17 results on '"Hümmer C"'
Search Results
2. Automated isolation of primary antigen-specific T cells from donor lymphocyte concentrates: results of a feasibility exercise
- Author
-
Bunos, M., Hümmer, C., Wingenfeld, E., Sorg, N., Pfirrmann, V., Bader, P., Seifried, E., and Bönig, H.
- Published
- 2015
- Full Text
- View/download PDF
3. Nicht-Radiologen in der Notaufnahme profitieren in der Röntgen-Thorax-Befundung deutlich von KI-Unterstützung.
- Author
-
Rudolph, J P, Hümmer, C, Preuhs, A, Buizza, G, Dinkel, J, Koliogiannis, V, Goller, S S, Fink, N, Schwarze, V, Fischer, M, Jörgens, M, Ben Khaled, N, Hoppe, B F, Liebig, T, Ricke, J, Rueckel, J, and Sabel, B
- Published
- 2024
- Full Text
- View/download PDF
4. A corpus-based lexical resource of German idioms
- Author
-
Neumann, G., primary, Stantcheva, D., additional, Stathi, E., additional, Fellbaum, C., additional, Geyken, A., additional, Herold, A., additional, Hümmer, C., additional, Körner, F., additional, Kramer, U., additional, Krell, K., additional, and Sokirko, A., additional
- Published
- 2004
- Full Text
- View/download PDF
5. 2D-SPLASH-Spektroskopie zur Bestimmung des Fett/Wasser-Verhältnisses in der Rotatorenmanschette
- Author
-
Köstler, H., primary, Kenn, W., additional, Hümmer, C., additional, Böhm, D., additional, and Hahn, D., additional
- Published
- 2002
- Full Text
- View/download PDF
6. Picoplanktonic Choricystis species (Chlorococcales, Chlorophyta) and problems surrounding the morphologically similar ‘Nannochloris-like algae’
- Author
-
Krienitz, L., primary, Huss, V. A. R., additional, and Hümmer, C., additional
- Published
- 1996
- Full Text
- View/download PDF
7. Introduction of principles of blood management to healthy donor bone marrow harvesting.
- Author
-
Kim-Wanner SZ, Luxembourg B, Schmidt AH, Schäfer R, Möller N, Herbert E, Poppe C, Hümmer C, Bunos M, Seifried E, and Bonig H
- Subjects
- Bone Marrow Transplantation, Female, Humans, Male, Patient Safety, Retrospective Studies, Stem Cell Transplantation, Bone Marrow, Tissue Donors, Tissue and Organ Harvesting methods
- Abstract
Background and Objectives: Patient blood (more accurately: haemoglobin, Hb) management (PBM) aims to optimize endogenous Hb production and to minimize iatrogenic Hb loss while maintaining patient safety and optimal effectiveness of medical interventions. PBM was adopted as policy for patients by the World Health Organization (WHO), and, all the more, should be applied to healthy donors., Materials and Methods: Observational data from 489 bone marrow (BM) donors were retrospectively analysed, and principles of patient blood management were applied to healthy volunteer BM donations., Results and Conclusion: We managed to render BM aspiration safe for donors, notably completely avoiding the collection of autologous blood units and blood transfusions through iron management, establishment and curation of high-yield aspiration technique, limitation of collection volume to 1·5% of donor body weight and development of volume prediction algorithms for the requested cell dose., (© 2020 The Authors. Vox Sanguinis published by John Wiley & Sons Ltd on behalf of International Society of Blood Transfusion.)
- Published
- 2020
- Full Text
- View/download PDF
8. Erythrocyte depletion from bone marrow: performance evaluation after 50 clinical-scale depletions with Spectra Optia BMC.
