Activation of mitochondrial Raf-1 is involved in the antiapoptotic effects of Akt

Cancer Res. 1999 Jun 15;59(12):2815-9.

Abstract

The Akt serine/threonine kinase is required for the survival of many cell types and for transformation of hematopoietic cells by the BCR/ABL oncogenic tyrosine kinase. Analysis of the potential mechanisms whereby Akt promotes survival of hematopoietic cells revealed that it induced the activity of plasma membrane and mitochondrial Raf-1 in a Ras-independent, but PKC-dependent manner. Inhibition of plasma membrane Raf-1-dependent mitogen-activated protein kinase activity had no effect on the enhanced survival of cells expressing Akt. By contrast, suppression of mitochondrial Raf-1 enzymatic activity by expression of a mitochondria-targeted Raf-1 dominant-negative mutant rendered Akt-expressing cells susceptible to apoptosis induced by growth factor deprivation and was accompanied by inhibition of BAD, but not mitogen-activated protein kinase, phosphorylation. Together, these data indicate that PKC-dependent activation of Raf-1 plays an important role in Akt-dependent antiapoptotic effects.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Apoptosis / physiology*
  • Cell Line
  • Enzyme Activation
  • Mice
  • Mitochondria / metabolism*
  • Oncogene Protein v-akt
  • Proto-Oncogene Proteins c-raf / metabolism*
  • Retroviridae Proteins, Oncogenic / physiology*

Substances

  • Retroviridae Proteins, Oncogenic
  • Oncogene Protein v-akt
  • Proto-Oncogene Proteins c-raf