Membrane dynamics and protein targets of lipid droplet microautophagy during ER stress-induced proteostasis in the budding yeast, Saccharomyces cerevisiae.

ABSTRACT: Our previous studies reveal a mechanism for lipid droplet (LD)-mediated proteostasis in the endoplasmic reticulum (ER) whereby unfolded proteins that accumulate in the ER in response to lipid imbalance-induced ER stress are removed by LDs and degraded by microlipophagy (µLP), autophagosome-independent LD uptake into the vacuole (the yeast lysosome). Here, we show that dithiothreitol- or tunicamycin-induced ER stress also induces µLP and identify an unexpected role for vacuolar membrane dynamics in this process. All stressors studied induce vacuolar fragmentation prior to µLP. Moreover, during µLP, fragmented vacuoles fuse to form cup-shaped structures that encapsulate and ultimately take up LDs. Our studies also indicate that proteins of the endosome sorting complexes required for transpor

SUBMITTER: Garcia EJ 

PROVIDER: S-EPMC8496710 | biostudies-literature | 2021 Sep

REPOSITORIES: biostudies-literature