Bifurcation of the mitotic checkpoint pathway in budding yeast.
The coordination of mitotic events is ensured through the spindle assembly checkpoint. BFA1 is required for this checkpoint in budding yeast because its disruption abolishes the mitotic arrest when spindle assembly is inhibited. Analysis of the genetic interaction of BFA1 with known mitotic checkpoint genes suggest that Bfa1 functions in the same pathway with Bub2 but not with Mad1 or Mad2. Both Bfa1 and Bub2 localize to spindle poles, and overexpression of Bfa1 arrests the cell cycle in anaphase. These findings suggest a bifurcation of the spindle assembly checkpoint: whereas one branch of the pathway, consisting of Mad1-3, Bub1 and 3, and Mps1, may prevent premature disjunction of sister chromosomes, the other, consisting of Bfa1 and Bub2, may function at spindle poles to prevent cytokinesis before the completion of chromosome segregation.
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Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA. Rli@hms.harvard.edu
D018797:Cell Cycle Proteins; D003001:Cloning, Molecular; D003598:Cytoskeletal Proteins; D005656:Fungal Proteins / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D008938:Mitosis / Q000235:genetics*; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D004718:Saccharomycetales / Q000166:cytology* / Q000235:genetics; D029702:Schizosaccharomyces pombe Proteins; D012689:Sequence Homology, Nucleic Acid
C119117:BFA1 protein, S cerevisiae; C100413:Byr4 protein, S pombe; D018797:Cell Cycle Proteins; D003598:Cytoskeletal Proteins; D005656:Fungal Proteins; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins