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On the dephosphorylation of the ATP,Mg‐dependent protein phosphatase modulator
Author(s) -
Vandenheede Jackie R.,
Abeele Carline Vanden,
Merlevede Wilfried
Publication year - 1987
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(87)80708-1
Subject(s) - dephosphorylation , phosphatase , protein subunit , chemistry , divalent , phosphorylation , adenosine triphosphate , phosphorylase kinase , substrate (aquarium) , biochemistry , biophysics , glycogen phosphorylase , enzyme , protein kinase a , biology , ecology , organic chemistry , gene
The dephosphorylation of the modulator subunit is an essential step in the kinase F A ‐mediated activation of the ATP,Mg‐dependent protein phosphatase. Mg 2+ is implicated in this autocatalytic dephosphorylation which is not effected by the addition of phosphoinhibitor‐1. Dephosphorylation of free modulator by the catalytic subunit is also largely Mg 2+ ‐dependent but can be abolished by phosphoinhibitor‐1 in concentrations comparable to the amount of modulator used as substrate (micromolar). The phosphorylase phosphatase activity of the catalytic subunit is inhibited by nanomolar concentrations of phosphoinhibitor‐1 and is completely independent of divalent cations.