title: RMD-1, a novel microtubule-associated protein, functions in chromosome segregation in Caenorhabditis elegans.
abstract: For proper chromosome segregation, the sister kinetochores must attach to microtubules extending from the opposite spindle poles. Any errors in microtubule attachment can induce aneuploidy. In this study, we identify a novel conserved Caenorhabditis elegans microtubule-associated protein, regulator of microtubule dynamics 1 (RMD-1), that localizes to spindle microtubules and spindle poles. Depletion of RMD-1 induces severe defects in chromosome segregation, probably through merotelic attachments between microtubules and chromosomes. Although rmd-1 embryos also have a mild defect in microtubule growth, we find that mutants of the microtubule growth regulator XMAP215/ZYG-9 show much weaker segregation defects. This suggests that the microtubule growth defect in rmd-1 embryos does not cause abnormal chromosome segregation. We also see that RMD-1 interacts with aurora B in vitro. Our results suggest that RMD-1 functions in chromosome segregation in C. elegans embryos, possibly through the aurora B-mediated pathway. Human homologues of RMD-1 could also bind microtubules, which would suggest a function for these proteins in chromosome segregation during mitosis in other organisms as well.
authors: Laboratory for Cell Fate Decision, RIKEN Center for Developmental Biology, Chuo-ku, Kobe 650-0047, Japan.
authors: Kumiko
authors: K
authors: Oishi
authors: Hideyuki
authors: H
authors: Okano
authors: Hitoshi
authors: H
authors: Sawa
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D064107:Aurora Kinase B; D064127:Aurora Kinases; D017173:Caenorhabditis elegans / Q000196:embryology / Q000235:genetics* / Q000648:ultrastructure; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D020090:Chromosome Segregation / Q000502:physiology*; D004625:Embryo, Nonmammalian / Q000378:metabolism / Q000648:ultrastructure; D006801:Humans; D018386:Kinetochores / Q000378:metabolism; D051379:Mice; D008869:Microtubule-Associated Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D008870:Microtubules / Q000378:metabolism / Q000648:ultrastructure; D008969:Molecular Sequence Data; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D008941:Spindle Apparatus / Q000378:metabolism / Q000648:ultrastructure; D014982:Xenopus laevis; D015027:Zebrafish / Q000378:metabolism
chemical_list: D029742:Caenorhabditis elegans Proteins; D008869:Microtubule-Associated Proteins; C526067:Rmd-1 protein, C elegans; C112750:ZYG-9 protein, C elegans; C576921:AURKB protein, human; C576924:Aurkb protein, mouse; D064107:Aurora Kinase B; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases; C491506:air-2 protein, C elegans