Aurora controls sister kinetochore mono-orientation and homolog bi-orientation in meiosis-I

EMBO J. 2007 Oct 31;26(21):4475-86. doi: 10.1038/sj.emboj.7601880. Epub 2007 Oct 11.

Abstract

Aurora-B kinases are important regulators of mitotic chromosome segregation, where they are required for the faithful bi-orientation of sister chromatids. In contrast to mitosis, sister chromatids have to be oriented toward the same spindle pole in meiosis-I, while homologous chromosomes are bi-oriented. We find that the fission yeast Aurora kinase Ark1 is required for the faithful bi-orientation of sister chromatids in mitosis and of homologous chromosomes in meiosis-I. Unexpectedly, Ark1 is also necessary for the faithful mono-orientation of sister chromatids in meiosis-I, even though the canonical mono-orientation pathway, which depends on Moa1 and Rec8, seems intact. Our data suggest that Ark1 prevents unified sister kinetochores during metaphase-I from merotelic attachment to both spindle poles and thus from being torn apart during anaphase-I, revealing a novel mechanism promoting monopolar attachment. Furthermore, our results provide an explanation for the previously enigmatic observation that fission yeast Shugoshin Sgo2, which assists in loading Aurora to centromeres, and its regulator Bub1 are required for the mono-orientation of sister chromatids in meiosis-I.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Aurora Kinases
  • Cell Nucleus / metabolism
  • Chromatids / ultrastructure
  • Chromosomal Proteins, Non-Histone / physiology
  • Image Processing, Computer-Assisted
  • Kinetochores / metabolism*
  • Meiosis*
  • Mitosis
  • Models, Biological
  • Models, Genetic
  • Phosphoproteins / metabolism
  • Protein-Serine-Threonine Kinases / physiology*
  • Schizosaccharomyces / genetics*
  • Schizosaccharomyces / physiology
  • Schizosaccharomyces pombe Proteins / metabolism
  • Schizosaccharomyces pombe Proteins / physiology
  • Sister Chromatid Exchange

Substances

  • Chromosomal Proteins, Non-Histone
  • Phosphoproteins
  • Schizosaccharomyces pombe Proteins
  • Sgo2 protein, S pombe
  • REC8 protein, S pombe
  • Aurora Kinases
  • Bub1 protein, S pombe
  • Protein-Serine-Threonine Kinases