Resolution of bovine brain calcineurin subunits: stimulatory effect of subunit B on subunit A phosphatase activity

FEBS Letters

Gupta, Ramesh C.²  Khandelwal, Ramji L.¹  Sulakhe, Prakash V.² 

[1] Department of Biochemistry, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N OWO, Canada;Department of Physiology, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N OWO, Canada

关键词: Calcineurin;    Calcineurin subunit;    Protein phosphatase;    Calmodulin;    Divalent cation;   

DOI  :  10.1016/0014-5793(85)80437-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Calcineurin was dissociated into subunits A and B by SDS and the dissociated subunits were separated by Sephadex G-100 column chromatography in SDS. The phosphatase activity was associated with the A subunit and was detected only in the presence of MnCl₂ of the various divalent cations tested. The Mn²⁺-dependent phosphatase of A subunit was stimulated (4-5-fold) by calmodulin. The subunit B increased only modestly Mn²⁺ stimulated phosphatase activity of subunit A but markedly increased it when assay also contained calmodulin. These results support the view that subunit B plays an important role in Mn²⁺/calmodulin regulation of subunit A phosphatase activity. They also lend further support to our earlier postulate ([1984] FEBS Lett. 169, 251-255) that Mn²⁺ is a powerful regulator of calcineurin phosphatase.

【 授权许可】

Unknown