Fas-activated serine/threonine phosphoprotein (FAST) is a regulator of alternative splicing
Fas-activated serine/threonine phosphoprotein (FAST) is a regulator of alternative splicing
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DOI：
10.1073/pnas.0704964104
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发表时间：
2007-07-03
影响因子：
11.1
通讯作者：
Anderson, Paul
中科院分区：
文献类型：
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作者：
Simarro, Maria;Mauger, David;Anderson, Paul
fas激活的丝氨酸/苏氨酸磷酸化蛋白（FAST）是一种附着在线粒体外膜上的存活蛋白。在遭受环境应激的细胞中，FAST移动到应激颗粒，在那里它与TIA1相互作用以调节应激诱导的翻译沉默过程。FAST和TIAll也存在于细胞核中，其中TIA1促进包含弱剪接识别位点的外显子，如成纤维细胞生长因子受体2 (FGFR2) mRNA的外显子Illb。双杂交相互作用筛选和生化分析显示FAST结合了几个可选的和组成的剪接调节因子，表明FAST可能参与了这一过程。FAST集中在核斑点上的发现也支持了这一论点。我们发现FAST，像TIA1一样，促进FGFR2 mRNA外显子Illb的包含。FAST和TIA1都靶向位于外显子Illb 5'剪接位点附近的富u内含子序列（IAS1）。然而，与TIA1不同的是，FAST不与IAS1序列结合。令人惊讶的是，敲除实验显示FAST和TIA1相互独立地促进外显子Illb的包含。突变分析表明，FAST介导的选择性剪接与FAST的生存效应是可分离的。我们的数据显示，核FAST可以调节FGFR2转录物的剪接。
Fas-activated serine/threonine phosphoprotein (FAST) is a survival protein that is tethered to the outer mitochondrial membrane. In cells subjected to environmental stress, FAST moves to stress granules, where it interacts with TIA1 to modulate the process of stress-induced translational silencing. Both FAST and TIAll are also found in the nucleus, where TIA1 promotes the inclusion of exons f lanked by weak splice recognition sites such as exon Illb of the fibroblast growth factor receptor 2 (FGFR2) mRNA. Two-hybrid interaction screens and biochemical analysis reveal that FAST binds to several alternative and constitutive splicing regulators, suggesting that FAST might participate in this process. The finding that FAST is concentrated at nuclear speckles also supports this contention. We show that FAST, like TIA1, promotes the inclusion of exon Illb of the FGFR2 mRNA. Both FAST and TIA1 target a U-rich intronic sequence (IAS1) adjacent the 5' splice site of exon Illb. However, unlike TIA1, FAST does not bind to the IAS1 sequence. Surprisingly, knockdown experiments reveal that FAST and TIA1 act independently of one another to promote the inclusion of exon Illb. Mutational analysis reveals that FAST-mediated alternative splicing is separable from the survival effects of FAST. Our data reveal that nuclear FAST can regulate the splicing of FGFR2 transcripts.