Echevarría C, Vidal J, Jiao J A, Chollet R
Department of Biochemistry, University of Nebraska-Lincoln 68583-0718.
FEBS Lett. 1990 Nov 26;275(1-2):25-8. doi: 10.1016/0014-5793(90)81430-v.
C4-leaf phosphoenolpyruvate carboxylase (PEPC; EC 4.1.1.31) undergoes reversible, light-induced increases in its activity-seryl phosphorylation-status in vivo. We now report that the PEPC-protein kinase activity in desalted crude extracts of light-adapted maize leaves is several-fold greater than that from the corresponding dark tissue when in vitro phosphorylation assays are performed with either endogenous or purified dark-form maize PEPC as substrate, both in the absence or presence of okadaic acid, a potent inhibitor of the PEPC type 2A protein phosphatase(s). These and related results indicate that the PEPC protein-serine kinase(s) per se is reversibly light activated in vivo by either covalent modification, protein turnover or, less likely, a tight-binding effector.
C4 植物叶片中的磷酸烯醇式丙酮酸羧化酶（PEPC；EC 4.1.1.31）在体内会经历由光诱导的、可逆的活性 - 丝氨酸磷酸化状态增加。我们现在报告，当以玉米暗形态 PEPC 内源性或纯化后的形式作为底物，在有或没有冈田酸（一种 PEPC 2A 型蛋白磷酸酶的有效抑制剂）存在的情况下进行体外磷酸化测定时，适应光照的玉米叶片脱盐粗提物中的 PEPC 蛋白激酶活性比相应黑暗组织中的活性高几倍。这些以及相关结果表明，PEPC 蛋白 - 丝氨酸激酶本身在体内通过共价修饰、蛋白质周转或者可能性较小的紧密结合效应物被光可逆激活。
