Changing the p53 master regulatory network: ELEMENTary, my dear Mr Watson.

The p53 master regulatory network provides for the stress-responsive direct control of a vast number of genes in humans that can be grouped into several biological categories including cell-cycle control, apoptosis and DNA repair. Similar to other sequence-specific master regulators, there is a matrix of key components, which provide for variation within the p53 master regulatory network that include p53 itself, target response element sequences (REs) that provide for p53 regulation of target genes, chromatin, accessory proteins and transcription machinery. Changes in any of these can impact the expression of individual genes, groups of genes and the eventual biological responses. The many REs represent the core of the master regulatory network. Since defects or altered expression of p53 are associated with over 50% of all cancers and greater than 90% of p53 mutations are in the sequence-specific DNA-binding domain, it is important to understand the relationship between wild-type or mutant p53 proteins and the target response elements. In the words of the legendary detective Sherlock Holmes, it is 'Elementary, my dear Mr. Watson'.