Konstantinidis, Theodosia A. Kalfa, Andrea Varga, Manuela Baccarini, Debbie L. Hay, Patrick M. Sexton, David R. Poyner, Carlo Petosa, Tomoki Nakashima, Hiroshi Takayanagi, Hoa B. Nguyen, Lawrence A. Quilliam, Michael S. Samuel, Philip E. Lapinski, Philip D. King, Eugenio Santos, Alberto Fernández-Medarde, John J. Priatel, Kevin Tsai, Kenneth W. Harder, Jose-Luis González de Aguilar, Pavel P. Philippov, Evgeni Yu Zernii, Masakazu Fujiwara, Mohammad Ghazizadeh, Roger J. Summers, Michelle L. Halls, Emma T. Westhuizen, Scott A. Busby, Thomas P. Burris, David P. Siderovski, Adam J. Kimple, Zhihui Xie, Kirk M. Druey, Nicolas Reymond, Francisco M. Vega, Anne J. Ridley, Gregory G. Tall, Weikang Cai, Jennifer L. Rudolph, Douglas A. Andres, John Colicelli, Pamela Y. Ting, Christine Janson, Michael F. Olson, James P. Brody, Julie A. Maupin-Furlow, Hugo V. Miranda, Philippe P. Roux, Filip Van Petegem, and Kelvin Lau
- Published
- 2012
36. RGS Protein Family
- Author
-
Kirill A. Martemyanov, Pooja Parameswaran, Irene Aligianis, Mark Handley, Marga Gual-Soler, Tomohiko Taguchi, Jennifer L. Stow, Carol Wicking, Soumik BasuRay, Jacob O. Agola, Patricia A. Jim, Matthew N. Seaman, Angela Wandinger-Ness, Heather H. Ward, Diamantis Konstantinidis, Theodosia A. Kalfa, Andrea Varga, Manuela Baccarini, Debbie L. Hay, Patrick M. Sexton, David R. Poyner, Carlo Petosa, Tomoki Nakashima, Hiroshi Takayanagi, Hoa B. Nguyen, Lawrence A. Quilliam, Michael S. Samuel, Philip E. Lapinski, Philip D. King, Eugenio Santos, Alberto Fernández-Medarde, John J. Priatel, Kevin Tsai, Kenneth W. Harder, Jose-Luis González de Aguilar, Pavel P. Philippov, Evgeni Yu Zernii, Masakazu Fujiwara, Mohammad Ghazizadeh, Roger J. Summers, Michelle L. Halls, Emma T. Westhuizen, Scott A. Busby, Thomas P. Burris, David P. Siderovski, Adam J. Kimple, Zhihui Xie, Kirk M. Druey, Nicolas Reymond, Francisco M. Vega, Anne J. Ridley, Gregory G. Tall, Weikang Cai, Jennifer L. Rudolph, Douglas A. Andres, John Colicelli, Pamela Y. Ting, Christine Janson, Michael F. Olson, James P. Brody, Julie A. Maupin-Furlow, Hugo V. Miranda, Philippe P. Roux, Filip Van Petegem, and Kelvin Lau
- Published
- 2012
37. RCN-1
- Author
-
Kirill A. Martemyanov, Pooja Parameswaran, Irene Aligianis, Mark Handley, Marga Gual-Soler, Tomohiko Taguchi, Jennifer L. Stow, Carol Wicking, Soumik BasuRay, Jacob O. Agola, Patricia A. Jim, Matthew N. Seaman, Angela Wandinger-Ness, Heather H. Ward, Diamantis Konstantinidis, Theodosia A. Kalfa, Andrea Varga, Manuela Baccarini, Debbie L. Hay, Patrick M. Sexton, David R. Poyner, Carlo Petosa, Tomoki Nakashima, Hiroshi Takayanagi, Hoa B. Nguyen, Lawrence A. Quilliam, Michael S. Samuel, Philip E. Lapinski, Philip D. King, Eugenio Santos, Alberto Fernández-Medarde, John J. Priatel, Kevin Tsai, Kenneth