title: Dynamics of inner kinetochore assembly and maintenance in living cells.
abstract: To investigate the dynamics of centromere organization, we have assessed the exchange rates of inner centromere proteins (CENPs) by quantitative microscopy throughout the cell cycle in human cells. CENP-A and CENP-I are stable centromere components that are incorporated into centromeres via a "loading-only" mechanism in G1 and S phase, respectively. A subfraction of CENP-H also stays stably bound to centromeres. In contrast, CENP-B, CENP-C, and some CENP-H and hMis12 exhibit distinct and cell cycle-specific centromere binding stabilities, with residence times ranging from seconds to hours. CENP-C and CENP-H are immobilized at centromeres specifically during replication. In mitosis, all inner CENPs become completely immobilized. CENPs are highly mobile throughout bulk chromatin, which is consistent with a binding-diffusion behavior as the mechanism to scan for vacant high-affinity binding sites at centromeres. Our data reveal a wide range of cell cycle-specific assembly plasticity of the centromere that provides both stability through sustained binding of some components and flexibility through dynamic exchange of other components.
authors.affiliation: Leibniz Institute for Age Research, Fritz Lipmann Institute, 07745 Jena, Germany. phemmer@fl i-leibniz.de
authors.forename: Peter
authors.initials: P
authors.lastname: Hemmerich
authors.forename: Stefanie
authors.initials: S
authors.lastname: Weidtkamp-Peters
authors.forename: Christian
authors.initials: C
authors.lastname: Hoischen
authors.forename: Lars
authors.initials: L
authors.lastname: Schmiedeberg
authors.forename: Indri
authors.initials: I
authors.lastname: Erliandri
authors.forename: Stephan
authors.initials: S
authors.lastname: Diekmann
mesh_terms: D001324:Autoantigens / Q000378:metabolism; D001665:Binding Sites / Q000502:physiology; D002453:Cell Cycle / Q000502:physiology*; D002455:Cell Division / Q000502:physiology*; D002460:Cell Line; D002503:Centromere / Q000378:metabolism* / Q000648:ultrastructure; D000076247:Centromere Protein A; D051936:Centromere Protein B / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism; D020090:Chromosome Segregation / Q000502:physiology; D004261:DNA Replication / Q000502:physiology; D004268:DNA-Binding Proteins / Q000378:metabolism; D016193:G1 Phase / Q000502:physiology; D006801:Humans; D018386:Kinetochores / Q000378:metabolism* / Q000648:ultrastructure; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D011485:Protein Binding / Q000502:physiology; D016196:S Phase / Q000502:physiology; D008941:Spindle Apparatus / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: D001324:Autoantigens; C000619700:CENPA protein, human; C497926:CENPB protein, human; C093717:Cenpi protein, rat; D000076247:Centromere Protein A; D051936:Centromere Protein B; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; C492664:MIS12 protein, human; D008869:Microtubule-Associated Proteins; C060905:centromere protein C