Townsley F M, Ruderman J V
Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
Yeast. 1998 Jun 15;14(8):747-57. doi: 10.1002/(SICI)1097-0061(19980615)14:8<747::AID-YEA271>3.0.CO;2-T.
UBC11 is the Saccharomyces cerevisiae gene that is most similar in sequence to E2-C, a ubiquitin carrier protein required for the destruction of mitotic cyclins and proteins that maintain sister chromatid cohesion in animal cells and in Schizosaccharomyces pombe. We have disrupted the UBC11 gene and found it is not essential for yeast cell viability even when combined with deletion of UBC4, a gene that has also been implicated in mitotic cyclin destruction. Ubc11p does not ubiquitinate cyclin B in clam cell-free extracts in vitro and the destruction of Clb2p is not impaired in extracts prepared from delta ubc11 or delta ubc4 delta ubc11 cells. These results suggest Ubc4p and Ubc11p together are not essential for mitotic cyclin destruction in S. cerevisiae and we can find no evidence to suggest that Ubc11p is the true functional homologue of E2-C.
UBC11是酿酒酵母中与E2-C序列最为相似的基因，E2-C是一种泛素载体蛋白，在动物细胞和粟酒裂殖酵母中，它是破坏有丝分裂周期蛋白以及维持姐妹染色单体黏连的蛋白质所必需的。我们破坏了UBC11基因，发现即使与UBC4基因（该基因也与有丝分裂周期蛋白的破坏有关）的缺失相结合，它对于酵母细胞的生存能力也不是必需的。在蛤无细胞提取物中，Ubc11p在体外不会使周期蛋白B泛素化，并且在从Δubc11或Δubc4Δubc11细胞制备的提取物中，Clb2p的破坏也没有受到损害。这些结果表明，Ubc4p和Ubc11p共同对于酿酒酵母中有丝分裂周期蛋白的破坏不是必需的，并且我们找不到证据表明Ubc11p是E2-C的真正功能同源物。
