Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854, USA.
Mol Cell. 2010 Nov 12;40(3):423-32. doi: 10.1016/j.molcel.2010.10.010.
Regulation of RNA degradation plays an important role in the control of gene expression. One mechanism of eukaryotic mRNA decay proceeds through an initial deadenylation followed by 5' end decapping and exonucleolytic decay. Dcp2 is currently believed to be the only cytoplasmic decapping enzyme responsible for decapping of all mRNAs. Here we report that Dcp2 protein modestly contributes to bulk mRNA decay and surprisingly is not detectable in a subset of mouse and human tissues. Consistent with these findings, a hypomorphic knockout of Dcp2 had no adverse consequences in mice. In contrast, the previously reported Xenopus nucleolar decapping enzyme, Nudt16, is an ubiquitous cytoplasmic decapping enzyme in mammalian cells. Like Dcp2, Nudt16 also regulates the stability of a subset of mRNAs including a member of the motin family of proteins involved in angiogenesis, Angiomotin-like 2. These data demonstrate mammalian cells possess multiple mRNA decapping enzymes, including Nudt16 to regulate mRNA turnover.
RNA 降解的调控在基因表达的控制中起着重要作用。真核 mRNA 衰变的一种机制是通过初始去腺苷酸化，然后是 5'端脱帽和外切核酸酶降解。Dcp2 目前被认为是唯一负责所有 mRNA 脱帽的细胞质脱帽酶。在这里，我们报告 Dcp2 蛋白对大量 mRNA 衰变有适度的贡献，令人惊讶的是，在一小部分小鼠和人类组织中无法检测到。与这些发现一致，Dcp2 的功能减弱型敲除在小鼠中没有产生不良后果。相比之下，先前报道的 Xenopus 核仁脱帽酶 Nudt16 是哺乳动物细胞中普遍存在的细胞质脱帽酶。与 Dcp2 一样，Nudt16 也调节包括参与血管生成的 motin 家族蛋白成员在内的一组 mRNA 的稳定性，即血管生成素样蛋白 2。这些数据表明，哺乳动物细胞拥有多种 mRNA 脱帽酶，包括 Nudt16 来调节 mRNA 周转。
