title: Ehp53, an Entamoeba histolytica protein, ancestor of the mammalian tumour suppressor p53.
abstract: This paper reports the identification of Ehp53, a p53-like Entamoeba histolytica protein, which binds to the human p53 DNA consensus sequence (oli-p53). Monoclonal antibodies against p53 (Ab-1 and Ab-2) recognized a single 53 kDa spot in two-dimensional gels and inhibited the formation of complexes produced by E. histolytica nuclear extracts and oli-p53. Additionally, E. histolytica gene promoter sequences with high homology to oli-p53 formed complexes with nuclear proteins that were abolished by oli-p53. Ehp53 protein levels increased in UV-irradiated trophozoites. This protein was also detected in Entamoeba moshkovskii and Entamoeba invadens. By confocal microscopy, Ehp53 was located in the nuclei, EhkO organelles and cytoplasm. The Ehp53-encoding gene was cloned and its predicted amino acid sequence showed 30-54 % and 50-57 % homology with important domains of the human and the Drosophila melanogaster p53 proteins, respectively. This homology included the tetramerization domain, the nuclear export signal and a nuclear localization signal. Ehp53 also contains seven of the eight DNA-binding residues and two of the four Zn(2+)-binding sites described for p53. A recombinant Ehp53 was recognized by Ab-2. Ehp53 is believed to be the first p53-like protein found in protozoa and may be the evolutionary ancestor of the mammalian p53.
authors.affiliation: Departamento de Patología Experimental, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), AP 14-740, DF 07000, Mexico.
authors.forename: L
authors.initials: L
authors.lastname: Mendoza
authors.affiliation: Departamento de Patología Experimental, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), AP 14-740, DF 07000, Mexico.
authors.forename: E
authors.initials: E
authors.lastname: Orozco
authors.affiliation: Departamento de Patología Experimental, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), AP 14-740, DF 07000, Mexico.
authors.forename: M A
authors.initials: MA
authors.lastname: Rodríguez
authors.affiliation: Departamento de Patología Experimental, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), AP 14-740, DF 07000, Mexico.
authors.forename: G
authors.initials: G
authors.lastname: García-Rivera
authors.affiliation: Departamento de Patología Experimental, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), AP 14-740, DF 07000, Mexico.
authors.forename: T
authors.initials: T
authors.lastname: Sánchez
authors.affiliation: Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), AP 14-740, DF 07000, Mexico.
authors.forename: E
authors.initials: E
authors.lastname: García
authors.affiliation: Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), AP 14-740, DF 07000, Mexico.
authors.forename: P
authors.initials: P
authors.lastname: Gariglio
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D016384:Consensus Sequence; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics; D004748:Entamoeba histolytica / Q000235:genetics / Q000254:growth & development / Q000378:metabolism* / Q000528:radiation effects; D019143:Evolution, Molecular; D006801:Humans; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D015534:Trans-Activators / Q000737:chemistry / Q000235:genetics; D016159:Tumor Suppressor Protein p53 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D014466:Ultraviolet Rays
chemical_list: D029721:Drosophila Proteins; D015800:Protozoan Proteins; D015534:Trans-Activators; D016159:Tumor Suppressor Protein p53; C474203:p53 protein, Drosophila