Hauf S, Waizenegger I C, Peters J M
Research Institute of Molecular Pathology (IMP), Dr.-Bohr Gasse 7, A-1030 Vienna, Austria.
Science. 2001 Aug 17;293(5533):1320-3. doi: 10.1126/science.1061376.
Cell division depends on the separation of sister chromatids in anaphase. In yeast, sister separation is initiated by cleavage of cohesin by the protease separase. In vertebrates, most cohesin is removed from chromosome arms by a cleavage-independent mechanism. Only residual amounts of cohesin are cleaved at the onset of anaphase, coinciding with its disappearance from centromeres. We have identified two separase cleavage sites in the human cohesin subunit SCC1 and have conditionally expressed noncleavable SCC1 mutants in human cells. Our results indicate that cohesin cleavage by separase is essential for sister chromatid separation and for the completion of cytokinesis.
细胞分裂依赖于后期姐妹染色单体的分离。在酵母中，姐妹染色单体的分离是由蛋白酶分离酶切割黏连蛋白引发的。在脊椎动物中，大多数黏连蛋白通过一种不依赖切割的机制从染色体臂上被移除。只有残余量的黏连蛋白在后期开始时被切割，这与它从着丝粒上消失同时发生。我们在人类黏连蛋白亚基SCC1中鉴定出了两个分离酶切割位点，并在人类细胞中条件性地表达了不可切割的SCC1突变体。我们的结果表明，分离酶对黏连蛋白的切割对于姐妹染色单体的分离以及胞质分裂的完成至关重要。
