Pericentromeric sister chromatid cohesion promotes kinetochore biorientation.
Accurate chromosome segregation depends on sister kinetochores making bioriented attachments to microtubules from opposite poles. An essential regulator of biorientation is the Ipl1/Aurora B protein kinase that destabilizes improper microtubule-kinetochore attachments. To identify additional biorientation pathways, we performed a systematic genetic analysis between the ipl1-321 allele and all nonessential budding yeast genes. One of the mutants, mcm21Delta, precociously separates pericentromeres and this is associated with a defect in the binding of the Scc2 cohesin-loading factor at the centromere. Strikingly, Mcm21 becomes essential for biorientation when Ipl1 function is reduced, and this appears to be related to its role in pericentromeric cohesion. When pericentromeres are artificially tethered, Mcm21 is no longer needed for biorientation despite decreased Ipl1 activity. Taken together, these data reveal a specific role for pericentromeric linkage in ensuring kinetochore biorientation.
Ng
Tessie M
TM
Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
Waples
William G
WG
Lavoie
Brigitte D
BD
Biggins
Sue
S
D064127:Aurora Kinases; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002842:Chromatids / Q000378:metabolism*; D020090:Chromosome Segregation; D004843:Epistasis, Genetic; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D018386:Kinetochores / Q000378:metabolism*; D056968:Lac Repressors / Q000235:genetics / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D008941:Spindle Apparatus / Q000378:metabolism*
D018797:Cell Cycle Proteins; D047908:Intracellular Signaling Peptides and Proteins; D056968:Lac Repressors; C118344:MCM21 protein, S cerevisiae; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D064127:Aurora Kinases; C576961:IPL1 protein, S cerevisiae; D017346:Protein Serine-Threonine Kinases