Exposure ofSaccharomyces cerevisiaeto Acetaldehyde Induces Sulfur Amino Acid Metabolism and Polyamine Transporter Genes, Which Depend on Met4p and Haa1p Transcription Factors, Respectively

Abstract

Acetaldehyde is a toxic compound produced by Saccharomyces cerevisiae cells under several growth conditions. The adverse effects of this molecule are important, as significant amounts accumulate inside the cells. By means of global gene expression analyses, we have detected the effects of acetaldehyde addition in the expression of about 400 genes. Repressed genes include many genes involved in cell cycle control, cell polarity, and the mitochondrial protein biosynthesis machinery. Increased expression is displayed in many stress response genes, as well as other families of genes, such as those encoding vitamin B1 biosynthesis machinery and proteins for aryl alcohol metabolism. The induction of genes involved in sulfur metabolism is dependent on Met4p and other well-known factors involved in the transcription of MET genes under nonrepressing conditions of sulfur metabolism. Moreover, the deletion of MET4 leads to increased acetaldehyde sensitivity. TPO genes encoding polyamine transporters are also induced by acetaldehyde; in this case, the regulation is dependent on the Haa1p transcription factor. In this paper, we discuss the connections between acetaldehyde and the processes affected by this compound in yeast cells with reference to the microarray data.

Effect of Low-concentration Furfural on Sulfur Amino Acid Biosynthesis in <i>Saccharomyces cerevisiae</i>

“…Although the changes in expression were slightly different from those found by microarray analysis, expression of both genes were in- 15) . A previous study showed that the sulfur metabolism pathway in S. cerevisiae is induced by acetaldehyde 16) . Acetaldehyde is produced during ethanol fermentation, so furfural might inhibit ethanol production by promoting the accumulation of intermediate compounds, such as acetaldehyde and glycerol 17) .…”

A sulphite-inducible form of the sulphite efflux gene SSU1 in a Saccharomyces cerevisiae wine yeast

“…Other studies focusing on wine yeasts have observed transcriptional control of the gene by a sulphur source (Aranda et al, 2006): methionine seems to repress SSU1, especially in the presence of sulphite. Moreover, since sulphite is an intermediate of the superpathway of sulfur amino acid biosynthesis, the expression of genes involved in this pathway (such as some MET genes) has been shown to be related with sulphite detoxification and acetaldehyde production (Aranda & del Olmo, 2004;Aranda et al, 2006).…”

Yct1p, a Novel, High-Affinity, Cysteine-Specific Transporter From the Yeast Saccharomyces cerevisiae

“…This analysis revealed an uncharacterized ORF, YLL055w, encoding a putative transporter that was specifically upregulated under sulfur-limiting conditions under both aerobiosis and anaerobiosis, similarly to other sulfur assimilatory enzymes (Boer et al 2003;Tai et al 2005). In addition, this ORF was also found to be induced in a gsh1D strain background (Wheeler et al 2003) (which has reduced intracellular levels of glutathione) and upon exposure to cadmium (Vido et al 2001;Fauchon et al 2002) or acetaldehyde (Aranda and del Olmo 2004), conditions under which most of the genes in the sulfur assimilation pathway were upregulated.…”

“…YCT1 is under sulfur regulation and is the major cysteine transporter under sulfur-derepressed conditions: As mentioned earlier, genomewide expression profiling studies have revealed that YCT1 is expressed under conditions of sulfur limitation, cadmium toxicity, lowglutathione levels, and acetaldehyde exposure, conditions under which the entire sulfur assimilation pathway has been shown to be upregulated (Vido et al 2001;Fauchon et al 2002;Boer et al 2003;Wheeler et al 2003;Aranda and del Olmo 2004;Tai et al 2005). To gain further insights into the physiological role of Yct1p, we decided to undertake a more detailed study on the expression pattern of YCT1 in response to different sulfur sources.…”

“…Cysteine is also the rate-limiting nutrient in glutathione biosynthesis (Alfafara et al 1992;Wen et al 2004), the major redox buffer and detoxification molecule in the cell. Studies have revealed that the entire sulfur assimilation pathway leading to cysteine biosynthesis is upregulated during increased cellular demands of glutathione upon exposure to heavy metals or other toxic compounds in yeasts and plants (Vido et al 2001;Fauchon et al 2002;Aranda and del Olmo 2004;Mendoza-Cozatl et al 2005). Despite the importance of cysteine in cellular metabolism, detoxification, and stress response, an increased cysteine level has been shown to be toxic to cells Kumar et al 2006).…”