Differential Regulation of Expression in Murine Airway Epithelia Through Altered Binding of ZFP148 to rs51434084.

Neutrophil chemotaxis to the airways is a key aspect of host response to microbes and a feature of multiple pulmonary diseases including asthma. Tight regulation of this recruitment is critical to prevent unwanted host tissue damage and inflammation. Using a mouse () model of asthma applied to the Collaborative Cross population, we previously identified a lung gene expression quantitative trait locus (eQTL) for Zinc finger protein 30 () that was also a QTL for neutrophil recruitment and the hallmark neutrophil chemokine CXCL1. The eQTL is defined by three functionally distinct haplotypes. In this study, we searched for causal genetic variants that underlie the eQTL to gain a better understanding of this candidate repressor's regulation. First, we identified a putative regulatory region spanning 500 bp upstream of , which contains 10 SNPs that form five haplotypes. In reporter gene assays , these haplotypes recapitulated the three previously identified expression patterns. Second, using site-directed mutagenesis followed by reporter gene assays, we identified a single variant, rs51434084, which explained the majority of variation in expression between two out of three haplotype groups. Finally, using a combination of predictions and electrophoretic mobility shift assays, we identified ZFP148 as a transcription factor that differentially binds to the promoter region harboring rs51434084. In conclusion, we provide evidence in support of rs51434084 being a causal variant for the eQTL, and have identified a mechanism by which this variant alters expression, namely differential binding of ZFP148.