title: p53 linear diffusion along DNA requires its C terminus.
abstract: In cells, sequence-specific transcription factors must search through an entire genome to find their target sites in promoters. Such sites may be identified by using one-dimensional (linear diffusion) and/or three-dimensional (association/dissociation) mechanisms. We show here that wild-type p53 possesses the ability to linearly diffuse on DNA. p53 lacking its C terminus is incapable of such sliding along DNA, while the isolated C terminus of p53 is even more effective than the full-length protein at one-dimensional linear diffusion. Importantly, neither acetylation-mimicking mutations nor phosphorylation of residues within the C terminus stimulates linear diffusion by p53. Supporting these in vitro observations, we found that C-terminally deleted p53 (p53Delta30) expressed at physiological levels is deficient in binding to and transactivating downstream promoters in vivo. Therefore, our data show that the C terminus is a positive regulator of DNA binding in vivo and in vitro, and indicate that the mechanism may involve linear diffusion.
authors.affiliation: Department of Biological Sciences, Columbia University, New York, NY 10027, USA.
authors.forename: Kristine
authors.initials: K
authors.lastname: McKinney
authors.forename: Melissa
authors.initials: M
authors.lastname: Mattia
authors.forename: Vanesa
authors.initials: V
authors.lastname: Gottifredi
authors.forename: Carol
authors.initials: C
authors.lastname: Prives
mesh_terms: D000107:Acetylation; D047369:Chromatin Immunoprecipitation; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D024202:Electrophoretic Mobility Shift Assay; D005786:Gene Expression Regulation; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D010766:Phosphorylation; D011401:Promoter Regions, Genetic / Q000235:genetics; D015533:Transcriptional Activation / Q000235:genetics*; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*
chemical_list: D016159:Tumor Suppressor Protein p53; D004247:DNA