Downstream sequence elements with different affinities for the hnRNP H/H′ protein influence the processing efficiency of mammalian polyadenylation signals
Downstream sequence elements with different affinities for the hnRNP H/H′ protein influence the processing efficiency of mammalian polyadenylation signals
复制标题
DOI：
10.1093/nar/30.8.1842
复制
发表时间：
2002-04-15
影响因子：
14.9
通讯作者：
Wilusz, J
中科院分区：
文献类型：
--
作者：
Arhin, GK;Boots, M;Wilusz, J
辅助因子可能在确定哺乳动物前MRNA的聚腺苷酸化效率方面起重要作用。我们先前鉴定了一个辅助因子HNRNP H/H'，该因子通过与SV40晚期聚烯基信号的核心元素下游的序列的相互作用刺激3'-End处理。使用体外重构测定法，我们已经证明，HNRNP H/H'可以通过在相似的相对下游位置结合但具有明显不同的亲和力来刺激两个其他模型聚腺苷酸化信号的处理。将短的G残基确定为所有三个HNRNP H/H'结合位点的共同特性。对哺乳动物聚腺苷酸化信号的调查确定了在类似的下游位置的潜在富含G-富富HNRNP H/H''结合位点，类似于这些信号的34％。发现所有测试的新型G富含G的元素都结合了HNRNP H/H'蛋白，并且在体内和体外均刺激了调查中鉴定的选定信号的处理。因此，下游富含G的富含G型是哺乳动物聚腺苷酸化信号中常见的辅助元件。能够结合具有不同亲和力的HNRNP H蛋白的序列可能在确定大量哺乳动物聚腺苷酸化信号的加工效率方面起作用。
Auxiliary factors likely play an important role in determining the polyadenylation efficiency of mammalian pre-mRNAs. We previously identified an auxiliary factor, hnRNP H/H', which stimulates 3'-end processing through an interaction with sequences downstream of the core elements of the SV40 late polyadenylation signal. Using in vitro reconstitution assays we have demonstrated that hnRNP H/H' can stimulate processing of two additional model polyadenylation signals by binding at similar relative downstream locations but with significantly different affinities. A short tract of G residues was determined to be a common property of all three hnRNP H/H' binding sites. A survey of mammalian polyadenylation signals identified potential G-rich hnRNP H/H' binding sites at similar downstream locations in similar to34% of these signals. All of the novel G-rich elements tested were found to bind hnRNP H/H' protein and the processing of selected signals identified in the survey was stimulated by the protein both in vivo and in vitro. Downstream G-rich tracts, therefore, are a common auxiliary element in mammalian polyadenylation signals. Sequences capable of binding hnRNP H protein with varying affinities may play a role in determining the processing efficiency of a significant number of mammalian polyadenylation signals.