Mutational Hotspots and Conserved Domains in P53 Tumour Suppressor Protein

Introduction: The tumour suppressor protein p53 commonly referred to as guardian of the genome plays important role in preserving the genome through the regulation of programmed cell death, DNA repair, energy metabolism, cell cycle entry or exit and senescence. Mutations in p53 can either result to a loss of tumour suppressor function or gain of oncogenic properties. Hence, mutations in p53 are the most frequent genetic mutational alteration in human cancers, associated with worse prognosis and more aggressive disease outcome. Methods: To assess the mutational hotspots and conserved regions of p53, I analyzed 76 complete p53 protein sequences covering whole exons from the NCBI GenBank database. Multiple sequence alignment (MSA) was done using ClustalX version 2.1. Results: Thirty-five (19) mutations were identified with more frequent mutations in amino acid (aa) position 72 and 79 (Exon 4), amino acid deletion in codon 112-122 (Exon 4), codon 213 (Exon 6), codon 248 (Exon 7), codon 273 (Exon 8) and codon 278 (Exon 8). Mutations at amino acid position 79, 248, 278 located in the DNA-binding domain exhibited more than one alteration in same position. Conclusions: Findings from this study revealed the prevalence of mutations in the DNA binding domain of p53 and the structure-function effect of the mutations. Assessing the pattern and frequency of p53 alterations, and analyzing it thoroughly for each carrier, could help in identifying correlations between p53 status and outcome and possible candidate for gene therapy.