title: Characterization of a MAPKK-like protein kinase TOPK.
abstract: A MAPKK-like protein kinase TOPK expresses in a wide range of proliferating cells and tissues such as cancer cells and testis. However, details of this kinase are still uncovered. We investigated the intracellular distribution of TOPK and its association with cdk1/cyclin B and microtubules. In interphase cells, TOPK expresses in cytosol and nucleus without any significant association with microtubule networks. During mitosis, TOPK-Thr-9 was phosphorylated by cdk1/cyclin B and TOPK significantly associates with mitotic spindles. When TOPK expression was suppressed, formation of spindle midzone was thinned and dimmed and cytokinesis was disturbed. We propose that TOPK plays a role in the formation of spindle midzone and in cytokinesis.
authors.affiliation: Department of Molecular Pathology, National University Corporation, Ehime University School of Medicine, Toh-on, Ehime 791-0295, Japan.
authors.forename: Suguru
authors.initials: S
authors.lastname: Matsumoto
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Abe
authors.forename: Taketsugu
authors.initials: T
authors.lastname: Fujibuchi
authors.forename: Takashi
authors.initials: T
authors.lastname: Takeuchi
authors.forename: Katsumi
authors.initials: K
authors.lastname: Kito
authors.forename: Norifumi
authors.initials: N
authors.lastname: Ueda
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Shigemoto
authors.forename: Kiyofumi
authors.initials: K
authors.lastname: Gyo
mesh_terms: D000818:Animals; D019556:COS Cells; D002453:Cell Cycle; D045744:Cell Line, Tumor; D002522:Chlorocebus aethiops; D019926:Cyclin B / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008870:Microtubules / Q000378:metabolism; D020929:Mitogen-Activated Protein Kinase Kinases; D012516:Osteosarcoma / Q000201:enzymology* / Q000473:pathology*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D013045:Species Specificity
chemical_list: D019926:Cyclin B; D017346:Protein Serine-Threonine Kinases; D020929:Mitogen-Activated Protein Kinase Kinases; C409022:PDZ-binding kinase