The role of tetramerization in p53 function.

The tumour suppressor gene p53 is extensively studied for its importance in cancer. In its active conformation, p53 is tetrameric and one domain - the tetramerization domain - permits the oligomerization of this protein. Until recently, little attention was given to this domain because, in contrast to the DNA-binding domain, it is not often mutated in cancer. However, various experimental studies have shown evidence that the tetramerization domain is essential for DNA binding, protein-protein interactions, post-translational modifications, and p53 degradation. Moreover, single mutations in the tetramerization domain can inactivate the wild-type protein in a manner similar to that seen with mutations in the DNA-binding domain. Interestingly, the phenotype of several tetramerization domain mutants differs from that observed with DNA-binding domain mutants. In this review, current knowledge about the importance of the tetramerization domain to the function of p53 will be summarized.