Examination of the autophagy regulating gene ARL3 in Saccharomyces cerevisiae

Abstract

Autophagy is a process critical to maintain cellular homeostasis. This study reviews published literature on a gene important to autophagy in Saccharomyces cerevisiae, ARL3. Arl3p belongs to the Arf-like family of proteins, and is known through both wide-scale genetic screening and highly specific studies to play a role in vesicle transport of compounds from the Golgi apparatus to the endosome. Upon N-terminal acetylation by NatCp, Arl3p localizes to the trans-Golgi network where it is activated by the membrane protein Sys1p. Physical and genetic interactions have been found in studies between Arl3p and Arl1p, which act in a cascade to influence both the conserved oligomeric Golgi complex, as well as to activate vesicle tethering factor Imh1p. This is relevant in the cytoplasm-to-vacuole pathway, an important homeostatic pathway in selective autophagy. Null mutant strains of arl3 have been found to result in a decrease in aminopeptidase I maturation, an important protein for the formation of the phagophore during autophagy, and fragmented vacuoles due to loss of Imh1p localization. Future research directions include investigations of the specific mechanisms of interactions between Arl3p and its associated proteins, with applications for improved human cell viability.