The structure of human Nocturnin reveals a conserved ribonuclease domain that represses target transcript translation and abundance in cells.
The structure of human Nocturnin reveals a conserved ribonuclease domain that represses target transcript translation and abundance in cells.
复制标题
DOI：
10.1093/nar/gky412
复制
发表时间：
2018-07-06
影响因子：
14.9
通讯作者：
Trievel RC
中科院分区：
文献类型：
--
作者：
Abshire ET;Chasseur J;Bohn JA;Del Rizzo PA;Freddolino PL;Goldstrohm AC;Trievel RC
昼夜节律蛋白Nocturnin （NOCT）属于核酸外切酶、核酸内切酶和磷酸酶超家族，与降解mrna多腺苷尾部的ccr4类deadenylase最相似。nnt缺乏的小鼠对高脂肪饮食引起的体重增加有抵抗力，并表现出骨形成失调。然而，NOCT调节这些过程的机制仍有待确定。在这里，我们描述了一对人类NOCT催化域的高分辨率晶体结构。NOCT的活性位点与其他外核糖核酸酶高度保守，当指向细胞中的转录物时，NOCT可以以依赖于关键活性位点残基的方式降低mRNA的翻译和丰度。与相关的deadenylase CNOT6L相比，纯化的重组NOCT缺乏体外核糖核酸酶活性，这表明未知因素是酶活性的必要条件。我们还发现，NOCT抑制细胞中报告基因mRNA的能力取决于mRNA的3 ‘端，因为以3 ’ MALAT1结构终止的报告基因不能被NOCT抑制。总之，这些数据表明，NOCT是一种外核糖核酸酶，可以降解mrna，抑制蛋白质表达，提示其在脂质代谢和骨发育中的调节作用的分子机制。
The circadian protein Nocturnin (NOCT) belongs to the exonuclease, endonuclease and phosphatase superfamily and is most similar to the CCR4-class of deadenylases that degrade the poly-adenosine tails of mRNAs. NOCT-deficient mice are resistant to high-fat diet induced weight gain, and exhibit dysregulation of bone formation. However, the mechanisms by which NOCT regulates these processes remain to be determined. Here, we describe a pair of high-resolution crystal structures of the human NOCT catalytic domain. The active site of NOCT is highly conserved with other exoribonucleases, and when directed to a transcript in cells, NOCT can reduce translation and abundance of that mRNA in a manner dependent on key active site residues. In contrast to the related deadenylase CNOT6L, purified recombinant NOCT lacks in vitro ribonuclease activity, suggesting that unidentified factors are necessary for enzymatic activity. We also find the ability of NOCT to repress reporter mRNAs in cells depends upon the 3′ end of the mRNA, as reporters terminating with a 3′ MALAT1 structure cannot be repressed by NOCT. Together, these data demonstrate that NOCT is an exoribonuclease that can degrade mRNAs to inhibit protein expression, suggesting a molecular mechanism for its regulatory role in lipid metabolism and bone development.
登录
查看更多内容
影响因子：
3.7
作者：
Doidge R;Mittal S;Aslam A;Winkler GS
通讯作者：
Winkler GS
束缚功能分析是阐明RNA结合蛋白的分子作用的工具。
影响因子：
--
作者：
Bos TJ;Nussbacher JK;Aigner S;Yeo GW
通讯作者：
Yeo GW
DOI：
10.1016/j.bpg.2014.07.008
发表时间：
2014-08-01
影响因子：
3.2
作者：
Dietrich, Peter;Hellerbrand, Claus
通讯作者：
Hellerbrand, Claus
影响因子：
3.3
作者：
Aslam, Akhmed;Mittal, Saloni;Winkler, G. Sebastiaan
通讯作者：
Winkler, G. Sebastiaan
影响因子：
13.8
作者：
Dlakic, M
通讯作者：
Dlakic, M