Britney Weng L&S Sciences
Applying Proximity-Assisted Photoactivation to Study PTEF-b Regulation
In humans, Positive Transcription Elongation Factor b (P-TEFb) is an RNA Polymerase II regulator crucial for proper gene expression. To execute its regulatory function, P-TEFb itself is precisely regulated via reversible interactions with an snRNP complex. Using biochemical techniques, past studies have confirmed LARP7, HEXIM1, and BRD4 to be protein partners of P-TEFb. My project aims to study the dynamic regulatory role of known protein partners LARP7, HEXIM1, and BRD4 in P-TEFb regulation. I will apply a new technique called proximity-assisted photoactivation (PAPA) to single particle tracking (SPT) and live cell imaging in order to examine protein-protein interactions between P-TEFb and each protein partner in human osteosarcoma cells. PAPA involves a sender fluorophore reactivating a receiver fluorophore when the two are in proximity. By tagging P-TEFb and each partner with these fluorophores, PAPA can be used to detect their interaction corresponding to the sub-population of protein complexes showing sender and receiver fluorescence.