title: Effect of nonprotein thiols on protein synthesis in isolated rat hepatocytes.
abstract: The ability of nonprotein thiols to modulate rates of protein synthesis was investigated in isolated rat hepatocytes. Addition of cysteine stimulates protein labelling by [14C]Leucine. Glutathione depletion, induced by in vivo administration of L-buthionine sulfoximine and diethylmaleate, did not alter the effect of cysteine, although it decreased the rate of protein synthesis by 32%. The effect of cysteine on protein synthesis does not seem to be related to a perturbation of the redox state of the NAD+/NADH system or to changes in the rate of gluconeogenic pathway. The following observations indicate that cysteine may stimulate protein synthesis by increasing intracellular levels of aspartate: 1. Amino-oxyacetate, an inhibitor of pyridoxal-dependent enzymes, inhibits protein labelling and decreases aspartate cellular content, whereas most amino acids accumulate or remain unchanged; 2. Cysteine, in the absence or in the presence of amino-oxyacetate, stimulates protein labelling and induces aspartate accumulation, although most amino acids diminish or remain unchanged.
authors.affiliation: Departamento de Fisiología, Faculatad de Medicina, Universidad de Valencia, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Asensi
authors.forename: A
authors.initials: A
authors.lastname: Garcia-España
authors.forename: F V
authors.initials: FV
authors.lastname: Pallardó
authors.forename: J
authors.initials: J
authors.lastname: Vina
authors.forename: J M
authors.initials: JM
authors.lastname: Estrela
mesh_terms: D000596:Amino Acids / Q000378:metabolism*; D000625:Aminooxyacetic Acid / Q000494:pharmacology; D000818:Animals; D000963:Antimetabolites / Q000494:pharmacology; D019328:Buthionine Sulfoximine; D002250:Carbon Radioisotopes; D002478:Cells, Cultured; D003545:Cysteine / Q000494:pharmacology*; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008298:Maleates / Q000494:pharmacology; D008715:Methionine / Q000378:metabolism; D008717:Methionine Sulfoximine / Q000031:analogs & derivatives / Q000494:pharmacology; D014176:Protein Biosynthesis; D051381:Rats; D017208:Rats, Wistar; D013438:Sulfhydryl Compounds / Q000494:pharmacology*
chemical_list: D000596:Amino Acids; D000963:Antimetabolites; D002250:Carbon Radioisotopes; D008298:Maleates; D013438:Sulfhydryl Compounds; D000625:Aminooxyacetic Acid; D008717:Methionine Sulfoximine; D019328:Buthionine Sulfoximine; D008715:Methionine; C014476:diethyl maleate; D003545:Cysteine