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.
CAS Key Laboratory for Structure Biology and Hefei National Laboratory for Physical Sciences at Microscale, Hefei 230027, China.
Hongmei
H
Wang
Xiaoyu
X
Hu
Xia
X
Ding
Zhen
Z
Dou
Zhihong
Z
Yang
Andrew W
AW
Shaw
Maikun
M
Teng
Don W
DW
Cleveland
Michael L
ML
Goldberg
Liwen
L
Niu
Xuebiao
X
Yao
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