Dephosphorylation of the deinhibitor protein by the PCSH protein phosphatase.
The deinhibitor protein, responsible for the decreased sensitivity of the ATP,Mg-dependent protein phosphatase to inhibitor-1 and the modulator protein, is inactivated by cyclic AMP-dependent protein kinase and reactivated by dephosphorylation. The specificity of this reaction was tested with the ATP,Mg-dependent phosphatase in its activated or spontaneously active form, four different forms of polycation-stimulated phosphatases (PCSH, PCSM, PCSL and PCSC) and calcineurin. Only the high -Mr polycation-stimulated protein phosphatase (PCSH), but not its catalytic subunit (PCSC), shows a high degree of specificity for the deinhibitor protein. Deinhibitor phosphatase activity of PCSH is affected neither by polycations nor by Mn ions.
Goris
J
J
Waelkens
E
E
Merlevede
W
W
D000255:Adenosine Triphosphate; D000818:Animals; D002148:Calmodulin-Binding Proteins; D002384:Catalysis; D004793:Enzyme Reactivators; D008274:Magnesium; D009132:Muscles / Q000378:metabolism; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D010766:Phosphorylation; D011073:Polyamines; D000071228:Polyelectrolytes; D011108:Polymers; D011506:Proteins / Q000378:metabolism*; D011817:Rabbits
D000255:Adenosine Triphosphate; D002148:Calmodulin-Binding Proteins; D004793:Enzyme Reactivators; D008274:Magnesium; D010749:Phosphoprotein Phosphatases; D011073:Polyamines; D000071228:Polyelectrolytes; D011108:Polymers; D011506:Proteins; C488948:deinhibitor protein, Oryctolagus cuniculus