A novel protein phosphatase-1 inhibitory protein potentiated by protein kinase C. Isolation from porcine aorta media and characterization

J Biochem. 1995 Dec;118(6):1104-7. doi: 10.1093/oxfordjournals.jbchem.a124993.

Abstract

A novel phosphorylation-dependent inhibitory protein (IP) of porcine aorta myosin light chain phosphatase (PA-MLCP) was purified to homogeneity from porcine aorta media. The molecular mass of IP was 20 kDa. IP phosphorylated by endogenous potentiating kinase (IP-K) inhibited not only PA-MLCP activity, but also that of the catalytic subunit of protein phosphatase-1. The amino acid sequence of a peptide derived from IP phosphorylated with IP-K, RHARVT*VK, shared one of the consensus sequences phosphorylatable by protein kinase C (PKC), where T* was phosphorylated. IP was phosphorylated by PKC and the phosphorylated product inhibited PA-MLCP as strongly as IP phosphorylated with IP-K.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Aorta / metabolism*
  • Carrier Proteins*
  • Chromatography
  • Chromatography, Ion Exchange
  • Durapatite
  • Enzyme Inhibitors / isolation & purification
  • Enzyme Inhibitors / metabolism
  • Intracellular Signaling Peptides and Proteins*
  • Kinetics
  • Molecular Sequence Data
  • Peptide Fragments / chemistry
  • Peptide Fragments / isolation & purification
  • Phosphoprotein Phosphatases / antagonists & inhibitors*
  • Protein Kinase C / metabolism*
  • Protein Phosphatase 1
  • Proteins / chemistry
  • Proteins / isolation & purification*
  • Proteins / metabolism*
  • Swine
  • Tunica Media / metabolism*

Substances

  • Carrier Proteins
  • Enzyme Inhibitors
  • Intracellular Signaling Peptides and Proteins
  • Peptide Fragments
  • Proteins
  • protein phosphatase inhibitor-1
  • Durapatite
  • Protein Kinase C
  • Phosphoprotein Phosphatases
  • Protein Phosphatase 1