Department of Microbiology and Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon, Republic of Korea.
PLoS One. 2019 Jul 19;14(7):e0220137. doi: 10.1371/journal.pone.0220137. eCollection 2019.
Loc1 and Puf6, which are localized predominantly to the nucleus, are required for the localization and translational repression of the ASH1 mRNA in the yeast, Saccharomyces cerevisiae. During its transport to the daughter cell, the ASH1 mRNA is translationally repressed via associations with She2, Loc1, and Puf6. Here, we investigated the roles of Loc1 and Puf6 in the translation of mRNAs other than that encoding ASH1. In loc1 or puf6 deletion strains, expression of the mating-specific transcription factor, Ste12, was significantly increased at the post-transcriptional level. These phenotypes required the 5' untranslated region (UTR) of STE12, which carries the putative Puf6-binding sequences. The RNA helicase, Dhh1, which is a known positive regulator for the translation of STE12 mRNA, was found to be functionally connected with Loc1 and Puf6 in the context of Ste12 expression. Our results collectively show that the phosphorylation of the N-terminal Thr16 residue of Dhh1 affects the protein interactions of Dhh1 with Loc1 or Puf6, and consequently regulates Ste12 expression.
在酵母酿酒酵母中，Loc1 和 Puf6 主要定位于细胞核，是 ASH1 mRNA 定位和翻译抑制所必需的。在其运输到子细胞的过程中，ASH1 mRNA 通过与 She2、Loc1 和 Puf6 的结合而被翻译抑制。在这里，我们研究了 Loc1 和 Puf6 在翻译除编码 ASH1 的 mRNA 之外的其他 mRNA 中的作用。在 loc1 或 puf6 缺失菌株中，交配特异性转录因子 Ste12 的表达在转录后水平显著增加。这些表型需要 STE12 的 5'非翻译区（UTR），该区域携带假定的 Puf6 结合序列。RNA 解旋酶 Dhh1 是已知的 Ste12 mRNA 翻译的正调节剂，在 Ste12 表达的情况下，发现 Dhh1 与 Loc1 和 Puf6 具有功能联系。我们的研究结果表明，Dhh1 的 N 端 Thr16 残基的磷酸化影响 Dhh1 与 Loc1 或 Puf6 的蛋白相互作用，从而调节 Ste12 的表达。
