Transactivational and DNA Binding Abilities of Endogenous p53 in p53 Mutant Cell Lines

摘要: Cells with divergent mutant alleles of the p53 gene have different biological and biochemical properties in vitro. Increasing evidence indicates that is a transcriptional activator, recently, high affinity DNA binding sites for been identified. The purpose this study was to determine vivo, effect various proteins on their ability mediate transactivation bind specifically DNA. Either responsive or control reporter transfected into 18 human carcinoma cell lines, having mutations, either without wild-type expression vector. CAT activity gel retardation were studied measure by these endogenous p53s. As expected, endogenously produced binds sequences can transactivate construct containing site. Four five lines homozygous mutations at codon 273 (273His), contained which had transactivate. In contrast, all homozygous, non-codon p53s (156Pro, 175His, 223Leu, 248Gln, 248Trp, 280Lys) present other no transactivating ability. These findings suggest biology cancers may be than those sites. from WRO, thyroid line mutation 223 (223Leu), able recognition sequences, but unable Interestingly, vulvar (A431) gave an aberrant band retardation. Both CEM SK-UT-1, compound heterozygous codons 175/248 (175His/248His), complex DNA, as well 175His 248His response element. A (NPA) 266Glu mutation, efficiently site, therefore showing dominant negative allele. summary, vivo further supports idea affect function.