Identification of a family of closely related human ubiquitin conjugating enzymes
Identification of a family of closely related human ubiquitin conjugating enzymes
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DOI：
10.1074/jbc.270.51.30408
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发表时间：
1995-12-22
影响因子：
4.8
通讯作者：
Weissman, AM
中科院分区：
文献类型：
--
作者：
Jensen, JP;Bates, PW;Weissman, AM
两个非常密切相关的人E2泛素结合酶，UbcH5B和UbcH5C，已经确定。这些酶是不同基因的产物，氨基酸序列与最近描述的人类E2相同88-89%，UbcH5（现在称为UbcH5A）， UbcH5A- c同源于拟南芥AtUBC8-12的5个泛素偶联酶家族。它们还与酿酒酵母（Saccharomyces cerevisiae）的ScUBC4和ScUBC5密切相关，这两个基因参与应激反应，并在短寿命调节蛋白的靶向降解中发挥核心作用，编码UbcH5A-C的mrna在所有被评估的细胞系和组织中共表达，其中UbcH5C转录本通常表达水平最高，Southern blots分析表明可能存在该家族的其他相关成员。UbcH5B和UbcH5C与泛素形成巯基酯加合物，在人泛素蛋白连接酶E6-AP存在的情况下，与UbcH5A和AtUBC8在泛素与靶蛋白结合方面具有相似的活性。这些结果建立了一个高度保守和广泛表达的人泛素偶联酶家族的存在。
Two very closely related human E2 ubiquitin conjugating enzymes, UbcH5B and UbcH5C, have been iden tified. These enzymes are products of distinct genes and are 88-89% identical in amino acid sequence to the recently described human E2, UbcH5 (now designated UbcH5A), UbcH5A-C are homologous to a family of five ubiquitin conjugating enzymes from Arabidopsis thaliana, AtUBC8-12. They are also closely related to Saccharomyces cerevisiae ScUBC4 and ScUBC5, which are involved in the stress response, and play a central role in the targeting of short-lived regulatory proteins for degradation, mRNAs encoding UbcH5A-C were co-expressed in all cell lines and tissues evaluated, with UbcH5C transcripts generally expressed at the highest levels, Analysis of Southern blots suggests that there are likely to be other related members of this family, Both UbcH5B and UbcH5C form thiol ester adducts with ubiquitin, and have activities similar to UbcH5A and AtUBC8 in the conjugation of ubiquitin to target proteins in the presence of the human ubiquitin protein ligase E6-AP. These results establish the existence of a highly conserved, and widely expressed, family of human ubiquitin conjugating enzymes.