11 results on '"Turner, C. E."'
Search Results
2. Nerve growth factor triggers microfilament assembly and paxillin phosphorylation in human B lymphocytes.
- Author
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Melamed, I, primary, Turner, C E, additional, Aktories, K, additional, Kaplan, D R, additional, and Gelfand, E W, additional
- Published
- 1995
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3. Tyrosine phosphorylation of paxillin and pp125FAK accompanies cell adhesion to extracellular matrix: a role in cytoskeletal assembly.
- Author
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Burridge, K, primary, Turner, C E, additional, and Romer, L H, additional
- Published
- 1992
- Full Text
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4. Paxillin is a major phosphotyrosine-containing protein during embryonic development.
- Author
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Turner, C E, primary
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- 1991
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5. Paxillin: a new vinculin-binding protein present in focal adhesions.
- Author
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Turner, C E, primary, Glenney, J R, additional, and Burridge, K, additional
- Published
- 1990
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6. Functional studies of the domains of talin.
- Author
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Nuckolls, G H, primary, Turner, C E, additional, and Burridge, K, additional
- Published
- 1990
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7. The LD4 motif of paxillin regulates cell spreading and motility through an interaction with paxillin kinase linker (PKL).
- Author
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West KA, Zhang H, Brown MC, Nikolopoulos SN, Riedy MC, Horwitz AF, and Turner CE
- Subjects
- Amino Acid Motifs, Animals, Binding Sites, Blotting, Western, CHO Cells, Cell Movement, Cells, Cultured, Cricetinae, Cytoskeletal Proteins genetics, Cytoskeletal Proteins metabolism, Cytoskeleton metabolism, Enzyme Activation, Fibroblasts metabolism, Fibronectins metabolism, Gene Deletion, Glutathione Transferase metabolism, Green Fluorescent Proteins, Luminescent Proteins metabolism, Microscopy, Fluorescence, Microscopy, Video, Models, Genetic, Mutagenesis, Site-Directed, Mutation, Paxillin, Phenotype, Phosphoproteins genetics, Phosphoproteins metabolism, Precipitin Tests, Protein Binding, Protein Structure, Tertiary, Pseudopodia metabolism, Recombinant Fusion Proteins metabolism, Time Factors, Transfection, ADP-Ribosylation Factors metabolism, Cytoskeletal Proteins chemistry, GTPase-Activating Proteins metabolism, Phosphoproteins chemistry
- Abstract
The small GTPases of the Rho family are intimately involved in integrin-mediated changes in the actin cytoskeleton that accompany cell spreading and motility. The exact means by which the Rho family members elicit these changes is unclear. Here, we demonstrate that the interaction of paxillin via its LD4 motif with the putative ARF-GAP paxillin kinase linker (PKL) (Turner et al., 1999), is critically involved in the regulation of Rac-dependent changes in the actin cytoskeleton that accompany cell spreading and motility. Overexpression of a paxillin LD4 deletion mutant (paxillinDeltaLD4) in CHO.K1 fibroblasts caused the generation of multiple broad lamellipodia. These morphological changes were accompanied by an increase in cell protrusiveness and random motility, which correlated with prolonged activation of Rac. In contrast, directional motility was inhibited. These alterations in morphology and motility were dependent on a paxillin-PKL interaction. In cells overexpressing paxillinDeltaLD4 mutants, PKL localization to focal contacts was disrupted, whereas that of focal adhesion kinase (FAK) and vinculin was not. In addition, FAK activity during spreading was not compromised by deletion of the paxillin LD4 motif. Furthermore, overexpression of PKL mutants lacking the paxillin-binding site (PKLDeltaPBS2) induced phenotypic changes reminiscent of paxillinDeltaLD4 mutant cells. These data suggest that the paxillin association with PKL is essential for normal integrin-mediated cell spreading, and locomotion and that this interaction is necessary for the regulation of Rac activity during these events.
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- 2001
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8. Actopaxin, a new focal adhesion protein that binds paxillin LD motifs and actin and regulates cell adhesion.
