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Dynamics of CENP-N kinetochore binding during the cell cycle |
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Published in | Journal of cell science. 2011, vol. 124, no. Pt 22, p. 3871-83 | |
Abstract | Accurate chromosome segregation requires the assembly of kinetochores, multiprotein complexes that assemble on the centromere of each sister chromatid. A key step in this process involves binding of the constitutive centromere-associated network (CCAN) to CENP-A, the histone H3 variant that constitutes centromeric nucleosomes. This network is proposed to operate as a persistent structural scaffold for assembly of the outer kinetochore during mitosis. Here, we show by fluorescence resonance energy transfer (FRET) that the N-terminus of CENP-N lies in close proximity to the N-terminus of CENP-A in vivo, consistent with in vitro data showing direct binding of CENP-N to CENP-A. Furthermore, we demonstrate in living cells that CENP-N is bound to kinetochores during S phase and G2, but is largely absent from kinetochores during mitosis and G1. By measuring the dynamics of kinetochore binding, we reveal that CENP-N undergoes rapid exchange in G1 until the middle of S phase when it becomes stably associated with kinetochores. The majority of CENP-N is loaded during S phase and dissociates again during G2. We propose a model in which CENP-N functions as a fidelity factor during centromeric replication and reveal that the CCAN network is considerably more dynamic than previously appreciated. | |
Keywords | Autoantigens/genetics/metabolism — Cell Cycle — Cell Line — Centromere/genetics/metabolism — Chromosomal Proteins, Non-Histone/genetics/metabolism — DNA Replication — Humans — Kinetochores/metabolism — Protein Binding | |
Identifiers | DOI: 10.1242/jcs.088625 PMID: 22100916 | |
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Citation (ISO format) | HELLWIG, Daniela et al. Dynamics of CENP-N kinetochore binding during the cell cycle. In: Journal of cell science, 2011, vol. 124, n° Pt 22, p. 3871-83. doi: 10.1242/jcs.088625 https://archive-ouverte.unige.ch/unige:25853 |