ASURA (PHB2) Interacts with Scc1 through Chromatin

Abstract

Sister chromatid cohesion mediated by the cohesin complex is essential for faithful chromosome segregation. Previously we reported that PHB2 (prohibitin2/ASURA), a multifunctional protein, has a role in sister chromatid cohesion. Nevertheless, how ASURA is involved in sister chromatid cohesion still remains unclear. The present co-immunoprecipitation analysis reveals that ASURA interacts with cohesin subunit Scc1 in vivo. We show that ASURA associates with chromatin in a similar manner as Scc1 throughout the cell cycle. Furthermore, our observation using the Fucci (fluorescent ubiquitination-based cell cycle indicator) system indicates that ASURA is important for cohesin maintenance at early mitosis. We have also identified that the conserved PHB domain is responsible for chromatin targeting of ASURA. Our results suggest that the regulation of sister chromatid cohesion is mediated by ASURA binding to chromatin, where ASURA might be involved in cohesin protection through ASURA-Scc1 interactions.

Prohibitin 2 localizes in nucleolus to regulate ribosomal RNA transcription and facilitate cell proliferation in RD cells

“…Furthermore, we observed that upon PHB2 silencing, RD cells showed a stable tendency of cell cycle G1 phase arrest. These results are consistent with the study by Equilibrina et al ., which demonstrated that PHB2 was required for G1/S progression since the number of cells undergoing extended G1 phase increased significantly under the PHB2 knockdown condition 33 . We also found that PHB2 silencing could induce apoptosis in a small proportion of RD cells.…”