PHOSPHORYLATION OF ELONGATION FACTOR-II BY EF-2 KINASE AFFECTS RATE OF TRANSLATION
PHOSPHORYLATION OF ELONGATION FACTOR-II BY EF-2 KINASE AFFECTS RATE OF TRANSLATION
复制标题
DOI：
10.1038/334170a0
复制
发表时间：
1988-07-14
期刊：
影响因子：
64.8
通讯作者：
NATAPOV, PG
中科院分区：
文献类型：
--
作者：
RYAZANOV, AG;SHESTAKOVA, EA;NATAPOV, PG
最近在哺乳动物细胞中发现了一种新的 Ca2+/钙调蛋白依赖性蛋白激酶1,2。该激酶的主要底物是相对分子质量 (Mr) 约 100,000 (100K) 的蛋白质，已被鉴定为延伸因子 2 (EF-2)3,4，参与蛋白质合成。 EF-2 激酶的体内活性取决于生长因子和其他影响 Ca2+ 和 cAMP5 水平的试剂，6。然而，它对 EF-2 活性的影响仍然不清楚。这项工作表明，EF-2 激酶对 EF-2 的磷酸化会导致聚（U）定向翻译中聚苯丙氨酸合成的剧烈抑制。磷酸化的 EF-2 在翻译中完全失活，并且抑制非磷酸化的 EF-2 的活性。磷酸酶使 EF-2 去磷酸化，恢复其活性。因此，EF-2的磷酸化直接影响翻译的延伸阶段，从而代表了一种新的翻译控制机制。
A new Ca2+/calmodulin-dependent protein kinase has been recently discovered in mammalian cells1,2. The major substrate of this kinase, a protein of relative molecular mass (Mr) ≈100,000 (100K), has been identified as elongation factor 2 (EF-2)3,4, which participates in protein synthesis. Thein vivoactivity of the EF-2 kinase depends upon growth factors and other agents affecting the level of Ca2+and cAMP5,6. Its effect on EF-2 activity, however, remained obscure. This work shows that the phosphorylation of EF-2 by the EF-2 kinase results in a drastic inhibition of polyphenylalanine synthesis in poly(U)-directed translation. Phosphorylated EF-2 is completely inactive in translation and, moreover, inhibits the activity of non-phosphorylated EF-2. Dephosphorylation of EF-2 by phosphatase restores its activity. Hence, the phosphorylation of EF-2 directly affects the elongation stage of translation and thus represents a novel mechanism of translational control.