The SRSF1 linker induces semi-conservative ESE binding by cooperating with the RRMs
The SRSF1 linker induces semi-conservative ESE binding by cooperating with the RRMs
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DOI：
10.1093/nar/gkr663
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发表时间：
2011-11-01
影响因子：
14.9
通讯作者：
Ghosh, Gourisankar
中科院分区：
文献类型：
--
作者：
Cho, Suhyung;Hoang, Amy;Ghosh, Gourisankar
SR蛋白通过识别前mRNA剪接过程中的外显子剪接增强子(ESES)促进剪接体的形成。每个SR蛋白都使用尚未阐明的策略与不同的ESES结合。在这里，我们证明了SRSF1的RNA结合域(RBD)最佳地与富含嘌呤的十聚体ESE序列结合，尽管没有严格指定嘌呤的位置。识别部位内外的尿嘧啶的存在都不利于与SRSF1的结合。整个RBD由两个RRMS和一个富含甘氨酸的连接子组成，对于ESE结合是必不可少的。每个片段内的突变减少或几乎取消了结合，表明这些片段介导了协同结合。连接子在组织ESE结合中起决定性作用。连接子两侧的碱性区域似乎相互通信，使两个RRMS靠近，形成与RNA的复合体。因此，我们的研究表明ESE和SRSF1之间存在半保守的适应性相互作用，这种结合模式不仅对于识别过多的生理ESE序列是必不可少的，而且对于剪接体组装过程中与各种因素的相互作用也可能是必不可少的。
SR proteins promote spliceosome formation by recognizing exonic splicing enhancers (ESEs) during pre-mRNA splicing. Each SR protein binds diverse ESEs using strategies that are yet to be elucidated. Here, we show that the RNA-binding domain (RBD) of SRSF1 optimally binds to decameric purine rich ESE sequences although locations of purines are not stringently specified. The presence of uracils either within or outside of the recognition site is detrimental for binding with SRSF1. The entire RBD, comprised of two RRMs and a glycine-rich linker, is essential for ESE binding. Mutation within each segment reduced or nearly abolished binding, suggesting that these segments mediate cooperative binding. The linker plays a decisive role in organizing ESE binding. The flanking basic regions of the linker appear to communicate with each other in bringing the two RRMs close together to form the complex with RNA. Our study thus suggests semi-conservative adaptable interaction between ESE and SRSF1, and such binding mode is not only essential for the recognition of plethora of physiological ESE sequences but may also be essential for the interaction with various factors during the spliceosome assembly.