A role for the FEAR pathway in nuclear positioning during anaphase

Dev Cell. 2004 May;6(5):729-35. doi: 10.1016/s1534-5807(04)00128-5.


In budding yeast, cells lacking separase function exit mitosis with an undivided nucleus localized to the daughter cell. Here we show that the inability to separate sister chromatids per se is not sufficient to cause the daughter preference. Rather, separase affects nuclear positioning as part of the Cdc14 early anaphase release (FEAR) pathway. The role of the FEAR pathway in nuclear positioning is exerted during anaphase and is not shared by the mitotic exit network. We find that the nuclear segregation defect in FEAR mutants does not stem from nonfunctional spindle poles or the absence of cytoplasmic microtubules. Instead, the concomitant inactivation of sister chromatid separation and the FEAR pathway uncovered a mother-directed force in anaphase that was previously masked by the elongating spindle. We propose that at anaphase onset, the FEAR pathway activates cytoplasmic microtubule-associated forces that facilitate chromosome segregation to the mother cell.

Publication types

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

MeSH terms

  • Anaphase / genetics*
  • Cell Cycle Proteins / genetics*
  • Cell Cycle Proteins / metabolism
  • Cell Nucleus / metabolism*
  • Chromosome Segregation / physiology*
  • Cytoplasm / genetics
  • Cytoplasm / metabolism
  • Endopeptidases / genetics
  • Endopeptidases / metabolism
  • Metaphase / genetics
  • Microtubules / genetics
  • Microtubules / metabolism
  • Mitosis / genetics*
  • Mutation / genetics
  • Protein Tyrosine Phosphatases / genetics*
  • Protein Tyrosine Phosphatases / metabolism
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae / ultrastructure
  • Saccharomyces cerevisiae Proteins / genetics*
  • Saccharomyces cerevisiae Proteins / metabolism
  • Separase
  • Signal Transduction / genetics
  • Spindle Apparatus / genetics
  • Spindle Apparatus / metabolism


  • CDC14 protein, S cerevisiae
  • Cell Cycle Proteins
  • Saccharomyces cerevisiae Proteins
  • Protein Tyrosine Phosphatases
  • Endopeptidases
  • ESP1 protein, S cerevisiae
  • Separase