Abstract:
Cytoplasmic RNA granules compartmentalize phases of the translation cycle in eukaryotes. We previously reported the localization of oxidized RNA to cytoplasmic foci called oxidized RNA bodies (ORBs) in human cells. We show here that ORBs are RNA granules in Saccharomyces cerevisiae. Several lines of evidence support a role for ORBs in the compartmentalization of no-go decay and ribosome quality control, the translation quality control pathways that recognize and clear aberrant mRNAs, including those with oxidized bases. Translation is required by these pathways and ORBs. Translation quality control factors localize to ORBs. A substrate of translation quality control, a stalled mRNA-ribosome-nascent-chain complex, localizes to ORBs. Translation quality control mutants have altered ORB numbers, sizes or both. In addition, we identify 68 ORB proteins by immunofluorescence staining directed by proteomics, which further support their role in translation quality control and reveal candidate new factors for these pathways.
摘要:
细胞质RNA颗粒划分真核生物翻译周期的阶段。我们先前报道了氧化RNA在人细胞中被称为氧化RNA体(ORB)的细胞质灶的定位。我们在这里显示ORB是酿酒酵母中的RNA颗粒。一些证据支持ORB在无衰变和核糖体质量控制的分区中的作用,识别和清除异常mRNA的翻译质量控制途径,包括那些有氧化碱的。这些途径和ORB需要翻译。翻译质量控制因素局限于ORB。翻译质量控制的基础,停滞的mRNA-核糖体-新生链复合物,本地化为ORB。翻译质量控制突变体改变了ORB数量,大小或两者。此外,我们通过蛋白质组学指导的免疫荧光染色鉴定了68个ORB蛋白,这进一步支持了它们在翻译质量控制中的作用,并揭示了这些途径的候选新因素。