title: Coordinated requirements of human topo II and cohesin for metaphase centromere alignment under Mad2-dependent spindle checkpoint surveillance.
abstract: Cohesin maintains sister chromatid cohesion until its Rad21/Scc1/Mcd1 is cleaved by separase during anaphase. DNA topoisomerase II (topo II) maintains the proper topology of chromatid DNAs and is essential for chromosome segregation. Here we report direct observations of mitotic progression in individual HeLa cells after functional disruptions of hRad21, NIPBL, a loading factor for hRad21, and topo II alpha,beta by RNAi and a topo II inhibitor, ICRF-193. Mitosis is delayed in a Mad2-dependent manner after disruption of either or both cohesin and topo II. In hRad21 depletion, interphase pericentric architecture becomes aberrant, and anaphase is virtually permanently delayed as preseparated chromosomes are misaligned on the metaphase spindle. Topo II disruption perturbs centromere organization leading to intense Bub1, but no Mad2, on kinetochores and sustains a Mad2-dependent delay in anaphase onset with persisting securin. Thus topo II impinges upon centromere/kinetochore function. Disruption of topo II by RNAi or ICRF-193 overrides the mitotic delay induced by cohesin depletion: sister centromeres are aligned and anaphase spindle movements occur. The ensuing accumulation of catenations in preseparated sister chromatids may overcome the reduced tension arising from cohesin depletion, causing the override. Cohesin and topo II have distinct, yet coordinated functions in metaphase alignment.
authors.affiliation: Department of Gene Mechanisms, Graduate School of Biostudies, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Toyoda
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Yanagida
mesh_terms: D002135:Calcium-Binding Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D002503:Centromere / Q000378:metabolism*; D002843:Chromatin / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D002877:Chromosomes, Human / Q000378:metabolism; D019926:Cyclin B / Q000378:metabolism; D056744:Cyclin B1; D004250:DNA Topoisomerases, Type II / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins; D054659:Diketopiperazines; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006367:HeLa Cells; D006801:Humans; D018386:Kinetochores / Q000737:chemistry / Q000378:metabolism; D064246:Mad2 Proteins; D008677:Metaphase / Q000235:genetics; D008938:Mitosis / Q000235:genetics; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D010879:Piperazines / Q000494:pharmacology; D011494:Protein Kinases / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics; D012097:Repressor Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D008941:Spindle Apparatus / Q000378:metabolism*; D016615:Telomere / Q000378:metabolism; D059005:Topoisomerase II Inhibitors; D000097722:Cohesins
chemical_list: D002135:Calcium-Binding Proteins; D018797:Cell Cycle Proteins; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D019926:Cyclin B; D056744:Cyclin B1; D004250:DNA Topoisomerases, Type II; D004268:DNA-Binding Proteins; D054659:Diketopiperazines; D004791:Enzyme Inhibitors; D064246:Mad2 Proteins; D009687:Nuclear Proteins; D010750:Phosphoproteins; D010879:Piperazines; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; D011506:Proteins; D012097:Repressor Proteins; D059005:Topoisomerase II Inhibitors; D000097722:Cohesins; C534699:CCNB1 protein, human; C577697:MAD2L1 protein, human; C487465:NIPBL protein, human; C429022:RAD21 protein, human; C070899:4,4'-(1,2-dimethyl-1,2-ethanediyl)bis-2,6-piperazinedione; C584277:BUB1 protein, human; C090464:Bub1 spindle checkpoint protein