W. Harder, Jose-Luis González de Aguilar, Pavel P. Philippov, Evgeni Yu Zernii, Masakazu Fujiwara, Mohammad Ghazizadeh, Roger J. Summers, Michelle L. Halls, Emma T. Westhuizen, Scott A. Busby, Thomas P. Burris, David P. Siderovski, Adam J. Kimple, Zhihui Xie, Kirk M. Druey, Nicolas Reymond, Francisco M. Vega, Anne J. Ridley, Gregory G. Tall, Weikang Cai, Jennifer L. Rudolph, Douglas A. Andres, John Colicelli, Pamela Y. Ting, Christine Janson, Michael F. Olson, James P. Brody, Julie A. Maupin-Furlow, Hugo V. Miranda, Philippe P. Roux, Filip Van Petegem, and Kelvin Lau
- Published
- 2012
38. Resistance to Inhibitors of Cholinesterase 8
- Author
-
Kirill A. Martemyanov, Pooja Parameswaran, Irene Aligianis, Mark Handley, Marga Gual-Soler, Tomohiko Taguchi, Jennifer L. Stow, Carol Wicking, Soumik BasuRay, Jacob O. Agola, Patricia A. Jim, Matthew N. Seaman, Angela Wandinger-Ness, Heather H. Ward, Diamantis Konstantinidis, Theodosia A. Kalfa, Andrea Varga, Manuela Baccarini, Debbie L. Hay, Patrick M. Sexton, David R. Poyner, Carlo Petosa, Tomoki Nakashima, Hiroshi Takayanagi, Hoa B. Nguyen, Lawrence A. Quilliam, Michael S. Samuel, Philip E. Lapinski, Philip D. King, Eugenio Santos, Alberto Fernández-Medarde, John J. Priatel, Kevin Tsai, Kenneth W. Harder, Jose-Luis González de Aguilar, Pavel P. Philippov, Evgeni Yu Zernii, Masakazu Fujiwara, Mohammad Ghazizadeh, Roger J. Summers, Michelle L. Halls, Emma T. Westhuizen, Scott A. Busby, Thomas P. Burris, David P. Siderovski, Adam J. Kimple, Zhihui Xie, Kirk M. Druey, Nicolas Reymond, Francisco M. Vega, Anne J. Ridley, Gregory G. Tall, Weikang Cai, Jennifer L. Rudolph, Douglas A. Andres, John Colicelli, Pamela Y. Ting, Christine Janson, Michael F. Olson, James P. Brody, Julie A. Maupin-Furlow, Hugo V. Miranda, Philippe P. Roux, Filip Van Petegem, and Kelvin Lau
- Published
- 2012
39. Rho-Associated Protein Kinase
- Author
-
Kirill A. Martemyanov, Pooja Parameswaran, Irene Aligianis, Mark Handley, Marga Gual-Soler, Tomohiko Taguchi, Jennifer L. Stow, Carol Wicking, Soumik BasuRay, Jacob O. Agola, Patricia A. Jim, Matthew N. Seaman, Angela Wandinger-Ness, Heather H. Ward, Diamantis Konstantinidis, Theodosia A. Kalfa, Andrea Varga, Manuela Baccarini, Debbie L. Hay, Patrick M. Sexton, David R. Poyner, Carlo Petosa, Tomoki Nakashima, Hiroshi Takayanagi, Hoa B. Nguyen, Lawrence A. Quilliam, Michael S. Samuel, Philip E. Lapinski, Philip D. King, Eugenio Santos, Alberto Fernández-Medarde, John J. Priatel, Kevin Tsai, Kenneth W. Harder, Jose-Luis González de Aguilar, Pavel P. Philippov, Evgeni Yu Zernii, Masakazu Fujiwara, Mohammad Ghazizadeh, Roger J. Summers, Michelle L. Halls, Emma T. Westhuizen, Scott A. Busby, Thomas P. Burris, David P. Siderovski, Adam J. Kimple, Zhihui Xie, Kirk M. Druey, Nicolas Reymond, Francisco M. Vega, Anne J. Ridley, Gregory G. Tall, Weikang Cai, Jennifer L. Rudolph, Douglas A. Andres, John Colicelli, Pamela Y. Ting, Christine Janson, Michael F. Olson, James P. Brody, Julie A. Maupin-Furlow, Hugo V. Miranda, Philippe P. Roux, Filip Van Petegem, and Kelvin Lau
