Distinct residues of human p53 implicated in binding to DNA, simian virus 40 large T antigen, 53BP1, and 53BP2.

AUTOR(ES)

Thukral, S K

RESUMO

We identified a minimal domain of human p53 required for the transactivation of a p53 response element in Saccharomyces cerevisiae. This domain contains the central region of p53 sufficient for specific DNA binding, which colocalizes with the region responsible for binding simian virus 40 large T antigen, 53BP1, and 53BP2. Thirty amino acid positions, including natural mutational hot spots (R175, R213, R248, R249, and R273), in the minimal DNA-binding domain were mutated by alanine substitution. Alanine substitutions at positions R213, R248, R249, D281, R282, R283, E286, and N288 affected transactivation but allowed binding to at least one of the three interacting proteins; these amino acids may be involved in amino acid-base pair contacts. Surprisingly, alanine substitution at the mutational hot spot R175 did not affect DNA binding, transactivation, or T-antigen binding, although it nearly eliminated binding to 53BP1 and 53BP2. Mutation of H168 significantly affected only T-antigen binding, and mutation of E285 affected only 53BP1 binding. Thus, we implicate specific residues of p53 in different DNA and protein interactions.

Documentos Relacionados

• p53 Targets Simian Virus 40 Large T Antigen for Acetylation by CBP
• Dephosphorylation of simian virus 40 large-T antigen and p53 protein by protein phosphatase 2A: inhibition by small-t antigen.
• Expression and complex formation of simian virus 40 large T antigen and mouse p53 in insect cells.
• Simian virus 40 can overcome the antiproliferative effect of wild-type p53 in the absence of stable large T antigen-p53 binding.
• Two distinct regions of the murine p53 primary amino acid sequence are implicated in stable complex formation with simian virus 40 T antigen.