Multiple DSB Resection Activities Redundantly Promote Alternative End Joining-Mediated Class Switch Recombination.
Multiple DSB Resection Activities Redundantly Promote Alternative End Joining-Mediated Class Switch Recombination.
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多个 DSB 切除活动冗余地促进替代末端连接介导的类别转换重组
DOI：
10.3389/fcell.2021.767624
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发表时间：
2021
影响因子：
5.5
通讯作者：
Dong J
中科院分区：
文献类型：
--
作者：
Sun X;Bai J;Xu J;Xi X;Gu M;Zhu C;Xue H;Chen C;Dong J
选择性末端连接（A-EJ）在缺乏经典非同源末端连接的B细胞中催化实质水平的抗体类别转换重组（CSR），其特征在于增加的转换（S）区域DSB切除和连接微同源性（MH）。虽然已经提出切除在使用工程化核酸内切酶的模型DSB修复系统中启动A-EJ，但切除因子对A-EJ介导的CSR的贡献仍不清楚。在这项研究中，我们系统地剖析了在A-EJ介导的类转换与基于细胞的测定系统和高通量测序的个别DSB切除因子的要求。我们发现，虽然CtIP和Mre 11都是轻微需要的野生型细胞中的CSR，他们在介导A-EJ CSR，这取决于Mre 11的核酸外切酶活性发挥更关键的作用。虽然DNA 2和BLM的解旋酶/HRDC结构域通过介导长S区DSB切除而为A-EJ所需，但相比之下，Exo 1的切除相关功能对于c-NHEJ或A-EJ细胞中的类别转换不起任何明显作用，或者通过连接Cas9断裂以不依赖于AIDS的方式介导。此外，ATM及其激酶活性的功能至少部分独立于CtIP/Mre 11介导Lig 4缺陷细胞中的A-EJ转换。与Lig 4缺陷形成鲜明对比的是，53 BP 1缺陷细胞不依赖于ATM/Mre 11/CtIP进行残余连接。我们讨论了A-EJ介导的CSR中每个切除因子的作用，并建议切除的要求程度是上下文相关的。
Alternative end joining (A-EJ) catalyzes substantial level of antibody class switch recombination (CSR) in B cells deficient for classical non-homologous end joining, featuring increased switch (S) region DSB resection and junctional microhomology (MH). While resection has been suggested to initiate A-EJ in model DSB repair systems using engineered endonucleases, the contribution of resection factors to A-EJ-mediated CSR remains unclear. In this study, we systematically dissected the requirement for individual DSB resection factors in A-EJ-mediated class switching with a cell-based assay system and high-throughput sequencing. We show that while CtIP and Mre11 both are mildly required for CSR in WT cells, they play more critical roles in mediating A-EJ CSR, which depend on the exonuclease activity of Mre11. While DNA2 and the helicase/HRDC domain of BLM are required for A-EJ by mediating long S region DSB resection, in contrast, Exo1’s resection-related function does not play any obvious roles for class switching in either c-NHEJ or A-EJ cells, or mediated in an AID-independent manner by joining of Cas9 breaks. Furthermore, ATM and its kinase activity functions at least in part independent of CtIP/Mre11 to mediate A-EJ switching in Lig4-deficient cells. In stark contrast to Lig4 deficiency, 53BP1-deficient cells do not depend on ATM/Mre11/CtIP for residual joining. We discuss the roles for each resection factor in A-EJ-mediated CSR and suggest that the extent of requirements for resection is context dependent.
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影响因子：
16.8
作者：
Andres, Sara N.;Appel, C. Denise;Westmoreland, James W.;Williams, Jessica S.;Nguyen, Yvonne;Robertson, Patrick D.;Resnick, Michael A.;Williams, R. Scott
通讯作者：
Williams, R. Scott
影响因子：
64.5
作者：
Buis J;Wu Y;Deng Y;Leddon J;Westfield G;Eckersdorff M;Sekiguchi JM;Chang S;Ferguson DO
通讯作者：
Ferguson DO
影响因子：
16
作者：
Callen, Elsa;Jankovic, Mila;Wong, Nancy;Zha, Shan;Chen, Hua-Tang;Difilippantonio, Simone;Di Virgilio, Michela;Heidkamp, Gordon;Alt, Frederick W.;Nussenzweig, Andre;Nussenzweig, Michel
通讯作者：
Nussenzweig, Michel
DOI：
10.1073/pnas.0915067107
发表时间：
2010-02-16
影响因子：
11.1
作者：
Boboila, Cristian;Jankovic, Mila;Alt, Frederick W.
通讯作者：
Alt, Frederick W.
影响因子：
16
作者：
Bothmer A;Robbiani DF;Di Virgilio M;Bunting SF;Klein IA;Feldhahn N;Barlow J;Chen HT;Bosque D;Callen E;Nussenzweig A;Nussenzweig MC
通讯作者：
Nussenzweig MC