- Published
- 2012
40. Ric-8A
- Author
-
Kirill A. Martemyanov, Pooja Parameswaran, Irene Aligianis, Mark Handley, Marga Gual-Soler, Tomohiko Taguchi, Jennifer L. Stow, Carol Wicking, Soumik BasuRay, Jacob O. Agola, Patricia A. Jim, Matthew N. Seaman, Angela Wandinger-Ness, Heather H. Ward, Diamantis Konstantinidis, Theodosia A. Kalfa, Andrea Varga, Manuela Baccarini, Debbie L. Hay, Patrick M. Sexton, David R. Poyner, Carlo Petosa, Tomoki Nakashima, Hiroshi Takayanagi, Hoa B. Nguyen, Lawrence A. Quilliam, Michael S. Samuel, Philip E. Lapinski, Philip D. King, Eugenio Santos, Alberto Fernández-Medarde, John J. Priatel, Kevin Tsai, Kenneth W. Harder, Jose-Luis González de Aguilar, Pavel P. Philippov, Evgeni Yu Zernii, Masakazu Fujiwara, Mohammad Ghazizadeh, Roger J. Summers, Michelle L. Halls, Emma T. Westhuizen, Scott A. Busby, Thomas P. Burris, David P. Siderovski, Adam J. Kimple, Zhihui Xie, Kirk M. Druey, Nicolas Reymond, Francisco M. Vega, Anne J. Ridley, Gregory G. Tall, Weikang Cai, Jennifer L. Rudolph, Douglas A. Andres, John Colicelli, Pamela Y. Ting, Christine Janson, Michael F. Olson, James P. Brody, Julie A. Maupin-Furlow, Hugo V. Miranda, Philippe P. Roux, Filip Van Petegem, and Kelvin Lau
- Published
- 2012
41. Retinoic Acid Receptors (RARA, RARB, and RARC)
- Author
-
Kirill A. Martemyanov, Pooja Parameswaran, Irene Aligianis, Mark Handley, Marga Gual-Soler, Tomohiko Taguchi, Jennifer L. Stow, Carol Wicking, Soumik BasuRay, Jacob O. Agola, Patricia A. Jim, Matthew N. Seaman, Angela Wandinger-Ness, Heather H. Ward, Diamantis Konstantinidis, Theodosia A. Kalfa, Andrea Varga, Manuela Baccarini, Debbie L. Hay, Patrick M. Sexton, David R. Poyner, Carlo Petosa, Tomoki Nakashima, Hiroshi Takayanagi, Hoa B. Nguyen, Lawrence A. Quilliam, Michael S. Samuel, Philip E. Lapinski, Philip D. King, Eugenio Santos, Alberto Fernández-Medarde, John J. Priatel, Kevin Tsai, Kenneth W. Harder, Jose-Luis González de Aguilar, Pavel P. Philippov, Evgeni Yu Zernii, Masakazu Fujiwara, Mohammad Ghazizadeh, Roger J. Summers, Michelle L. Halls, Emma T. Westhuizen, Scott A. Busby, Thomas P. Burris, David P. Siderovski, Adam J. Kimple, Zhihui Xie, Kirk M. Druey, Nicolas Reymond, Francisco M. Vega, Anne J. Ridley, Gregory G. Tall, Weikang Cai, Jennifer L. Rudolph, Douglas A. Andres, John Colicelli, Pamela Y. Ting, Christine Janson, Michael F. Olson, James P. Brody, Julie A. Maupin-Furlow, Hugo V. Miranda, Philippe P. Roux, Filip Van Petegem, and Kelvin Lau
- Published
- 2012
42. Rhodopsin Kinase
- Author
