The DEAD box helicase, Dhh1p, functions in mRNA decapping and interacts with both the decapping and deadenylase complexes
The DEAD box helicase, Dhh1p, functions in mRNA decapping and interacts with both the decapping and deadenylase complexes
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DOI：
10.1017/s135583820101994x
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发表时间：
2001-12-01
期刊：
影响因子：
4.5
通讯作者：
Parker, R
中科院分区：
文献类型：
--
作者：
Coller, JM;Tucker, M;Parker, R
真核细胞中mRNA周转的主要途径起始于去腺苷酸化，导致mRNA去帽和随后的5'至3'核酸外切酶消化。我们发现，一个高度保守的DEAD盒解旋酶，Dhh 1 p家族成员，刺激酵母中的mRNA脱帽。在dhh 1 Delta突变体中，mRNA以去腺苷化、加帽的形式积累。Dhhlp对脱帽的影响只发生在正常的信息上，因为无义介导的衰变仍然发生在dhh 1 Delta突变体中。Dhh 1 p在脱帽中的作用似乎是直接的，因为Dhh 1 p与参与mRNA脱帽的几种蛋白质相互作用，包括脱帽酶Dcp 1 p，以及Lsm 1 p和Pat 1 p/Mrt 1 p，其功能是提高脱帽率。额外的观察表明Dhh 1 p的功能，以协调mRNA功能和衰变的不同步骤。Dhh 1 p还与mRNA去腺苷酶的亚基Pop 2 p相关联。此外，遗传表型表明Dhh 1 p还具有第二种生物学功能。有趣的是，Dhh 1 p同源物在其他物种的功能在母体mRNA的存储。这提供了一个新的脱帽和母体mRNA翻译抑制的机制之间的联系。
A major pathway of mRNA turnover in eukaryotic cells initiates with deadenylation, leading to mRNA decapping and subsequent 5' to 3' exonuclease digestion. We show that a highly conserved member of the DEAD box family of helicases, Dhh1p, stimulates mRNA decapping in yeast. In dhh1 Delta mutants, mRNAs accumulate as deadenylated, capped species. Dhhlp's effects on decapping only occur on normal messages as nonsense-mediated decay still occurs in dhh1 Delta mutants. The role of Dhh1p in decapping appears to be direct, as Dhh1p physically interacts with several proteins involved in mRNA decapping including the decapping enzyme Dcp1p, as well as Lsm1p and Pat1p/ Mrt1p, which function to enhance the decapping rate. Additional observations suggest Dhh1p functions to coordinate distinct steps in mRNA function and decay. Dhh1p also associates with Pop2p, a subunit of the mRNA deadenylase. In addition, genetic phenotypes suggest that Dhh1p also has a second biological function. Interestingly, Dhh1p homologs in others species function in maternal mRNA storage. This provides a novel link between the mechanisms of decapping and maternal mRNA translational repression.