Evidence that the Ipl1-Sli15 (Aurora kinase-INCENP) complex promotes chromosome bi-orientation by altering kinetochore-spindle pole connections.
How sister kinetochores attach to microtubules from opposite spindle poles during mitosis (bi-orientation) remains poorly understood. In yeast, the ortholog of the Aurora B-INCENP protein kinase complex (Ipl1-Sli15) may have a role in this crucial process, because it is necessary to prevent attachment of sister kinetochores to microtubules from the same spindle pole. We investigated IPL1 function in cells that cannot replicate their chromosomes but nevertheless duplicate their spindle pole bodies (SPBs). Kinetochores detach from old SPBs and reattach to old and new SPBs with equal frequency in IPL1+ cells, but remain attached to old SPBs in ipl1 mutants. This raises the possibility that Ipl1-Sli15 facilitates bi-orientation by promoting turnover of kinetochore-SPB connections until traction of sister kinetochores toward opposite spindle poles creates tension in the surrounding chromatin.
Tanaka
Tomoyuki U
TU
School of Life Sciences, University of Dundee, MSI/WTB complex, DD1 5EH, Dundee, United Kingdom. t.tanaka@dundee.ac.uk
Rachidi
Najma
N
Janke
Carsten
C
Pereira
Gislene
G
Galova
Marta
M
Schiebel
Elmar
E
Stark
Michael J R
MJ
Nasmyth
Kim
K
D064127:Aurora Kinases; D002868:Chromosomal Proteins, Non-Histone / Q000502:physiology*; D015825:Chromosomes, Fungal / Q000502:physiology* / Q000648:ultrastructure; D004261:DNA Replication; D004271:DNA, Fungal / Q000502:physiology; D047908:Intracellular Signaling Peptides and Proteins; D018386:Kinetochores / Q000502:physiology / Q000648:ultrastructure; D008938:Mitosis / Q000502:physiology*; D009154:Mutation; D011494:Protein Kinases / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins; D008941:Spindle Apparatus / Q000502:physiology* / Q000648:ultrastructure
D002868:Chromosomal Proteins, Non-Histone; D004271:DNA, Fungal; D047908:Intracellular Signaling Peptides and Proteins; D029701:Saccharomyces cerevisiae Proteins; D011494:Protein Kinases; D064127:Aurora Kinases; C576961:IPL1 protein, S cerevisiae; D017346:Protein Serine-Threonine Kinases