Phospho-HLXB9 binding sites in mouse insulinoma cells

We have shown that increased β-cell proliferation in functioning pancreatic neuroendocrine tumors (insulinomas) correlated with expression of phosphorylated isoform of the transcription factor HLXB9 which is an embryonic beta-cell differentiation factor (HLXB9 is also known as HB9, MNR2, and MNX1). To investigate the target genes of phospho-HLXB9 we did ChIP-seq using anti-HB9-PO4. This would help us better understand how phospho-HLXB9 regulates its targets and affects β-cell proliferation in insulinoma cells. Chromatin was prepared from 10 million cells of a mouse pancreatic islet β-cell line overexpressing HLXB9. ChIPs with rabbit anti-HB9-PO4 were done using the Millipore ChIP-assay kit. ChIP-Seq libraries (input and anti-HB9-PO4-ChIP) were prepared with the Illumina ChIP-Seq DNA sample prep kit (catalog #: IP-102-1001). ChIP-Seq libraries were sequenced for 36 bp, and sequences were analyzed (Illumina, NIDDK genomics core facility).