Protein arginine methylation is an important means by which protein function can be regulated. In the budding yeast, this modification is catalyzed by the major protein arginine methyltransferase Hmt1. Here, we provide evidence that the Hmt1-mediated methylation of Rpc31, a subunit of RNA polymerase III, plays context-dependent roles in tRNA gene transcription: under conditions optimal for growth, it positively regulates tRNA gene transcription, and in the setting of stress, it promotes robust transcriptional repression. In the context of stress, methylation of Rpc31 allows for its optimal interaction with RNA polymerase III global repressor Maf1. Interestingly, mammalian Hmt1 homologue is able to methylate one of Rpc31's human homologue, RPC32β, but not its paralogue, RPC32α. Our data led us to propose an efficient model whereby protein arginine methylation facilitates metabolic economy and coordinates protein-synthetic capacity.

中文翻译：

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胁迫期间对tRNA基因转录的强大抑制作用需要蛋白质精氨酸甲基化。

蛋白质精氨酸甲基化是调节蛋白质功能的重要手段。在出芽的酵母中，这种修饰被主要的蛋白质精氨酸甲基转移酶Hmt1催化。在这里，我们提供的证据表明，RNA聚合酶III的亚基Rpc31的Hmt1介导的甲基化在tRNA基因转录中起上下文相关的作用：在最适合生长的条件下，它正调控tRNA基因的转录，并在压力的情况下，它促进了强大的转录抑制。在压力的情况下，Rpc31的甲基化可使其与RNA聚合酶III全局阻遏物Maf1发生最佳相互作用。有趣的是，哺乳动物的Hmt1同源物能够甲基化Rpc31的人类同源物之一RPC32β，但不能使它的旁系同源物RPC32α甲基化。