Send to

Choose Destination
Proc Natl Acad Sci U S A. 1985 Nov;82(22):7565-9.

Inhibition of the Mg(II).ATP-dependent phosphoprotein phosphatase by the regulatory subunit of cAMP-dependent protein kinase.


We report potent inhibition of the Mg(II).ATP-dependent protein phosphatase, Fc.M, by the regulatory subunit dimer of type II cAMP-dependent protein kinase, RII2. The protein kinase catalytic subunit has no effect on phosphatase activity and is unable to substitute for kinase FA in the kinase FA- and Mg(II).ATP-mediated phosphatase activation reaction. Phosphatase inhibition was investigated as a function of RII2 concentration. The results suggest that RII2 both inhibits the active phosphatase and inhibits phosphatase activation. The inhibition is shown to be noncompetitive with respect to substrate (phosphorylase a). The potential physiological significance of this inhibition is discussed in terms of phosphorylation/dephosphorylation cascade systems involving this kinase and phosphatase.

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center