Programmable DNA loops between PU.1 gene regulatory elements

点击翻译按钮获取中文摘要

Disruption of spatial chromosomal architecture is an emerging mechanism in human disease, thus presenting a yet unexplored potential therapeutic option. However, the spatial chromosomal requirements of most genes are yet unknown, especially of those involved in diseases. The ETS-domain transcription factor PU.1 is essential for the production of myeloid and lymphoid progenitor cells and disturbed PU.1 expression can lead to leukemia. Previous work by us and others revealed that PU.1 expression is under tight control of a multilayered interplay of lineage-specific transcription factors with distal gene regulatory elements. Furthermore, we have recently published high-resolution chromosome conformation maps revealing the three-dimensional organization of the PU.1 locus in both healthy and leukemic cells. Our work linked PU.1 autoregulation with specific long-range intrachromosomal contacts, and correlated dynamic chromatin looping with PU.1 expression. With the present proposal, we will engineer reversible chromatin loops between different PU.1 regulatory elements by a new CRISPR-dCas9-based method, and thus will functionally access involvement of the three-dimensional chromosomal architecture in driving lineage-specific and disease-associated PU.1 expression levels. Our work will provide causal information on how the spatial chromatin landscape orchestrates myeloid differentiation and malignant transformation.