Exploration of Genetically Encoded Sensors for DNA Methylation in Live Cells
- Author(s): Fang, Chih-Yu
- Advisor(s): Talbot, Prudence
- et al.
Epigenetic modification refers to heritable changes that influence gene function without changing the DNA sequence. Besides histone modification, DNA methylation and hydroxymethylation have been reported to be major epigenetic factors involved in cellular events. Histone modifications often refer to the various post-translational modifications applicable to histone proteins, including methylation, acetylation, phosphorylation, ubiquitination, and sumoylation, all of which typically influence gene expression by changing the chromatin structure or recruiting histone modifiers. DNA methylation is a process through which methyl groups are added to DNA, particularly cytosine bases, typically leading to gene repression. DNA methylation has been identified to be an important participant in embryogenesis, cell division, and cell development. Unusual DNA methylation leads to various diseases, such as cancers and neurological disorders. Therefore, technologies that can detect DNA methylation have become in high demand in the biomedical and pharmaceutical science fields. Several recent studies have reported fluorescent reagents for live-cell labeling of DNA methylation, but these reagents suffer from high background noise, low specificity, and implementation difficulties. Genetically encoded fluorescent protein (FP)-based probes have recently been demonstrated as powerful tools for imaging targets and processes in living cells and tissues. In this research project, we explore dimerization-dependent red FPs to enable the development of genetically encoded fluorogenic reagents to label global DNA methylation in live cells. This new ability to image live-cell genome-wide DNA methylation is expected to catalyze a large array of basic and translational studies related to epigenetics and genetics at the single-cell level.