ChIP-Seq analysis of Histone H3 acetylation (K27) changes in response to vasopressin in mouse renal collecting duct mpkCCD cells

In mammals, the peptide hormone vasopressin controls renal water excretion, largely through regulation of the molecular water channel aquaporin-2 (AQP2) in the renal collecting duct. Regulatory mechanisms of AQP2 show: 1) short-term regulation by membrane trafficking; and 2) long-term regulation involving vasopressin-induced changes in the abundance of the aquaporin-2 protein. Vasopressin activates a G protein-coupled receptor (V2R) increasing cyclic AMP and activating protein kinase PKA. Crebbp and Ep300 are known targets of PKA. They are histone acetyltransferases that acetylate histone H3 lysine-27, a histone mark associated with open chromatin and increased transcription (Tie F et al. Development 2009). The translocation of CREBBP and Ep300 into the nucleus in response to vasopressin in the collecting duct cells, predicts that vasopressin, working through PKA, may increase histone H3K27 acetylation of some genes. We tested this by performing ChIP-Seq for this modification. To identify changes of Histone modification (acetylation) in response to vasopressin in cultured mouse collecting duct cells (mpkCCD), we carried out ChIP-seq for genome-wide distribution of histone 3 acetylation (H3K27ac) (n=2). Observations were made both after 24-hr treatment with the vasopressin analog dDAVP and with vehicle.