Mechanism of elongation factor 2 (EF‐2) inactivation upon phosphorylation Phosphorylated EF‐2 is unable to catalyze translocation

FEBS Letters

Davydova, Elena K.¹  Ryazanov, Alexey G.¹ 

[1] Institute of Protein Research, Academy of Sciences of the USSR, 142292 Pushchino, Moscow Region, USSR

关键词: Elongation factor 2;    Protein phosphorylation;    EF-2 kinase;    Calmodulin;    Ribosomal translocation;    Translational control;    EF-1;    elongation factor 1;    EF-2;    elongation factor 2;    GMPPCP;    guanosine 5′-(β;    γ-methylene)triphosphate;    GMPPNP;    guanosine 5′-(β;    γ-imino)triphosphate;   

DOI  :  10.1016/0014-5793(89)81452-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Previously we have found that elongation factor 2 (EF-2) from mammalian cells can be phosphorylated by a special Ca²⁺/calmodulin-dependent protein kinase (EF-2 kinase). Phosphorylation results in complete inactivation of EF-2 in the poly(U)-directed cell-free translation system. However, the partial function of EF-2 affected by phosphorylation remained unknown. Here we show that phosphorylated EF-2, unlike non-phosphorylated EF-2, is unable to switch ribosomes carrying poly(U) and Phe-tRNA in the A site to a puromycin-reactive state. Thus, phosphorylation of EF-2 seems to block its ability to promote a shift of the aminoacyl(peptidyl)-tRNA from the A site to the P site i.e. translocation itself.

【 授权许可】

Unknown