title: The microtubule-binding and coiled-coil domains of Kid are required to turn off the polar ejection force at anaphase.
abstract: Mitotic chromosomes move dynamically along the spindle microtubules using the forces generated by motor proteins such as chromokinesin Kid (also known as KIF22). Kid generates a polar ejection force and contributes to alignment of the chromosome arms during prometaphase and metaphase, whereas during anaphase, Kid contributes to chromosome compaction. How Kid is regulated and how this regulation is important for chromosome dynamics remains unclear. Here, we address these questions by expressing mutant forms of Kid in Kid-deficient cells. We demonstrate that Cdk1-mediated phosphorylation of Thr463 is required to generate the polar ejection force on Kid-binding chromosomes, whereas dephosphorylation of Thr463 prevents generation of the ejection force on such chromosomes. In addition to activation of the second microtubule-binding domain through dephosphorylation of Thr463, the coiled-coil domain is essential in suspending generation of the polar ejection force, preventing separated chromosomes from becoming recongressed during anaphase. We propose that phosphorylation of Thr463 switches the mitotic chromosome movement from an anti-poleward direction to a poleward direction by converting the Kid functional mode from polar-ejection-force-ON to -OFF during the metaphase-anaphase transition, and that both the second microtubule-binding domain and the coiled-coil domain are involved in this switching process.
authors.affiliation: Division of Oncology, Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo 108-8639, Japan Department of Life Science, Graduate school of Arts and Sciences, The University of Tokyo, Meguro-ku, Tokyo 153-8902, Japan Department of Biophysics and Biochemistry, Graduate school of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan Japan Society for the Promotion of Science Research Fellow, Chiyoda-Ku, Tokyo 102-0083, Japan.
authors.forename: Shou
authors.initials: S
authors.lastname: Soeda
authors.affiliation: Division of Oncology, Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo 108-8639, Japan Department of Obstetrics and Gynecology, The University of Toyama, Toyama-shi, Toyama 930-0194, Japan.
authors.forename: Kaori
authors.initials: K
authors.lastname: Yamada-Nomoto
authors.affiliation: Division of Oncology, Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo 108-8639, Japan Department of Life Science, Graduate school of Arts and Sciences, The University of Tokyo, Meguro-ku, Tokyo 153-8902, Japan Department of Biophysics and Biochemistry, Graduate school of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan mohsugi@bio.c.u-tokyo.ac.jp.
authors.forename: Miho
authors.identifier: 0000-0003-0288-3428
authors.initials: M
authors.lastname: Ohsugi
mesh_terms: D000705:Anaphase; D000818:Animals; D001696:Biomechanical Phenomena; D020090:Chromosome Segregation; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D016547:Kinesins / Q000737:chemistry / Q000378:metabolism*; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008870:Microtubules / Q000378:metabolism*; D009865:Oocytes / Q000378:metabolism; D010641:Phenotype; D010766:Phosphorylation; D010769:Phosphothreonine / Q000378:metabolism; D000072417:Protein Domains
chemical_list: D004268:DNA-Binding Proteins; D010769:Phosphothreonine; D049452:Green Fluorescent Proteins; C527520:Kid protein, mouse; D016547:Kinesins
keywords: Cell division; Chromosome dynamics; Kinesin; Phosphorylation status