Ccr4p is the catalytic subunit of a Ccr4p/Pop2p/Notp mRNA deadenylase complex in Saccharomyces cerevisiae
Ccr4p is the catalytic subunit of a Ccr4p/Pop2p/Notp mRNA deadenylase complex in Saccharomyces cerevisiae
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DOI：
10.1093/emboj/21.6.1427
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发表时间：
2002-03-15
期刊：
影响因子：
11.4
通讯作者：
Parker, R
中科院分区：
文献类型：
--
作者：
Tucker, M;Staples, RR;Parker, R
真核细胞中mRNA转换的主要途径是由poly(A)尾巴的缩短启动的。最近的工作已经确定了Ccr4p和Pop2p是酵母中主要的细胞质deadenylase的组分。我们现在证明CCR4编码去烯基酶的催化亚基，而Pop2p在催化中是不可缺少的。此外，我们证明至少有一些Ccr4p/ pop2p相关的非蛋白存在于细胞质中，一些非基因的损伤会导致mRNA死基化率的缺陷。体外实验中，Ccr4p的死烯基化酶可以通过添加聚A结合蛋白（Pab1p）而受到抑制，这表明Pab1p与聚A尾部的分离可能是体内死烯基化的限速因子。此外，COX17 mRNA的快速死烯化是由死烯化激活因子Puf3p的Pumilio家族成员控制的，它需要一个活跃的Ccr4p/Pop2p/Not死烯化酶。这些结果确定了Ccr4p/Pop2p/Not复合体是酵母细胞质deadenylase，并确定了该酶复合体的阳性和阴性调节因子。
The major pathways of mRNA turnover in eukaryotic cells are initiated by shortening of the poly(A) tail. Recent work has identified Ccr4p and Pop2p as components of the major cytoplasmic deadenylase in yeast. We now demonstrate that CCR4 encodes the catalytic subunit of the deadenylase and that Pop2p is dispensable for catalysis. In addition, we demonstrate that at least some of the Ccr4p/Pop2p-associated Not proteins are cytoplasmic, and lesions in some of the NOT genes can lead to defects in mRNA deadenylation rates. The Ccr4p deadenylase is inhibited in vitro by addition of the poly(A) binding protein (Pab1p), suggesting that dissociation of Pab1p from the poly(A) tail may be rate limiting for deadenylation in vivo. In addition, the rapid deadenylation of the COX17 mRNA, which is controlled by a member of the Pumilio family of deadenylation activators Puf3p, requires an active Ccr4p/Pop2p/Not deadenylase. These results define the Ccr4p/Pop2p/Not complex as the cytoplasmic deadenylase in yeast and identify positive and negative regulators of this enzyme complex.