There are currently several active projects in our laboratory. These projects are essentially focused on either on DNA/RNA structure or interaction of DNA with relevant proteins. We use single molecule fluorescence microscopy techniques as the main tool. In particular, single molecule Förster Resonance Energy Transfer (FRET) and high resolution particle tracking are the methods commonly used in our laboratory. Our methods take advantage of the high signal to noise ratio provided by total internal reflection to achieve single molecule resolution.
1) A guanine-rich sequence in the promoter region of Thyrosine Hydroxylase regulates its activity
Aberrant TH expression is linked to many psychiatric problems including bipolar disorder, manic depression, Parkinson’s disease, and schizophrenia. To address this problem, we are studying a 45 nt segment of human TH promoter containing seven stretches of Gs’ located within a conserved region and is just 24 nucleotide upstream of the transcription start site. It is hypothesized that this G-rich segment can adopt multiple GQ structures that vary in stability and conformation and is a key regulatory element in TH promoter. Preliminary studies on this 45 nt DNA and a subset of its fragments suggest the presence of multiple GQs that vary in stability and conformation. This project aims to characterize the dynamicity and variability in conformations associated with the ensemble of GQs formed in the 45 nt segment by utilizing the unique capabilities of single molecule FRET in combination with other biophysical and biochemical techniques.
2) G-Quadruplex unfolding activity of Replication Protein A