Living organisms experience diverse external environments throughout life; one common situation is nutrient limitation. To survive nutrient stress, eukaryotic cells utilize macroautophagy/autophagy. During autophagy, cells remove unwanted material by packaging them within double-membraned autophagosomes and delivering the cargo to vacuoles for degradation. Here, we summarize different nutrient contexts and signaling pathways that regulate autophagy, specifically in Saccharomyces cerevisiae.

Macroautophagy/autophagy is a highly conserved catabolic process vital for cellular stress responses and maintaining equilibrium within the cell. Malfunctioning autophagy has been implicated in the pathogenesis of various diseases, including certain neurodegenerative disorders, diabetes, metabolic diseases, and cancer. Cells face diverse metabolic challenges, such as limitations in nitrogen, carbon, and minerals such as phosphate and iron, necessitating the integration of complex metabolic information. Cells utilize a signal transduction network of sensors, transducers, and effectors to coordinate the execution of the autophagic response, concomitant with the severity of the nutrient-starvation condition. This review presents the current mechanistic understanding of how cells regulate the initiation of autophagy through various nutrient-dependent signaling pathways. Emphasizing findings from studies in yeast, we explore the emerging principles that underlie the nutrient-dependent regulation of autophagy, significantly shaping stress-induced autophagy responses under various metabolic stress conditions.