Tissue-Specific Functions of p53 During Kidney Development.

p53 is best identified as a tumor suppressor for its transcriptional control of genes involved in cell cycle progression and apoptosis. Beyond its irrefutable involvement in restraining unchecked cell proliferation, research over the past several years has indicated a requirement for p53 function in sustaining normal development. Here I summarize the role of p53 in embryonic development, with a focus on knowledge gained from p53 loss and overexpression during kidney development. In contrast to its classical role in suppressing proliferative pathways, p53 positively regulates nephron progenitor cell (NPC) renewal. Emerging evidence suggests p53 may control cell fate decisions by preserving energy metabolism homeostasis of progenitors in the nephrogenic niche. Maintaining a critical level of p53 function appears to be a prerequisite for optimal nephron endowment. Defining the molecular networks targeted by p53 in the NPC may well provide new targets not only for regenerative medicine but also for cancer treatment.