Phospholipid‐sensitive Ca2+‐dependent protein kinase phosphorylates the β subunit of eukaryotic initiation factor 2 (eIF‐2)

FEBS Letters

Kuo, J.F.¹  Grifo, Jamie A.²  Schatzman, Randall C.¹  Merrick, William C.² 

[1] Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA;Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA

关键词: Ca2+;    Phospholipid;    Protein synthesis;    Protein kinase;    eIF-2;    β-Subunit;    eIF-2;    eukaryotic initiation factor 2;    PL-Ca-PK;    phospholipid-sensitive Ca2+-dependent protein kinase;    MLCK;    myosin light chain kinase;    cA-PK and cG-PK;    cyclic AMP and cyclic GMP-dependent protein kinases;    respectively;   

DOI  :  10.1016/0014-5793(83)80439-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The ability of homogeneous phospholipid-sensitive Ca²⁺-dependent protein kinase (PL-Ca-PK) from pig spleen to phosphorylate eukaryotic initiation factor 2 (eIF-2) was examined. PL-Ca-PK phosphorylated the β-subunit of eIF-2, whereas myosin light chain kinase (MLCK) and cyclic AMP- and cyclic GMP-dependent protein kinases (cA-PK and cG-PK) did not. PL-Ca-PK could incorporate a maximum of 1.6 mol phosphate/mol eIF-2. The app. K _m and V _max for PL-Ca-PK phosphorylation of eIF-2 were 0.13 μM and 0.02 μmol. min⁻¹.mg enzyme⁻¹, respectively. Phosphoamino acid analysis revealed that incorporation of phosphate into eIF-2 occurred almost exclusively at serine residues. These findings indicate that eIF-2 was an effective substrate for PL-Ca-PK, suggesting that this enzyme may play a role in the regulation of protein synthesis.

【 授权许可】

Unknown