Title Roles of Dhh1 RNA helicase in yeast filamentous growth: Analysis of N-terminal phosphorylation residues and ATPase domains
Author Eunji Lee, Daehee Jung, and Jinmi Kim
Address Department of Microbiology and Molecular Biology, College of Bioscience and Biotechnology, Chungnam National University, Daejeon 34134, Republic of Korea
Bibliography Journal of Microbiology, 58(10),853–858, 2020,
DOI 10.1007/s12275-020-0431-7
Key Words pseudohyphal growth, Dhh1, Ste12 expression, ATPase domain, phosphorylation
Abstract In yeast Saccharomyces cerevisiae, the Dhh1 protein, a member of the DEAD-box RNA helicase, stimulates Dcp2/Dcp1- mediated mRNA decapping and functions as a general translation repressor. Dhh1 also positively regulates translation of a selected set of mRNAs, including Ste12, a transcription factor for yeast mating and pseudohyphal growth. Given the diverse functions of Dhh1, we investigated whether the putative phosphorylation sites or the conserved motifs for the DEADbox RNA helicases were crucial in the regulatory roles of Dhh1 during pseudohyphal growth. Mutations in the ATPase A or B motif (DHH1-K96R or DHH1-D195A) showed significant defects in pseudohyphal colony morphology and agar invasive phenotypes. The N-terminal phospho-mimetic mutation, DHH1-T16E, showed defects in pseudohyphal phenotypes. Decreased levels of Ste12 protein were also observed in these pseudohyphal-defective mutant cells under filamentous- inducing low nitrogen conditions. We suggest that the ATPase motifs and the Thr16 phosphorylation site of Dhh1 are crucial to its regulatory roles in pseudohyphal growth under low nitrogen conditions.