Identification of MAPKAP Kinase 2 as a Major Enzyme Responsible for the Phosphorylation of the Small Mammalian Heat Shock Proteins

FEBS Lett. 1992 Nov 30;313(3):307-13. doi: 10.1016/0014-5793(92)81216-9.

Abstract

MAP kinase-activated protein kinase-2 (MAPKAP kinase-2) phosphorylates the serine residues in murine heat shock protein 25 (hsp25) and human heat shock protein 27 (hsp27) which are phosphorylated in vivo in response to growth factors and heat shock, namely Ser15 and Ser86 (hsp25) and Ser15, Ser78 and Ser82 (hsp27). Ser86 of hsp25 and the equivalent residue in hsp27 (Ser82) are phosphorylated preferentially in vitro. The small heat shock protein is present in rabbit skeletal muscle and hsp25 kinase activity in skeletal muscle extracts co-purifies with MAPKAP kinase-2 activity throughout the purification of the latter enzyme. These results suggest that MAPKAP kinase-2 is the enzyme responsible for the phosphorylation of these small heat shock proteins in mammalian cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Calcium-Calmodulin-Dependent Protein Kinases
  • Enzyme Activation
  • Heat-Shock Proteins / metabolism*
  • Molecular Sequence Data
  • Phosphoproteins / metabolism
  • Phosphorylation
  • Protein Kinases / metabolism*
  • Rabbits
  • Substrate Specificity

Substances

  • Heat-Shock Proteins
  • Phosphoproteins
  • Protein Kinases
  • Calcium-Calmodulin-Dependent Protein Kinases