Transcriptome profiling based on the presence of Usf2 and nutrient starvation

Intricate regulation of lysosome and autophagy processes is essential for maintaining cellular homeostasis and basal metabolism. While the consequences of disrupting or attenuating lysosome and autophagy systems have been extensively studied, little is known about the impact of hyper-activation of lysosomal and autophagy genes on homeostasis. Our research uncovers previously unknown transcriptional repression mechanism by upstream stimulatory factor 2 (USF2), which inhibits lysosomal and autophagy genes in nutrient-rich conditions. USF2 binds to the CLEAR motif within lysosomal genes along with HDAC1, which diminishes H3K27 acetylation levels, restrains chromatin accessibility, and lowers lysosomal gene expression. Under starvation, USF2 competes with TFEB, a master transcriptional activator of lysosomal and autophagy genes, to bind target gene promoters in phosphorylation-dependent manner. Phosphorylation of the S155 site by GSK3b plays a pivotal role in controlling USF2's DNA binding activity for the repression of lysosomal genes while GSK3b-mediated phosphorylation of TFEB enhances its cytoplasmic retention. Applying these discoveries has potential for treating diseases associated with protein aggregation, including alpha-1 antitrypsin deficiency. These findings demonstrate that the USF2 repression mechanism could be a potent therapeutic strategy for various lysosome and autophagy-related diseases. Overall design: To investigate the roles of Usf2 in the regulation of autophagy and lysosome, we performed mRNA expression profiles of Usf2 WT and Usf2 KO MEF cells with normal media, glucose starvation media, or amino acid starvation media