title: Interaction of mutant p53 with p73: a Surface Plasmon Resonance and Atomic Force Spectroscopy study.
abstract: BACKGROUND
  TP53 tumor suppressor gene is mutated in more than 50% of human tumors. Mutated p53 proteins could sequestrate and inactivate p73 reducing the apoptotic and anti-proliferative effects of the transcription factor, and yielding cancer cells more aggressive and chemoresistant. The possibility of using drugs to prevent the mutant p53/p73 complex formation preserving the p73 function, calls for a deeper insight into the molecular and biochemical mechanisms of mutant p53/p73 protein interaction.
  
  
  METHODS
  The kinetics of the mutant p53R175H/p73 complex was investigated with innovative and complementary techniques, operating in real time, in near physiological conditions and without any labeling. Specifically, Atomic Force Spectroscopy and Surface Plasmon Resonance working at single-molecule level and in bulk condition, respectively, were used.
  
  
  RESULTS
  The two techniques revealed that a stable complex is formed between mutant p53R175H and p73 proteins; the complex being characterized by a high interaction force and a dissociation equilibrium constant in the order of 10(-7)M, as expected for specific interactions. No binding was instead observed between p73 and wild type p53.
  
  
  CONCLUSIONS
  Mutant p53R175H protein, unlike wild type p53, can form a stable complex with p73. The mutant p53R175H/p73 protein complex could be a target for innovative pharmaceutical drugs that, by dissociating it or preventing biomolecule interaction thus preserving the p73 function, could enhance the response of cancerous cells carrying mutant p53R175H protein to common chemotherapeutic agents.
  
  
  CONCLUSIONS
  The kinetic information obtained in vitro may help to design specific pharmaceutical drugs directed against cancerous cells carrying mutant p53 proteins.
authors.affiliation: Biophysics and Nanoscience Centre, CNISM, Dipartimento DEB, Università della Tuscia, Viterbo, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Santini
authors.affiliation: Translational Oncogenomic Unit, Italian National Cancer Institute 'Regina Elena'-IFO, via Elio Chianesi 53, 00144 Rome, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Di Agostino
authors.affiliation: Biophysics and Nanoscience Centre, CNISM, Dipartimento DEB, Università della Tuscia, Viterbo, Italy.
authors.forename: Emilia
authors.initials: E
authors.lastname: Coppari
authors.affiliation: Biophysics and Nanoscience Centre, CNISM, Dipartimento DEB, Università della Tuscia, Viterbo, Italy.
authors.forename: Anna Rita
authors.initials: AR
authors.lastname: Bizzarri
authors.affiliation: Translational Oncogenomic Unit, Italian National Cancer Institute 'Regina Elena'-IFO, via Elio Chianesi 53, 00144 Rome, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Blandino
authors.affiliation: Biophysics and Nanoscience Centre, CNISM, Dipartimento DEB, Università della Tuscia, Viterbo, Italy. Electronic address: cannistr@unitus.it.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Cannistraro
mesh_terms: D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000648:ultrastructure; D006801:Humans; D018625:Microscopy, Atomic Force / Q000379:methods*; D009154:Mutation; D009687:Nuclear Proteins / Q000737:chemistry* / Q000648:ultrastructure; D020349:Surface Plasmon Resonance / Q000379:methods*; D000072160:Tumor Protein p73; D016159:Tumor Suppressor Protein p53 / Q000737:chemistry* / Q000648:ultrastructure; D025521:Tumor Suppressor Proteins / Q000737:chemistry* / Q000648:ultrastructure
chemical_list: D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; C495901:TP53 protein, human; C000606460:TP73 protein, human; D000072160:Tumor Protein p73; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins
keywords: Atomic Force Spectroscopy; Mutated p53; Surface Plasmon Resonance; p73