Active establishment of centromeric CENP-A chromatin by RSF complex

Abstract

Centromeres are chromosomal structures required for equal DNA segregation to daughter cells, comprising specialized nucleosomes containing centromere protein A (CENP-A) histone, which provide the basis for centromeric chromatin assembly. Discovery of centromere protein components is progressing, but knowledge related to their establishment and maintenance remains limited. Previously, using anti-CENP-A native chromatin immunoprecipitation, we isolated the interphase–centromere complex (ICEN). Among ICEN components, subunits of the remodeling and spacing factor (RSF) complex, Rsf-1 and SNF2h proteins, were found. This paper describes the relationship of the RSF complex to centromere structure and function, demonstrating its requirement for maintenance of CENP-A at the centromeric core chromatin in HeLa cells. The RSF complex interacted with CENP-A chromatin in mid-G1. Rsf-1 depletion induced loss of centromeric CENP-A, and purified RSF complex reconstituted and spaced CENP-A nucleosomes in vitro. From these data, we propose the RSF complex as a new factor actively supporting the assembly of CENP-A chromatin.

Detrimental incorporation of excess Cenp-A/Cid and Cenp-C intoDrosophilacentromeres is prevented by limiting amounts of the bridging factor Cal1

“…The number of factors shown to be required for normal CenH3 deposition is increasing rapidly, which suggests that there is an intricate control mechanism. Various and often dedicated chaperones (Hayashi et al, 2004;Furuyama et al, 2006;Dunleavy et al, 2009;Foltz et al, 2009), chromatin modifying and remodelling factors (Fujita et al, 2007;Maddox et al, 2007;Perpelescu et al, 2009), as well as other centromere components (Takahashi et al, 2000;Okada et al, 2006;Pidoux et al, 2009;Williams et al, 2009) are involved.…”

The Centromere: Epigenetic Control of Chromosome Segregation during Mitosis

“…MgcRacGAP is also known to have important roles in cell proliferation through regulation of cytokinesis, as a member of the centralspindlin complex (White and Glotzer 2012). In addition to MgcRacGAP, subunits of the RSF complex (remodeling and spacing factor), which regulates canonical histone modification, have also been implicated in CENP-A chromatin stabilization (Obuse et al 2004;Izuta et al 2006;Perpelescu et al 2009). …”

Regulation of ISWI chromatin remodelling activity

“…Histone variants ISWI chromatin remodelling reactions can be influenced not only by covalent modifications of histones, but also by their non-allelic isoforms, named histone variants (Konev et al 2007;Mizuguchi et al 2004;Okada et al 2009;Perpelescu et al 2009). To date, the majority of histone variants acting as regulators of chromatin remodellers are members of H2A family.…”