RBMX is a component of the centromere noncoding RNP complex involved in cohesion regulation

Satellite I RNA, a noncoding (nc)RNA transcribed from repetitive regions in human centromeres, binds to Aurora kinase B and forms a ncRNP complex required for chromosome segregation. To examine its function in this process, we purified satellite I ncRNP complex from nuclear extracts prepared from asynchronized or mitotic (M) phase‐arrested HeLa cells and then carried out LC/MS to identify proteins bound to satellite I RNA. RBMX (RNA‐binding motif protein, X‐linked), which was isolated from M phase‐arrested cells, was selected for further characterization. We found that RBMX associates with satellite I RNA only during M phase. Knockdown of RBMX induced premature separation of sister chromatid cohesion and abnormal nuclear division. Likewise, knockdown of satellite I RNA also caused premature separation of sister chromatids during M phase. The amounts of RBMX and Sororin, a cohesion regulator, were reduced in satellite I RNA‐depleted cells. These results suggest that satellite I RNA plays a role in stabilizing RBMX and Sororin in the ncRNP complex to maintain proper sister chromatid cohesion.

We found that RBMX (RNA‐binding motif protein, X‐linked) associates with satellite I noncoding RNA transcribed from human centromeres to form the ncRNP complex. Our results suggest that satellite I ncRNA plays a role in stabilizing RBMX and Sororin in the ncRNP complex to maintain proper sister chromatid cohesion.

Source: Genes to Cells - January 1, 2018 Category: Genetics & Stem Cells Authors: Yukiko Cho, Takashi Ideue, Megumi Nagayama, Norie Araki, Tokio Tani Tags: ORIGINAL ARTICLE Source Type: research