BIOCHEMISTRY, MOLECULAR & CELL BIOLOGY FIELD SEMINAR – Qingqing Huang (Fromme Lab). Wednesday, April 9th, 2025 – 12:15 PM | 146 Stocking Hall.

Anr2 – A Novel Arf1 GAP on Lipid Droplets.

Arf1 is an essential GTPase regulating vesicular trafficking and maintaining the structural integrity and functional organization of the Golgi apparatus. Although the role of Arf1 at the Golgi is well-characterized, its function on lipid droplets remains less understood. An AlphaFold interaction screen against Arf1 in Saccharomyces cerevisiae was performed by our lab and Avl9 family proteins were found to be among the potential interactors. Our hypothesis is that Avl nine-related family 2 (Anr2) on lipid droplets acts as a GTPase activating protein (GAP) regulating the activity of Arf GTPases, most likely Arf1, participating in lipid metabolism and dynamics. In this seminar, I will present my preliminary data examining the molecular function of Anr2 as an Arf1 GAP using in vivo live-cell microscopy and in vitro GAP assays. Furthermore, I will briefly talk about Anr2 cellular function based on the phenotype of cells lacking Anr2 exhibiting smaller lipid droplets and fragmented mitochondria. I will also discuss my plans to perform TurboID proximity labelling to identify potential interactors. This study will add a significant layer to our understanding of broader Arf1 regulation not just at the Golgi, but also on lipid droplets, suggesting a novel regulatory mechanism impacting key cellular processes.

Committee: Chris Fromme, Richard Cerione, Richa Sardana, Martin Graef.