-
Kirill A. Martemyanov, Pooja Parameswaran, Irene Aligianis, Mark Handley, Marga Gual-Soler, Tomohiko Taguchi, Jennifer L. Stow, Carol Wicking, Soumik BasuRay, Jacob O. Agola, Patricia A. Jim, Matthew N. Seaman, Angela Wandinger-Ness, Heather H. Ward, Diamantis Konstantinidis, Theodosia A. Kalfa, Andrea Varga, Manuela Baccarini, Debbie L. Hay, Patrick M. Sexton, David R. Poyner, Carlo Petosa, Tomoki Nakashima, Hiroshi Takayanagi, Hoa B. Nguyen, Lawrence A. Quilliam, Michael S. Samuel, Philip E. Lapinski, Philip D. King, Eugenio Santos, Alberto Fernández-Medarde, John J. Priatel, Kevin Tsai, Kenneth W. Harder, Jose-Luis González de Aguilar, Pavel P. Philippov, Evgeni Yu Zernii, Masakazu Fujiwara, Mohammad Ghazizadeh, Roger J. Summers, Michelle L. Halls, Emma T. Westhuizen, Scott A. Busby, Thomas P. Burris, David P. Siderovski, Adam J. Kimple, Zhihui Xie, Kirk M. Druey, Nicolas Reymond, Francisco M. Vega, Anne J. Ridley, Gregory G. Tall, Weikang Cai, Jennifer L. Rudolph, Douglas A. Andres, John Colicelli, Pamela Y. Ting, Christine Janson, Michael F. Olson, James P. Brody, Julie A. Maupin-Furlow, Hugo V. Miranda, Philippe P. Roux, Filip Van Petegem, and Kelvin Lau
- Published
- 2012
43. Regulator of G-Protein Signaling 13
- Author
-
Kirill A. Martemyanov, Pooja Parameswaran, Irene Aligianis, Mark Handley, Marga Gual-Soler, Tomohiko Taguchi, Jennifer L. Stow, Carol Wicking, Soumik BasuRay, Jacob O. Agola, Patricia A. Jim, Matthew N. Seaman, Angela Wandinger-Ness, Heather H. Ward, Diamantis Konstantinidis, Theodosia A. Kalfa, Andrea Varga, Manuela Baccarini, Debbie L. Hay, Patrick M. Sexton, David R. Poyner, Carlo Petosa, Tomoki Nakashima, Hiroshi Takayanagi, Hoa B. Nguyen, Lawrence A. Quilliam, Michael S. Samuel, Philip E. Lapinski, Philip D. King, Eugenio Santos, Alberto Fernández-Medarde, John J. Priatel, Kevin Tsai, Kenneth W. Harder, Jose-Luis González de Aguilar, Pavel P. Philippov, Evgeni Yu Zernii, Masakazu Fujiwara, Mohammad Ghazizadeh, Roger J. Summers, Michelle L. Halls, Emma T. Westhuizen, Scott A. Busby, Thomas P. Burris, David P. Siderovski, Adam J. Kimple, Zhihui Xie, Kirk M. Druey, Nicolas Reymond, Francisco M. Vega, Anne J. Ridley, Gregory G. Tall, Weikang Cai, Jennifer L. Rudolph, Douglas A. Andres, John Colicelli, Pamela Y. Ting, Christine Janson, Michael F. Olson, James P. Brody, Julie A. Maupin-Furlow, Hugo V. Miranda, Philippe P. Roux, Filip Van Petegem, and Kelvin Lau
- Published
- 2012
44. Ras Guanyl-Releasing Protein
- Author
-
