Related Experiment Video
Updated: Jun 7, 2025

Exploring the Regulation of Lipid Droplet Catabolism through Lipophagy
Published on: January 31, 2025
VPS4A is the selective receptor for lipophagy in mice and humans
Debajyoti Das1, Mridul Sharma1, Deepanshi Gahlot2
1Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA; Division of Digestive Diseases, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.
Abstract:
Lipophagy is a ubiquitous mechanism for degradation of lipid droplets (LDs) in lysosomes. Autophagy receptors selectively target organelles for lysosomal degradation. The selective receptor for lipophagy remains elusive. Using mouse liver phosphoproteomics and human liver transcriptomics, we identify vacuolar-protein-sorting-associated protein 4A (VPS4A), a member of a large family AAA+ ATPases, as a selective receptor for lipophagy. We show that phosphorylation of VPS4A on Ser95,97 and its localization to LDs in response to fasting drives lipophagy. Imaging/three-dimensional (3D) reconstruction and biochemical analyses reveal the concomitant degradation of VPS4A and LDs in lysosomes in an autophagy-gene-7-sensitive manner. Either silencing VPS4A or targeting VPS4AS95,S97 phosphorylation or VPS4A binding to LDs or LC3 blocks lipophagy without affecting other forms of selective autophagy. Finally, VPS4A levels and markers of lipophagy are markedly reduced in human steatotic livers-revealing a fundamental role of VPS4A as the lipophagy receptor in mice and humans.
Related Concept Videos
Receptor-mediated Endocytosis
Delivery Pathways to the Lysosome
Endocytosis
In endocytosis, the cell membrane takes up macromolecules and particles from the surrounding medium. Clathrin-mediated...
Receptor Downregulation in MVBs
The EGFR can initiate signaling pathways that lead to cell proliferation, migration, and differentiation. Overexpression of EGFR stimulates cells to proliferate. Excessive EGFR...

