Zhang Nenggang, Pati Debananda
a Texas Children's Cancer Center ; Department of Pediatric Hematology/Oncology ; Baylor College of Medicine ; Houston , TX USA.
Cell Cycle. 2015;14(6):820-6. doi: 10.1080/15384101.2014.1000206.
Sororin is a conserved protein required for accurate separation of sister chromatids in each cell cycle. Sororin is recruited to chromatin during DNA replication, protects sister chromatid cohesion in S and G2 phase, and regulates the resolution of sister chromatid cohesion in mitosis. Sororin binds to cohesin complex, but how Sororin and cohesin subunits interact remains unclear. Here we report that the C-terminus of Sororin, especially the last 12 amino acid (aa) residues, is important for Sororin to bind cohesin core subunit SA2. Deletion of the last 12aa residues not only inhibits the interactions between Sororin and SA2 but also causes precocious chromosome separation. Our data suggest that the C-terminus of Sororin functions as an anchor binding to SA2, which facilitates other conserved motifs on Sororin to interact with other proteins to regulate sister chromatid cohesion and separation.
Sororin是一种保守蛋白，在每个细胞周期中姐妹染色单体的精确分离都需要它。在DNA复制过程中，Sororin被招募到染色质上，在S期和G2期保护姐妹染色单体的黏连，并在有丝分裂中调节姐妹染色单体黏连的解离。Sororin与黏连蛋白复合体结合，但Sororin与黏连蛋白亚基如何相互作用仍不清楚。在此我们报告，Sororin的C末端，尤其是最后12个氨基酸（aa）残基，对于Sororin结合黏连蛋白核心亚基SA2很重要。删除最后12个aa残基不仅会抑制Sororin与SA2之间的相互作用，还会导致染色体过早分离。我们的数据表明，Sororin的C末端作为与SA2结合的锚定物，促进Sororin上的其他保守基序与其他蛋白质相互作用，从而调节姐妹染色单体的黏连和解离。
