C. elegans MAC-1, an essential member of the AAA family of ATPases, can bind CED-4 and prevent cell death

Development. 1999 May;126(9):2021-31. doi: 10.1242/dev.126.9.2021.

Abstract

In the nematode Caenorhabditis elegans, CED-4 plays a central role in the regulation of programmed cell death. To identify proteins with essential or pleiotropic activities that might also regulate cell death, we used the yeast two-hybrid system to screen for CED-4-binding proteins. We identified MAC-1, a member of the AAA family of ATPases that is similar to Smallminded of Drosophila. Immunoprecipitation studies confirm that MAC-1 interacts with CED-4, and also with Apaf-1, the mammalian homologue of CED-4. Furthermore, MAC-1 can form a multi-protein complex that also includes CED-3 or CED-9. A MAC-1 transgene under the control of a heat shock promoter prevents some natural cell deaths in C. elegans, and this protection is enhanced in a ced-9(n1950sd)/+ genetic background. We observe a similar effect in mammalian cells, where expression of MAC-1 can prevent CED-4 and CED-3 from inducing apoptosis. Finally, mac-1 is an essential gene, since inactivation by RNA-mediated interference causes worms to arrest early in larval development. This arrest is similar to that observed in Smallminded mutants, but is not related to the ability of MAC-1 to bind CED-4, since it still occurs in ced-3 or ced-4 null mutants. These results suggest that MAC-1 identifies a new class of proteins that are essential for development, and which might regulate cell death in specific circumstances.

Publication types

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

MeSH terms

  • Adenosine Triphosphatases / chemistry
  • Adenosine Triphosphatases / genetics*
  • Adenosine Triphosphatases / metabolism*
  • Amino Acid Sequence
  • Animals
  • Animals, Genetically Modified
  • Apoptosis / physiology*
  • Apoptotic Protease-Activating Factor 1
  • Caenorhabditis elegans / cytology
  • Caenorhabditis elegans / genetics*
  • Caenorhabditis elegans / growth & development*
  • Caenorhabditis elegans Proteins*
  • Calcium-Binding Proteins / metabolism*
  • Cell Cycle Proteins / genetics
  • Cell Line
  • Cloning, Molecular
  • Drosophila
  • Drosophila Proteins*
  • Gene Expression Regulation, Developmental
  • Helminth Proteins / metabolism*
  • Humans
  • Insect Proteins / genetics
  • Larva
  • Molecular Sequence Data
  • Proteins / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Saccharomyces cerevisiae / growth & development
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Transfection

Substances

  • APAF1 protein, human
  • Apoptotic Protease-Activating Factor 1
  • Caenorhabditis elegans Proteins
  • Calcium-Binding Proteins
  • Ced-4 protein, C elegans
  • Cell Cycle Proteins
  • Drosophila Proteins
  • Helminth Proteins
  • Insect Proteins
  • Proteins
  • smid protein, Drosophila
  • Adenosine Triphosphatases