Abstract 2049 Analyzing the localization of uncharacterized Atg27 Mannose-6-phosphate Receptor Domain Mutants

Autophagy, or cellular self-eating, is a process that eukaryotic organisms bring about in cases of cellular damage or environmental stress. In the budding yeast, Saccharomyces cerevisiae, one of the proteins responsible for bringing about autophagy is Atg27, a small, single-pass, membrane protein, with a cytoplasmic C-terminus and a lumenal N-terminus. While we know that the C-terminus of Atg27 is responsible for its localization to organelles like the late Golgi, the vacuole, and the endosomes, the role of its N-terminus remains unknown. The N-terminus of Atg27 is structurally predicted to be a Mannose-6-Phosphate Receptor Homology (MRH) domain. Through the use of fluorescence microscopy, we aim to better understand the consequences of mutations in this uncharacterized domain. While the MRH domain in Atg27 is like those found in mammalian cells, very little is known about the role of MRH domains in budding yeast. An analysis of the vacuolar membrane localization of Atg27 mutants abrogated for their MRH domain revealed that mutation of this putative function impacts its ability to reach the vacuole. Funding provided by Goucher College.