Proteolytic activation of PKN by caspase-3 or related protease during apoptosis

Proc Natl Acad Sci U S A. 1998 Sep 29;95(20):11566-71. doi: 10.1073/pnas.95.20.11566.

Abstract

PKN, a fatty acid- and Rho-activated serine/threonine kinase having a catalytic domain highly homologous to protein kinase C (PKC), was cleaved at specific sites in apoptotic Jurkat and U937 cells on Fas ligation and treatment with staurosporin or etoposide, respectively. The cleavage of PKN occurred with a time course similar to that of PKCdelta, a known caspase substrate. This proteolysis was inhibited by a caspase inhibitor, acetyl-Asp-Glu-Val-Asp-aldehyde. The cleavage fragments were generated in vitro from PKN by treatment with recombinant caspase-3. Site-directed mutagenesis of specific aspartate residues prevented the appearance of these fragments. These results indicate that PKN is cleaved by caspase-3 or related protease during apoptosis. The major proteolysis took place between the amino-terminal regulatory domain and the carboxyl-terminal catalytic domain, and it generated a constitutively active kinase fragment. The cleavage of PKN may contribute to signal transduction, eventually leading to apoptosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Apoptosis / physiology*
  • Binding Sites / genetics
  • COS Cells
  • Caspase 3
  • Caspases*
  • Cell Line
  • Cysteine Endopeptidases / chemistry
  • Cysteine Endopeptidases / genetics
  • Cysteine Endopeptidases / metabolism*
  • Cysteine Proteinase Inhibitors / pharmacology
  • Endopeptidases / metabolism
  • Enzyme Activation
  • Humans
  • Jurkat Cells
  • Kinetics
  • Mutagenesis, Site-Directed
  • Oligopeptides / pharmacology
  • Peptide Fragments / chemistry
  • Peptide Fragments / genetics
  • Peptide Fragments / metabolism
  • Protein Kinase C / metabolism
  • Protein-Serine-Threonine Kinases / chemistry
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / metabolism*
  • Protein-Tyrosine Kinases / chemistry
  • Protein-Tyrosine Kinases / genetics
  • Protein-Tyrosine Kinases / metabolism*
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Signal Transduction

Substances

  • Cysteine Proteinase Inhibitors
  • Oligopeptides
  • Peptide Fragments
  • Recombinant Proteins
  • aspartyl-glutamyl-valyl-aspartal
  • protein kinase N
  • Protein-Tyrosine Kinases
  • Protein-Serine-Threonine Kinases
  • Protein Kinase C
  • Endopeptidases
  • CASP3 protein, human
  • Caspase 3
  • Caspases
  • Cysteine Endopeptidases