Genetic Framework for GATA Factor Function in Vascular Biology

Vascular endothelial dysfunction underlies the genesis and progression of numerous diseases. Whereas the GATA transcription factor GATA-2 is expressed in endothelial cells and is implicated in coronary heart disease, it has been studied predominantly as a master regulator of hematopoiesis. As many questions remain unanswered regarding GATA-2 function in the vascular biology realm, we used ChIP-seq and loss-of-function strategies to define the GATA-2-instigated genetic network in human endothelial cells. By contrast to erythroid cells, GATA-2 occupied a unique target gene ensemble, consisting of genes encoding key determinants of endothelial cell identity and inflammation. GATA-2-occupied sites characteristically contained motifs that bind Activator Protein-1 (AP-1), a pivotal regulator of inflammatory genes. GATA-2 frequently occupied the same chromatin sites as c-JUN and c-FOS, heterodimeric components of AP-1. Though all three components were required for maximal AP-1 target gene expression, GATA-2 was not required for AP-1 chromatin occupancy. GATA-2 conferred maximal phosphorylation of chromatin-bound c-JUN at Ser 73, which stimulates AP-1-dependent transactivation, in a chromosomal context-dependent manner. This work establishes a link between a GATA factor and inflammation, mechanistic insights underlying GATA-2-AP-1 cooperativity, and a rigorous genetic framework for understanding GATA-2 function in normal and pathophysiological vascular states. For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf Examination of GATA2 ChIP-seq in HUVEC cells.