Dominant-negative cyclin-selective ubiquitin carrier protein E2-C/UbcH10 blocks cells in metaphase
Dominant-negative cyclin-selective ubiquitin carrier protein E2-C/UbcH10 blocks cells in metaphase
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DOI：
10.1073/pnas.94.6.2362
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发表时间：
1997-03-18
影响因子：
11.1
通讯作者：
Ruderman, JV
中科院分区：
文献类型：
--
作者：
Townsley, FM;Aristarkhov, A;Ruderman, JV
泛素依赖的蛋白分解是细胞完成有丝分裂并进入下一个细胞周期间期所必需的。在文蛤卵中，这一过程是由周期蛋白选择性泛素载体蛋白E2-C和环体/后期促进复合体(APC)催化的，APC是一个含有周期蛋白选择性泛素连接酶活性的20S颗粒，报道克隆了人类E2-C的同源物UbcH10，它与文蛤E2-C有61%的氨基酸同源性，在体外可以替代文蛤E2-C。显性负性的文蛤E2-C和人UbcH10蛋白，通过将催化半胱氨酸改变为丝氨酸，在体外抑制泛素化和破坏文蛤卵母细胞提取物中的周期蛋白B。当转染到哺乳动物细胞时，突变的UbcH10抑制了对周期蛋白A和B的破坏，阻止了细胞处于Hi期，并抑制了后期的开始，可能是通过阻断负责姐妹染色单体分离的蛋白质的泛素依赖的蛋白分解来实现的，因此，E2-C/UbcH10介导的泛素化参与了cdc2失活和姐妹染色单体分离过程，这两个过程在有丝分裂退出时通常是协调的。
Destruction of mitotic cyclins by ubiquitin-dependent proteolysis is required for cells to complete mitosis and enter interphase of the next cell cycle, In clam eggs, this process is catalyzed by a cyclin-selective ubiquitin carrier protein, E2-C, and the cyclosome/anaphase promoting complex (APC), a 20S particle containing cyclin-selective ubiquitin ligase activity, sere me report cloning a human homolog of E2-C, UbcH10, which shares 61% amino acid identity with clam E2-C and can substitute for clam E2-C in vitro. Dominant-negative clam E2-C and human UbcH10 proteins, created by altering the catalytic cysteine to serine, inhibit the in vitro ubiquitination and destruction of cyclin B in clam oocyte extracts, When transfected into mammalian cells, mutant UbcH10 inhibits the destruction of both cyclin A and B, arrests cells in hi phase, and inhibits the onset of anaphase, presumably by blocking the ubiquitin-dependent proteolysis of proteins responsible for sister chromatid separation, Thus, E2-C/UbcH10-mediated ubiquitination is involved in both cdc2 inactivation and sister chromatid separation, processes that are normally coordinated during exit from mitosis.