Center for Theoretical Biological Physics
Biochemistry and Cell Biology
Chemical and Biomolecular Engineering
Department of Biophysics and Biophysical Chemistry, John Hopkins University
"Gene Regulation at the Single-Molecule Level”
Tuesday, April 15, 2014
to 1:30 PM
1060 A/B Brown College
6100 Main St
Houston, Texas, USA
Gene regulation primarily occurs at the level of transcription In prokaryotes. Transcription factors (TFs) play important roles in determining when, where and at what level a gene is transcribed. Many transcription factors are expressed at low levels and mutually regulate other TFs in a network. We developed single-molecule gene expression reporter systems to probe gene regulation dynamics in real time. We first developed a novel strategy, Co-Translational Activation by Cleavage (CoTrAC), to monitor the stochastic expression of a TF, ? repressor CI, in its natural regulatory context in live E. coli cells at the single-molecule level. We further expanded the CoTrAC strategy to allow the simultaneous monitoring of the real-time interplay of two TFs that mutually repress each other. The information we obtained from these measurements allowed us to analyze how fluctuations in gene expression are minimized and what roles they may play in determining the fate of a cell.
Biography of Jie Xiao:
Jie received her undergraduate education in Biochemistry at Nanjing University. In 1997, Jie came to the United States and enrolled in the Graduate Program in Biochemistry and Cell Biology at Rice University. She worked with Prof. Scott F. Singleton on the mechanism of RecA mediated strand exchange reaction. Later in her graduate years she found herself deeply fascinated by single molecule biophysics and joined Prof. Sunney Xie's group as a postdoctoral fellow at Harvard University in 2002. She spent four good years learning single molecule fluorescence microscopy and physical chemistry, while contributing to the group with her biological background and perspectives. In 2006, she decided to escape the cold winter of Boston and found her home in the Department of Biophysics and Biophysical Chemistry at Johns Hopkins School of Medicine. She is continuing the line of research where she takes single molecule assays into living cells to probe many different aspects of cellular dynamics. In addition to working in the lab, Jie loves the beautiful weather of Maryland and spicy food.