The transcription factor associated Ccr4 and Caf1 proteins are components of the major cytoplasmic mRNA deadenylase in Saccharomyces cerevisiae
The transcription factor associated Ccr4 and Caf1 proteins are components of the major cytoplasmic mRNA deadenylase in Saccharomyces cerevisiae
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DOI：
10.1016/s0092-8674(01)00225-2
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发表时间：
2001-02-09
期刊：
影响因子：
64.5
通讯作者：
Parker, R
中科院分区：
文献类型：
--
作者：
Tucker, M;Valencia-Sanchez, MA;Parker, R
真核生物中mRNA周转的主要途径起始于poly（A）尾的缩短。我们证明了几个标准，CCR 4和CAF 1编码的主要细胞质脱腺苷酶在酵母中的关键组成部分。首先，Ccr 4p和Caf 1 p都是体内正常mRNA去腺苷化所必需的。其次，两种蛋白质都定位于细胞质。第三，Caf 1 p的纯化与Ccr 4p依赖性poly（A）特异性核酸外切酶活性共纯化。我们还提供了证据，Pan 2 p/Pan 3 p核酸酶复合物编码的主要替代deadenylase。这些结果，和以前的工作Pan 2 p/Pan 3 p，定义的mRNA deadenylases在酵母。Ccr 4p、Caf 1 p、Pan 2 p和Pan 3 p的高度保守性表明它们将在其他真核生物中作为deadenylases起作用。有趣的是，由于Ccr 4p和Caf 1 p与转录因子相互作用，这些结果表明mRNA合成和周转之间存在意想不到的联系。
The major pathways of mRNA turnover in eukaryotes initiate with shortening of the poly(A) tail. We demonstrate by several criteria that CCR4 and CAF1 encode critical components of the major cytoplasmic deadenylase in yeast. First, both Ccr4p and Caf1p are required for normal mRNA deadenylation in vivo. Second, both proteins localize to the cytoplasm. Third, purification of Caf1p copurifies with a Ccr4p-dependent poly(A)-specific exonuclease activity. We also provide evidence that the Pan2p/Pan3p nuclease complex encodes the predominant alternative deadenylase. These results, and previous work on Pan2p/Pan3p, define the mRNA deadenylases in yeast. The strong conservation of Ccr4p, Caf1p, Pan2p, and Pan3p indicates that they will function as deadenylases in other eukaryotes. Interestingly, because Ccr4p and Caf1p interact with transcription factors, these results suggest an unexpected link between mRNA synthesis and turnover.