Ume6 Coordinates Lysosomal Remodeling and Autophagy Through Transcriptional Repression in S. cerevisiae

Lysosome function and autophagy are highly regulated processes that must be coordinated to enable cellular adaptation to stress. However, the transcriptional mechanisms linking these pathways remain incompletely understood. Here, we identify Ume6 as a transcriptional repressor that regulates vacuolar protein composition and autophagy in Saccharomyces cerevisiae (budding yeast). Dysregulation of Ume6 alters vacuolar protein composition through two distinct mechanisms: increased abundance of multiple vacuolar components and enhanced degradation of selected vacuolar membrane proteins by elevated expression of the vacuolar E3 ubiquitin ligases. UME6 deletion also increases autophagic activity, whereas UME6 overexpression delays autophagy induction. Furthermore, we find that Ume6 coordinates with another transcriptional repressor, Rph1, and its regulatory activity is regulated by multiple protein kinases, including Rim15, Rim11, and Mck1. Together, our study reveal a broad transcriptional regulatory mechanism through which Ume6 coordinates vacuolar protein composition and autophagy, providing new insights into the regulation of lysosome-related functions in response to cellular stress.