ChIP-Seq for ERK2/MAPK1 and ELK1 in human embryonic stem cells
The ERK/MAPK signal transduction cascade is one of the key pathways regulating proliferation and differentiation in development and disease. In human embryonic stem cells (hESCs), ERK signaling is required for their self-renewing property. Here we studied the convergence of the ERK signaling cascade at the DNA by mapping genome-wide kinase-chromatin interactions for ERK2 in hESCs. We observe that ERK2 targets genes coding for small RNAs, histones, and genes involved in cellular metabolism and cell cycle. We find that the transcription factor ELK1 is essential in hESCs and that ERK2 co-occupies promoters bound by ELK1. Strikingly, promoters bound by ELK1 without ERK2 are occupied by Polycomb group proteins that repress genes involved in lineage commitment. In summary, we propose a model where extracellular signaling-stimulated proliferation and intrinsic repression of differentiation is integrated to maintain the identity of hESCs.