Multisite phosphorylation of the glycogen‐binding subunit of protein phosphatase‐1G by cyclic AMP‐dependent protein kinase and glycogen synthase kinase‐3

FEBS Letters

Dent, Paul¹  Hubbard, Michael J.¹  Campbell, David G.¹  Cohen, Philip¹ 

[1] Department of Biochemistry, Medical Sciences Institute, University of Dundee, Dundee DD1 4HN, Scotland

关键词: Protein kinase;    Protein phosphatase;    cyclic AMP;    Glycogen metabolism;    Glycogen synthase;   

DOI  :  10.1016/0014-5793(89)80433-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The glycogen-binding (G) subunit of protein phosphatase-1_G is phosphorylated stoichiometrically by glycogen synthase kinase-3 (GSK3), and with a greater catalytic efficiency than glycogen synthase, but only after prior phosphorylation by cyclic AMP-dependent protein kinase (A-kinase) at site 1. The residues phosphorylated are the first two serines in the sequence AIFKPGFSPQPSRRGS-, while the C-terminal serine (site 1) is one of the two residues phosphorylated by A-kinase. These findings demonstrate that (i) the G subunit undergoes multisite phosphorylation in vitro; (ii) phosphorylation by GSK3 requires the presence of a C-terminal phosphoserine residue; (iii) GSK3 can synergise with protein kinases other than casein kinase-2.

【 授权许可】

Unknown