Kirill A. Martemyanov, Pooja Parameswaran, Irene Aligianis, Mark Handley, Marga Gual-Soler, Tomohiko Taguchi, Jennifer L. Stow, Carol Wicking, Soumik BasuRay, Jacob O. Agola, Patricia A. Jim, Matthew N. Seaman, Angela Wandinger-Ness, Heather H. Ward, Diamantis Konstantinidis, Theodosia A. Kalfa, Andrea Varga, Manuela Baccarini, Debbie L. Hay, Patrick M. Sexton, David R. Poyner, Carlo Petosa, Tomoki Nakashima, Hiroshi Takayanagi, Hoa B. Nguyen, Lawrence A. Quilliam, Michael S. Samuel, Philip E. Lapinski, Philip D. King, Eugenio Santos, Alberto Fernández-Medarde, John J. Priatel, Kevin Tsai, Kenneth W. Harder, Jose-Luis González de Aguilar, Pavel P. Philippov, Evgeni Yu Zernii, Masakazu Fujiwara, Mohammad Ghazizadeh, Roger J. Summers, Michelle L. Halls, Emma T. Westhuizen, Scott A. Busby, Thomas P. Burris, David P. Siderovski, Adam J. Kimple, Zhihui Xie, Kirk M. Druey, Nicolas Reymond, Francisco M. Vega, Anne J. Ridley, Gregory G. Tall, Weikang Cai, Jennifer L. Rudolph, Douglas A. Andres, John Colicelli, Pamela Y. Ting, Christine Janson, Michael F. Olson, James P. Brody, Julie A. Maupin-Furlow, Hugo V. Miranda, Philippe P. Roux, Filip Van Petegem, and Kelvin Lau
- Published
- 2012
45. Rapamycin and FKBP12 Target-1 Protein (RAFT1)
- Author
-
Kirill A. Martemyanov, Pooja Parameswaran, Irene Aligianis, Mark Handley, Marga Gual-Soler, Tomohiko Taguchi, Jennifer L. Stow, Carol Wicking, Soumik BasuRay, Jacob O. Agola, Patricia A. Jim, Matthew N. Seaman, Angela Wandinger-Ness, Heather H. Ward, Diamantis Konstantinidis, Theodosia A. Kalfa, Andrea Varga, Manuela Baccarini, Debbie L. Hay, Patrick M. Sexton, David R. Poyner, Carlo Petosa, Tomoki Nakashima, Hiroshi Takayanagi, Hoa B. Nguyen, Lawrence A. Quilliam, Michael S. Samuel, Philip E. Lapinski, Philip D. King, Eugenio Santos, Alberto Fernández-Medarde, John J. Priatel, Kevin Tsai, Kenneth W. Harder, Jose-Luis González de Aguilar, Pavel P. Philippov, Evgeni Yu Zernii, Masakazu Fujiwara, Mohammad Ghazizadeh, Roger J. Summers, Michelle L. Halls, Emma T. Westhuizen, Scott A. Busby, Thomas P. Burris, David P. Siderovski, Adam J. Kimple, Zhihui Xie, Kirk M. Druey, Nicolas Reymond, Francisco M. Vega, Anne J. Ridley, Gregory G. Tall, Weikang Cai, Jennifer L. Rudolph, Douglas A. Andres, John Colicelli, Pamela Y. Ting, Christine Janson, Michael F. Olson, James P. Brody, Julie A. Maupin-Furlow, Hugo V. Miranda, Philippe P. Roux, Filip Van Petegem, and Kelvin Lau
- Published
- 2012
46. ret-GC
- Author
-
Kirill A. Martemyanov, Pooja Parameswaran, Irene Aligianis, Mark Handley, Marga Gual-Soler, Tomohiko Taguchi, Jennifer L. Stow, Carol Wicking, Soumik BasuRay, Jacob O. Agola, Patricia A. Jim, Matthew N. Seaman, Angela Wandinger-Ness, Heather H. Ward, Diamantis Konstantinidis, Theodosia A. Kalfa, Andrea Varga, Manuela Baccarini, Debbie L. Hay, Patrick M. Sexton, David R. Poyner, Carlo Petosa, Tomoki Nakashima, Hiroshi Takayanagi, Hoa B. Nguyen, Lawrence A. Quilliam, Michael S. Samuel, Philip E. Lapinski, Philip D. King, Eugenio Santos, Alberto Fernández-Medarde, John J. Priatel, Kevin Tsai, Kenneth W. Harder, Jose-Luis