The Janicki laboratory is using synthetic biology to develop technologies to study transcriptional and epigenetic regulatory mechanisms in single living mammalian cells. In synthetic biology, systems that do not exist in the natural world are engineered for the purpose of simplifying them or designing new functions. Synthetic biology has already been used extensively to study genetic circuitry in yeast and bacteria—typically by measuring protein expression. Application to mammalian systems, however, has been limited by the genomic complexity and restrictive growth conditions of mammalian cells.
For these synthetic biology studies, gene elements are inserted into an inducible transcription unit, which allows DNA, RNA and proteins to be simultaneously and dynamically visualized in single living cells. These constructs are then stably integrated into single genomic sites in mammalian cells as multi-copy arrays. Reporter elements engineered into the transgene allow the productions of both RNA and protein to be directly measured. In this way, it is possible to directly visualize regulatory factor recruitment, RNA synthesis and chromatin decondensation at a molecularly defined transcription site, in real time, in single living mammalian cells.
We have used synthetic biology to investigate mechanisms of transcriptional activation and gene silencing. We are currently expanding our imaging platform and developing new systems to study non-coding RNA, disease-causing mutations, and intron-encoded microRNAs.
It is our long-term goal to use synthetic biology to develop technologies, which will merge molecular biology with high-resolution cellular imaging in order to:
1) Investigate how gene expression mechanisms are coordinated and regulated at chromatin.
2) Discover new transcriptional and epigenetic regulatory mechanisms.
3) Gain insight into how the misregulations of epigenetic and transcriptional mechanisms cause disease.
4) Develop technologies for high-throughput screening to identify and validate disease prevention and treatment therapies.