- Author
-
Kim-Wanner SZ, Bug G, Steinmann J, Ajib S, Sorg N, Poppe C, Bunos M, Wingenfeld E, Hümmer C, Luxembourg B, Seifried E, and Bonig H
- Subjects
- Antigens, CD34 metabolism, Bone Marrow Transplantation, Cell Lineage, Feasibility Studies, Hematopoiesis, Humans, Transplantation, Homologous, Blood Component Removal methods, Bone Marrow metabolism, Erythrocytes metabolism
- Abstract
Background: Red blood cell (RBC) depletion is a standard graft manipulation technique for ABO-incompatible bone marrow (BM) transplants. The BM processing module for Spectra Optia, "BMC", was previously introduced. We here report the largest series to date of routine quality data after performing 50 clinical-scale RBC-depletions., Methods: Fifty successive RBC-depletions from autologous (n = 5) and allogeneic (n = 45) BM transplants were performed with the Spectra Optia BMC apheresis suite. Product quality was assessed before and after processing for volume, RBC and leukocyte content; RBC-depletion and stem cell (CD34+ cells) recovery was calculated there from. Clinical engraftment data were collected from 26/45 allogeneic recipients., Results: Median RBC removal was 98.2% (range 90.8-99.1%), median CD34+ cell recovery was 93.6%, minimum recovery being 72%, total product volume was reduced to 7.5% (range 4.7-23.0%). Products engrafted with expected probability and kinetics. Performance indicators were stable over time., Discussion: Spectra Optia BMC is a robust and efficient technology for RBC-depletion and volume reduction of BM, providing near-complete RBC removal and excellent CD34+ cell recovery.
- Published
- 2017
- Full Text
- View/download PDF
9. Automation of cellular therapy product manufacturing: results of a split validation comparing CD34 selection of peripheral blood stem cell apheresis product with a semi-manual vs. an automatic procedure.
- Author
-
Hümmer C, Poppe C, Bunos M, Stock B, Wingenfeld E, Huppert V, Stuth J, Reck K, Essl M, Seifried E, and Bonig H
- Subjects
- Flow Cytometry, Humans, Reproducibility of Results, Antigens, CD34 metabolism, Automation, Blood Component Removal methods, Cell- and Tissue-Based Therapy, Hematopoietic Stem Cells cytology
- Abstract
Background: Automation of cell therapy manufacturing promises higher productivity of cell factories, more economical use of highly-trained (and costly) manufacturing staff, facilitation of processes requiring manufacturing steps at inconvenient hours, improved consistency of processing steps and other benefits. One of the most broadly disseminated engineered cell therapy products is immunomagnetically selected CD34+ hematopoietic "stem" cells (HSCs)., Methods: As the clinical GMP-compliant automat CliniMACS Prodigy is being programmed to perform ever more complex sequential manufacturing steps, we developed a CD34+ selection module for comparison with the standard semi-automatic CD34 "normal scale" selection process on CliniMACS Plus, applicable for 600 × 10(6) target cells out of 60 × 10(9) total cells. Three split-validation processings with healthy donor G-CSF-mobilized apheresis products were performed; feasibility, time consumption and product quality were assessed., Results: All processes proceeded uneventfully. Prodigy runs took about 1 h longer than CliniMACS Plus runs, albeit with markedly less hands-on operator time and therefore also suitable for less experienced operators. Recovery of target cells was the same for both technologies. Although impurities, specifically T- and B-cells, were 5 ± 1.6-fold and 4 ± 0.4-fold higher in the Prodigy products (p = ns and p = 0.013 for T and B cell depletion, respectively), T cell contents per kg of a virtual recipient receiving 4 × 10(6) CD34+ cells/kg was below 10 × 10(3)/kg even in the worst Prodigy product and thus more than fivefold below the specification of CD34+ selected mismatched-donor stem cell products. The products' theoretical clinical usability is thus confirmed., Conclusions: This split validation exercise of a relatively short and simple process exemplifies the potential of automatic cell manufacturing. Automation will further gain in attractiveness when applied to more complex processes, requiring frequent interventions or handling at unfavourable working hours, such as re-targeting of T-cells.
