Department of Microbiology and Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon, 34134, Republic of Korea.
J Microbiol. 2022 Aug;60(8):843-848. doi: 10.1007/s12275-022-2213-x. Epub 2022 Jul 14.
Decapping of mRNA is a key regulatory step for mRNA decay and translation. The RNA helicase, Dhh1, is known as a decapping activator and translation repressor in yeast Saccharomyces cerevisiae. Dhh1 also functions as a gene-specific positive regulator in the expression of Ste12, a mating-specific transcription factor. A previous study showed that the N-erminal phosphorylation of Dhh1 regulates its association with the mRNA-binding protein, Puf6, to affect the protein translation of Ste12. Here, we investigated the roles of the phosphorylated residues of Dhh1 in yeast mating process and Ste12 expression. The phospho-deficient mutation, DHH1-T10A, was associated with decreased diploid formation during mating and decreased level of the Ste12 protein in response to α-mating pheromone. A kinase overexpression analysis revealed that Ste12 protein expression was affected by overexpression of Fus3 MAP kinase or Tpk2 kinase. Tpk2 was shown to be responsible for phosphorylation of Dhh1 at Thr10. Our study shows that overexpression of Fus3 or Tpk2 alters the Dhh1-Puf6 protein interaction and thereby affects Ste12 protein expression.
mRNA 的去帽是 mRNA 降解和翻译的关键调控步骤。RNA 解旋酶 Dhh1 在酵母酿酒酵母中被称为去帽激活因子和翻译抑制因子。Dhh1 还作为一种基因特异性的正调控因子，在交配特异性转录因子 Ste12 的表达中发挥作用。先前的研究表明，Dhh1 的 N 端磷酸化调节其与 mRNA 结合蛋白 Puf6 的结合，从而影响 Ste12 的蛋白质翻译。在这里，我们研究了 Dhh1 中磷酸化残基在酵母交配过程和 Ste12 表达中的作用。磷酸缺陷突变 DHH1-T10A 与交配过程中二倍体形成减少以及对α交配信息素反应的 Ste12 蛋白水平降低有关。激酶过表达分析表明，Ste12 蛋白表达受 Fus3 MAP 激酶或 Tpk2 激酶的过表达影响。结果表明，Tpk2 负责 Dhh1 在 Thr10 上的磷酸化。我们的研究表明，Fus3 或 Tpk2 的过表达改变了 Dhh1-Puf6 蛋白相互作用，从而影响了 Ste12 蛋白的表达。
