Abstract
Sodium dodecyl sulfate is a detergent that disrupts cell membranes, activates cell wall integrity signaling and restricts cell growth in Saccharomyces cerevisiae. However, the underlying mechanism of how sodium dodecyl sulfate inhibits cell growth is not fully understood. Previously, we have shown that deletion of the MCK1 gene leads to sensitivity to sodium dodecyl sulfate; thus, we implemented a suppressor gene screening revealing that the overexpression of TAT2 tryptophan permease rescues cell growth in sodium dodecyl sulfate-treated Δmck1 cells. Therefore, we questioned the involvement of tryptophan in the response to sodium dodecyl sulfate treatment. In this work, we show that trp1-1 cells have a disadvantage in the response to sodium dodecyl sulfate compared to auxotrophy for adenine, histidine, leucine or uracil when cells are grown on rich media. While also critical in the response to tea tree oil, TRP1 does not avert growth inhibition due to other cell wall/membrane perturbations that activate cell wall integrity signaling such as Calcofluor White, Congo Red or heat stress. This implicates a distinction from the cell wall integrity pathway and suggests specificity to membrane stress as opposed to cell wall stress. We discovered that tyrosine biosynthesis is also essential upon sodium dodecyl sulfate perturbation whereas phenylalanine biosynthesis appears dispensable. Finally, we observe enhanced tryptophan import within minutes upon exposure to sodium dodecyl sulfate indicating that these cells are not starved for tryptophan. In summary, we conclude that internal concentration of tryptophan and tyrosine makes cells more resistant to detergent such as sodium dodecyl sulfate.
Highlights
In the wild, yeast cells experience a variety of external conditions that cause stress, such as changes in resource availability, temperature, osmotic fluctuations, oxidation, noxious chemicals, pressure and physical stress
We found that the TAT2 plasmid did not rescue Δmck1 sensitivity to stress in yeastSodium Dodecyl Sulfate (SDS) on synthetic media plates (SD) (S1 Fig) indicating that TAT2 plays a role in the response to membrane stress when excess amount of amino acids and/or other components in rich media are available
It is known that during times of stress or nutrient starvation, Tat2p is sorted to the vacuole for degradation and tryptophan uptake is maintained by Gap1p, the General Amino acid Permease [31,32,33,34]
Summary
Yeast cells experience a variety of external conditions that cause stress, such as changes in resource availability, temperature, osmotic fluctuations, oxidation, noxious chemicals, pressure and physical stress. We found that the TAT2 plasmid did not rescue Δmck1 sensitivity to SDS on synthetic media plates (SD) (S1 Fig) indicating that TAT2 plays a role in the response to membrane stress when excess amount of amino acids and/or other components in rich media are available. We found that the presence of wild type TRP1 in BY4741 cells confers resistance to SDS-induced growth inhibition on YPD plates containing SDS (Fig 1C, rows 3 and 4).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
