Three RNA recognition motifs participate in RNA recognition and structural organization by the pro-apoptotic factor TIA-1.
Three RNA recognition motifs participate in RNA recognition and structural organization by the pro-apoptotic factor TIA-1.
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DOI：
10.1016/j.jmb.2011.11.040
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发表时间：
2012-01-27
影响因子：
5.6
通讯作者：
Kielkopf, Clara L.
中科院分区：
文献类型：
--
作者：
Bauer, William J.;Heath, Jason;Jenkins, Jermaine L.;Kielkopf, Clara L.
关键词：
T细胞胞内抗原-1(TIA-1)通过不同的活性在mRNA前剪接和翻译水平上调节发育和应激反应通路。TIA-1多肽含有三个RNA识别基序(RRMS)。中央RRM2和C末端RRM3与细胞内的mRNAs相关。N-末端RRM1增强了TIA-1的C-末端富Q结构域与U1-C剪接因子的相互作用，尽管TIA-1序列中的结构域是线性分离的。鉴于RRM家族的扩展功能谱系，尚不清楚TIA-1 RRM1是否有助于RNA结合和已知的蛋白质相互作用。为了解决这个问题，我们使用等温滴定量热法和小角X射线散射(SAXS)来分析TIA-1 RRMS在RNA识别中的作用。值得注意的是，Fas RNA显示了两个与TIA-1具有难以区分的亲和力的结合位点。对TIA-1变异体的分析表明，RRM1对于结合AU丰富的Fas位点是必不可少的，但所有三个RRMS都需要以高亲和力结合PolyU RNA。SAXS分析表明，TIA-1结构由三个RRMS组成，其尺寸在RNA结合状态下变得更加紧凑。TIA-1 RRM1在RNA识别中的序列选择性参与表明RNA序列可能在调节TIA-1的不同功能中发挥作用。讨论了Fas前-mRNA的相邻TIA-1结合位点和弯曲的TIA-1形状(组织蛋白质同一侧的N-端和C-端)对U1-C招募的进一步影响。
T-cell intracellular antigen-1 (TIA-1) regulates developmental and stress-responsive pathways through distinct activities at the levels of alternative pre-mRNA splicing and mRNA translation. The TIA-1 polypeptide contains three RNA recognition motifs (RRMs). The central RRM2 and C-terminal RRM3 associate with cellular mRNAs. The N-terminal RRM1 enhances interactions of a C-terminal Q-rich domain of TIA-1 with the U1-C splicing factor, despite linear separation of the domains in the TIA-1 sequence. Given the expanded functional repertoire of the RRM family, it was unknown whether TIA-1 RRM1 contributes to RNA binding as well as documented protein interactions. To address this question, we used isothermal titration calorimetry and small-angle X-ray scattering (SAXS) to dissect the roles of the TIA-1 RRMs in RNA recognition. Notably, the fas RNA exhibited two binding sites with indistinguishable affinities for TIA-1. Analyses of TIA-1 variants established that RRM1 was dispensable for binding AU-rich fas sites, yet all three RRMs were required to bind a polyU RNA with high affinity. SAXS analyses demonstrated a `V' shape for a TIA-1 construct comprising the three RRMs, and revealed that its dimensions became more compact in the RNA-bound state. The sequence-selective involvement of TIA-1 RRM1 in RNA recognition suggests a possible role for RNA sequences in regulating the distinct functions of TIA-1. Further implications for U1-C recruitment by the adjacent TIA-1 binding sites of the fas pre-mRNA and the bent TIA-1 shape, which organizes the N- and C-termini on the same side of the protein, are discussed.
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影响因子：
11.4
作者：
Crichlow, Gregg V.;Zhou, Hongwen;Hsiao, Hsin-hao;Frederick, Kendra B.;Debrosse, Maxime;Yang, Yuande;Folta-Stogniew, Ewa J.;Chung, Hye-Jung;Fan, Chengpeng;De La Cruz, Enrique M.;Levens, David;Lolis, Elias;Braddock, Demetrios
通讯作者：
Braddock, Demetrios
影响因子：
6.1
作者：
Konarev, PV;Volkov, VV;Svergun, DI
通讯作者：
Svergun, DI
影响因子：
6.1
作者：
Kozin, MB;Svergun, DI
通讯作者：
Svergun, DI
影响因子：
5.6
作者：
Deardorff, JA;Sachs, AB
通讯作者：
Sachs, AB
影响因子：
5.6
作者：
Bae, Euiyoung;Reiter, Nicholas J.;Brow, David A.
通讯作者：
Brow, David A.