Calpain-mediated Proteolysis of Microtubule-Associated Protein 2 (MAP-2) Is Inhibited by Phosphorylation by cAMP-dependent Protein Kinase, but Not by Ca2+/calmodulin-dependent Protein Kinase II

J Neurosci Res. 1993 Apr 15;34(6):642-7. doi: 10.1002/jnr.490340607.

Abstract

The effects of cAMP-dependent protein kinase (cAMP-PK) and Ca2+/calmodulin-dependent protein kinase II (CaMKII) phosphorylation on the calpain-mediated degradation of microtubule-associated protein 2 (MAP-2) were studied. Both cAMP-PK and CaMKII readily phosphorylated MAP-2. However, cAMP-PK phosphorylated MAP-2 to a significantly greater extent than did CaMKII (4.5 mol 32P/mol MAP-2 and 1.4 mol 32P/mol MAP-2, respectively). Phosphorylation of MAP-2 by cAMP-PK, but not by CaMKII, significantly inhibited the calpain-induced hydrolysis of MAP-2. These results demonstrate that the phosphorylation of sites on the MAP-2 molecule accessible to cAMP-PK, but not to CaMKII, result in increased resistance to calpain proteolysis.

MeSH terms

  • Animals
  • Calcium-Calmodulin-Dependent Protein Kinases
  • Calpain / pharmacology*
  • Cattle
  • Cytoskeleton / metabolism
  • Hydrolysis
  • Immunoblotting
  • In Vitro Techniques
  • Microtubule-Associated Proteins / metabolism*
  • Phosphorus Radioisotopes
  • Phosphorylation
  • Protein Kinases / metabolism*

Substances

  • Microtubule-Associated Proteins
  • Phosphorus Radioisotopes
  • Protein Kinases
  • Calcium-Calmodulin-Dependent Protein Kinases
  • Calpain