Splicing modulators act at the branch point adenosine binding pocket defined by the PHF5A-SF3b complex.
Splicing modulators act at the branch point adenosine binding pocket defined by the PHF5A-SF3b complex.
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DOI：
10.1038/ncomms15522
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发表时间：
2017-05-25
影响因子：
16.6
通讯作者：
Zhu P
中科院分区：
文献类型：
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作者：
Teng T;Tsai JH;Puyang X;Seiler M;Peng S;Prajapati S;Aird D;Buonamici S;Caleb B;Chan B;Corson L;Feala J;Fekkes P;Gerard B;Karr C;Korpal M;Liu X;T Lowe J;Mizui Y;Palacino J;Park E;Smith PG;Subramanian V;Wu ZJ;Zou J;Yu L;Chicas A;Warmuth M;Larsen N;Zhu P
Pladienolide、herboxidiene和spliceostatatin已被鉴定为针对SF3b亚复合物中SF3B1的剪接调节剂。在这里，我们报道了该亚复合物的另一个成分PHF5A也被这些化合物靶向。PHF5A-Y36、SF3B1-K1071、SF3B1-R1074和SF3B1-V1078的突变赋予了对这些调节剂的抗性，表明存在共同的相互作用位点。RNA-seq分析显示，PHF5A-Y36C对基础剪接的影响很小，但抑制剪接调节剂的全局作用。此外，PHF5A-Y36C改变剪接调制器诱导的内含子保留/外显子跳变，这与相邻内含子和外显子之间的GC含量差异有关。我们测定了人类PHF5A的晶体结构，表明Y36位于一个高度保守的表面。低温电镜（cro - em）分析显示，抗性突变聚集在分支点腺苷周围的口袋中，表明其作用方式是竞争性的。总之，我们提出PHF5A-SF3B1形成一个与这些剪接调节剂结合的中心节点。已知许多天然存在的小分子剪接调节剂。在这里，作者结合化学基因组学、结构和生化方法，表明这些化合物也靶向剪接体相关蛋白PHF5A，并在PHF5A - sf3b1复合体中提出了一个潜在的调节剂结合位点。
Pladienolide, herboxidiene and spliceostatin have been identified as splicing modulators that target SF3B1 in the SF3b subcomplex. Here we report that PHF5A, another component of this subcomplex, is also targeted by these compounds. Mutations in PHF5A-Y36, SF3B1-K1071, SF3B1-R1074 and SF3B1-V1078 confer resistance to these modulators, suggesting a common interaction site. RNA-seq analysis reveals that PHF5A-Y36C has minimal effect on basal splicing but inhibits the global action of splicing modulators. Moreover, PHF5A-Y36C alters splicing modulator-induced intron-retention/exon-skipping profile, which correlates with the differential GC content between adjacent introns and exons. We determine the crystal structure of human PHF5A demonstrating that Y36 is located on a highly conserved surface. Analysis of the cryo-EM spliceosome Bact complex shows that the resistance mutations cluster in a pocket surrounding the branch point adenosine, suggesting a competitive mode of action. Collectively, we propose that PHF5A–SF3B1 forms a central node for binding to these splicing modulators. A number of natural occurring small-molecule splicing modulators are known. Here, the authors combine chemogenomic, structural and biochemical methods and show that these compounds also target the spliceosome-associated protein PHF5A and propose a potential modulator binding site in the PHF5A–SF3B1 complex.