title: Glutamine regulates glutamine synthetase expression in skeletal muscle cells in culture.
abstract: Metabolite control of glutamine synthetase expression (by glutamine) was studied in L6 skeletal muscle cells. Depletion of glutamine from the culture medium for 24 hours resulted in a 3-4-fold increase in glutamine synthetase activity. This effect was blocked by cycloheximide but not by actinomycin D. Addition of glutamine to L6 cells maintained in glutamine-free medium caused a rapid return of glutamine synthetase activity to the control level. As reported, dexamethasone caused a striking increase in the glutamine synthetase mRNA level. In contrast, neither depletion nor addition of glutamine caused a change in the glutamine synthetase mRNA level. Therefore, regulation of glutamine synthetase by glutamine is exerted at a post-transcriptional level.
authors.affiliation: Department of Neurology, University of Maryland School of Medicine, Baltimore 21201.
authors.forename: B
authors.initials: B
authors.lastname: Feng
authors.forename: S K
authors.initials: SK
authors.lastname: Shiber
authors.forename: S R
authors.initials: SR
authors.lastname: Max
mesh_terms: D000818:Animals; D002460:Cell Line; D003513:Cycloheximide / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D003907:Dexamethasone / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D005974:Glutamate-Ammonia Ligase / Q000096:biosynthesis*; D005973:Glutamine / Q000502:physiology*; D009132:Muscles / Q000201:enzymology*; D014176:Protein Biosynthesis / Q000187:drug effects; D012333:RNA, Messenger / Q000032:analysis; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D012333:RNA, Messenger; D005973:Glutamine; D003609:Dactinomycin; D003907:Dexamethasone; D003513:Cycloheximide; D005974:Glutamate-Ammonia Ligase