TRAP150 interacts with the RNA-binding domain of PSF and antagonizes splicing of numerous PSF-target genes in T cells.
TRAP150 interacts with the RNA-binding domain of PSF and antagonizes splicing of numerous PSF-target genes in T cells.
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DOI：
10.1093/nar/gkv816
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发表时间：
2015-10-15
影响因子：
14.9
通讯作者：
Lynch KW
中科院分区：
文献类型：
--
作者：
Yarosh CA;Tapescu I;Thompson MG;Qiu J;Mallory MJ;Fu XD;Lynch KW
PSF(也称为SFPQ)是一种普遍表达的必需核蛋白，在DNA损伤修复和RNA生物发生中发挥重要作用。在受刺激的T细胞中，PSF结合并抑制CD45外显子4在最终mRNA中的包含；然而，在静止细胞中，TRAP150结合PSF并阻止获得CD45 RNA，尽管这种抑制的机制尚不清楚。在这里，我们证明了TRAP150通过一个以前未描述的70个残基的区域结合了一个包含PSF的RNA识别基序(RRMS)的区域，我们称之为PSF相互作用结构域(PID)。TRAP150‘S的PID直接抑制PSF RRMS与RNA的相互作用，这种作用是通过RRM2介导的。然而，PSF与TRAP150的相互作用似乎并不能抑制PSF与其他果蝇行为--人类剪接(DBHS)蛋白的二聚化，后者也依赖于RRM2。最后，我们使用RASL-SEQ来识别对Psf基因敲除敏感的∼40T细胞剪接事件，并表明对于其中的大多数事件，Psf的作用被TRAP150所拮抗。综上所述，这些数据表明了一种模型，在该模型中，TRAP150与二聚体PSF相互作用，阻止RNA对RRM2的访问，从而调节PSF的活性，使其朝向T细胞中一系列广泛的剪接事件。
PSF (a.k.a. SFPQ) is a ubiquitously expressed, essential nuclear protein with important roles in DNA damage repair and RNA biogenesis. In stimulated T cells, PSF binds to and suppresses the inclusion of CD45 exon 4 in the final mRNA; however, in resting cells, TRAP150 binds PSF and prevents access to the CD45 RNA, though the mechanism for this inhibition has remained unclear. Here, we show that TRAP150 binds a region encompassing the RNA recognition motifs (RRMs) of PSF using a previously uncharacterized, 70 residue region we have termed the PSF-interacting domain (PID). TRAP150's PID directly inhibits the interaction of PSF RRMs with RNA, which is mediated through RRM2. However, interaction of PSF with TRAP150 does not appear to inhibit the dimerization of PSF with other Drosophila Behavior, Human Splicing (DBHS) proteins, which is also dependent on RRM2. Finally, we use RASL-Seq to identify ∼40 T cell splicing events sensitive to PSF knockdown, and show that for the majority of these, PSF's effect is antagonized by TRAP150. Together these data suggest a model in which TRAP150 interacts with dimeric PSF to block access of RNA to RRM2, thereby regulating the activity of PSF toward a broad set of splicing events in T cells.