- Author
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Nikolopoulos SN and Turner CE
- Subjects
- Actinin, Amino Acid Motifs, Amino Acid Sequence, Animals, Base Sequence, Blotting, Western, Cell Adhesion, Cell Line, Cell Movement, Cloning, Molecular, DNA-Binding Proteins metabolism, Fluorescent Antibody Technique, HeLa Cells, Humans, Intracellular Signaling Peptides and Proteins, LIM Domain Proteins, Microfilament Proteins chemistry, Microfilament Proteins genetics, Molecular Sequence Data, Mutation genetics, Paxillin, Protein Binding, Protein Structure, Tertiary, Protein Transport, RNA, Messenger analysis, RNA, Messenger genetics, Rats, Recombinant Fusion Proteins metabolism, Sequence Alignment, Substrate Specificity, Wound Healing, Actins metabolism, Cytoskeletal Proteins chemistry, Cytoskeletal Proteins metabolism, Focal Adhesions chemistry, Microfilament Proteins metabolism, Phosphoproteins chemistry, Phosphoproteins metabolism
- Abstract
Paxillin is a focal adhesion adapter protein involved in the integration of growth factor- and adhesion-mediated signal transduction pathways. Paxillin LD motifs have been demonstrated to bind to several proteins associated with remodeling of the actin cytoskeleton including the focal adhesion kinase, vinculin, and a complex of proteins comprising p95PKL, PIX, and PAK (Turner, C.E., M. C. Brown, J.A. Perrotta, M.C. Riedy, S.N. Nikolopoulos, A.R. McDonald, S. Bagrodia, S. Thomas, and P.S. Leventhal. 1999. J. Cell Biol. 145:851-863). In this study, we report the cloning and initial characterization of a new paxillin LD motif-binding protein, actopaxin. Analysis of the deduced amino acid sequence of actopaxin reveals a 42-kD protein with two calponin homology domains and a paxillin-binding subdomain (PBS). Western blotting identifies actopaxin as a widely expressed protein. Actopaxin binds directly to both F-actin and paxillin LD1 and LD4 motifs. It exhibits robust focal adhesion localization in several cultured cell types but is not found along the length of the associated actin-rich stress fibers. Similar to paxillin, it is absent from actin-rich cell-cell adherens junctions. Also, actopaxin colocalizes with paxillin to rudimentary focal complexes at the leading edge of migrating cells. An actopaxin PBS mutant incapable of binding paxillin in vitro cannot target to focal adhesions when expressed in fibroblasts. In addition, ectopic expression of the PBS mutant and/or the COOH terminus of actopaxin in HeLa cells resulted in substantial reduction in adhesion to collagen. Together, these results suggest an important role for actopaxin in integrin-dependent remodeling of the actin cytoskeleton during cell motility and cell adhesion.
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- 2000
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- View/download PDF
9. Phosphorylation of tyrosine residues 31 and 118 on paxillin regulates cell migration through an association with CRK in NBT-II cells.
