From p63 to p53 across p73

Most genes are members of a family. It is generally believed that a gene family derives from an ancestral gene by duplication and divergence. The tumor suppressor p53 was a striking exception to this established rule. However, two new p53 homologs, p63 and p73, have recently been described [1, 2, 3, 4, 5 and 6]. At the sequence level, p63 and p73 are more similar to each other than each is to p53, suggesting the possibility that the ancestral gene is a gene resembling p63/p73, while p53 is phylogenetically younger [1 and 2].

The complexity of the family has also been enriched by the alternatively spliced forms of p63 and p73, which give rise to a complex network of proteins involved in the control of cell proliferation, apoptosis and development [1, 2, 4, 7, 8 and 9].

In this review we will mainly focus on similarities and differences as well as relationships among p63, p73 and p53.