Purification of the hepatic glycogen-associated form of protein phosphatase-1 by microcystin-Sepharose affinity chromatography

FEBS Lett. 1995 Apr 3;362(2):101-5. doi: 10.1016/0014-5793(95)00197-h.

Abstract

The form of protein phosphatase-1 associated with hepatic glycogen (PP1G) was purified to near homogeneity from rat liver by affinity chromatography on microcystin-Sepharose and gel-filtration. The enzyme is a heterodimer consisting of the catalytic subunit of PP1 (the alpha and beta isoforms) complexed to a 33 kDa glycogen-binding (GL) subunit. The GL subunit binds phosphorylase a with high affinity, and is responsible for the enhanced dephosphorylation of glycogen synthase by PP1G and its allosteric inhibition by phosphorylase a.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Chickens
  • Chromatography, Affinity / methods*
  • Chromatography, Gel
  • Gizzard, Avian / enzymology
  • Glycogen / metabolism*
  • Glycogen Synthase / metabolism
  • Liver / enzymology*
  • Macromolecular Substances
  • Microcystins
  • Molecular Sequence Data
  • Peptide Fragments / chemistry
  • Peptides, Cyclic*
  • Phosphoprotein Phosphatases / antagonists & inhibitors
  • Phosphoprotein Phosphatases / chemistry
  • Phosphoprotein Phosphatases / isolation & purification*
  • Phosphorylase a / metabolism
  • Phosphorylase a / pharmacology
  • Phosphorylation
  • Protein Phosphatase 1
  • Rabbits
  • Rats
  • Rats, Wistar

Substances

  • Macromolecular Substances
  • Microcystins
  • Peptide Fragments
  • Peptides, Cyclic
  • microcystin
  • Glycogen
  • Phosphorylase a
  • Glycogen Synthase
  • Phosphoprotein Phosphatases
  • Protein Phosphatase 1