Email
sjp54@cornell.edu

Research Interests

The Lis lab is interested in understanding the molecular mechanisms of transcriptional activation and efficient elongation of RNA Polymerase II (Pol II). One ubiquitous barrier that Pol II must overcome to efficiently transcribe genes is imposed by nucleosomes and higher order chromatin structures. How Pol II and its battery of transcriptional factors are able to overcome this barrier has been a long standing question in the transcription and chromatin fields and is the focus of my research in the Lis lab. To try and answer this question I use high-resolution micrococcal nuclease mapping and chromatin immunoprecipitation to track the position and composition of nucleosomes in vivo. These techniques provide the high spatial and temporal resolution needed to address how nucleosomes are changing as transcription is activated and Poll II elongates into the gene. Additionally, I employ other techniques such as RNAi and chemical inhibition that allow me to interrogate how a specific factor affects chromatin structure in vivo.

Education

• B.S. in Chemistry (2005) Harvey Mudd College, Claremont, CA

Previous Research Experience

• 2004-2005 Undergraduate research, "Location Mechanism of Adenine-8-Oxoguanine Mismatches by MutY Adenine DNA Glycosylase," Harvey Mudd College, Advisor: Dr. Karl Haushalter

Publications

• Petesch SJ and Lis JT (2008) "Rapid, Transcription-Independent Loss of Nucleosomes over a Large Chromatin Domain at Hsp70 Loci." Cell 134(1): 74-84. (PubMed)
  
• Van Ryswyk H, Hall EW, Petesch SJ, Wiedeman AE (2007) "Extending the Marine Microcosm Laboratory." Journal of Chemical Education 84: 306-309.

Abstracts and Talks

• Steven Petesch and John Lis (2008). Extensive nucleosome disruption prior to RNA Polymerase II passage across the entire Drosophila Hsp70 gene. FASEB Summer Research Conferences: Transcriptional Regulation During Cell Growth, Differentiation and Development. Poster Presentation. June 22-27, 2008. Snowmass, CO.
  
• Steven Petesch, Karl A. Haushalter (2005).  How does the DNA glycosylase MutY repair nucleosomal DNA?.  229th National Meeting of the American Chemical Society. Poster Presentation.  March 13-17, 2005.  San Diego, CA.

Awards

• “Outstanding Graduate Teaching Assistant” in the department of Molecular Biology and Genetics, Cornell University, May 2007.