Research
Mechanisms of Eukaryotic Transcription
The overall objective of my research is to gain a better understanding of the regulation of transcription by eukaryotic RNA polymerases II and III (Pol II and III). Transcriptional regulation plays a fundamental role in all biological processes and has profound significance in development, virology and cancer research. Research in my lab uses genetic, biochemical, and biophysical methods to study the macromolecular interactions that regulate RNA Polymerases. The main research focuses are described as follows:
I. Protein Interactions in the Pol II and III Transcription Complexes
I have developed a series of in vitro assays utilizing site-specific photocrosslinking and hydroxyl-radical cleavage to identify specific protein interactions within fully assembled and functional Pol II pre-initiation complex (PIC). These assays have been used to identify the PIC-specific binding targets of individual transcription factors from the model organism Saccharomyces cerevisiae (yeast). The findings have important implications for understanding the architecture of the PIC, as well as revealing a mechanism for Pol II transcription start site selection. I will further investigate protein interactions in the complex assemblies during all stages of the Pol II transcription cycle. The biochemical approach will also be applied to investigate the mechanisms of Pol III transcriptional regulation.
II. Biophysical Studies of the Transcription Machinery
I am interested in applying a hybrid approach to determine the structural models of macromolecular complexes during the transcription cycle. I plan to develop a new biophysical method utilizing single-pair fluorescence resonance energy transfer (spFRET) to obtain site-specific distance parameters between protein pairs in transcription complexes. Structural information derived from spFRET will be combined with high-resolution structures of individual transcription factors and complexes to elucidate the structural organization, conformational changes, and reaction kinetics of the transcription machinery.
