Publication details

Preferential Binding of Hot Spot Mutant p53 Proteins to Supercoiled DNA In Vitro and in Cells

Authors

BRÁZDOVÁ Marie NAVRATILOVA Lucie TICHÝ Vlastimil NĚMCOVÁ Kateřina LEXA Matej HRSTKA Roman PECINKA Petr ADÁMIK Matej VOJTĚŠEK Bořivoj PALECEK Emil DEPPERT Wolfgang FOJTA Miroslav

Year of publication 2013
Type Article in Periodical
Magazine / Source Plos One
MU Faculty or unit

Faculty of Informatics

Citation
Web Brazdova et al. 2013
Doi http://dx.doi.org/10.1371/journal.pone.0059567
Field Genetics and molecular biology
Keywords p53 tumor supressor; mutp53 oncogenic mutations; DNA topology; superhelicity; DNA binding; BAX MSP/MST1 promoter
Description Hot spot mutant p53 (mutp53) proteins exert oncogenic gain-of-function activities. Binding of mutp53 to DNA is assumed to be involved in mutp53-mediated repression or activation of several mutp53 target genes. To investigate the importance of DNA topology on mutp53-DNA recognition in vitro and in cells, we analyzed the interaction of seven hot spot mutp53 proteins with topologically different DNA substrates (supercoiled, linear and relaxed) containing and/or lacking mutp53 binding sites (mutp53BS) using a variety of electrophoresis and immunoprecipitation based techniques. All seven hot spot mutp53 proteins (R175H, G245S, R248W, R249S, R273C, R273H and R282W) were found to have retained the ability of wild-type p53 to preferentially bind circular DNA at native negative superhelix density, while linear or relaxed circular DNA was a poor substrate. The preference of mutp53 proteins for supercoiled DNA (supercoil-selective binding) was further substantiated by competition experiments with linear DNA or relaxed DNA in vitro and ex vivo. Using chromatin immunoprecipitation, the preferential binding of mutp53 to a sc mutp53BS was detected also in cells. Furthermore, we have shown by luciferase reporter assay that the DNA topology influences p53 regulation of BAX and MSP/MST1 promoters. Possible modes of mutp53 binding to topologically constrained DNA substrates and their biological consequences are discussed.
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