- Published
- 2016
- Full Text
- View/download PDF
10. Automated CD34+ cell isolation of peripheral blood stem cell apheresis product.
- Author
-
Spohn G, Wiercinska E, Karpova D, Bunos M, Hümmer C, Wingenfeld E, Sorg N, Poppe C, Huppert V, Stuth J, Reck K, Essl M, Seifried E, and Bönig H
- Subjects
- Antilymphocyte Serum immunology, Automation, Laboratory, B-Lymphocytes immunology, Cells, Cultured, Flow Cytometry, Granulocyte Colony-Stimulating Factor immunology, Hematopoietic Stem Cell Transplantation methods, Hematopoietic Stem Cells immunology, Humans, Lymphocyte Depletion methods, T-Lymphocytes immunology, Antigens, CD34 immunology, Blood Component Removal methods, Cell Separation methods, Hematopoietic Stem Cells cytology, Immunomagnetic Separation methods
- Abstract
Background Aims: Immunomagnetic enrichment of CD34+ hematopoietic "stem" cells (HSCs) using paramagnetic nanobead coupled CD34 antibody and immunomagnetic extraction with the CliniMACS plus system is the standard approach to generating T-cell-depleted stem cell grafts. Their clinical beneficence in selected indications is established. Even though CD34+ selected grafts are typically given in the context of a severely immunosuppressive conditioning with anti-thymocyte globulin or similar, the degree of T-cell depletion appears to affect clinical outcomes and thus in addition to CD34 cell recovery, the degree of T-cell depletion critically describes process quality. An automatic immunomagnetic cell processing system, CliniMACS Prodigy, including a protocol for fully automatic CD34+ cell selection from apheresis products, was recently developed. We performed a formal process validation to support submission of the protocol for CE release, a prerequisite for clinical use of Prodigy CD34+ products., Methods: Granulocyte-colony stimulating factor-mobilized healthy-donor apheresis products were subjected to CD34+ cell selection using Prodigy with clinical reagents and consumables and advanced beta versions of the CD34 selection software. Target and non-target cells were enumerated using sensitive flow cytometry platforms., Results: Nine successful clinical-scale CD34+ cell selections were performed. Beyond setup, no operator intervention was required. Prodigy recovered 74 ± 13% of target cells with a viability of 99.9 ± 0.05%. Per 5 × 10E6 CD34+ cells, which we consider a per-kilogram dose of HSCs, products contained 17 ± 3 × 10E3 T cells and 78 ± 22 × 10E3 B cells., Conclusions: The process for CD34 selection with Prodigy is robust and labor-saving but not time-saving. Compared with clinical CD34+ selected products concurrently generated with the predecessor technology, product properties, importantly including CD34+ cell recovery and T-cell contents, were not significantly different. The automatic system is suitable for routine clinical application., (Copyright © 2015 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
11. Red blood cell depletion from bone marrow and peripheral blood buffy coat: a comparison of two new and three established technologies.
- Author
-
Sorg N, Poppe C, Bunos M, Wingenfeld E, Hümmer C, Krämer A, Stock B, Seifried E, and Bonig H
- Subjects
- Blood Cells, Blood Component Removal economics, Blood Component Removal instrumentation, Blood Group Incompatibility prevention & control, Bone Marrow Cells, Cell Separation economics, Cell Separation instrumentation, Centrifugation, Density Gradient economics, Centrifugation, Density Gradient instrumentation, Equipment Design, Erythrocyte Volume, Ficoll, Hematocrit, Humans, Blood Buffy Coat cytology, Blood Component Removal methods, Cell Separation methods, Centrifugation, Density Gradient methods, Erythrocytes
- Abstract
Background: Red blood cell (RBC) depletion is a standard technique for preparation of ABO-incompatible bone marrow transplants (BMTs). Density centrifugation or apheresis are used successfully at clinical scale. The advent of a bone marrow (BM) processing module for the Spectra Optia (Terumo BCT) provided the initiative to formally compare our standard technology, the COBE2991 (Ficoll, manual, "C") with the Spectra Optia BMP (apheresis, semiautomatic, "O"), the Sepax II NeatCell (Ficoll, automatic, "S"), the Miltenyi CliniMACS Prodigy density gradient separation system (Ficoll, automatic, "P"), and manual Ficoll ("M"). C and O handle larger product volumes than S, P, and M., Study Design and Methods: Technologies were assessed for RBC depletion, target cell (mononuclear cells [MNCs] for buffy coats [BCs], CD34+ cells for BM) recovery, and cost/labor. BC pools were simultaneously purged with C, O, S, and P; five to 18 BM samples were sequentially processed with C, O, S, and M., Results: Mean RBC removal with C was 97% (BCs) or 92% (BM). From both products, O removed 97%, and P, S, and M removed 99% of RBCs. MNC recovery from BC (98% C, 97% O, 65% P, 74% S) or CD34+ cell recovery from BM (92% C, 90% O, 67% S, 70% M) were best with C and O. Polymorphonuclear cells (PMNs) were depleted from BCs by P, S, and C, while O recovered 50% of PMNs. Time savings compared to C or M for all tested technologies are considerable., Conclusion: All methods are in principle suitable and can be selected based on sample volume, available technology, and desired product specifications beyond RBC depletion and MNC and/or CD34+ cell recovery., (© 2015 AABB.)
