CED-4 forms a 2 : 2 heterotetrameric complex with CED-9 until specifically displaced by EGL-1 or CED-13

Cell Death Differ. 2006 Mar;13(3):426-34. doi: 10.1038/sj.cdd.4401762.

Abstract

The pathway to cell death in Caenorhabditis elegans is well established. In cells undergoing apoptosis, the Bcl-2 homology domain 3 (BH3)-only protein EGL-1 binds to CED-9 at the mitochondrial membrane to cause the release of CED-4, which oligomerises and facilitates the activation of the caspase CED-3. However, despite many studies, the biophysical features of the CED-4/CED-9 complex have not been fully characterised. Here, we report the purification of a soluble and stable 2 : 2 heterotetrameric complex formed by recombinant CED-4 and CED-9 coexpressed in bacteria. Consistent with previous studies, synthetic peptides corresponding to the BH3 domains of worm BH3-only proteins (EGL-1, CED-13) dissociate CED-4 from CED-9, but not from the gain-of-function CED-9 (G169E) mutant. Surprisingly, the ability of worm BH3 domains to dissociate CED-4 was specific since mammalian BH3-only proteins could not do so.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Apoptosis Regulatory Proteins / chemistry
  • Apoptosis Regulatory Proteins / isolation & purification
  • Apoptosis Regulatory Proteins / metabolism*
  • Caenorhabditis elegans Proteins / chemistry
  • Caenorhabditis elegans Proteins / isolation & purification
  • Caenorhabditis elegans Proteins / metabolism*
  • Calcium-Binding Proteins / chemistry
  • Calcium-Binding Proteins / isolation & purification
  • Calcium-Binding Proteins / metabolism*
  • Molecular Sequence Data
  • Protein Structure, Tertiary
  • Proto-Oncogene Proteins / chemistry
  • Proto-Oncogene Proteins / isolation & purification
  • Proto-Oncogene Proteins / metabolism*
  • Proto-Oncogene Proteins c-bcl-2
  • Repressor Proteins / chemistry
  • Repressor Proteins / metabolism*
  • Sequence Alignment

Substances

  • Apoptosis Regulatory Proteins
  • Caenorhabditis elegans Proteins
  • Calcium-Binding Proteins
  • Ced-13 protein, C elegans
  • Ced-4 protein, C elegans
  • Ced-9 protein, C elegans
  • EGL-1 protein, C elegans
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-bcl-2
  • Repressor Proteins