Figure 7: Peptide microarrays for validation of novel motifs (A) Casein Kinase I (CKI) assay was performed on custom peptide microarrays spotted with peptides from sequences not known to be phosphorylated but containing the predicted motifs. (B) Magnification of a section of the peptide microarray showing two peptides that were significantly phosphorylated. The peptides were spotted in triplicate and are indicated by circles. (C) A kernel distribution curve showing the intensity values calculated from CKI assays from exposure of peptide microarrays to a phosphorimager screen. The blue line represents intensity values of negative controls and the black line represents intensity values of peptides containing novel motifs (D) A bar graph showing the number of peptides containing novel predicted motifs that were spotted on the peptide microarrays and the number of peptides containing novel motifs that were phosphorylated by CKI.