- Published
- 2015
- Full Text
- View/download PDF
12. Inactivation of thioredoxin f1 leads to decreased light activation of ADP-glucose pyrophosphorylase and altered diurnal starch turnover in leaves of Arabidopsis plants.
- Author
-
Thormählen I, Ruber J, von Roepenack-Lahaye E, Ehrlich SM, Massot V, Hümmer C, Tezycka J, Issakidis-Bourguet E, and Geigenberger P
- Subjects
- Arabidopsis genetics, Arabidopsis growth & development, Chloroplast Thioredoxins genetics, Chloroplasts enzymology, Circadian Rhythm, Enzyme Activation, Gas Chromatography-Mass Spectrometry, Gene Knockout Techniques, Light, Oxidation-Reduction, Photosynthesis, Sucrose metabolism, Arabidopsis enzymology, Chloroplast Thioredoxins metabolism, Glucose-1-Phosphate Adenylyltransferase metabolism, Plant Leaves metabolism, Starch biosynthesis
- Abstract
Chloroplast thioredoxin f (Trx f) is an important regulator of primary metabolic enzymes. However, genetic evidence for its physiological importance is largely lacking. To test the functional significance of Trx f in vivo, Arabidopsis mutants with insertions in the trx f1 gene were studied, showing a drastic decrease in Trx f leaf content. Knockout of Trx f1 led to strong attenuation in reductive light activation of ADP-glucose pyrophosphorylase (AGPase), the key enzyme of starch synthesis, in leaves during the day and in isolated chloroplasts, while sucrose-dependent redox activation of AGPase in darkened leaves was not affected. The decrease in light-activation of AGPase in leaves was accompanied by a decrease in starch accumulation, an increase in sucrose levels and a decrease in starch-to-sucrose ratio. Analysis of metabolite levels at the end of day shows that inhibition of starch synthesis was unlikely due to shortage of substrates or changes in allosteric effectors. Metabolite profiling by gas chromatography-mass spectrometry pinpoints only a small number of metabolites affected, including sugars, organic acids and ethanolamine. Interestingly, metabolite data indicate carbon shortage in trx f1 mutant leaves at the end of night. Overall, results provide in planta evidence for the role played by Trx f in the light activation of AGPase and photosynthetic carbon partitioning in plants., (© 2012 Blackwell Publishing Ltd.)
- Published
- 2013
- Full Text
- View/download PDF
13. Barley grains, deficient in cytosolic small subunit of ADP-glucose pyrophosphorylase, reveal coordinate adjustment of C:N metabolism mediated by an overlapping metabolic-hormonal control.
