Novel enhancers conferring compensatory transcriptional regulation of Nkx2-5 in heart development
Jiejie Zhang,
Chen C. Li,
Xin Li,
Yaxi Liu,
Qianhao Wang,
Guangyu Zhang,
Haiqing Xiong,
Aibin He,
Shanshan Ai
Affiliations
Jiejie Zhang
Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China
Chen C. Li
Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China
Xin Li
Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China
Yaxi Liu
Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China
Qianhao Wang
Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China
Guangyu Zhang
State Key Laboratory of Experimental Hematology, Fifth Medical Center of Chinese PLA General Hospital, Beijing 100039, China
Haiqing Xiong
Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China; Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
Aibin He
Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China; Corresponding author
Shanshan Ai
Department of Physiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China; Corresponding author
Summary: Cell type-specific expression of the developmental gene is conferred by distinct enhancer elements. Current knowledge about mechanisms in Nkx2-5 transcriptional regulation and its specific roles in multistage heart morphogenesis is limited. We comprehensively interrogate enhancers U1 and U2 in controlling Nkx2-5 transcription during heart development. Serial genomic deletions in mice reveal U1 and U2 function redundantly to confer Nkx2-5 expression at early stages, but U2 instead of U1 supports its expression at later stages. Combined deletions markedly reduce Nkx2-5 dosage as early as E7.5, despite being largely reinstated two days later, displaying heart malformations with precocious differentiation of cardiac progenitors. Cutting-edge low-input chromatin immunoprecipitation sequencing (ChIP-seq) confirmed that not only genomic NKX2-5 occupancy but also its regulated enhancer landscape is mostly disturbed in the double-deletion mouse hearts. Together, we propose a model that the temporal and partially compensatory regulatory function of two enhancers dictates a transcription factor (TF)’s dosage and specificity during development.
