Article

CENP-U Cooperates with Hec1 to Orchestrate Kinetochore-Microtubule Attachment

Anhui Laboratory of Cellular Dynamics and Chemical Biology, Hefei National Laboratory for Physical Sciences at Nanoscale, Hefei 230027, China.
Journal of Biological Chemistry (Impact Factor: 4.57). 11/2010; 286(2):1627-38. DOI: 10.1074/jbc.M110.174946
Source: PubMed

ABSTRACT

Mitosis is an orchestration of dynamic interaction between chromosomes and spindle microtubules by which genomic materials are equally distributed into two daughter cells. Previous studies showed that CENP-U is a constitutive centromere component essential for proper chromosome segregation. However, the precise molecular mechanism has remained elusive. Here, we identified CENP-U as a novel interacting partner of Hec1, an evolutionarily conserved kinetochore core component essential for chromosome plasticity. Suppression of CENP-U by shRNA resulted in mitotic defects with an impaired kinetochore-microtubule attachment. Interestingly, CENP-U not only binds microtubules directly but also displays a cooperative microtubule binding activity with Hec1 in vitro. Furthermore, we showed that CENP-U is a substrate of Aurora-B. Importantly, phosphorylation of CENP-U leads to reduced kinetochore-microtubule interaction, which contributes to the error-correcting function of Aurora-B. Taken together, our results indicate that CENP-U is a novel microtubule binding protein and plays an important role in kinetochore-microtubule attachment through its interaction with Hec1.

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    • "Minoshima et al. (2005) have documented that MLF1IP was localized to centromeres throughout the cell cycle. The depletion of MLF1IP in HeLa cells caused severe mitotic defects with aberrant kinetochore attachments (Hua et al., 2011). Mice homozygous for a knock-out allele exhibited embryonic lethality between E7.5 and E9.5, small embryo size and thickened visceral endoderm, embryos died at the gastrula stage (Wang et al., 2013). "
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    • "Minoshima et al. (2005) have documented that MLF1IP was localized to centromeres throughout the cell cycle. The depletion of MLF1IP in HeLa cells caused severe mitotic defects with aberrant kinetochore attachments (Hua et al., 2011). Mice homozygous for a knock-out allele exhibited embryonic lethality between E7.5 and E9.5, small embryo size and thickened visceral endoderm, embryos died at the gastrula stage (Wang et al., 2013). "

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    • "Here we analysed the CENP-O class protein packaging at kinetochores in living human cells by measuring which proteins are in close proximity. We tagged all five CENP-O class proteins with fluorescent proteins, either EGFP or mCherry, at either termini, and confirmed by live cell imaging in human U2OS cells that all tagged CENP-O class proteins localise to kinetochores during interphase and mitosis, consistent with published results [5], [6], [10], [33], [36], [39]. This kinetochore localisation was independent of which terminus of the CENP proteins was tagged. "
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