RESEARCH ARTICLE The VFH1 (YLL056C) promoter is vanillin‐inducible and enables mRNA translation despite pronounced translation repression caused by severe vanillin stress in Saccharomyces cerevisiae Trinh Thi My Nguyen 1,2 | Yoko Ishida 1 | Sae Kato 1 | Aya Iwaki 1 | Shingo Izawa 1 1 Department of Applied Biology, Graduate School of Science and Technology, Kyoto Institute of Technology, Matsugasaki, Kyoto, Japan 2 Department of Molecular and Environmental Biotechnology, University of Science, Vietnam National University in Ho Chi Minh City, Ho Chi Minh City, Vietnam Correspondence Shingo Izawa, Department of Applied Biology, Graduate School of Science and Technology, Kyoto Institute of Technology, Matsugasaki, Kyoto, Japan Email: thioredoxin@kit.ac.jp Funding information Japan Society for the Promotion of Science, Grant/Award Numbers: 26292039, 17H03795 and 15J08781; Nagase Science and Technology Foundation; Noda Institute for Scientific Research Abstract Vanillin, furfural and 5‐hydroxymethylfurfural (HMF) are representative fermentation inhibitors generated during the pretreatment process of lignocellulosic biomass in bioethanol production. These biomass conversion inhibitors, particularly vanillin, are known to repress translation activity in Saccharomyces cerevisiae. We have reported that the mRNAs of ADH7 and BDH2 were efficiently translated under severe vanillin stress despite marked repression of overall protein synthesis. In this study, we found that expression of VFH1 (YLL056C) was also significantly induced at the protein level by severe vanillin stress. Additionally, we demonstrated that the VFH1 promoter enabled the protein synthesis of other genes including GFP and ALD6 under severe vanillin stress. It is known that transcriptional activation of VFH1 is induced by furfural and HMF, and we verified that Vfh1 protein synthesis was also induced by furfural and HMF. The null mutant of VFH1 delayed growth in the presence of vanillin, furfural and HMF, indicating the importance of Vfh1 for sufficient tolerance against these inhibitors. The protein levels of Vfh1 induced by the inhibitors tested were markedly higher than those of Adh7 and Bdh2, suggesting the superior utility of the VFH1 pro- moter over the ADH7 or BDH2 promoter for breeding optimized yeast strains for bioethanol production from lignocellulosic biomass. KEYWORDS 5‐hydroxymethylfurfural, furfural, lignocellulosic biomass, translation repression, vanillin, YLL056C 1 | INTRODUCTION The saccharification pretreatment of lignocellulosic biomass inevitably produces biomass conversion inhibitors including vanillin, furfural and 5‐hydroxymethylfurfural (HMF) as byproducts (Antal, Mok, & Richards, 1990; Klinke, Thomsen, & Ahring, 2004; Lu, Yamauchi, Phaiboonsilpa, et al., 2009; Piotrowski, Zhang, Bates, et al., 2014). Since they strongly inhibit the growth of yeast cells and subsequent alcoholic fermentation, their toxicity to yeast cells obstructs the effi- cient and economical production of second‐generation bioethanol from lignocellulosic biomass (Helle, Cameron, Lam, et al., 2003; Jönsson, Alriksson, & Nilvebrant, 2013; Klinke et al., 2004; Palmqvist & Hahn‐Hägerdal, 2000). Vanillin is a lignin‐derived product and one of the most serious stressors to yeast cells in lignocellulose hydrolysates (Klinke et al., 2004). Previous studies reported that severe vanillin stress (>7.5 mM) causes bulk translation repression and induces the formation of P‐bodies and stress granules in Saccharomyces cerevisiae (Iwaki, Ohnuki, et al., 2013; Nguyen, Kitajima, & Izawa, 2014, 2015). On the other hand, we recently showed that the mRNAs of ADH7 gene (encoding a NADPH‐dependent alcohol dehydrogenase) and BDH2 gene (encoding a putative medium‐chain alcohol dehydrogenase) may be preferentially translated despite the pronounced translation repression caused by severe vanillin stress (Ishida, Nguyen, Kitajima, et al., 2016; Nguyen, Iwaki, & Izawa, 2015). Since Adh7 and Bdh2 are important for vanillin detoxification, the induced expression of Received: 19 October 2017 Revised: 28 February 2018 Accepted: 3 March 2018 DOI: 10.1002/yea.3313 Yeast. 2018;35:465–475. Copyright © 2018 John Wiley & Sons, Ltd. wileyonlinelibrary.com/journal/yea 465