Reconstitution of a Mg‐ATP‐dependent protein phosphatase and its activation through a phosphorylation mechanism

Open Access
Publisher Website
Google Scholar
Abstract
A Mg‐ATP‐dependent protein phosphatase has been reconstituted from the catalytic subunit of protein phosphatase‐1 and inhibitor‐2, and consists of a 1:1 complex between these proteins. Activation of this enzyme by glycogen synthase kinase‐3 and Mg‐ATP results from the phosphorylation of inhibitor‐2 on a threonine residue(s) and is accompanied by the dissociation of the complex. The results prove that protein phosphatase‐1 and the Mg‐ATP‐dependent protein phosphatase contain the same catalytic subunit, and that they are interconvertible forms of the same enzyme.