Gene Expression; Molecular and Cellular Biology; Molecular Basis of Disease; Molecular genetics; Protein Function and Structure; Transcription and Translation
Our laboratory utilizes combined genetic, biochemical and molecular biological approaches to investigate the molecular mechanisms involved in the initiation and regulation of eukaryotic transcription. Previous work in our laboratory utilizing both the budding yeast Saccharomyces cerevisiae and human cells resulted in the identification and biochemical characterization of mutants of nuclear RNA polymerase II (RNAPII) and the general transcription factors TFIIB and TFIIF that coordinately affect transcription start site utilization and transcript elongation. These studies supported a model where yeast and human TFIIF induce global conformational changes in RNAPII that result in structural and functional changes in the polymerase active center.
Our current studies are focused on elucidating the mechanisms of kinetoplast transcription by the mitochondrial RNA polymerase of Trypanosoma brucei. T. brucei is a protozoan parasite that is the causative agent of African sleeping sickness (trypanosomiasis) in humans and nagana in animals. Procyclic trypanosomes growing in the midgut of the tsetse fly have a fully functional mitochondrion whereas trypanosomes in the mammalian bloodstream exhibit repressed mitochondrial function. The mitochondrial DNA in trypanosomes is unusual in its structure, comprising a highly catenated network of maxicircles and minicircles termed kinetoplast DNA (kDNA). Surprisingly, very little is known about the cis-acting elements and the trans-acting factors governing the transcription of maxicircles and minicircles. Our objective is to elucidate the mechanisms and regulation of T. brucei kDNA transcription with the ultimate goal of developing therapeutic agents.