Brian A. Lewis, Ph.D.
- Center for Cancer Research
- National Cancer Institute
- Building 10, Room 2N105
- Bethesda, MD 20892
I am interested in the regulation of transcription by RNA pol II in humans. I apply a variety of approaches to this very large, complex and important problem. The central resource of the research is a novel cell-free in vitro transcription system that recapitulates pol II pausing. This system allows me to dissect the regulation of pausing and elongation and identify the protein machinery involved in these processes. This is supported with in vivo approaches, such as shRNA depletions and small molecule inhibitors, that target this machinery in cells. A more recent addition to this toolbox is the development of an in vivo transcription assay based on 4sU-labeling of nascent RNA. These tools will allow me to expand our understanding of pol II pausing and elongation, as it is essential in order to understand the MYC oncoprotein function in stimulating pol II elongation.
Areas of Expertise
1) transcription, 2) protein purification, 3) molecular biology, 4) biochemistry
My research falls under an umbrella topic of understanding the regulation of human RNA polymerase II-directed transcription. I have three main lines of investigation currently. The first is understanding the regulation of RNA pol II pausing and elongation; the second is understanding how the MYC oncoprotein regulates those two processes; the third is directed at understanding the larger scale organization and self-assembly of the transcriptional machinery. There is considerable overlap between the three projects.
In addition to my own work, I help supervise several postdoctoral fellows in the Levens lab.
Human RNA Polymerase II Promoter Recruitment in Vitro Is Regulated by O-Linked N-Acetylglucosaminyltransferase (OGT)
Brian A. Lewis, Ph.D.
I received my Ph.D. in molecular biology from Princeton University. I did postdoctoral work with Dr. Stuart Orkin at Harvard Medical School where I discovered a novel downstream core promoter element in the human beta-globin gene. I continued this line of investigation in the lab of Dr. Danny Reinberg at the University of Medicine and Dentistry of New Jersey (UMDNJ) in order to learn the necessary transcription biochemistry. While there I worked out the protein machinery required for the function of these downstream core promoter elements and showed different elements had different factor requirements, which was quite unexpected. Additional work showed the cofactor requirements for the RARbeta nuclear hormone receptor. It is quite likely that additional cofactors for both activators and core promoter elements remain to be discovered.
I came to the NCI in 2006 on a sabbatical and have remained here since. I began my present research at that time, originally looking at the role of O-GlcNAcylation in RNA pol II transcription. This line of investigation led to the discovery of O-GlcNAc cycling regulating pol II pausing and elongation, the discovery of a cell-free pausing system, how the MYC oncoprotein regulates these processes, and the discovery of larger-scale self organization and assembly of the pol II transcriptional machinery. In 2016 I joined the lab of David Levens where I was able to continue my research and also expand into discoveries of MYC function and topoI regulation.