The survivin-like C. elegans BIR-1 protein acts with the Aurora-like kinase AIR-2 to affect chromosomes and the spindle midzone.
Baculoviral IAP repeat proteins (BIRPs) may affect cell death, cell division, and tumorigenesis. The C. elegans BIRP BIR-1 was localized to chromosomes and to the spindle midzone. Embryos and fertilized oocytes lacking BIR-1 had defects in chromosome behavior, spindle midzone formation, and cytokinesis. We observed indistinguishable defects in fertilized oocytes and embryos lacking the Aurora-like kinase AIR-2. AIR-2 was not present on chromosomes in the absence of BIR-1. Histone H3 phosphorylation and HCP-1 staining, which marks kinetochores, were reduced in the absence of either BIR-1 or AIR-2. We propose that BIR-1 localizes AIR-2 to chromosomes and perhaps to the spindle midzone, where AIR-2 phosphorylates proteins that affect chromosome behavior and spindle midzone organization. The human BIRP survivin, which is upregulated in tumors, could partially substitute for BIR-1 in C. elegans. Deregulation of bir-1 promotes changes in ploidy, suggesting that similar deregulation of mammalian BIRPs may contribute to tumorigenesis.
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Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge 02139, USA.
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Vaux
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Horvitz
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D000818:Animals; D064107:Aurora Kinase B; D064127:Aurora Kinases; D017173:Caenorhabditis elegans / Q000235:genetics / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins; D002453:Cell Cycle / Q000502:physiology*; D002455:Cell Division; D002874:Chromosome Mapping; D002875:Chromosomes / Q000502:physiology*; D004625:Embryo, Nonmammalian / Q000502:physiology; D005260:Female; D017238:Genes, Helminth; D015801:Helminth Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins; D008297:Male; D008869:Microtubule-Associated Proteins; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins; D009865:Oocytes / Q000502:physiology; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism; D013094:Spermatozoa / Q000502:physiology; D008941:Spindle Apparatus / Q000502:physiology*; D000077022:Survivin
C107489:BIRC5 protein, human; D029742:Caenorhabditis elegans Proteins; D015801:Helminth Proteins; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins; D009363:Neoplasm Proteins; D011506:Proteins; D000077022:Survivin; C118999:bir-1 protein, C elegans; D064107:Aurora Kinase B; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases; C491506:air-2 protein, C elegans