Mitosin/CENP-F is a conserved kinetochore protein subjected to cytoplasmic dynein-mediated poleward transport.
Mitosin/CENP-F is a human nuclear protein transiently associated with the outer kinetochore plate in M phase and is involved in M phase progression. LEK1 and CMF1, which are its murine and chicken orthologs, however, are implicated in muscle differentiation and reportedly not distributed at kinetochores. We therefore conducted several assays to clarify this issue. The typical centromere staining patterns were observed in mitotic cells from both human primary culture and murine, canine, and mink cell lines. A C-terminal portion of LEK1 also conferred centromere localization. Our analysis further suggests conserved kinetochore localization of mammalian mitosin orthologs. Moreover, mitosin was associated preferentially with kinetochores of unaligned chromosomes. It was also constantly transported from kinetochores to spindle poles by cytoplasmic dynein. These properties resemble those of other kinetochore proteins important for the spindle checkpoint, thus implying a role of mitosin in this checkpoint. Therefore, mitosin family may serve as multifunctional proteins involved in both mitosis and differentiation.
Yang
Zhen Ye
ZY
Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China.
Guo
Jing
J
Li
Ning
N
Qian
Min
M
Wang
Sheng Nian
SN
Zhu
Xue Liang
XL
D000595:Amino Acid Sequence; D000818:Animals; D001692:Biological Transport / Q000502:physiology; D002453:Cell Cycle; D002478:Cells, Cultured; D002868:Chromosomal Proteins, Non-Histone / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004398:Dyneins / Q000378:metabolism*; D006801:Humans; D018386:Kinetochores; D008840:Microfilament Proteins; D020409:Molecular Motor Proteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D011485:Protein Binding; D016415:Sequence Alignment
D002868:Chromosomal Proteins, Non-Histone; D008840:Microfilament Proteins; D020409:Molecular Motor Proteins; C094772:centromere protein F; D004398:Dyneins