Purification and cloning of type A/B hnRNP proteins involved in transcriptional activation from the rat spi 2 gene GAGA box
Purification and cloning of type A/B hnRNP proteins involved in transcriptional activation from the rat spi 2 gene GAGA box
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DOI：
10.1515/bc.2000.127
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发表时间：
2000-11-01
影响因子：
3.7
通讯作者：
Legraverend, C
中科院分区：
文献类型：
--
作者：
Leverrier, S;Cinato, E;Legraverend, C
大鼠丝氨酸蛋白酶抑制因子2(SPI2)基因的GagA盒不仅是一个基本的启动子元件，而且还介导了生长激素和白介素6的转录激活。Gaga盒与TATA盒之间只有12bp的距离，这种紧密的结合是高效转录所必需的。因此，GagA盒可能通过GagA盒结合蛋白与RNA聚合酶II复合体的某些成分之间的相互作用而影响转录效率。在这里，我们报道了两个GagA盒结合蛋白p38和p40的克隆，这两个蛋白属于A/B异质性核糖核蛋白亚群。GagA盒突变降低了对p38和p40的亲和力，降低了基础和GH诱导的报告基因的表达。此外，p38和p40缺失的核提取液不再支持GagA盒依赖的体外转录。因此，先前分配给RNA加工蛋白家族的两个多肽也可以作为DNA结合的启动子特异性转录因子。
The GAGA box of the rat serine protease inhibitor 2 (spi 2) genes not only acts as a basal promoter element, but also mediates transcriptional activation by growth hormone and interleukin-6. The GAGA box is separated from the TATA box by only 12 bp, and this close association is required for efficient transcription. Hence, the GAGA box may influence transcription efficiency through interactions between GAGA box binding proteins and some components of the RNA polymerase II complex. Here we report the cloning of two GAGA box-binding proteins termed p38 and p40, that belong to the type A/B heterogeneous nuclear ribonucleoprotein subgroup. GAGA box mutations that diminish the affinity for p38 and p40 decrease basal and GH-induced reporter gene expression. Furthermore, nuclear extracts depleted of p38 and p40 can no longer support GAGA box-dependent in vitro transcription. Therefore, two polypeptides previously assigned to a family of RNA processing proteins also act as DNA-binding, promoter-specific transcription factors.