H2B ubiquitylation enhances H3K4 methylation activities of human KMT2 family complexes
H2B ubiquitylation enhances H3K4 methylation activities of human KMT2 family complexes
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DOI：
10.1093/nar/gkaa317
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发表时间：
2020-06-04
影响因子：
14.9
通讯作者：
Kim, Jaehoon
中科院分区：
文献类型：
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作者：
Kwon, Minjung;Park, Kihyun;Kim, Jaehoon
在哺乳动物细胞中，不同的H3K4甲基化状态是由多个组蛋白赖氨酸甲基转移酶2 （KMT2）家族蛋白复合物的甲基沉积而产生的。为了进行全面的分析，直接比较所有六种人类KMT2复合物的催化性能，我们采用了一个生物化学定义的系统，该系统由重组KMT2核心复合物（KMT2(core)Cs）重组，其中包含核小体H3K4甲基化活性所需的最小组分。我们发现每个KMT2(Core)C产生不同的状态和不同水平的H3K4甲基化，除了MLL3外，都受到H2Bub的刺激。值得注意的是，SET1B(Core)C表现出最强的H3K4甲基化活性，令我们惊讶的是，它不需要H2B泛素化（H2Bub）；相比之下，H2Bub是平行序列SET1A(Core)C的H3K4me2/3活性所必需的。我们还发现WDR5、RbBP5、ASH2L和DPY30是除MLL3外所有KMT2(Core)Cs高效的H3K4甲基转移酶活性所必需的，MLL3可以在缺乏WDR5的情况下产生H3K4me1。重要的是，在H2Bub存在的情况下，CFP1的PHD2结构域的缺失导致SET1A/(bc)-Cs-Core的H3K4me2/3活性完全丧失，这表明该结构域在H2Bub刺激的H3K4甲基化中起着关键作用。总的来说，我们的研究结果表明，每个KMT2复合物通过不同的机制甲基化H3K4，其中单个亚基不同地参与。
In mammalian cells, distinct H3K4 methylation states are created by deposition of methyl groups by multiple complexes of histone lysine methyltransferase 2 (KMT2) family proteins. For comprehensive analyses that directly compare the catalytic properties of all six human KMT2 complexes, we employed a biochemically defined system reconstituted with recombinant KMT2 core complexes (KMT2(Core)Cs) containing minimal components required for nucleosomal H3K4 methylation activity. We found that each KMT2(Core)C generates distinct states and different levels of H3K4 methylation, and except for MLL3 all are stimulated by H2Bub. Notably, SET1B(Core)C exhibited the strongest H3K4 methylation activity and, to our surprise, did not require H2B ubiquitylation (H2Bub); in contrast, H2Bub was required for the H3K4me2/3 activity of the paralog SET1A(Core)C. We also found that WDR5, RbBP5, ASH2L and DPY30 are required for efficient H3K4 methyltransferase activities of all KMT2(Core)Cs except MLL3, which could produce H3K4me1 in the absence of WDR5. Importantly, deletion of the PHD2 domain of CFP1 led to complete loss of the H3K4me2/3 activities of SET1A/(BCs)-Cs-Core in the presence of H2Bub, indicating a critical role for this domain in the H2Bub-stimulated H3K4 methylation. Collectively, our results suggest that each KMT2 complex methylates H3K4 through distinct mechanisms in which individual subunits differentially participate.