"Regulation of Cellular Fat Storage at the ER-lipid Droplet Interface"

Ho Yi Mak, Ph.D.
Associate Professor
Division of Life Science 
Hong Kong University of Science & Technology

ABSTRACT
Lipid droplets are evolutionarily conserved organelles for cellular fat storage.  Although close apposition of lipid droplets with the endoplasmic reticulum (ER) has been shown, the molecular mechanisms that enable their interaction and facilitate neutral fat storage are poorly understood.  We have previously shown that physical and functional coupling of lipid droplets to the ER is facilitated by a macro-molecular complex and requires an intact tubular ER network. From a forward genetic screen, we uncovered a role of atlastin, which is required for homotypic fusion of ER membranes, in regulating lipid droplet size. More recently, we propose that nano-scale interaction between ER sub-domains and lipid droplets promotes functional diversification. Using a combination of genetic and imaging approaches, we discovered that a subset of lipid droplets is surrounded by a membranous cage that favors fat storage. Our results have implications on how cellular fat storage and insulin sensitivity can be fine-tuned by lipid droplets heterogeneity.

MAK's RESEARCH
Obesity is the leading cause of type-2 diabetes, cardiovascular diseases and hypertension, the so-called Metabolic Syndrome. We are broadly interested in how body fat level is maintained in animals and how it can be disrupted through genetic and dietary perturbations. Our laboratory uses the nematode C. elegans and mammalian cells to elucidate the genetic pathways and molecular mechanisms that regulate food intake, fat storage and mobilization. Most of our studies begin with large-scale forward genetic screens in C. elegans. We then employ genetics, lipid and protein biochemistry, high-throughput sequencing technology, fluorescence microscopy and nanoscopy to address our questions at a molecular level.

Faculty host - Hang Lu, Ph.D.

The Parker H. Petit Institute for Bioengineering and Bioscience, an internationally recognized hub of multidisciplinary research at the Georgia Institute of Technology, brings engineers, scientists, and clinicians together to solve some of the world’s most complex health challenges. With 17 research centers, more than 170 faculty members, and $24 million in state-of-the-art facilities, the Petit Institute is translating scientific discoveries into game-changing solutions to solve real-world problems.