Mol Biol Rep 2018 Oct 31;45(5):1311-1319. Epub 2018 Jul 31.
Biodiversity and Biotechnological Resource Research Unit, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Thailand Science Park, Phahonyothin Road, Khlong Nueng, Khlong Luang, Pathum Thani, 12120, Thailand.
In yeast, the accumulation of unfolded proteins in the ER triggers the unfolded protein response (UPR) pathway, which is mediated by Hac1 transcription factor. Here, we characterized the function of a gene encoding Hac1 in the thermotolerant methylotrophic yeast Ogataea thermomethanolica TBRC656 (OtHAC1). OtHAC1 mRNA contains a non-canonical intron of 176 nt, which was demonstrated to be spliced by RT-PCR. To characterize the function of this gene, we compared the proteome of a Othac1 mutant with wild-type. A total of 463 proteins with differential abundance were detected. The functions of these proteins were annotated in oxidative stress, metabolic pathways, transcription, translation, and of particular interest in secretory pathway. While many intracellular proteins differentially expressed in the mutant were similar to proteins with altered expression in UPR-stressed Saccharomyces cerevisiae, two novel OtHAC1-dependent proteins (Iml1 and Npr2) were identified that are potentially involved in the regulation of autophagy. The data show that OtHAC1 is an important regulator of several different processes in O. thermomethanolica TBRC656.