Phosphorylation of the modulator protein of the ATP,Mg‐dependent protein phosphatase by casein kinase TS

FEBS Letters

Goris, Jozef²  Merlevede, Wilfried²  Vandenheede, Jackie R.²  Waelkens, Etienne²  Pinna, Lorenzo A.¹  Agostinis, Patrizia² 

[1] Istituto di Chimica Biologica, Universitá di Padova, Padova, Italy;Afdeling Biochemie, Faculteit Geneeskunde, Katholieke Universiteit te Leuven, Leuven B-3000, Belgium

关键词: Polycation-stimulated protein phosphatase;    ATP;    Mg-dependent protein phosphatase;    Modulator protein;    Protein kinase FA;    Casein kinase TS (II);   

DOI  :  10.1016/0014-5793(86)80033-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The phosphorylation by casein kinase TS (II) of the modulator protein of the ATP,Mg-dependent phosphatase increases after preineubation with the PCS_H1 phosphatase or with the catalytic subunit of the ATP,Mg-dependent phosphatase. Dephosphorylation by the two phosphatases combined leads to the incorporation of 2 mol phosphate per mol modulator (at Ser residues). Occupancy of the ATP,Mg-dependent phosphatase phosphorylation site(s) is a negative determinant in the phosphorylation of the modulator by kinase TS. Among the PCS phosphatases PCS_h1 shows the highest activity toward the ³²P-Ser residues labeled by kinase TS in untreated or previously dephosphorylated modulator, while the ATP,Mg-dependent phosphatase is totally ineffective. Protamine stimulates all phosphatase activities, so that the catalytic subunit of the ATP,Mg-dependent phosphatase becomes almost as effective as the PCS_C phosphatase in dephosphorylating the kinase TS sites.

【 授权许可】

Unknown