- Author
-
Faix B, Radchuk V, Nerlich A, Hümmer C, Radchuk R, Emery RJ, Keller H, Götz KP, Weschke W, Geigenberger P, and Weber H
- Subjects
- Abscisic Acid biosynthesis, Amino Acids metabolism, Amylases genetics, Amylases metabolism, Citric Acid Cycle, Cytokinins biosynthesis, Endosperm genetics, Endosperm metabolism, Endosperm physiology, Gene Expression Regulation, Plant, Glucose-1-Phosphate Adenylyltransferase genetics, Glycolysis, Hordeum genetics, Hordeum metabolism, Hordeum physiology, Isocitrate Dehydrogenase genetics, Isocitrate Dehydrogenase metabolism, Mitochondria enzymology, Mitochondria genetics, Mitochondria metabolism, Mutation, Plant Growth Regulators genetics, Plant Proteins genetics, Plant Proteins metabolism, Promoter Regions, Genetic, Seed Storage Proteins genetics, Seed Storage Proteins metabolism, Starch biosynthesis, Carbon metabolism, Cytosol metabolism, Glucose-1-Phosphate Adenylyltransferase metabolism, Hordeum enzymology, Nitrogen metabolism, Plant Growth Regulators metabolism
- Abstract
The barley Risø16 mutation leads to inactivation of cytosolic ADP-Glc pyrophosphorylase, and results in decreased ADP-Glc and endospermal starch levels. Here we show that this mutation is accompanied by a decrease in storage protein accumulation and seed size, which indicates that alteration of a single enzymatic step can change the network of storage metabolism as a whole. We used comprehensive transcript, metabolite and hormonal profiling to compare grain metabolism and development of Risø16 and wild-type endosperm. Despite increased sugar availability in mutant endosperm, glycolytic intermediates downstream of hexose phosphates remained unchanged or decreased, while several glycolytic enzymes were downregulated at the transcriptional level. Metabolite and transcript profiling also indicated an inhibition of the tricarboxylic acid cycle at the level of mitochondrial nicotinamide adenine dinucleotide (NAD)-isocitrate dehydrogenase and an attendant decrease in alpha-ketoglutarate and amino acids levels in Risø16, compared with wild type. Decreased levels of cytokinins in Risø16 endosperm suggested co-regulation between starch synthesis, abscisic acid (ABA) deficiency and cytokinin biosynthesis. Comparative cis-element analysis in promoters of jointly downregulated genes in Risø16 revealed an overlap between metabolic and hormonal regulation, which leds to a coordinated downregulation of endosperm-specific and ABA-inducible gene expression (storage proteins) together with repression by sugars (isocitrate dehydrogenase, amylases). Such co-regulation ensured that decreased carbon fluxes into starch lead to a coordinated inhibition of glycolysis, amino acid and storage proteins biosynthesis, which is useful in the prevention of osmotic imbalances and oxidative stress due to increased accumulation of sugars., (© 2011 The Authors. The Plant Journal © 2011 Blackwell Publishing Ltd.)
