14-3-3 ADAPTOR PROTEINS RECRUIT AID TO 5'-AGCT-3'-RICH SWITCH REGIONS

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 类别转换DNA重组（CSR）是使抗体的生物效应子功能多样化的机制。激活诱导的胞苷脱氨酶（AID）是CSR中的关键蛋白，靶向免疫球蛋白H（IgH）开关区，其核心含有5 '-AGCT-3'重复序列。目前还不清楚如何招募国际开发署人员来转移地区。在这里，我们表明14-3-3衔接蛋白在CSR中具有重要作用。14-3-3蛋白特异性结合5 '-AGCT-3'重复序列，在经历CSR的B细胞中上调，并且用AID募集到参与CSR事件的开关区域（Smu-> Sgamma 1、Smu-> Sgamma 3或Smu->Salpha）。此外，通过difopein阻断14-3-3、14-3-3gamma缺陷或显性阴性14-3-3sigma突变体的表达会损害AID向转换区域的募集并降低CSR。最后，14-3-3蛋白直接与AID相互作用，并增强AID介导的体外DNA脱氨基作用，进一步强调了这些衔接子在CSR中的重要作用。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Class switch DNA recombination (CSR) is the mechanism that diversifies the biological effector functions of antibodies. Activation-induced cytidine deaminase (AID), a key protein in CSR, targets immunoglobulin H (IgH) switch regions, which contain 5'-AGCT-3' repeats in their core. How AID is recruited to switch regions remains unclear. Here we show that 14-3-3 adaptor proteins have an important role in CSR. 14-3-3 proteins specifically bound 5'-AGCT-3' repeats, were upregulated in B cells undergoing CSR and were recruited with AID to the switch regions that are involved in CSR events (Smu-->Sgamma1, Smu-->Sgamma3 or Smu-->Salpha). Moreover, blocking 14-3-3 by difopein, 14-3-3gamma deficiency or expression of a dominant-negative 14-3-3sigma mutant impaired recruitment of AID to switch regions and decreased CSR. Finally, 14-3-3 proteins interacted directly with AID and enhanced AID-mediated in vitro DNA deamination, further emphasizing the important role of these adaptors in CSR.