Cyclic-AMP-dependent protein kinase A regulates apoptosis by stabilizing the BH3-only protein Bim

EMBO Rep. 2011 Jan;12(1):77-83. doi: 10.1038/embor.2010.190. Epub 2010 Dec 10.

Abstract

The proapoptotic Bcl2 homology domain 3(BH3)-only protein Bim is controlled by stringent post-translational regulation, predominantly through alterations in phosphorylation status. To identify new kinases involved in its regulation, we carried out a yeast two-hybrid screen using a non-spliceable variant of the predominant isoform--Bim(EL)--as the bait and identified the regulatory subunit of cyclic-AMP-dependent protein kinase A--PRKAR1A--as an interacting partner. We also show that protein kinase A (PKA) is a Bim(EL) isoform-specific kinase that promotes its stabilization. Inhibition of PKA or mutation of the PKA phosphorylation site within Bim(EL) resulted in its accelerated proteasome-dependent degradation. These results might have implications for human diseases that are characterized by abnormally increased PKA activity, such as the Carney complex and dilated cardiomyopathy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Apoptosis Regulatory Proteins / metabolism*
  • Apoptosis*
  • Bcl-2-Like Protein 11
  • Cyclic AMP-Dependent Protein Kinase RIalpha Subunit / metabolism*
  • Cyclic AMP-Dependent Protein Kinases / physiology*
  • Humans
  • Membrane Proteins / metabolism*
  • Mice
  • Phosphorylation
  • Protein Binding
  • Protein Stability
  • Proto-Oncogene Proteins / metabolism*
  • Sequence Alignment
  • Two-Hybrid System Techniques

Substances

  • Apoptosis Regulatory Proteins
  • BCL2L11 protein, human
  • Bcl-2-Like Protein 11
  • Bcl2l11 protein, mouse
  • Cyclic AMP-Dependent Protein Kinase RIalpha Subunit
  • Membrane Proteins
  • Prkar1a protein, mouse
  • Proto-Oncogene Proteins
  • Cyclic AMP-Dependent Protein Kinases