title: Mammalian Polo-like kinase 1 (Plk1) promotes proper chromosome segregation by phosphorylating and delocalizing the PBIP1·CENP-Q complex from kinetochores.
abstract: Mammalian Plk1 is critically required for proper M phase progression. Plk1 is self-recruited to prekinetochores/kinetochores by phosphorylating and binding to the Thr-78 motif of a kinetochore scaffold protein, PBIP1 (also called CENP-U/50), which forms a stable complex with another kinetochore component, CENP-Q. However, the mechanism regulating Plk1 localization to this site remains largely unknown. Here, we demonstrate that the PBIP1·CENP-Q complex became hyperphosphorylated and rapidly delocalized from kinetochores as cells entered mitosis. Plk1 phosphorylated the CENP-Q subunit of the PBIP1·CENP-Q complex at multiple sites, and mutation of nine Plk1-dependent phosphorylation sites to Ala (9A) enhanced CENP-Q association with chromatin and prolonged CENP-Q localization to kinetochores. Conversely, mutation of the nine sites to phospho-mimicking Asp/Glu (9D/E) residues dissociated CENP-Q from chromatin and kept the CENP-Q(9D/E) mutant from localizing to interphase prekinetochores. Strikingly, both the 9A and 9D/E mutants induced a defect in proper chromosome segregation, suggesting that both timely localization of the PBIP1·CENP-Q complex to prekinetochores and delocalization from kinetochores are critical for normal M phase progression. Notably, although Plk1 did not alter the level of PBIP1 and CENP-Q ubiquitination, Plk1-dependent phosphorylation and delocalization of these proteins from kinetochores appeared to indirectly lead to their degradation in the cytosol. Thus, we propose that Plk1 regulates the timing of the delocalization and ultimate destruction of the PBIP1·CENP-Q complex and that these processes are important not only for promoting Plk1-dependent mitotic progression, but also for resetting the timing of Plk1 recruitment to prekinetochores in the next cell cycle.
authors: From the Laboratory of Metabolism, NCI, National Institutes of Health, Bethesda, Maryland 20892-4258.
authors: Chi Hoon
authors: CH
authors: Park
authors: From the Laboratory of Metabolism, NCI, National Institutes of Health, Bethesda, Maryland 20892-4258.
authors: Jung-Eun
authors: JE
authors: Park
authors: From the Laboratory of Metabolism, NCI, National Institutes of Health, Bethesda, Maryland 20892-4258.
authors: Tae-Sung
authors: TS
authors: Kim
authors: the Immune and Vascular Cell Network Research Center, Department of Life Science and GT5 Program, Ewha Womans University, Seoul 120-750, Korea.
authors: Young Hwi
authors: YH
authors: Kang
authors: the Chemical Biology Research Center, Korea Research Institute of Bioscience and Biotechnology, Ochang, Chungbuk 363-883, Korea.
authors: Nak-Kyun
authors: NK
authors: Soung
authors: the Laboratory of Proteomics and Analytical Technologies, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702.
authors: Ming
authors: M
authors: Zhou
authors: the Department of Animal Sciences, Chungbuk National University, Cheongju, Chungbuk, 361-763 Korea, and.
authors: Nam-Hyung
authors: NH
authors: Kim
authors: the Division of Magnetic Resonance, Korea Basic Science Institute, Ochang, Chungbuk, 363-883 Korea.
authors: Jeong Kyu
authors: JK
authors: Bang
authors: From the Laboratory of Metabolism, NCI, National Institutes of Health, Bethesda, Maryland 20892-4258, kyunglee@mail.nih.gov.
authors: Kyung S
authors: KS
authors: Lee
mesh_terms: D018797:Cell Cycle Proteins / Q000502:physiology*; D002843:Chromatin / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D020090:Chromosome Segregation; D057809:HEK293 Cells; D006367:HeLa Cells; D006657:Histones; D006801:Humans; D018386:Kinetochores / Q000378:metabolism; D046912:Multiprotein Complexes / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism*; D010766:Phosphorylation; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D017346:Protein Serine-Threonine Kinases / Q000502:physiology*; D055550:Protein Stability; D021381:Protein Transport; D059748:Proteolysis; D011518:Proto-Oncogene Proteins / Q000502:physiology*; D054875:Ubiquitination; D000097869:Polo-Like Kinase 1
chemical_list: D018797:Cell Cycle Proteins; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D006657:Histones; D046912:Multiprotein Complexes; D009687:Nuclear Proteins; D046988:Proteasome Endopeptidase Complex; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D000097869:Polo-Like Kinase 1; C559900:CENPQ protein, human; C485917:CENPU protein, human
keywords: Cell Cycle; Centromere; Chromosomes; Kinetochore; Mitosis; Plk1, CENP-Q