Research

Research focus 1: To elucidate molecular mechanisms regulating surface delivery of signaling receptors and signaling molecules in the secretory pathway

Signal transduction pathway is initiated by the interaction between signaling receptors on the target cell and signal molecules secreted by the producing cell. Although fundamentally important, it remains largely unclear how newly synthesized signal molecules and signal receptors are delivered to the plasma membrane to perform their physiological functions.

Utilizing systematic biochemical and cell biological approaches, we aim to understand the sorting and surface delivery of various transmembrane signaling receptors (planar cell polarity proteins and EGFR) and soluble signaling molecules (sonic hedgehog, Insulin-like growth factor-2, and collagen) in the secretory pathway. These analyses provide novel insights into biosynthetic trafficking of these cargo proteins that is critical for them to perform their physiological functions. Our study also provides useful guidance on the development of novel inhibitors to downregulate the activity of a specific signaling receptor or signaling molecule by blocking its surface delivery process.

Research focus 2: To investigate protein profiling of transport vesicles

What are the spectrum of cargo proteins that depends on a specific cellular factor to be enriched into transport vesicles? What are the binding partners of a cellular factor on the vesicle membrane that regulate membrane trafficking? Which cellular factors co-enrich with specific cargo in trans Golgi network (TGN)-derived vesicles to regulate targeting and fusion of vesicles to the target membranes? To address these questions, we have developed a large scale vesicle formation assay in combination with quantitative mass spectrometry analysis to profile proteins associated with transport vesicles. This method allows us to profile proteins associated with transport vesicles. Our goal is to use this approach to identify cargo clients that depend on a particular cellular factor for packaging into transport vesicles. Additionally, we aim to uncover novel factors associated with vesicles that mediate trafficking.