Human Zwint-1 specifies localization of Zeste White 10 to kinetochores and is essential for mitotic checkpoint signaling.
Chromosome segregation in mitosis is orchestrated by dynamic interaction between spindle microtubules and the kinetochore, a multiprotein complex assembled onto centromeric DNA of the chromosome. Here we show that Zwint-1 is required and is sufficient for kinetochore localization of Zeste White 10 (ZW10) in HeLa cells. Zwint-1 specifies the kinetochore association of ZW10 by interacting with its N-terminal domain. Suppression of synthesis of Zwint-1 by small interfering RNA abolishes the localization of ZW10 to the kinetochore, demonstrating the requirement of Zwint-1 for ZW10 kinetochore localization. In addition, depletion of Zwint-1 affects no mitotic arrest but causes aberrant premature chromosome segregation. These Zwint-1-suppressed cells display chromosome bridge phenotype with sister chromatids inter-connected. Moreover, Zwint-1 is required for stable association of CENP-F and dynamitin but not BUB1 with the kinetochore. Finally, our studies show that Zwint-1 is a new component of the mitotic check-point, as cells lacking Zwint-1 fail to arrest in mitosis when exposed to microtubule inhibitors, yielding interphase cells with multinuclei. As ZW10 and Zwint-1 are absent from yeast, we reasoned that metazoans evolved an elaborate spindle checkpoint machinery to ensure faithful chromosome segregation in mitosis.
Wang
Hongmei
H
CAS Key Laboratory for Structure Biology and Hefei National Laboratory for Physical Sciences at Microscale, Hefei 230027, China.
Hu
Xiaoyu
X
Ding
Xia
X
Dou
Zhen
Z
Yang
Zhihong
Z
Shaw
Andrew W
AW
Teng
Maikun
M
Cleveland
Don W
DW
Goldberg
Michael L
ML
Niu
Liwen
L
Yao
Xuebiao
X
D000818:Animals; D001665:Binding Sites; D002352:Carrier Proteins / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D002868:Chromosomal Proteins, Non-Histone / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D020090:Chromosome Segregation / Q000502:physiology; D000072159:Dynactin Complex; D015870:Gene Expression; D005982:Glutathione Transferase / Q000235:genetics; D049452:Green Fluorescent Proteins / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D018386:Kinetochores / Q000737:chemistry / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008840:Microfilament Proteins; D008869:Microtubule-Associated Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D008938:Mitosis / Q000502:physiology*; D009687:Nuclear Proteins; D010446:Peptide Fragments / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics / Q000502:physiology; D011993:Recombinant Fusion Proteins; D015398:Signal Transduction / Q000502:physiology*; D014162:Transfection
D002352:Carrier Proteins; D002868:Chromosomal Proteins, Non-Histone; C000606361:DCTN2 protein, human; C000606365:Dctn2 protein, mouse; D000072159:Dynactin Complex; D047908:Intracellular Signaling Peptides and Proteins; D008840:Microfilament Proteins; D008869:Microtubule-Associated Proteins; D009687:Nuclear Proteins; D010446:Peptide Fragments; D034741:RNA, Small Interfering; D011993:Recombinant Fusion Proteins; C488261:ZW10 protein, human; C413695:ZWINT protein, human; C094772:centromere protein F; C485192:green fluorescent protein, Aequorea victoria; D049452:Green Fluorescent Proteins; D005982:Glutathione Transferase