- Author
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Petit V, Boyer B, Lentz D, Turner CE, Thiery JP, and Vallés AM
- Subjects
- Amino Acid Substitution, Animals, Binding Sites genetics, Cell Adhesion, Clone Cells, Collagen metabolism, Collagen pharmacology, Cytoskeletal Proteins genetics, Focal Adhesion Kinase 1, Focal Adhesion Protein-Tyrosine Kinases, Mutagenesis, Site-Directed, Paxillin, Phosphoproteins genetics, Phosphorylation drug effects, Protein Binding genetics, Protein Kinases genetics, Protein Kinases metabolism, Protein-Tyrosine Kinases metabolism, Proto-Oncogene Proteins c-crk, Rats, Tumor Cells, Cultured, Urinary Bladder Neoplasms pathology, src Homology Domains genetics, Cell Adhesion Molecules metabolism, Cell Movement genetics, Cytoskeletal Proteins metabolism, Phosphoproteins metabolism, Proto-Oncogene Proteins, Tyrosine metabolism, Urinary Bladder Neoplasms metabolism
- Abstract
Identification of signaling molecules that regulate cell migration is important for understanding fundamental processes in development and the origin of various pathological conditions. The migration of Nara Bladder Tumor II (NBT-II) cells was used to determine which signaling molecules are specifically involved in the collagen-mediated locomotion. We show here that paxillin is tyrosine phosphorylated after induction of motility on collagen. Overexpression of paxillin mutants in which tyrosine 31 and/or tyrosine 118 were replaced by phenylalanine effectively impaired cell motility. Moreover, stimulation of motility by collagen preferentially enhanced the association of paxillin with the SH2 domain of the adaptor protein CrkII. Mutations in both tyrosine 31 and 118 diminished the phosphotyrosine content of paxillin and prevented the formation of the paxillin-Crk complex, suggesting that this association is necessary for collagen-mediated NBT-II cell migration. Other responses to collagen, such as cell adhesion and spreading, were not affected by these mutations. Overexpression of wild-type paxillin or Crk could bypass the migration-deficient phenotype. Both the SH2 and the SH3 domains of CrkII are shown to play a critical role in this collagen-mediated migration. These results demonstrate the important role of the paxillin-Crk complex in the collagen-induced cell motility.
- Published
- 2000
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10. Paxillin LD4 motif binds PAK and PIX through a novel 95-kD ankyrin repeat, ARF-GAP protein: A role in cytoskeletal remodeling.
- Author
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Turner CE, Brown MC, Perrotta JA, Riedy MC, Nikolopoulos SN, McDonald AR, Bagrodia S, Thomas S, and Leventhal PS
- Subjects
- ADP-Ribosylation Factors, Amino Acid Sequence, Animals, Ankyrins genetics, Binding Sites, CHO Cells, COS Cells, Carrier Proteins genetics, Carrier Proteins metabolism, Cell Adhesion Molecules metabolism, Cell Cycle Proteins metabolism, Cell Movement, Cricetinae, DNA-Binding Proteins metabolism, Focal Adhesion Protein-Tyrosine Kinases, GTP Phosphohydrolases, GTPase-Activating Proteins, Intracellular Signaling Peptides and Proteins, LIM Domain Proteins, Molecular Sequence Data, Paxillin, Protein-Tyrosine Kinases metabolism, Repetitive Sequences, Nucleic Acid, Sequence Analysis, DNA, Subcellular Fractions, Vinculin metabolism, cdc42 GTP-Binding Protein, p21-Activated Kinases, Ankyrins metabolism, Carrier Proteins physiology, Cytoskeletal Proteins metabolism, Cytoskeleton physiology, GTP-Binding Proteins metabolism, Phosphoproteins metabolism, Protein Serine-Threonine Kinases metabolism, Proteins metabolism
- Abstract
Paxillin is a focal adhesion adaptor protein involved in the integration of growth factor- and adhesion-mediated signal transduction pathways. Repeats of a leucine-rich sequence named paxillin LD motifs (Brown M.C., M.S. Curtis, and C.E. Turner. 1998. Nature Struct. Biol. 5:677-678) have been implicated in paxillin binding to focal adhesion kinase (FAK) and vinculin. Here we demonstrate that the individual paxillin LD motifs function as discrete and selective protein binding interfaces. A novel scaffolding function is described for paxillin LD4 in the binding of a complex of proteins containing active p21 GTPase-activated kinase (PAK), Nck, and the guanine nucleotide exchange factor, PIX. The association of this complex with paxillin is mediated by a new 95-kD protein, p95PKL (paxillin-kinase linker), which binds directly to paxillin LD4 and PIX. This protein complex also binds to Hic-5, suggesting a conservation of LD function across the paxillin superfamily. Cloning of p95PKL revealed a multidomain protein containing an NH2-terminal ARF-GAP domain, three ankyrin-like repeats, a potential calcium-binding EF hand, calmodulin-binding IQ motifs, a myosin homology domain, and two paxillin-binding subdomains (PBS). Green fluorescent protein- (GFP-) tagged p95PKL localized to focal adhesions/complexes in CHO.K1 cells. Overexpression in neuroblastoma cells of a paxillin LD4 deletion mutant inhibited lamellipodia formation in response to insulin-like growth fac- tor-1. Microinjection of GST-LD4 into NIH3T3 cells significantly decreased cell migration into a wound. These data implicate paxillin as a mediator of p21 GTPase-regulated actin cytoskeletal reorganization through the recruitment to nascent focal adhesion structures of an active PAK/PIX complex potentially via interactions with p95PKL.