González de Aguilar, Pavel P. Philippov, Evgeni Yu Zernii, Masakazu Fujiwara, Mohammad Ghazizadeh, Roger J. Summers, Michelle L. Halls, Emma T. Westhuizen, Scott A. Busby, Thomas P. Burris, David P. Siderovski, Adam J. Kimple, Zhihui Xie, Kirk M. Druey, Nicolas Reymond, Francisco M. Vega, Anne J. Ridley, Gregory G. Tall, Weikang Cai, Jennifer L. Rudolph, Douglas A. Andres, John Colicelli, Pamela Y. Ting, Christine Janson, Michael F. Olson, James P. Brody, Julie A. Maupin-Furlow, Hugo V. Miranda, Philippe P. Roux, Filip Van Petegem, and Kelvin Lau
- Published
- 2012
47. Ras-Related Protein Rab-7a
- Author
-
Kirill A. Martemyanov, Pooja Parameswaran, Irene Aligianis, Mark Handley, Marga Gual-Soler, Tomohiko Taguchi, Jennifer L. Stow, Carol Wicking, Soumik BasuRay, Jacob O. Agola, Patricia A. Jim, Matthew N. Seaman, Angela Wandinger-Ness, Heather H. Ward, Diamantis Konstantinidis, Theodosia A. Kalfa, Andrea Varga, Manuela Baccarini, Debbie L. Hay, Patrick M. Sexton, David R. Poyner, Carlo Petosa, Tomoki Nakashima, Hiroshi Takayanagi, Hoa B. Nguyen, Lawrence A. Quilliam, Michael S. Samuel, Philip E. Lapinski, Philip D. King, Eugenio Santos, Alberto Fernández-Medarde, John J. Priatel, Kevin Tsai, Kenneth W. Harder, Jose-Luis González de Aguilar, Pavel P. Philippov, Evgeni Yu Zernii, Masakazu Fujiwara, Mohammad Ghazizadeh, Roger J. Summers, Michelle L. Halls, Emma T. Westhuizen, Scott A. Busby, Thomas P. Burris, David P. Siderovski, Adam J. Kimple, Zhihui Xie, Kirk M. Druey, Nicolas Reymond, Francisco M. Vega, Anne J. Ridley, Gregory G. Tall, Weikang Cai, Jennifer L. Rudolph, Douglas A. Andres, John Colicelli, Pamela Y. Ting, Christine Janson, Michael F. Olson, James P. Brody, Julie A. Maupin-Furlow, Hugo V. Miranda, Philippe P. Roux, Filip Van Petegem, and Kelvin Lau
- Published
- 2012
48. RAS D1/DEXRAS1 (AGS1)
- Author
-
Kirill A. Martemyanov, Pooja Parameswaran, Irene Aligianis, Mark Handley, Marga Gual-Soler, Tomohiko Taguchi, Jennifer L. Stow, Carol Wicking, Soumik BasuRay, Jacob O. Agola, Patricia A. Jim, Matthew N. Seaman, Angela Wandinger-Ness, Heather H. Ward, Diamantis Konstantinidis, Theodosia A. Kalfa, Andrea Varga, Manuela Baccarini, Debbie L. Hay, Patrick M. Sexton, David R. Poyner, Carlo Petosa, Tomoki Nakashima, Hiroshi Takayanagi, Hoa B. Nguyen, Lawrence A. Quilliam, Michael S. Samuel, Philip E. Lapinski, Philip D. King, Eugenio Santos, Alberto Fernández-Medarde, John J. Priatel, Kevin Tsai, Kenneth W. Harder, Jose-Luis González de Aguilar, Pavel P. Philippov, Evgeni Yu Zernii, Masakazu Fujiwara, Mohammad Ghazizadeh, Roger J. Summers, Michelle L. Halls, Emma T. Westhuizen, Scott A. Busby, Thomas P. Burris, David P. Siderovski, Adam J. Kimple, Zhihui Xie, Kirk M. Druey, Nicolas Reymond, Francisco M. Vega, Anne J. Ridley, Gregory G. Tall, Weikang Cai, Jennifer L. Rudolph, Douglas A. Andres, John Colicelli, Pamela Y. Ting, Christine Janson, Michael F. Olson, James P. Brody, Julie A. Maupin-Furlow, Hugo V. Miranda, Philippe P. Roux, Filip Van Petegem, and Kelvin Lau
