KLF4 is involved in the organization and regulation of pluripotency-associated 3D enhancer networks

Abstract

Cell fate transitions are accompanied by global transcriptional, epigenetic and topological changes driven by transcription factors (TFs), as is strikingly exemplified by reprogramming somatic cells to pluripotent stem cells (PSCs) via expression of OCT4, KLF4, SOX2 and cMYC. How TFs orchestrate the complex molecular changes around their target gene loci in a temporal manner remains incompletely understood. Here, using KLF4 as a paradigm, we provide the first TF-centric view of chromatin reorganization and its association to 3D enhancer rewiring and transcriptional changes of linked genes during reprogramming of mouse embryonic fibroblasts (MEFs) to PSCs. Inducible depletion of KLF factors in PSCs caused a genome-wide decrease in the connectivity of enhancers, while disruption of individual KLF4 binding sites from PSC-specific enhancers was sufficient to impair enhancer-promoter contacts and reduce expression of associated genes. Our study provides an integrative view of the complex activities of a lineage-specifying TF during a controlled cell fate transition and offers novel insights into the order and nature of molecular events that follow TF binding.