Pdr18 is involved in yeast response to acetic acid stress counteracting the decrease of plasma membrane ergosterol content and order

Abstract

Saccharomyces cerevisiae has the ability to become less sensitive to a broad range of chemically and functionally unrelated cytotoxic compounds. Among multistress resistance mechanisms is the one mediated by plasma membrane efflux pump proteins belonging to the ABC superfamily, questionably proposed to enhance the kinetics of extrusion of all these compounds. This study provides new insights into the biological role and impact in yeast response to acetic acid stress of the multistress resistance determinant Pdr18 proposed to mediate ergosterol incorporation in plasma membrane. The described coordinated activation of the transcription of PDR18 and of several ergosterol biosynthetic genes (ERG2-4, ERG6, ERG24) during the period of adaptation to acetic acid inhibited growth provides further support to the involvement of Pdr18 in yeast response to maintain plasma membrane ergosterol content in stressed cells. Pdr18 role in ergosterol homeostasis helps the cell to counteract acetic acid-induced decrease of plasma membrane lipid order, increase of the non-specific membrane permeability and decrease of transmembrane electrochemical potential. Collectively, our results support the notion that Pdr18-mediated multistress resistance is closely linked to the status of plasma membrane lipid environment related with ergosterol content and the associated plasma membrane properties.

The Paralogous Genes PDR18 and SNQ2, Encoding Multidrug Resistance ABC Transporters, Derive From a Recent Duplication Event, PDR18 Being Specific to the Saccharomyces Genus

“…Several A TP- b inding c assette (ABC) transporters that catalyze the ATP-dependent active solute transport across cell membranes in yeasts are associated with multidrug/multixenobiotic resistance (MDR/MXR) ( Jungwirth and Kuchler, 2006 ; Monk and Goffeau, 2008 ; Piecuch and Obłak, 2014 ). Although these transporters are usually considered drug/xenobiotic pumps, evidence is arising supporting the idea that their involvement in MDR/MXR may result from their specific and, in general, not yet determined biological role in the active transport of physiological substrates ( Prasad and Panwar, 2004 ; Cabrito et al, 2011 ; Prasad et al, 2016 ; Godinho et al, 2018 ). Moreover, the presence of a large number of ABC transporters involved in MDR/MXR in the genomes of yeasts and other organisms, from bacteria to man, also strongly suggests that these transporters may play important physiological roles even in the absence of the cytotoxic compounds to which they confer resistance.…”

“…The S. cerevisiae plasma membrane transporter Pdr18 was described as a MDR/MXR determinant required for ergosterol transport at the plasma membrane level ( Cabrito et al, 2011 ; Teixeira et al, 2012 ; Godinho et al, 2018 ). Pdr18 expression was found to lead to increased yeast tolerance to the herbicides 2,4-dichlorophenoxyacetic acid (2,4-D), 2-methyl-4-chlorophenoxyacetic acid (MCPA), and barban, the agricultural fungicide mancozeb, the metal cations Zn 2+ , Mn 2+ , Cu 2+ , and Cd 2+ ( Cabrito et al, 2011 ) and to ethanol ( Teixeira et al, 2012 ) and acetic acid ( Godinho et al, 2018 ). The involvement of Pdr18 in the maintenance of yeast plasma membrane ergosterol content under 2,4-D or acetic acid stresses was related with its role as a determinant of resistance to multiple stresses in yeast ( Cabrito et al, 2011 ; Teixeira et al, 2012 ; Godinho et al, 2018 ).…”

“…Pdr18 expression was found to lead to increased yeast tolerance to the herbicides 2,4-dichlorophenoxyacetic acid (2,4-D), 2-methyl-4-chlorophenoxyacetic acid (MCPA), and barban, the agricultural fungicide mancozeb, the metal cations Zn 2+ , Mn 2+ , Cu 2+ , and Cd 2+ ( Cabrito et al, 2011 ) and to ethanol ( Teixeira et al, 2012 ) and acetic acid ( Godinho et al, 2018 ). The involvement of Pdr18 in the maintenance of yeast plasma membrane ergosterol content under 2,4-D or acetic acid stresses was related with its role as a determinant of resistance to multiple stresses in yeast ( Cabrito et al, 2011 ; Teixeira et al, 2012 ; Godinho et al, 2018 ). A coordinated response involving the transcriptional activation of PDR18 and several ergosterol biosynthetic genes was found to occur in response to acetic acid stress, strongly suggesting the involvement of Pdr18 in ergosterol homeostasis in stressed yeast cells ( Godinho et al, 2018 ).…”

“…The involvement of Pdr18 in the maintenance of yeast plasma membrane ergosterol content under 2,4-D or acetic acid stresses was related with its role as a determinant of resistance to multiple stresses in yeast ( Cabrito et al, 2011 ; Teixeira et al, 2012 ; Godinho et al, 2018 ). A coordinated response involving the transcriptional activation of PDR18 and several ergosterol biosynthetic genes was found to occur in response to acetic acid stress, strongly suggesting the involvement of Pdr18 in ergosterol homeostasis in stressed yeast cells ( Godinho et al, 2018 ). Moreover, the proposed role for Pdr18 in ergosterol homeostasis was demonstrated to be important to counteract acetic acid-induced decrease of plasma membrane lipid order, increase of plasma membrane non-specific permeability and decrease of transmembrane electrochemical potential ( Godinho et al, 2018 ).…”

Improved bioconversion of lignocellulosic biomass by Saccharomyces cerevisiae engineered for tolerance to acetic acid

“…Studies on identifying mechanisms involved in yeast stress response to acetic acid have also provided insights into tolerance engineering and offered novel candidate genes (Meijnen et al, ; Mira, Palma, Guerreiro, & Sa‐Correia, ). The previous rational engineering involved the direct manipulation of known genetic factors associated with acid transcriptional regulation ( HAA1 , MSN2 ), metal metabolism ( AFT1 ), purine biosynthesis ( ADE1 , ADE13 , ADE17 ), plasma membrane ergosterol synthesis ( ERG ‐genes and PDR18 ), and others (Chen et al, ; Godinho et al, ; Oh et al, ; Tanaka, Ishii, Ogawa, & Shima, ; Zhang et al, ). However, due to the complex trait of the acetic acid stress response and the limited understanding of coordinated regulations of multiple genes (Ling, Teo, Chen, Leong, & Chang, ), it is still challenging to discover a set of effective gene targets for efficient sugar fermentation under acidic stress via knowledge‐based rational engineering approaches.…”