Redefining the p53 response element.
The tumor suppressor p53 is a master transcriptional regulator that affects a diverse range of cellular events. Surprisingly, even with >100 validated p53 response element (RE) sequences available, the effect of p53 binding on transcriptional behavior is seldom predictable and no functional rules have been described. Here, we report a systematic study on the role of specific nucleotides within the p53RE by using p21, a well-known target for p53 activation and contrasting it with Lasp1, a gene recently identified to be repressed by p53. Functional assays revealed a specific dinucleotide core combination within the CWWG motif of the p53RE to be the key factor that determines whether p53 transcriptionally activates or represses a target gene. The triplet RRR and YYY sequences flanking the core CWWG motif were also shown to play an important role in modulating the transcriptional behavior of p53. With the establishment of a set of predictive rules, we were able to reassess 162 published p53REs and showed that the attributed function for 20/162 p53REs studied were in fact erroneous. A significant proportion of p53REs (39/162) were found to be repressive, which is substantially higher than what is currently thought. Hence this clearer definition of the transcriptional behavior of p53 interaction with its RE will provide better insight toward the understanding of its fundamental role in cellular networks.
Wang
Bei
B
Laboratory of Immunogenetics, Singapore Immunology Network, A*STAR, 8A Biomedical Grove, Immunos, Singapore.
Xiao
Ziwei
Z
Ren
Ee Chee
EC
D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism; D020816:Amino Acid Motifs / Q000235:genetics; D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D015153:Blotting, Western; D047369:Chromatin Immunoprecipitation; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D045325:HCT116 Cells; D006801:Humans; D060588:LIM Domain Proteins; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D009841:Oligonucleotides / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D034741:RNA, Small Interfering / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D020218:Response Elements / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic; D014162:Transfection; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*
D048868:Adaptor Proteins, Signal Transducing; C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D003598:Cytoskeletal Proteins; C096353:LASP1 protein, human; D060588:LIM Domain Proteins; D009841:Oligonucleotides; D034741:RNA, Small Interfering; D011993:Recombinant Fusion Proteins; D016159:Tumor Suppressor Protein p53; D008156:Luciferases