Stephen Buratowski, Ph.D. (He/ Him/ His)
Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School
Member, Harvard Center for Cancer Research
The Buratowski Lab studies eukaryotic gene transcription, chromatin regulation, and RNA processing using a wide range of biochemical, molecular, and genetic techniques.
The Buratowski lab studies eukaryotic gene expression, focusing on mRNA transcription and processing. Our lab has made fundamental contributions to the understanding of transcription activation, initiation, elongation, and termination. These studies include the mechanisms by which mRNA processing and histone modifying enzymes are coupled to transcription, and how non-coding RNA transcription is used to modulate gene expression. The Buratowski lab is particularly known for its work on the C-terminal domain (CTD) of the RNA polymerase II largest subunit, Rpb1. Our work revealed the "CTD code", a programmed series of phosphorylations and dephosphorylations create dynamic patterns that direct binding of various transcription-coupled factors to specific stages of transcription.
Research in the lab primarily uses the yeast Saccharomyces cerevisiae, a model system that allows a powerful combination of genetics, genomics, and biochemical approaches to be used. In recent years, our lab has been using two technologies particularly suited for Biophysics students: quantitative mass spectrometry and single molecule microscopy. We developed an in vitro transcription system that was adapted for quantitative proteomics experiments. Yeast nuclear extracts recapitulate transcription initiation and elongation, including progression of the CTD cycle. Co-transcriptional histone modifications can also be studied using recombinant chromatin templates. Mass spectrometry provides a level of quantitation and temporal resolution that is impossible with in vivo experiments. This in vitro system was further exploited by immobilizing transcription templates to microscope slides. Using fluorescent genetic tags, four color TIRF microscopy allows multiple proteins to be imaged in real time. These experiments are providing unprecedented information about kinetics, order-of-binding, cooperative binding, etc. Already, several unexpected features of gene expression have been revealed that were previously obscured in ensemble or in vivo experiments. We hope to extend these studies to mammalian cells.
The ultimate goal of the lab is to combine classical molecular genetic approaches with cutting edge technologies to provide a full mechanistic picture of transcription initiation, elongation, and termination. We seek to understand how these steps are integrated with other aspects of gene expression. This information is essential for understanding fundamental processes of life, but is also relevant to the many diseases that result from mutations in transcription/epigenetic factors.
Harvard Medical School
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