Investigating the function and regulation of UbcH10-APC/C

后期促进复合物/环小体（APC/C）是一种E3泛素连接酶，通过靶向蛋白质底物进行多泛素化和26S蛋白酶体介导的降解，通过有丝分裂和细胞周期的连续G1期协调细胞的进程。当e2 -泛素偶联酶UbcH10和Ube2S存在时，APC/C E3连接酶的活性通过两种相关激活蛋白（Cdc20或Cdh1）中的一种暂时协调募集到APC/C上而受到刺激；Cdc20和Cdh1也与特定的APC/C亚基结合底物。我们实验室先前发表的工作已经确定APC/C的泛素连接酶活性是由转录共激活剂CBP和p300调节的。我们还确定DNA损伤反应和支架蛋白MDC1通过促进Cdc20与APC/C的结合来调节有丝分裂过程中APC/C-Cdc20的活性，而转录抑制因子TIF1y也调节有丝分裂过程中APC/C-Cdc20的活性。我们还确定DDR蛋白53BP1既是APC/C的抑制剂，也是底物，并调节有丝分裂的进入和进展。为了进一步了解APC/C功能，我们最近表征了APC/C e2偶联酶UbcH10的相互作用。目前的项目将研究ubch10相互作用蛋白调节UbcH10-APC/C活性和功能的能力。

The Anaphase-Promoting Complex/Cyclosome (APC/C) is an E3 ubiquitin ligase that, through targeting protein substrates for polyubiquitylation and 26S proteasome-mediated degradation coordinates the progression of cells through mitosis and the successive G1 phase of the cell-cycle. APC/C E3 ligase activity is stimulated, in the presence of the E2-ubiquitin conjugating enzymes UbcH10 and Ube2S, by the temporally coordinated recruitment of one of two related activator proteins, Cdc20 or Cdh1, to the APC/C; Cdc20 and Cdh1 also serve in conjunction with particular APC/C subunits to bind substrates. Published work from our laboratory has previously determined that the ubiquitin ligase activity of the APC/C is regulated by the transcriptional co-activators CBP and p300. We have also determined that the DNA damage response, and scaffold protein, MDC1 regulates APC/C-Cdc20 activity during mitosis by promoting Cdc20 association with the APC/C, whilst the transcriptional repressor, TIF1y, also regulates APC/C-Cdc20 activity in mitosis. We have also established that the DDR protein, 53BP1, is both an inhibitor, and substrate of the APC/C, and regulates entry into, and progression through, mitosis. To further our understanding of APC/C function we have recently characterized the interactome of the APC/C E2-conjugating enzyme, UbcH10. The current project will investigate the ability of UbcH10-interacting proteins to modulate UbcH10-APC/C activity and function.