Common amino acid sequence motifs in p53, 14-3-3 and Akt protein families

The tumour suppressor p53 is a multifunctional phosphoprotein able to induce apoptosis, differentiation or growth arrest, by acting as a transcription factor (capable of recognising DNA specific sequences) and targeting expression of genes involved in cell cycle control. p53 is a member of a family of related proteins (p63/CUSP/KET/p51/p40 and p73) characterised by multiple isoforms which share similar biological functions. Recently, we have shown that p53 binds to trk A (the receptor for nerve growth factor (NGF)) in the presence of the non-receptor tyrosine kinase c-abl. Importantly, p53 induces trk A hyperphosphorylation and stimulation of signalling cascades in the absence of NGF stimulation. Therefore, because of its role in trk A signalling, the aim has been to determine whether p53 has sequence homology to proteins involved in signal transduction pathways