Peterkofsky A, Gazdar C
Proc Natl Acad Sci U S A. 1975 Aug;72(8):2920-4. doi: 10.1073/pnas.72.8.2920.
Transient repression by glucose of induced enzyme synthesis involves lowering of intracellular cAMP levels. This glucose effect is partially explained by a glucose inhibition of adenylate cyclase [EC 4.6.1.1; ATP pyrophosphate-lyase(cyclizing)]. Since the phosphoenolpyruvate:sugar phosphotransferase system has been implicated in repression phenomena, an investigation was made of adenylate cyclase activity in mutants of that transport system. The results suggest that glucose phosphorylation is not necessary for inhibition of adenylate cyclase since an HPr mutant retained sensitivity to glucose inhibition. The results also suggest that adenylate cyclase activity requires the presence of Enzyme I in a phosphorylated form and that adenylate cyclase activity may be regulated by a phosphorylation-dephosphorylation mechanism.
葡萄糖对诱导酶合成的短暂抑制涉及细胞内cAMP水平的降低。这种葡萄糖效应部分可由葡萄糖对腺苷酸环化酶[EC 4.6.1.1;ATP焦磷酸裂解酶(环化)]的抑制来解释。由于磷酸烯醇丙酮酸:糖磷酸转移酶系统与抑制现象有关,因此对该转运系统突变体中的腺苷酸环化酶活性进行了研究。结果表明,葡萄糖磷酸化对于抑制腺苷酸环化酶并非必要,因为一个HPr突变体仍对葡萄糖抑制敏感。结果还表明,腺苷酸环化酶活性需要磷酸化形式的酶I存在,并且腺苷酸环化酶活性可能受磷酸化-去磷酸化机制调控。