Okadaic acid‐sensitive protein phosphatases dephosphorylate MARCKS, a major protein kinase C substrate

FEBS Letters

Siddhanti, Suresh R.²  Blackshear, Perry J.²  Clarke, Paul R.¹  Cohen, Philip¹ 

[1] Department of Biochemistry, University of Dundee, Dundee, DD1 4HN, Scotland, UK;Howard Hughes Medical Institute Laboratories, Departments of Medicine and Biochemistry, Duke University Medical Center, Durham, NC 27710, USA

关键词: MARCKS;    Okadaic acid;    Protein kinase C;    Protein phosphatase;   

DOI  :  10.1016/0014-5793(93)81604-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The myristoylated alanine-rich C kinase substrate (MARCKS) undergoes a rapid and, in certain circumstances, transient increase in phosphorylation in response to stimuli that activate protein kinase C. We have investigated the protein-serine/threonine phosphatase activity responsible for reversing the phosphorylation of MARCKS. In cell-free assays, protein phosphatases 1, 2A and 2C (PP1, PP2A and PP2C) all dephosphorylate recombinant MARCKS or a synthetic peptide based on its phosphorylation site domain. In intact Swiss 3T3 cells, okadaic acid, a specific inhibitor of PP1 and PP2A, had little effect on MARCKS phosphorylation on its own, but largely prevented the dephosphorylation of MARCKS that occured following activation of protein kinase C by bombesin with subsequent receptor blockade. These results indicate that although the dephosphorylation of MARCKS can be mediated by PP2C in vitro, this protein is dephosphorylated by okadaic acid-sensitive phosphatases in the intact cell.

【 授权许可】

Unknown