A B-CELL COACTIVATOR OF OCTAMER-BINDING TRANSCRIPTION FACTORS
A B-CELL COACTIVATOR OF OCTAMER-BINDING TRANSCRIPTION FACTORS
复制标题
DOI：
10.1038/373360a0
复制
发表时间：
1995-01-26
期刊：
影响因子：
64.8
通讯作者：
HOVENS, CM
中科院分区：
文献类型：
--
作者：
GSTAIGER, M;KNOEPFEL, L;HOVENS, CM
矛盾的是，八聚体基序 (ATGCAAAT) 在介导 B 细胞特异性和普遍存在的启动子的活性中发挥着核心作用。人们普遍认为主要是淋巴限制性八聚体结合因子 Oct-2 介导组织特异性启动子活性，而普遍表达的 Oct-1 介导一般启动子活性，但这一观点受到了挑战 (1-6)。在这里，我们使用改良的酵母单杂交测定来分离 B 细胞因子 Bob1，它与 Oct-2 或 Oct-1 相关。在转染实验中，该因子可增强 Oct-1 介导的启动子活性，并在较小程度上增强 Oct-2 的启动子活性。这种共激活严格依赖于与 Oct-1 或 Oct-2 的特异性相互作用，因为八聚体基序的删除会消除共激活。我们得出结论，Bob1 可能代表一种新的组织特异性转录共激活因子，它可以将普遍表达的转录因子转化为细胞类型特异性激活因子。
THE octamer motif (ATGCAAAT) paradoxically plays a central role in mediating the activity of both B-cell specific and ubiquitous promoters. It has been widely assumed that the predominantly lymphoid-restricted octamer-binding factor Oct-2 mediates tissue-specific promoter activity, whereas the ubiquitously expressed Oct-1 mediates general promoter activity, but this view has been challenged(1-6). Here we use a modified yeast one-hybrid assay to isolate a B-cell factor, Bob1, which associates with either Oct-2 or Oct-1. In transfection experiments, this factor boosts Oct-1-mediated promoter activity and to a lesser extent, that of Oct-2. This coactivation is strictly dependent on the specific interaction with Oct-1 or Oct-2 because deletion of the octamer motif abolishes coactivation. We conclude that Bob1 could represent a new tissue-specific transcriptional coactivator which may convert a ubiquitously expressed transcription factor to a cell-type-specific activator.