Induction of type I PACAP receptor expression by the new zinc finger protein Zac1 and p53.

We reported recently the cloning of the type I PACAP receptor by a functional expression cloning technique. Unexpectedly, we observed additional PACAP-positive pools that turned out to encode the wild-type form of the tumor suppressor gene p53 and the novel zinc finger protein Zac1, which regulates apoptosis and cell cycle arrest. Both Zac1 and p53 caused, under transient or stably regulated expression, induction of the type I PACAP receptor by transcriptional mechanisms. Transactivation of the type I PACAP receptor gene by Zac1 and p53 points to a subtle balance between death promoting and protective mechanisms. The control of these processes is central to various physiological conditions ranging from development to senescence, whereas dysregulation may lead to overt pathological outcomes, notably cancer, immune deficiency syndromes, and neurodegenerative disorders.