Michelob_x is the missing inhibitor of apoptosis protein antagonist in mosquito genomes

EMBO Rep. 2005 Aug;6(8):769-74. doi: 10.1038/sj.embor.7400473.


Apoptosis is implicated in the life cycle of the malaria parasite in mosquitoes. The genome project for the primary malaria vector Anopheles gambiae showed a significant expansion of the inhibitor of apoptosis protein (IAP) and caspase gene families in comparison with Drosophila. However, because of extensive sequence divergence, no orthologue was identified for the reaper/grim-like IAP antagonist genes that have a pivotal role in cell death regulation in Drosophila. Using a customized searching strategy, we identified michelob_x(mx), a gene not predicted by the genome project, as the missing IAP antagonist in the An. gambiae and other mosquito genomes. Mx has a highly conserved amino-terminal IAP-binding motif. Expression of Mx induces rapid cell death in insect cell lines and is a potent tissue ablator in vivo. Its proapoptotic activity is totally dependent on the IAP-binding motif. Like reaper in Drosophila, mx is transcriptionally induced by ultraviolet irradiation to mediate cell death.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aedes
  • Amino Acid Motifs
  • Amino Acid Sequence
  • Animals
  • Anopheles / genetics*
  • Apoptosis*
  • Carrier Proteins / genetics*
  • Carrier Proteins / physiology*
  • Cell Line
  • Cloning, Molecular
  • Computational Biology
  • Drosophila
  • Drosophila melanogaster
  • Genes, Insect
  • Genome
  • Immunoprecipitation
  • Insect Proteins / genetics*
  • Insect Proteins / physiology*
  • Molecular Sequence Data
  • Phylogeny
  • Protein Structure, Tertiary
  • RNA / metabolism
  • RNA Interference
  • RNA, Double-Stranded / chemistry
  • Sequence Homology, Amino Acid
  • Time Factors
  • Transcription, Genetic
  • Ultraviolet Rays


  • Carrier Proteins
  • Insect Proteins
  • RNA, Double-Stranded
  • RNA