Genomic location and sequence of a putative AP-1 binding site in the mouse promoter of IL-23p19. Blockade of c-Jun/AP-1 TF binding by inhibition of phosphorylation (JNKi, red), or mutation of the binding sequence (mut 1 = T -> C; green | mut 2 = TG -> AT; blue) reduces IL-23p19 promoter activity (see Fig 4J). 