Development of high throughput methods to decode the function of enhancers

Enhancers control development and cellular function by spatiotemporal regulation of gene expression. A large number of genomic regions identified by genome-wide association studies (GWAS) of human disease fall within enhancer regions, however the gene-specific regulatory mechanism for these enhancers is not known. Histone modifications, such as acetylation of histone H3 at lysine 27 (H3K27ac) and H3K4me1, have been widely used for identification of active enhancers. Using these marks alone for enhancer identification gives only an incomplete catalogue of active enhancer repertoire. We have discovered a novel class of putative enhancers in mouse embryonic stem cells (ESCs) marked by an H3 globular modification – H3K122ac but not H3K27ac. The importance of histone modifications is still not clear; moreover, functional characterisation of the full panel of these enhancers is challenging and requires efficient high throughput methods. 

By performing enhancer reporter assays and by deleting enhancers together by recruiting synthetic transcriptional repressors to enhancers, we have demonstrated the functionality candidate enhancers. We will perform high throughput screening of enhancer activity for putative enhancers in ES cells and screen for functionality of enhancers by recruiting synthetic transcriptional modulators at these enhancers.