Identification of a regulatory element for yeast tryptophan permease Tat2 ubiquitination using high hydrostatic pressure

ABSTRACT

Tryptophan uptake in the yeast Saccharomyces cerevisiae is extremely sensitive to high pressure; therefore, the growth of tryptophan auxotrophic strains is impaired. Degradation of tryptophan permease Tat2 is enhanced at 25 MPa, depending on Rsp5 ubiquitin ligase. Any defect in Tat2 ubiquitination confers high pressure growth capacity, which is a luminous phenotype of the yeast used to explore the mechanism by which Rsp5 mediates Tat2 ubiquitination. Here we show that the N-terminal four (K17, K20, K29, and K31) among five lysines are required for efficient Tat2 degradation under high pressure. We found that a domain spanning D70 to S76 is also critical for Tat2 degradation at 25 MPa probably because of the recognition by Bul1, an adaptor protein of Rsp5. Defects in Tat2 ubiquitination do not produce any remarkable mutant phenotype at 0.1 MPa. Therefore, we suggest that high pressure is a unique and advanced tool to explore ubiquitination-dependent Tat2 regulation.

KEYWORDS:

• Saccharomyces cerevisiae
• tryptophan permease Tat2
• Rsp5 ubiquitin ligase
• Rsp5-binding protein Bul1
• high pressure growth

Acknowledgements

We thank Satoshi Uemura, and Goyu Kurosaka for useful discussions. This work was supported by a grant from the Japan Society for the Promotion of Science (no. 18K05397 to F. Abe) and the Program for the Strategic Research Foundation at Private Universities by the Ministry of Education, Culture, Sports, Science, and Technology (2013–2017).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by a grant from the Japan Society for the Promotion of Science (no. 18K05397 to F. Abe) and the Program for the Strategic Research Foundation at Private Universities by the Ministry of Education, Culture, Sports, Science, and Technology (2013–2017).