- Published
- 1999
- Full Text
- View/download PDF
11. Quantitative changes in integrin and focal adhesion signaling regulate myoblast cell cycle withdrawal.
- Author
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Sastry SK, Lakonishok M, Wu S, Truong TQ, Huttenlocher A, Turner CE, and Horwitz AF
- Subjects
- Animals, Antigens, CD genetics, Antigens, CD metabolism, Calcium-Calmodulin-Dependent Protein Kinases metabolism, Cell Differentiation physiology, Cell Division physiology, Cells, Cultured, Coturnix, Cytoskeletal Proteins metabolism, Focal Adhesion Kinase 1, Focal Adhesion Protein-Tyrosine Kinases, Humans, Integrin alpha5, Integrin alpha6, Integrin beta1 genetics, Integrin beta1 metabolism, Integrins genetics, Paxillin, Phosphoproteins metabolism, Transfection, Cell Adhesion Molecules metabolism, Cell Cycle physiology, Integrins metabolism, Muscle, Skeletal cytology, Muscle, Skeletal metabolism, Protein-Tyrosine Kinases metabolism, Signal Transduction physiology
- Abstract
We previously demonstrated contrasting roles for integrin alpha subunits and their cytoplasmic domains in controlling cell cycle withdrawal and the onset of terminal differentiation (Sastry, S., M. Lakonishok, D. Thomas, J. Muschler, and A.F. Horwitz. 1996. J. Cell Biol. 133:169-184). Ectopic expression of the integrin alpha5 or alpha6A subunit in primary quail myoblasts either decreases or enhances the probability of cell cycle withdrawal, respectively. In this study, we addressed the mechanisms by which changes in integrin alpha subunit ratios regulate this decision. Ectopic expression of truncated alpha5 or alpha6A indicate that the alpha5 cytoplasmic domain is permissive for the proliferative pathway whereas the COOH-terminal 11 amino acids of alpha6A cytoplasmic domain inhibit proliferation and promote differentiation. The alpha5 and alpha6A cytoplasmic domains do not appear to initiate these signals directly, but instead regulate beta1 signaling. Ectopically expressed IL2R-alpha5 or IL2R-alpha6A have no detectable effect on the myoblast phenotype. However, ectopic expression of the beta1A integrin subunit or IL2R-beta1A, autonomously inhibits differentiation and maintains a proliferative state. Perturbing alpha5 or alpha6A ratios also significantly affects activation of beta1 integrin signaling pathways. Ectopic alpha5 expression enhances expression and activation of paxillin as well as mitogen-activated protein (MAP) kinase with little effect on focal adhesion kinase (FAK). In contrast, ectopic alpha6A expression suppresses FAK and MAP kinase activation with a lesser effect on paxillin. Ectopic expression of wild-type and mutant forms of FAK, paxillin, and MAP/erk kinase (MEK) confirm these correlations. These data demonstrate that (a) proliferative signaling (i.e., inhibition of cell cycle withdrawal and the onset of terminal differentiation) occurs through the beta1A subunit and is modulated by the alpha subunit cytoplasmic domains; (b) perturbing alpha subunit ratios alters paxillin expression and phosphorylation and FAK and MAP kinase activation; (c) quantitative changes in the level of adhesive signaling through integrins and focal adhesion components regulate the decision of myoblasts to withdraw from the cell cycle, in part via MAP kinase.
- Published
- 1999
- Full Text
- View/download PDF
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