Function of E-protein dimers expressed in catfish lymphocytes.
Function of E-protein dimers expressed in catfish lymphocytes.
复制标题
鲶鱼淋巴细胞中表达的E蛋白二聚体的功能。
DOI：
10.1016/j.molimm.2007.08.001
复制
发表时间：
2008
影响因子：
3.6
通讯作者：
Warr,GregoryW
中科院分区：
文献类型：
--
作者：
Hikima,Jun-ichi;LennardRichard,MaraL;Wilson,MelanieR;Miller,NormanW;Warr,GregoryW
E蛋白是在淋巴细胞发育中起作用的必需I类bHLH转录因子。在鲶鱼淋巴细胞中，主要表达的E蛋白是CFEB（HEB的同源物）和E2 A1，它们都强烈驱动转录。在这项研究中，同源二聚体与异源二聚体在这些鲶鱼的E-蛋白的功能的作用，通过使用编码强制二聚体的表达构建体来解决。将表达同源和异源二聚体的构建体转染到鲶鱼B细胞中，并显示其驱动鲶鱼IGH增强子的转录。从含有μE5基序三聚体的人工启动子的表达清楚地表明，在鲶鱼B和T细胞中，E2 A1的同源二聚体比CFEB同源二聚体更强烈地驱动转录（10-25倍），而异源二聚体显示出中等水平的转录激活。CFEB 1和E2 A1蛋白在体外均发生二聚化，异源二聚体CFEB 1-E2 A1显示结合典型的μE5基序。
E-proteins are essential class I bHLH transcription factors that play a role in lymphocyte development. In catfish lymphocytes the predominant E-proteins expressed are CFEB (a homologue of HEB) and E2A1, which both strongly drive transcription. In this study the role of homodimerization versus heterodimerization in the function of these catfish E-proteins was addressed through the use of expression constructs encoding forced dimers. Constructs expressing homo- and heterodimers were transfected into catfish B cells and shown to drive transcription from the catfish IGH enhancer. Expression from an artificial promoter containing a trimer of μE5 motifs clearly demonstrated that the homodimer of E2A1 drove transcription more strongly (by a factor of 10–25) than the CFEB homodimer in catfish B and T cells, while the heterodimer showed intermediate levels of transcriptional activation. Both CFEB1 and E2A1 proteins dimerized in vitro, and the heterodimer CFEB1–E2A1 was shown to bind the canonical μE5 motif.