SACCHAROMYCES-CEREVISIAE 26S PROTEASE MUTANTS ARREST CELL-DIVISION IN G2/METAPHASE
SACCHAROMYCES-CEREVISIAE 26S PROTEASE MUTANTS ARREST CELL-DIVISION IN G2/METAPHASE
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DOI：
10.1038/366358a0
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发表时间：
1993-11-25
期刊：
影响因子：
64.8
通讯作者：
MANN, C
中科院分区：
文献类型：
--
作者：
GHISLAIN, M;UDVARDY, A;MANN, C
我们从酿酒酵母中分离到两个突变体，cim3-1和cim5-1，它们在37℃的温度下阻止细胞在G2/中期分裂。CIM3(与SUG1相同；参考文献1)和CIM5彼此相似，都是被认为是26S蛋白酶亚单位2的ATPase家族的成员。我们在这里证明了CIM5是人类MSS1蛋白3的功能性酵母同系物，并且CIM3和CIM5的同源物存在于高纯度的果蝇26S蛋白酶4的制备中。短命的泛素-脯氨酸-β-半乳糖苷酶融合蛋白在cim突变体中稳定，但亮氨酸-β-半乳糖苷酶不稳定。Clb2和clb3细胞周期蛋白也在cim突变体中积累。因此，26S蛋白酶在体内是泛素化底物降解和后期染色体分离所必需的。
WE isolated two mutants from the yeast Saccharomyces cerevisiae, cim3-1 and cim5-1, that arrest cell division in G2/metaphase at 37-degrees-C. CIM3 (identical to SUG1; ref. 1) and CIM5 are similar to each other and are members of a family of putative ATPases that have been proposed to be 26S protease subunits2. We show here that CIM5 is the functional yeast homologue of the human MSS1 protein3 and that homologues of CIM3 and CIM5 are present in a highly purified preparation of the Drosophila 26S protease4. The short-lived ubiquitin-proline-beta-galactosidase fusion protein is stabilized in cim mutants, but Leu-beta-galactosidase is not. The CLB2 and CLB3 cyclins also accumulate in the cim mutants. Thus the 26S protease is required in vivo for the degradation of ubiquitinated substrates and for anaphase chromosome separation.