Centre for Gene Regulation and Expression, University of Dundee, Dundee DD1 5EH, UK.
Open Biol. 2013 Nov 20;3(11):130151. doi: 10.1098/rsob.130151.
Messenger RNA translation is regulated by RNA-binding proteins and small non-coding RNAs called microRNAs. Even though we know the majority of RNA-binding proteins and microRNAs that regulate messenger RNA expression, evidence of interactions between the two remain elusive. The role of the RNA-binding protein GLD-1 as a translational repressor is well studied during Caenorhabditis elegans germline development and maintenance. Possible functions of GLD-1 during somatic development and the mechanism of how GLD-1 acts as a translational repressor are not known. Its human homologue, quaking (QKI), is essential for embryonic development. Here, we report that the RNA-binding protein GLD-1 in C. elegans affects multiple microRNA pathways and interacts with proteins required for microRNA function. Using genome-wide RNAi screening, we found that nhl-2 and vig-1, two known modulators of miRNA function, genetically interact with GLD-1. gld-1 mutations enhance multiple phenotypes conferred by mir-35 and let-7 family mutants during somatic development. We used stable isotope labelling with amino acids in cell culture to globally analyse the changes in the proteome conferred by let-7 and gld-1 during animal development. We identified the histone mRNA-binding protein CDL-1 to be, in part, responsible for the phenotypes observed in let-7 and gld-1 mutants. The link between GLD-1 and miRNA-mediated gene regulation is further supported by its biochemical interaction with ALG-1, CGH-1 and PAB-1, proteins implicated in miRNA regulation. Overall, we have uncovered genetic and biochemical interactions between GLD-1 and miRNA pathways.
信使 RNA 的翻译受 RNA 结合蛋白和称为 microRNAs 的小非编码 RNA 的调节。尽管我们知道大多数调节信使 RNA 表达的 RNA 结合蛋白和 microRNAs，但它们之间相互作用的证据仍然难以捉摸。RNA 结合蛋白 GLD-1 在秀丽隐杆线虫生殖系发育和维持过程中作为翻译抑制剂的作用得到了很好的研究。GLD-1 在体发育过程中的可能功能以及 GLD-1 作为翻译抑制剂的作用机制尚不清楚。其人类同源物 quaking (QKI) 对胚胎发育至关重要。在这里，我们报告线虫中的 RNA 结合蛋白 GLD-1 影响多个 microRNA 途径，并与 microRNA 功能所需的蛋白质相互作用。通过全基因组 RNAi 筛选，我们发现 nhl-2 和 vig-1，这两种已知的 microRNA 功能调节剂，与 GLD-1 在遗传上相互作用。gld-1 突变增强了 mir-35 和 let-7 家族突变体在体发育过程中赋予的多种表型。我们使用稳定同位素标记与细胞培养中的氨基酸，对 let-7 和 gld-1 在动物发育过程中赋予的蛋白质组的全局变化进行了分析。我们确定了组蛋白 mRNA 结合蛋白 CDL-1 是部分负责观察到的 let-7 和 gld-1 突变体表型的原因。GLD-1 与 miRNA 介导的基因调控之间的联系进一步得到了其与 ALG-1、CGH-1 和 PAB-1 的生化相互作用的支持，这些蛋白参与了 miRNA 的调控。总的来说，我们已经发现了 GLD-1 与 miRNA 途径之间的遗传和生化相互作用。
