Regulation of Catalase Expression and Activity by Dh Hog1 in the Halotolerant Yeast Debaryomyces hansenii Under Saline and Oxidative Conditions

• Published in: Journal of fungi (Basel) 2024-10, Vol.10 (11)
• Main Authors: de la Fuente-Colmenares, Ileana, González, James, Sánchez, Norma Silvia, Ochoa-Gutiérrez, Daniel, Escobar-Sánchez, Viviana, Segal-Kischinevzky, Claudia
• Format: Article
• Language: English
• ISSN: 2309-608X

Efficient transcriptional regulation of the stress response is critical for microorganism survival. In yeast, stress-related gene expression, particularly for antioxidant enzymes like catalases, mitigates reactive oxygen species such as hydrogen peroxide (H O ), preventing cell damage. The halotolerant yeast shows oxidative stress tolerance, largely due to high catalase activity from and genes. This study evaluates s response to oxidative stress caused by H O under saline conditions, focusing on cell viability, gene expression, and catalase activity. Chromatin organization in the promoter of and was analyzed, revealing low nucleosome occupancy in promoter regions, correlating with active gene expression. Stress-related motifs for transcription factors like Msn2/4 and Sko1 were found, suggesting regulation by the MAP kinase. Analysis of a Δ mutant showed Hog1's role in expression under H O or NaCl conditions. These findings highlight Hog1's critical role in regulating the stress response in , offering insights for enhancing stress tolerance in halotolerant yeasts, particularly for industrial applications in saline wastewater management.