Cellular translation surveillance rescues ribosomes that stall on problematic mRNAs. During translation surveillance, endonucleolytic cleavage of the problematic mRNA is a critical step in rescuing stalled ribosomes. Here we identify NONU-1 as a factor required for translation surveillance pathways including no-go and nonstop mRNA decay. We show that (1) NONU-1 reduces nonstop and no-go mRNA levels; (2) NONU-1 contains an Smr RNase domain required for mRNA decay; (3) the domain architecture and catalytic residues of NONU-1 are conserved throughout metazoans and eukaryotes, respectively; and (4) NONU-1 is required for the formation of mRNA cleavage fragments in the vicinity of stalled ribosomes. We extend our results in C. elegans to homologous factors in S. cerevisiae, showing the evolutionarily conserved function of NONU-1. Our work establishes the identity of a factor critical to translation surveillance and will inform mechanistic studies at the intersection of translation and mRNA decay.

中文翻译：

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NONU-1编码mRNA翻译监测所需的保守核酸内切酶。

细胞翻译监测可以挽救停滞在有问题的mRNA上的核糖体。在翻译监控过程中，有问题的mRNA的内切核酸切割是挽救停滞的核糖体的关键步骤。在这里，我们将NONU-1确定为翻译监控途径（包括不停和不停mRNA衰减）所需的一个因素。我们显示（1）NONU-1减少不间断和不进行的mRNA水平；（2）NONU-1含有mRNA衰减所需的Smr RNase结构域；（3）在整个后生动物和真核生物中，NONU-1的结构域结构和催化残基分别是保守的；（4）在停滞的核糖体附近形成mRNA裂解片段需要NONU-1。我们将秀丽隐杆线虫的结果扩展到酿酒酵母中的同源因子，显示了NONU-1在进化上的保守功能。