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. |