Pat1 contributes to the RNA binding activity of the Lsm1-7-Pat1 complex.
Pat1 contributes to the RNA binding activity of the Lsm1-7-Pat1 complex.
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DOI：
10.1261/rna.045252.114
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发表时间：
2014-09
期刊：
影响因子：
--
通讯作者：
Tharun S
中科院分区：
文献类型：
--
作者：
Chowdhury A;Kalurupalle S;Tharun S
Lsm1-7-Pat1复合体在体内增强了信使核糖核酸的分解。本研究分别检测了Lsm1-7和Pat1的RNA结合活性，并将其作为复合体进行了研究。结果表明，LSM复合体和Pat1本身都表现出很低的RNA结合活性，但结合在一起，该复合体具有很强的RNA结合活性。在真核生物中，一个主要的mRNA衰变途径是通过去烯化，然后去掉寡腺苷化的mRNAs，然后是无囊化的mRNA5‘-到-3’核外降解。在这一途径中，解离是一个限速步骤，需要异八聚体Lsm1-7-Pat1复合体在体内以正常速度发生。该复合体由七个类Sm蛋白Lsm1至Lsm7和Pat1蛋白组成。它与RNA结合，对寡腺化RNA比多腺化RNA有独特的结合偏好。这种结合能力对其在体内的mRNA衰变功能至关重要。为了确定PAT1对Lsm1-7-PAT1复合体功能的贡献，我们比较了从PAT1Δ细胞中纯化的Lsm1-7复合体和纯化的PAT1片段与野生型Lsm1-7-PAT1复合体的结合特性。我们的研究表明，Lsm1-7复合体和纯化的Pat1片段都具有很低的RNA结合活性，并且识别RNA上的寡聚(A)尾巴的能力受到损害。然而，由这些成分重组Lsm1-7-Pat1复合体后，恢复了这些能力。我们还观察到Pat1在Lsm1-7-Pat1复合体的背景下直接与RNA接触。这些研究表明，Lsm1-7-Pat1复合体独特的RNA结合特性和mRNA衰减功能涉及到Pat1和Lsm1-7环上残基的协同作用。最后，我们的研究还揭示了Pat1的中间结构域是Pat1与Lsm1-7复合体在体内相互作用的关键。
The Lsm1-7-Pat1 complex enhances mRNA decapping in vivo. This study examines the RNA binding activity of Lsm1-7 and Pat1 separately and as a complex. It is demonstrated that both the Lsm complex and Pat1 display very low RNA binding by themselves, but in combination, the complex has robust RNA binding activity. A major mRNA decay pathway in eukaryotes is initiated by deadenylation followed by decapping of the oligoadenylated mRNAs and subsequent 5′-to-3′ exonucleolytic degradation of the capless mRNA. In this pathway, decapping is a rate-limiting step that requires the hetero-octameric Lsm1-7–Pat1 complex to occur at normal rates in vivo. This complex is made up of the seven Sm-like proteins, Lsm1 through Lsm7, and the Pat1 protein. It binds RNA and has a unique binding preference for oligoadenylated RNAs over polyadenylated RNAs. Such binding ability is crucial for its mRNA decay function in vivo. In order to determine the contribution of Pat1 to the function of the Lsm1-7–Pat1 complex, we compared the RNA binding properties of the Lsm1-7 complex purified from pat1Δ cells and purified Pat1 fragments with that of the wild-type Lsm1-7–Pat1 complex. Our studies revealed that both the Lsm1-7 complex and purified Pat1 fragments have very low RNA binding activity and are impaired in the ability to recognize the oligo(A) tail on the RNA. However, reconstitution of the Lsm1-7–Pat1 complex from these components restored these abilities. We also observed that Pat1 directly contacts RNA in the context of the Lsm1-7–Pat1 complex. These studies suggest that the unique RNA binding properties and the mRNA decay function of the Lsm1-7–Pat1 complex involve cooperation of residues from both Pat1 and the Lsm1-7 ring. Finally our studies also revealed that the middle domain of Pat1 is essential for the interaction of Pat1 with the Lsm1-7 complex in vivo.
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影响因子：
11.4
作者：
Braun, Joerg E.;Tritschler, Felix;Haas, Gabrielle;Igreja, Catia;Truffault, Vincent;Weichenrieder, Oliver;Izaurralde, Elisa
通讯作者：
Izaurralde, Elisa
DOI：
10.1083/jcb.200910141
发表时间：
2010-04-19
期刊：
The Journal of cell biology
影响因子：
--
作者：
Haas G;Braun JE;Igreja C;Tritschler F;Nishihara T;Izaurralde E
通讯作者：
Izaurralde E
影响因子：
4.4
作者：
Elkon R;Zlotorynski E;Zeller KI;Agami R
通讯作者：
Agami R
影响因子：
5.3
作者：
Bonnerot, C;Boeck, R;Lapeyre, B
通讯作者：
Lapeyre, B
影响因子：
2.7
作者：
Gallo, Christopher M.;Munro, Edwin;Seydoux, Geraldine
通讯作者：
Seydoux, Geraldine