I 1, I1, Inhibitor 1, IPP1, Ppp1r1a, Protein phosphatase 1 regulatory (inhibitor) subunit 1A,
Plays a role in regulating the phosphorylation of other proteins, and is itself phosphorylated by a cyclic AMP-dependent protein kinase at Threonine 35. In addition, the proline-directed kinases Cdk1, Cdk5, and mitogen-activated protein kinase (MAPK) mediate in vitro phosphorylation of IPP-1 at the phylogenetically conserved position Serine 67.
