Temperature sensitivity for conformation is an intrinsic property of wild-type p53.
The tumour-suppressor protein p53 is a metal-binding transcription factor with sequence-specific DNA-binding capacity. In cancer, mutation of p53 disrupts protein conformation with consequent loss of DNA binding and associated tumour-suppressor function. In vitro, the conformation and DNA-binding activity of wild-type p53 are subject to redox modulation and are abrogated by exposure to metal chelators. In the present study, we have used the chelator 1, 10-phenanthroline (OP) to probe the effect of temperature on the conformational stability of p53 translated in vitro. Whereas low temperature (30 degrees C) stabilised wild-type p53 conformation and protected against chelation, high temperature (41 degrees C) promoted destabilisation and enhanced chelation, indicating that temperature influences the folding of wild-type p53. Destabilisation of p53 tertiary structure induced protein aggregation through hydrophobic interactions, consistent with the notion that wild-type p53 contains a hydrophobic core which may become exposed by metal chelation. These results indicate that temperature sensitivity for conformation is an intrinsic property of wild-type p53 and suggests that small changes in temperature may directly affect p53 function.
Department of Biology, University of York, Heslington, U.K.
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Hainaut
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Butcher
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Milner
D016475:3T3 Cells; D000818:Animals; D000952:Antigens, Polyomavirus Transforming / Q000378:metabolism / Q000494:pharmacology; D001483:Base Sequence; D001665:Binding Sites; D002614:Chelating Agents / Q000494:pharmacology; D003553:Cystine / Q000737:chemistry; D004247:DNA / Q000378:metabolism; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010618:Phenanthrolines / Q000494:pharmacology; D011485:Protein Binding / Q000187:drug effects; D011487:Protein Conformation / Q000187:drug effects; D017433:Protein Structure, Secondary; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D013696:Temperature; D016159:Tumor Suppressor Protein p53 / Q000737:chemistry* / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D015032:Zinc
D000952:Antigens, Polyomavirus Transforming; D002614:Chelating Agents; D010618:Phenanthrolines; D011993:Recombinant Fusion Proteins; D016159:Tumor Suppressor Protein p53; D003553:Cystine; D004247:DNA; D015032:Zinc; C025205:1,10-phenanthroline