Research

Molecular mechanisms of autophagy
 
Autophagy is a central process within cells that clears and disposes of damaged cellular components, misfolded proteins, and pathogens. Autophagy functions to maintain cellular homeostasis and mitigate metabolic stress. Hallmark of autophagy is the formation of double-membrane cytosolic vesicles, termed autophagosomes, which sequester cytoplasm and deliver it to the lysosome where it is degraded and recycled. Autophagosome formation is accomplished by the concerted actions of autophagy-related (ATG) proteins. Our research program focuses on the mechanistic understanding of protein machinery mediating membrane supply for autophagosome formation. In the long-term, we aim to translate basic biological research into potential therapeutic solutions by developing and implementing drug screening projects for drug-target identification and structure-activity relationship studies.
Autophagy is a highly regulated eukaryotic process of degradation and recycling of cellular components and intracellular pathogens.
Lipid droplet dynamics
 
Lipid droplets (LD) are dynamic cytoplasmic organelles that regulate the storage and hydrolysis of neutral lipids.  They are critical for cellular lipid metabolism and energy homeostasis.
LD formation in phagocytes and other non-adipocytic cells is frequently observed phenotype in infectious, neoplastic and inflammatory conditions, and their accumulation modulates disease progression. LDs are degraded by a special form of selective autophagy (lipophagy), but can also act as active contributors to autophagosome biogenesis by providing lipid precursors for nascent autophagosomes. Our lab is dedicated to gaining mechanistic insight into lipid droplet dynamics for the autophagic process by in vitro reconstitution of macromolecular assemblies and visualization by state-of-the-art cryo-electron microscopy (cryo-EM), as well as biochemical and biophysical assays.
LDs are degraded by a special form of selective autophagy (lipophagy), but can also act as active contributors to autophagosome biogenesis.
Method development
 
One of the major focuses of the laboratory is developing and integrating mass spectrometry and cryo-EM based strategies with molecular modeling to understand the role of lipids in the regulation of membrane protein assemblies. High-resolution visualization techniques used in structural biology are often limited by heterogeneity, flexibility, and intrinsic disorder. We work towards overcoming such limitations by combining the information gained from the high-resolution techniques, such as X-ray crystallography and cryo-EM with structural information derived from mass spectrometry. This approach allows us to determine molecular structure and monitor conformational changes, topological arrangements and dynamics of proteins both in solution and at membrane surfaces. 
 
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Interior of a 300kV Titan Krios
electron microscope 
Instrument setup for hydrogen-deuterium exchange (HDX-MS) and chemical crosslinking mass spectrometry (XL-MS).   
Funding:
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Kobilka Institute of Innovative Drug Discovery
The Chinese University of Hong Kong, Shenzhen
School of Life and Health Sciences (LHS)
H.L. Tu Building, Room RB705-3
Longxiang Road 2001, Longgang district,
Shenzhen, Guangdong, China, 518172