Adams B S, Leung K Y, Hanley E W, Nabel G J
Howard Hughes Medical Institute, University of Michigan Medical Center, Department of Internal Medicine, Ann Arbor 48109-0650.
New Biol. 1991 Nov;3(11):1063-73.
Transcriptional activation of the interleukin-2 receptor alpha (IL-2R alpha) gene in T cells is dependent on a regulatory element that can bind NF-kappa B but differs in sequence and function from the kappa B site of the immunoglobulin (Ig) enhancer. To define the molecular basis of gene-specific regulation by this variant kappa B site, we have used electrophoretic mobility shift assays to characterize a novel gene product, designated R kappa B, that binds preferentially to the related kappa B site in IL-2R alpha. A cDNA encoding this 107-kD protein has been isolated from a lambda gt11 expression library by screening with a probe containing the IL-2R alpha kappa B site. R kappa B is a tissue-specific transcription factor that contains an amino acid sequence similar to a discrete region of the myogenic regulatory protein MyoD, but is unrelated to other DNA-binding proteins, including those belonging to the rel/dorsal gene family. This novel kappa B binding protein may therefore contribute to the regulation of distinct cellular and viral genes with variant kappa B sites.
T细胞中白细胞介素2受体α（IL-2Rα）基因的转录激活依赖于一个能结合NF-κB的调控元件，但其序列和功能与免疫球蛋白（Ig）增强子的κB位点不同。为了确定这种变异κB位点进行基因特异性调控的分子基础，我们利用电泳迁移率变动分析来鉴定一种新的基因产物，命名为RκB，它优先结合IL-2Rα中相关的κB位点。通过用含有IL-2Rα κB位点的探针筛选λgt11表达文库，已分离出编码这种107-kD蛋白的cDNA。RκB是一种组织特异性转录因子，其氨基酸序列与成肌调节蛋白MyoD的一个离散区域相似，但与其他DNA结合蛋白无关，包括那些属于rel/背侧基因家族的蛋白。因此，这种新的κB结合蛋白可能有助于调控具有变异κB位点的不同细胞和病毒基因。
