CLONAL DIFFERENCES IN GLUTAMINE SYNTHETASE ACTIVITY OF HEPATOMA CELLS
نویسندگان
چکیده
منابع مشابه
Clonal Differences in Glutamine Synthetase Activity of Hepatoma Cells
Most hepatomas contain only traces of glutamine synthetase (GS) although they originate from liver which has high levels of the enzyme (1-3) The H T C cell line which was derived from Morris Hepa toma 7288C retained certain characteristics of liver cells, notably the induction of tyrosine amino transferase (4, 5), while other liver characteristics, among them GS activity, could not be detected ...
متن کاملRegulation of glutamine synthetase activity of hepatoma tissue culture cells by glutamine and dexamethasone.
Regulation of glutamine synthetase activity was studied in a glutamine-independent subclone of the hepatoma tissue culture cell line. In cells of this subclone glutamine synthetase activity was elevated by the synthetic corticosteroid hormone, dexamethasone, and depressed by glutamine. The increase in glutamine synthetase activity due to the addition of dexamethasone and that due to removal of ...
متن کاملEffect of glutamine on the degradation of glutamine synthetase in hepatoma tissue-culture cells.
In certain lines of hepatoma tissue-culture cells, the extracellular glutamine concentration regulates the specific activity of glutamine synthetase. By quantifying the radioactivity in immunoprecipitated glutamine synthetase on polyacrylamide gels, we found that the rate of degradation, but not of synthesis, of glutamine synthetase is a sensitive function of extracellular glutamine. The activi...
متن کاملClonal variation in albumin messenger RNA activity in hepatoma cells.
The clonal variation in rate of albumin synthesis in hepatoma cells is described as a tool for the study of epigenetic control of differentiation. Previous studies have demonstrated that, from a population of hepatome cells, variant subclones can be readily isolated that produce albumin at different rates. Each clonal variant had a characteristic rate of albumin production, and the clones clust...
متن کاملAssay for glutamine synthetase activity.
The use of phosphoenolpyruvate plus pyruvate kinase as an ATP-generating system in the assay for glutamine synthetase activity via the formation of gamma-glutamylhydroxamate from glutamate and hydroxylamine with crude tissue preparations is shown to give values far in excess of the true glutamine synthetase activity of the tissue. This is due to the generation of pyruvate, which reacts with hyd...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Cell Biology
سال: 1972
ISSN: 1540-8140,0021-9525
DOI: 10.1083/jcb.54.1.175