- Published
- 2012
- Full Text
- View/download PDF
14. Subcellular analysis of starch metabolism in developing barley seeds using a non-aqueous fractionation method.
- Author
-
Tiessen A, Nerlich A, Faix B, Hümmer C, Fox S, Trafford K, Weber H, Weschke W, and Geigenberger P
- Subjects
- Biological Transport, Carbohydrate Metabolism, Cytosol metabolism, Plant Tubers metabolism, Plastids metabolism, Solanum tuberosum metabolism, Hordeum metabolism, Seeds metabolism, Starch metabolism, Sucrose metabolism
- Abstract
Compartmentation of metabolism in developing seeds is poorly understood due to the lack of data on metabolite distributions at the subcellular level. In this report, a non-aqueous fractionation method is described that allows subcellular concentrations of metabolites in developing barley endosperm to be calculated. (i) Analysis of subcellular volumes in developing endosperm using micrographs shows that plastids and cytosol occupy 50.5% and 49.9% of the total cell volume, respectively, while vacuoles and mitochondria can be neglected. (ii) By using non-aqueous fractionation, subcellular distribution between the cytosol and plastid of the levels of metabolites involved in sucrose degradation, starch synthesis, and respiration were determined. With the exception of ADP and AMP which were mainly located in the plastid, most other metabolites of carbon and energy metabolism were mainly located outside the plastid in the cytosolic compartment. (iii) In developing barley endosperm, the ultimate precursor of starch, ADPglucose (ADPGlc), was mainly located in the cytosol (80-90%), which was opposite to the situation in growing potato tubers where ADPGlc was almost exclusively located in the plastid (98%). This reflects the different subcellular distribution of ADPGlc pyrophosphorylase (AGPase) in these tissues. (iv) Cytosolic concentrations of ADPGlc were found to be close to the published K(m) values of AGPase and the ADPGlc/ADP transporter at the plastid envelope. Also the concentrations of the reaction partners glucose-1-phosphate, ATP, and inorganic pyrophosphate were close to the respective K(m) values of AGPase. (v) Knock-out of cytosolic AGPase in Riso16 mutants led to a strong decrease in ADPGlc level, in both the cytosol and plastid, whereas knock-down of the ADPGlc/ADP transporter led to a large shift in the intracellular distribution of ADPGlc. (v) The thermodynamic structure of the pathway of sucrose to starch was determined by calculating the mass-action ratios of all the steps in the pathway. The data show that AGPase is close to equilibrium, in both the cytosol and plastid, whereas the ADPGlc/ADP transporter is strongly displaced from equilibrium in vivo. This is in contrast to most other tissues, including leaves and potato tubers. (vi) Results indicate transport rather than synthesis of ADPGlc to be the major regulatory site of starch synthesis in barley endosperm. The reversibility of AGPase in the plastid has important implications for the regulation of carbon partitioning between different biosynthetic pathways.
- Published
- 2012
- Full Text
- View/download PDF
15. 2D SPLASH: a new method to determine the fatty infiltration of the rotator cuff muscles.
- Author
-
Kenn W, Böhm D, Gohlke F, Hümmer C, Köstler H, and Hahn D
- Subjects
- Adult, Aged, Female, Humans, Male, Middle Aged, Muscular Atrophy pathology, Muscular Diseases diagnosis, Muscular Diseases surgery, ROC Curve, Rotator Cuff surgery, Adipose Tissue pathology, Magnetic Resonance Spectroscopy methods, Muscular Diseases pathology, Rotator Cuff pathology, Rotator Cuff Injuries
- Abstract
The objective of this paper is to quantify the fatty degeneration (infiltration) of rotator cuff muscles with a new spectroscopic FLASH (SPLASH) sequence. Before planned surgery (reconstruction or muscle transfer), 20 patients (13 men, 7 women; 35-75 years) with different stages of rotator cuff disease underwent an MR examination in a 1.5-T unit. The protocol consists of imaging sequences and a newly implemented SPLASH, which allows an exact quantification of the fat/water ratio with a high spatial resolution in an arbitrarily shaped region of interest (ROI). The percentages of fat in the rotator cuff muscles were determined. To determine statistically significant differences between the different stages of rotator cuff tear, a Kruskal-Wallis H test was used. Fatty infiltration of the supraspinatus muscle was correlated with cross-sectional area (CSA) measures (Bravais-Pearson). We found significant differences between different stages of rotator cuff disease, the fatty infiltration and the volume loss (determined by the occupation ratio) of the supraspinatus muscle. With the increasing extent of rotator cuff disease, fatty infiltration increases significantly, as does the volume loss of the supraspinatus muscle. Comparing fatty infiltration and the occupation ratio individually, there was only a moderate inverse correlation between fatty infiltration and the occupation ratio, with considerable variation of data. Fatty infiltration of the infraspinatus muscle occurred when the infraspinatus tendon was involved to a lesser extent. The SPLASH sequence allows exact quantification of fatty infiltration in an arbitrarily shaped ROI. The extent of atrophy and fatty infiltration correlates with the size of the tear. Atrophy and fatty infiltration correlate only moderately and should be evaluated separately.
- Published
- 2004
- Full Text
- View/download PDF
16. [2D-SPLASH spectroscopy to determine the fat/water ratio in the muscle of the rotator cuff].
