[Involvement of SH-groups in the regulation of adenylate cyclase signal system by isoproterenol and serotonin in cultured murine fibroblasts L (subline LSM)].
The adenylyl cyclase system (ACS) plays a key role in transduction of a hormonal signal into eukaryotic cells. The functional activity of the system depends on SH-groups of proteins involved in the ACS: receptor, G-protein, and enzyme adenylyl cyclase (AC). We studied the influence of thiols and SH-blockers on the regulation of AC activity by nonhormonal (NaF and Gpp[NH]p) and hormonal (biogenic amines isoproterenol and serotonin) agents in homogenates of cultured murine fibroblasts of line L (subline LSM). In the presence of thiols 2-mercaptoethanol (5 mM) and dithiothreitol (1 mM) the basal AC activity somewhat increased, whereas the stimulating effects of NaF, Gpp[NH]p, and hormones decreased. No potentiating action of Gpp[NH]p on hormonal effect in this case was found. The SH-blockers 25 mkM p-chloromercuribenzoic acid (CMBA) and 0.2 mM N-ethylmaleimide significantly inhibited both the basal AC activity and that stimulated by different agents. Thiols partially restored CMBA inhibited AC activity (in the case of N-ethylmaleimide restoring effects of thiols were insignificant). This, the ACS of murine fibroblasts of subline LSM is SH-sensitive. The forms of SH-groups in proteins involved in the ACS determine their functional activities and a possibility of transduction of the hormonal signal on the effector systems.
Shpakov
A O
AO
Institute of Evolutionary Physiology and Biochemistry RAS, St. Petersburg. shpakov@hormone.ief.spb.ru
Plesneva
S A
SA
Kuznetsova
L A
LA
Leont'eva
E A
EA
D000067956:Adenylyl Cyclase Inhibitors; D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007545:Isoproterenol / Q000494:pharmacology*; D007739:L Cells; D051379:Mice; D010084:Oxidation-Reduction; D012701:Serotonin / Q000494:pharmacology*; D015398:Signal Transduction; D013438:Sulfhydryl Compounds / Q000494:pharmacology*; D013439:Sulfhydryl Reagents / Q000494:pharmacology*
D000067956:Adenylyl Cyclase Inhibitors; D004791:Enzyme Inhibitors; D013438:Sulfhydryl Compounds; D013439:Sulfhydryl Reagents; D012701:Serotonin; D000262:Adenylyl Cyclases; D007545:Isoproterenol