Voliva C F, Aronheim A, Walker M D, Peterlin B M
Howard Hughes Medical Institute, University of California, San Francisco 94143-0724.
Mol Cell Biol. 1992 May;12(5):2383-90. doi: 10.1128/mcb.12.5.2383-2390.1992.
The X box in the DRA promoter of the human histocompatibility complex is required for expression of the DRA gene in B cells. We show that a B-cell factor binds to a sequence that is clearly distinguishable from binding sites for the previously described X box binding nuclear proteins RF-X, NF-X, NF-Xc, NF-S, hXBP, and AP-1. Mutations in the DRA X box that disrupt the binding of this factor result in a lower level of gene expression, as does the presence of Id (a trans-dominant regulatory protein that negatively regulates helix-loop-helix proteins). Furthermore, this factor is recognized by antibodies directed against the helix-loop-helix protein A1, a mouse homolog of the immunoglobulin enhancer binding proteins E12/E47, and it binds to sequences in other genes that were previously shown to bind these proteins. By these criteria, this factor is BCF-1.
人类组织相容性复合体DRA启动子中的X盒是DRA基因在B细胞中表达所必需的。我们发现一种B细胞因子能与一个序列结合，该序列与先前描述的X盒结合核蛋白RF-X、NF-X、NF-Xc、NF-S、hXBP和AP-1的结合位点明显不同。DRA X盒中破坏该因子结合的突变会导致基因表达水平降低，Id（一种对螺旋-环-螺旋蛋白起负调控作用的反式显性调节蛋白）的存在也会导致这种情况。此外，该因子能被针对螺旋-环-螺旋蛋白A1的抗体识别，A1是免疫球蛋白增强子结合蛋白E12/E47的小鼠同源物，并且它能与先前显示可结合这些蛋白的其他基因中的序列结合。根据这些标准，该因子为BCF-1。
