Modulation by copper of p53 conformation and sequence-specific DNA binding: role for Cu(II)/Cu(I) redox mechanism.
The tumor suppressor protein p53 is a metal-binding transcription factor whose conformation and function are altered by mutation in cancers. Using murine p53 translated in vitro, we report here that concentrations of copper within the physiological range (< 30 microM) alter the conformation of wild-type p53 and inhibit sequence-specific DNA-binding. Direct binding of copper to p53 in the form of Cu(I) was demonstrated by Electron Spin Resonance using a purified recombinant protein containing residues 1-343 of murine wild-type p53 fused to E. coli maltose binding protein. Moreover, protection against the effect of Cu(II) sulfate was achieved by the Cu(I)-specific chelator bathocuproinedisulfonic acid but not by scavengers of reactive oxygen species, suggesting that alteration of p53 by copper depends upon a Cu(II)/Cu(I) redox mechanism, but does not require the production of reactive oxygen species. Thus copper at physiological concentrations can interact with wild-type p53 and affect its DNA-binding capacity.
Hainaut
P
P
Department of Biology, University of York, Heslington, UK.
Rolley
N
N
Davies
M
M
Milner
J
J
D000818:Animals; D001483:Base Sequence; D003300:Copper / Q000378:metabolism*; D004247:DNA / Q000378:metabolism*; D004578:Electron Spin Resonance Spectroscopy; D051379:Mice; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D011485:Protein Binding; D011487:Protein Conformation; D016159:Tumor Suppressor Protein p53 / Q000737:chemistry / Q000378:metabolism*
D016159:Tumor Suppressor Protein p53; D003300:Copper; D004247:DNA