RNA Polymerase IV Functions in Paramutation in Zea mays
RNA Polymerase IV Functions in Paramutation in Zea mays
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DOI：
10.1126/science.1164508
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发表时间：
2009-02-27
期刊：
影响因子：
56.9
通讯作者：
Hollick, Jay B.
中科院分区：
文献类型：
--
作者：
Erhard, Karl F., Jr.;Stonaker, Jennifer L.;Hollick, Jay B.
植物具有不同的RNA聚合酶复合物（Pol IV和Pol V），在维持小RNA相关基因沉默中的作用很大程度上未知。奇怪的是，真双子叶植物拟南芥在失去任何一种功能时都不受影响。通过使用突变选择和定位克隆，我们发现，假定的玉米Pol IV的最大亚基参与副突变，一种遗传的表观遗传变化，促进了两个等位基因之间的相互作用，以及正常的玉米发育。生物信息学分析和核运行的转录测定表明，Pol IV不参与典型的三种主要的真核DNA依赖性RNA聚合酶的有效RNA合成。这些结果表明，Pol IV利用异常的RNA聚合酶活性来实现全基因组沉默，并且其缺失影响玉米发育和可遗传的表观遗传变化。
Plants have distinct RNA polymerase complexes (Pol IV and Pol V) with largely unknown roles in maintaining small RNA-associated gene silencing. Curiously, the eudicot Arabidopsis thaliana is not affected when either function is lost. By use of mutation selection and positional cloning, we showed that the largest subunit of the presumed maize Pol IV is involved in paramutation, an inherited epigenetic change facilitated by an interaction between two alleles, as well as normal maize development. Bioinformatics analyses and nuclear run-on transcription assays indicate that Pol IV does not engage in the efficient RNA synthesis typical of the three major eukaryotic DNA-dependent RNA polymerases. These results indicate that Pol IV employs abnormal RNA polymerase activities to achieve genome-wide silencing and that its absence affects both maize development and heritable epigenetic changes.