TY - JOUR T1 - Human replication licensing factor Cdt1 directly links mitotic kinetochores to spindle microtubules JF - bioRxiv DO - 10.1101/194993 SP - 194993 AU - Shivangi Agarwal AU - Kyle Paul Smith AU - Yizhuo Zhou AU - Aussie Suzuki AU - Richard James McKenney AU - Dileep Varma Y1 - 2017/01/01 UR - http://biorxiv.org/content/early/2017/09/27/194993.abstract N2 - Robust kinetochore-microtubule (kMT) attachment is critical for accurate chromosome segregation. G2/M-specific depletion of human Cdt1, a protein that localizes to kinetochores in an Ndc80 complex-dependent manner, leads to abnormal kMT attachments and mitotic arrest indicating an independent mitotic role for Cdt1 in addition to its prototypic DNA replication origin licensing function. Here, we show that Cdt1 directly binds to microtubules (MTs). Transiently expressed Cdt1 localizes to mitotic spindle MTs. Deletion mapping revealed that the C-terminus of Cdt1 carrying a winged-turn-helix domain is necessary but not sufficient for MT-binding. Mitotic kinase Aurora B interacts with and phosphorylates Cdt1. Aurora B-phosphomimetic Cdt1 exhibited attenuated MT-binding and its cellular expression induced defective kMT attachments and mitotic progression. Thus we provide evidence for a Cdt1-mediated MT-attachment site at kinetochores. We propose that Cdt1 links the loop domain of Ndc80 to MTs and enables an optimal MT-binding state for the complex.Short summaryCdt1 binds and diffuses on microtubulesThe winged-helix domain at the C-terminal region of Cdt1 is involved in MT-bindingAurora B Kinase phosphorylates Cdt1 and influences its MT-bindingAurora B-mediated Cdt1 phosphorylation is necessary for kMT stability and mitotic progressionAbbreviationskMTkinetochore-microtubuleMT(s)microtubule(s)Knl1Kinetochore null 1Ndc80Nuclear division cycle 80Mis12Missegregation 12CHCalponin homologyMAP(s)Microtubule associated protein(s)SkaSpindle and kinetochore-associated proteinTOGTumor overexpressed geneMTBDmicrotubule binding domainWHDWinged helix domain ER -