Homologous Superfamily

CPI-17 superfamily (IPR036658)

Short name: CPI-17_sf

Overlapping entries


Contractility of vascular smooth muscle depends on phosphorylation of myosin light chains, and is modulated by hormonal control of myosin phosphatase activity. Signaling pathways activate kinases such as PKC or Rho-dependent kinases that phosphorylate the myosin phosphatase inhibitor protein called CPI-17 (also known as protein phosphatase 1 regulatory subunit 14). Phosphorylation of CPI-17 at Thr-38 enhances its inhibitory potency 1000-fold, creating a molecular switch for regulating contraction [PMID: 11734001].

CPI-17 forms a novel four-helix, V-shaped bundle comprised of a central anti-parallel helix pair (B/C helices) flanked by two large spiral loops formed by the N and C termini that are held together by another anti-parallel helix pair (A/D helices) stabilized by intercalated aromatic and aliphatic side-chains [PMID: 11734001].

GO terms

Biological Process

GO:0042325 regulation of phosphorylation

Molecular Function

No terms assigned in this category.

Cellular Component

GO:0005737 cytoplasm

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.