Functional analysis of Hsh155/SF3b1 interactions with the U2 snRNA/branch site duplex.
Functional analysis of Hsh155/SF3b1 interactions with the U2 snRNA/branch site duplex.
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DOI：
10.1261/rna.065664.118
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发表时间：
2018-08
期刊：
影响因子：
--
通讯作者：
Hoskins AA
中科院分区：
文献类型：
--
作者：
Carrocci TJ;Paulson JC;Hoskins AA
SF 3b 1是参与分支位点（BS）识别的U2 snRNP的重要组分，并且发现在几种人类癌症中频繁突变。虽然最近的酵母和人SF 3b 1的结构揭示了它的分子结构，特定的RNA的重要性：蛋白质接触和构象变化仍然在很大程度上未被表征。在这里，我们进行了酵母SF 3b 1的突变分析，最近的剪接体结构的指导下。我们发现，保守的氨基酸接触的U2/BS双链体的U2 snRNA骨架是非必需的，酵母可以容忍截断的热重复含有这些氨基酸。容纳分支点腺苷（BP-A）的口袋也适合突变，尽管保守性很强。然而，支持生存力的突变仍然会导致剪接前体mRNA的缺陷，在相对于BP-A或分支点位置的-3、-2、-1和+1位置发现非共有BS取代。通过酵母和人类嵌合蛋白的产生，我们进一步定义了Hsh 155的功能保守区域，并确定了由于包含人SF 3b 1 HEAT重复序列而导致的BS使用的变化。此外，这些嵌合蛋白质赋予对小分子抑制的敏感性，所述小分子抑制由普拉地那肽B对酵母剪接。总之，这些数据揭示了Hsh 155/SF 3b 1与U2/BS双链体的个体接触的重要性，并定义了它们对剪接体使用BS的贡献。
SF3b1 is an essential component of the U2 snRNP implicated in branch site (BS) recognition and found to be frequently mutated in several human cancers. While recent structures of yeast and human SF3b1 have revealed its molecular architecture, the importance of specific RNA:protein contacts and conformational changes remains largely uncharacterized. Here, we performed mutational analysis of yeast SF3b1, guided by recent structures of the spliceosome. We find that conserved amino acids contacting the U2 snRNA backbone of the U2/BS duplex are nonessential, and that yeast can tolerate truncation of the HEAT repeats containing these amino acids. The pocket housing the branchpoint adenosine (BP-A) is also amenable to mutation despite strong conservation. However, mutations that support viability can still lead to defects in splicing pre-mRNAs with nonconsensus BS substitutions found at −3, −2, −1, and +1 positions relative to the BP-A or at the branchpoint position. Through the generation of yeast and human chimeric proteins, we further defined the functionally conserved regions of Hsh155 as well as identify changes in BS usage resulting from inclusion of human SF3b1 HEAT repeats. Moreover, these chimeric proteins confer a sensitivity to small molecule inhibition by pladienolide B to yeast splicing. Together, these data reveal the importance of individual contacts of Hsh155/SF3b1 to the U2/BS duplex and define their contribution to BS usage by the spliceosome.
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影响因子：
14.9
作者：
Carrocci TJ;Zoerner DM;Paulson JC;Hoskins AA
通讯作者：
Hoskins AA
DOI：
10.1038/nrm.2017.63
发表时间：
2017-10
期刊：
Nature reviews. Molecular cell biology
影响因子：
--
作者：
Herzel L;Ottoz DSM;Alpert T;Neugebauer KM
通讯作者：
Neugebauer KM
影响因子：
4
作者：
Kielkopf CL
通讯作者：
Kielkopf CL
影响因子：
10.5
作者：
Finci LI;Zhang X;Huang X;Zhou Q;Tsai J;Teng T;Agrawal A;Chan B;Irwin S;Karr C;Cook A;Zhu P;Reynolds D;Smith PG;Fekkes P;Buonamici S;Larsen NA
通讯作者：
Larsen NA
DOI：
10.1126/science.1198830
发表时间：
2011-03-11
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Hoskins AA;Friedman LJ;Gallagher SS;Crawford DJ;Anderson EG;Wombacher R;Ramirez N;Cornish VW;Gelles J;Moore MJ
通讯作者：
Moore MJ