Glucose Stress Response Through the PKA-Msn2 Axis in Saccharomyces cerevisiae
TL;DR
Investigating how PKA regulates Msn2 subcellular localization and its impact on expression of PRC1, a representative vacuolar lumenal hydrolase, reveals that PKA-mediated regulation of Msn2 is essential for glucose stress responses and provides insight into how signaling pathways control PRC1 expression in yeast.
Abstract
Cellular adaption to glucose availability requires precise coordination between signaling pathways and gene expression. In Saccharomyces cerevisiae, the vacuole serves as a metabolic hub whose protein composition and activity are dynamically regulated to nutrient availability. Additionally, the Protein Kinase A (PKA) pathway is a central mediator of glucose stress response, acting through the transcriptional factor Msn2. However, how PKA-Msn2 axis connects environmental cues to vacuolar gene expression remains poorly understood. In this study, we investigate how PKA regulates Msn2 subcellular localization and its impact on expression of PRC1, a representative vacuolar lumenal hydrolase. By combining Msn2 subcellular localization and gene expression analysis, we found glucose limitation induces PRC1 expression, which reduced after deletion of Msn2/4 and disruption of Stress Response Elements (STRE) in PRC1 promoter. Furthermore, reduced PKA activity is associated with nuclear accumulation of Msn2 and enhanced PRC1 expression, whereas deletion of Msn2/4 attenuates this effect. Results reveal that PKA-mediated regulation of Msn2 is essential for glucose stress responses and provide insight into how signaling pathways control PRC1 expression in yeast.