- Author
-
Köstler H, Kenn W, Hümmer C, Böhm D, and Hahn D
- Subjects
- Atrophy, Humans, Phantoms, Imaging, Prognosis, Rotator Cuff surgery, Rotator Cuff Injuries, Software, Adipose Tissue pathology, Body Water metabolism, Image Enhancement, Image Processing, Computer-Assisted, Magnetic Resonance Imaging, Magnetic Resonance Spectroscopy, Muscle, Skeletal pathology, Rotator Cuff pathology
- Abstract
Aim: The degree of fatty infiltration of the rotator cuff is an important factor for the prognosis of an operative reconstruction afterrotator cuff tear. The aim of this work was to develop a method using a clinical MR scanner that allows the quantification of the fat/water ratio with the necessary spatial resolution., Method: A SPLASH sequence consisting of 19 complex 2D-FLASH images was implemented on a clinical 1.5 T MR scanner. The echo time was gradually increased from 5.0 ms to 50.0 ms. A spatial in plane resolution of 1.17 mm, a spectral resolution of 0.33 ppm and a spectral width of 6.25 ppm were achieved in a total acquisition time of about 3 min. The quantitative evaluation of the spectra in arbitrarily shaped regions of interest (ROIs) was obtained using a home-built reconstruction program and the time domain fit program AMARES., Results: Phantom studies show a linear relation of the concentration determined by SPLASH spectroscopy (r = 0.997). Because of the high spatial resolution and the possibility to evaluate arbitrarily shaped ROIs, the determination of the fat/water ratio in single muscles in the shoulder has been possible., Conclusions: By the use of the 2D-SPLASH sequence the degree of fatty infiltration in the rotator cuff can now be determined quantitatively for the first time.
- Published
- 2002
- Full Text
- View/download PDF
17. AtSUC3, a gene encoding a new Arabidopsis sucrose transporter, is expressed in cells adjacent to the vascular tissue and in a carpel cell layer.
- Author
-
Meyer S, Melzer M, Truernit E, Hümmer C, Besenbeck R, Stadler R, and Sauer N
- Subjects
- Amino Acid Sequence, Arabidopsis cytology, Arabidopsis ultrastructure, Biological Transport, Cell Wall, Cloning, Molecular, Cytoplasm metabolism, DNA, Complementary, Energy Metabolism, Gene Expression, Maltose metabolism, Molecular Sequence Data, Monosaccharide Transport Proteins biosynthesis, Plant Leaves metabolism, Plant Leaves ultrastructure, Plant Stems metabolism, Plant Stems ultrastructure, Plant Structures, Sequence Homology, Amino Acid, Sucrose metabolism, Arabidopsis genetics, Membrane Transport Proteins, Monosaccharide Transport Proteins genetics, Plant Proteins
- Abstract
The cDNA corresponding to the open reading frame T17M13.3 from Arabidopsis chromosome II was isolated and the encoded protein was characterized as a member of a subgroup of higher plant sucrose transporters. The AtSUC3 (Arabidopsis thaliana sucrose transporter 3) open reading frame encodes a protein with 594 amino acid residues, being 81 and 82 residues longer than the previously described Arabidopsis sucrose carriers AtSUC1 and AtSUC2. About 50 of these additional amino acids are part of an extended cytoplasmic loop separating the N-terminal from the C-terminal half of the protein. For functional characterization the AtSUC3 cDNA was expressed in baker's yeast. Substrate specificities, energy dependence and K(m) values of the recombinant protein were determined. Removal of the enlarged cytoplasmic loop and expression of the truncated cDNA caused no detectable change in the kinetic properties of the protein, suggesting a transport-independent function for this cytoplasmic domain. Immunolocalization with an AtSUC3-specific antiserum identified the protein in a cell layer separating the phloem from the mesophyll and in a single, subepidermal cell layer of the carpels that is important for pod dehiscence. These localizations suggest a possible role of AtSUC3 in the funnelling of sucrose from the mesophyll towards the phloem, and possibly in pod shatter.
- Published
- 2000
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.