MARCH5 requires MTCH2 to coordinate proteasomal turnover of the MCL1:NOXA complex
MARCH5 requires MTCH2 to coordinate proteasomal turnover of the MCL1:NOXA complex
复制标题
DOI：
10.1038/s41418-020-0517-0
复制
发表时间：
2020-02-24
影响因子：
12.4
通讯作者：
van Delft, Mark F.
中科院分区：
文献类型：
--
作者：
Djajawi, Tirta Mario;Liu, Lei;van Delft, Mark F.
MCL 1是BCL 2的相对分子，对许多细胞的存活至关重要。它的营业额往往是严格控制通过泛素依赖性和非依赖性的蛋白酶体降解机制。已知几种细胞应激信号，包括DNA损伤和细胞周期停滞，引起不同的E3连接酶泛素化和降解MCL 1。另一个驱动MCL 1降解的触发因素是NOXA的参与，NOXA是其唯一的BH 3蛋白配体之一，但负责的机制仍不清楚。从无偏见的全基因组CRISPR-Cas9筛选中，我们发现泛素E3连接酶MARCH 5，泛素E2缀合酶UBE 2K和线粒体外膜蛋白MTCH 2合作标记MCL 1被蛋白酶体降解-特异性地当MCL 1被NOXA接合时。这种降解机制也需要MCL 1跨膜结构域和不同的MCL 1赖氨酸残基进行，这表明这些组分可能通过在线粒体外膜内以特定方向与MCL 1：NOXA复合物结合而作用于MCL 1：NOXA复合物。MTCH 2以前没有被报道调节蛋白质稳定性，但已知影响某些关键凋亡调节因子的线粒体定位并影响代谢。我们现在已经确定了MTCH 2在MARCH 5之前在MCL 1：NOXA复合物的周转中的重要但以前未被重视的作用，进一步加强了其与BCL 2调节的细胞凋亡的联系。
MCL1, a BCL2 relative, is critical for the survival of many cells. Its turnover is often tightly controlled through both ubiquitin-dependent and -independent mechanisms of proteasomal degradation. Several cell stress signals, including DNA damage and cell cycle arrest, are known to elicit distinct E3 ligases to ubiquitinate and degrade MCL1. Another trigger that drives MCL1 degradation is engagement by NOXA, one of its BH3-only protein ligands, but the mechanism responsible has remained unclear. From an unbiased genome-wide CRISPR-Cas9 screen, we discovered that the ubiquitin E3 ligase MARCH5, the ubiquitin E2 conjugating enzyme UBE2K, and the mitochondrial outer membrane protein MTCH2 co-operate to mark MCL1 for degradation by the proteasome-specifically when MCL1 is engaged by NOXA. This mechanism of degradation also required the MCL1 transmembrane domain and distinct MCL1 lysine residues to proceed, suggesting that the components likely act on the MCL1:NOXA complex by associating with it in a specific orientation within the mitochondrial outer membrane. MTCH2 has not previously been reported to regulate protein stability, but is known to influence the mitochondrial localization of certain key apoptosis regulators and to impact metabolism. We have now pinpointed an essential but previously unappreciated role for MTCH2 in turnover of the MCL1:NOXA complex by MARCH5, further strengthening its links to BCL2-regulated apoptosis.