Figure 9.

Model of up-regulation of gene expression by mutant p53. Three different molecular mechanisms of how mutant p53 may activate transcription from its target promoter are depicted. (A) Mutant p53 may induce histone acetylase(s) and/or inhibit histone deacetylase(s) and thereby cause the acetylation of histones and chromatin reorganization on the promoters of mutant p53 target genes; this would lead to activation of the promoter and transactivation. (B) Mutant p53 may induce the interaction of one or more transcription factor(s) with the promoter, leading to transactivation of the target gene. (C) The third possibility is that mutant p53 itself is nucleated on the target promoter and then modulates the recruitment of other factors on the promoter with eventual promoter activity enhancement. These 3 possibilities are not mutually exclusive.