Direct observation of frequency modulated transcription in single cells using light activation
Daniel R Larson,
Christoph Fritzsch,
Liang Sun,
Xiuhau Meng,
David S Lawrence,
Robert H Singer
Affiliations
Daniel R Larson
Laboratory of Receptor Biology and Gene Expression, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, United States
Christoph Fritzsch
Institute of Molecular Biology, Johannes Gutenberg University of Mainz, Mainz, Germany
Liang Sun
Department of Chemistry, Division of Chemical Biology and Medicinal Chemistry, University of North Carolina, Chapel Hill, United States; Department of Pharmacology, University of North Carolina, Chapel Hill, United States
Xiuhau Meng
Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, New York, United States
David S Lawrence
Department of Chemistry, Division of Chemical Biology and Medicinal Chemistry, University of North Carolina, Chapel Hill, United States; Department of Pharmacology, University of North Carolina, Chapel Hill, United States
Robert H Singer
Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, New York, United States; Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, New York, United States
Single-cell analysis has revealed that transcription is dynamic and stochastic, but tools are lacking that can determine the mechanism operating at a single gene. Here we utilize single-molecule observations of RNA in fixed and living cells to develop a single-cell model of steroid-receptor mediated gene activation. We determine that steroids drive mRNA synthesis by frequency modulation of transcription. This digital behavior in single cells gives rise to the well-known analog dose response across the population. To test this model, we developed a light-activation technology to turn on a single steroid-responsive gene and follow dynamic synthesis of RNA from the activated locus.
