Tripin/hSgo2 recruits MCAK to the inner centromere to correct defective kinetochore attachments.
hSgo2 (previously annotated as Tripin) was recently reported to be a new inner centromere protein that is essential for centromere cohesion (Kitajima et al., 2006). In this study, we show that hSgo2 exhibits a dynamic distribution pattern, and that its localization depends on the BUB1 and Aurora B kinases. hSgo2 is concentrated at the inner centromere of unattached kinetochores, but extends toward the kinetochores that are under tension. This localization pattern is reminiscent of MCAK, which is a microtubule depolymerase that is believed to be a key component of the error correction mechanism at kinetochores. Indeed, we found that hSgo2 is essential for MCAK to localize to the centromere. Delocalization of MCAK accounts for why cells depleted of hSgo2 exhibit kinetochore attachment defects that go uncorrected, despite a transient delay in the onset of anaphase. Consequently, these cells exhibit a high frequency of lagging chromosomes when they enter anaphase. We confirmed that hSgo2 is associated with PP2A, and we propose that it contributes to the spatial regulation of MCAK activity within inner centromere and kinetochore.
Huang
Haomin
H
Fox Chase Cancer Center, Philadelphia, PA 19111, USA.
Feng
Jie
J
Famulski
Jakub
J
Rattner
Jerome B
JB
Liu
Song Tao
ST
Kao
Gary D
GD
Muschel
Ruth
R
Chan
Gordon K T
GK
Yen
Tim J
TJ
D000705:Anaphase / Q000502:physiology*; D064107:Aurora Kinase B; D064127:Aurora Kinases; D018797:Cell Cycle Proteins / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D016547:Kinesins / Q000378:metabolism*; D018386:Kinetochores / Q000378:metabolism* / Q000648:ultrastructure; D010749:Phosphoprotein Phosphatases / Q000378:metabolism; D011485:Protein Binding / Q000502:physiology; D011494:Protein Kinases / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D021381:Protein Transport / Q000502:physiology
D018797:Cell Cycle Proteins; C091489:KIF2C protein, human; C510590:SGO2 protein, human; D011494:Protein Kinases; C576921:AURKB protein, human; D064107:Aurora Kinase B; D064127:Aurora Kinases; C584277:BUB1 protein, human; C090464:Bub1 spindle checkpoint protein; D017346:Protein Serine-Threonine Kinases; D010749:Phosphoprotein Phosphatases; D016547:Kinesins