- Published
- 2012
49. Reggie-1 (Reg-1)
- Author
-
Kirill A. Martemyanov, Pooja Parameswaran, Irene Aligianis, Mark Handley, Marga Gual-Soler, Tomohiko Taguchi, Jennifer L. Stow, Carol Wicking, Soumik BasuRay, Jacob O. Agola, Patricia A. Jim, Matthew N. Seaman, Angela Wandinger-Ness, Heather H. Ward, Diamantis Konstantinidis, Theodosia A. Kalfa, Andrea Varga, Manuela Baccarini, Debbie L. Hay, Patrick M. Sexton, David R. Poyner, Carlo Petosa, Tomoki Nakashima, Hiroshi Takayanagi, Hoa B. Nguyen, Lawrence A. Quilliam, Michael S. Samuel, Philip E. Lapinski, Philip D. King, Eugenio Santos, Alberto Fernández-Medarde, John J. Priatel, Kevin Tsai, Kenneth W. Harder, Jose-Luis González de Aguilar, Pavel P. Philippov, Evgeni Yu Zernii, Masakazu Fujiwara, Mohammad Ghazizadeh, Roger J. Summers, Michelle L. Halls, Emma T. Westhuizen, Scott A. Busby, Thomas P. Burris, David P. Siderovski, Adam J. Kimple, Zhihui Xie, Kirk M. Druey, Nicolas Reymond, Francisco M. Vega, Anne J. Ridley, Gregory G. Tall, Weikang Cai, Jennifer L. Rudolph, Douglas A. Andres, John Colicelli, Pamela Y. Ting, Christine Janson, Michael F. Olson, James P. Brody, Julie A. Maupin-Furlow, Hugo V. Miranda, Philippe P. Roux, Filip Van Petegem, and Kelvin Lau
- Published
- 2012
50. RA70 (Retinoic Acid-Induced Protein 70)
- Author
-
Kirill A. Martemyanov, Pooja Parameswaran, Irene Aligianis, Mark Handley, Marga Gual-Soler, Tomohiko Taguchi, Jennifer L. Stow, Carol Wicking, Soumik BasuRay, Jacob O. Agola, Patricia A. Jim, Matthew N. Seaman, Angela Wandinger-Ness, Heather H. Ward, Diamantis Konstantinidis, Theodosia A. Kalfa, Andrea Varga, Manuela Baccarini, Debbie L. Hay, Patrick M. Sexton, David R. Poyner, Carlo Petosa, Tomoki Nakashima, Hiroshi Takayanagi, Hoa B. Nguyen, Lawrence A. Quilliam, Michael S. Samuel, Philip E. Lapinski, Philip D. King, Eugenio Santos, Alberto Fernández-Medarde, John J. Priatel, Kevin Tsai, Kenneth W. Harder, Jose-Luis González de Aguilar, Pavel P. Philippov, Evgeni Yu Zernii, Masakazu Fujiwara, Mohammad Ghazizadeh, Roger J. Summers, Michelle L. Halls, Emma T. Westhuizen, Scott A. Busby, Thomas P. Burris, David P. Siderovski, Adam J. Kimple, Zhihui Xie, Kirk M. Druey, Nicolas Reymond, Francisco M. Vega, Anne J. Ridley, Gregory G. Tall, Weikang Cai, Jennifer L. Rudolph, Douglas A. Andres, John Colicelli, Pamela Y. Ting, Christine Janson, Michael F. Olson, James P. Brody, Julie A. Maupin-Furlow, Hugo V. Miranda, Philippe P. Roux, Filip Van Petegem, and Kelvin Lau
- Published
- 2012
Catalog
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