p63 and p73, members of the p53 gene family, transactivate PKCδ

The p53 family comprises three genes that encode for p53, p63 and p73. These genes have a significant degree of sequence homology, especially in the central sequence-specific DNA-binding domain. The high homology among the three DNA-binding domains indicates that these transcription factors have identical residues interacting with DNA, and thus potentially can recognize the same transcriptional targets. In this study, we demonstrate that PKCδ is induced by p63 and p73 in Saos2 cells. The putative human PKCδ promoter harbours three p53-like binding sites (RE I, RE II, RE III). In order to confirm the transactivation of PKCδ by p53 family members, we performed transcription assays using the entire or selected regions of the promoter upstream of a luciferase reporter gene. The results obtained demonstrated that, at least in vitro, the p53 family members tested (TAp63α, TAp73α, ΔNp63α, but not ΔNp73α) were able to drive transcription from the PKCδ promoter.