title: Entamoeba histolytica: functional characterization of the -234 to -196 bp promoter region of the multidrug resistance EhPgp1 gene.
abstract: The multidrug resistance EhPgp1 gene is constitutively expressed in drug resistant trophozoites from Entamoeba histolytica. It has been demonstrated that two CCAAT/enhancer binding sites located in the EhPgp1 gene promoter control its transcriptional activation. However, functional assays of the 5' end of its promoter showed that region from -234 to -196 bp (38 bp) is also important for the EhPgp1 gene transcription. Here, we demonstrated that in the 38 bp region putative cis-activator sequences are located. In silico analysis showed the presence of GATA1, Gal4, Nit-2, and C/EBP consensus sequences. Additionally, we identified three specific DNA-protein complexes, which were competed by a C/EBP, GATA1, and HOX oligonucleotides. Finally, we partially purified three proteins of 64.4, 56.7, and 27.4 kDa. Further investigations are currently in progress to determine the identity of these nuclear factors and how they are interacting with the EhPgp1 gene promoter.
authors.affiliation: Programa Institucional de Biomedicina Molecular, ENMyH-IPN, Guillermo Massieu Helguera, No. 239. Fracc. La Escalera, Ticomán, CP 07320 Mexico, D.F., Mexico.
authors.forename: M Esther
authors.initials: ME
authors.lastname: Ramirez
authors.forename: D Guillermo
authors.initials: DG
authors.lastname: Perez
authors.forename: Elvira
authors.initials: E
authors.lastname: Nader
authors.forename: Consuelo
authors.initials: C
authors.lastname: Gomez
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B / Q000235:genetics*; D000818:Animals; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics / Q000378:metabolism; D002846:Chromatography, Affinity; D016054:DNA, Protozoan / Q000378:metabolism; D018432:Drug Resistance, Multiple / Q000235:genetics; D004748:Entamoeba histolytica / Q000737:chemistry / Q000235:genetics*; D009687:Nuclear Proteins / Q000302:isolation & purification / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000502:physiology*; D015800:Protozoan Proteins / Q000235:genetics*; D014162:Transfection; D000097202:ATP-Binding Cassette Sub-Family B Member 4
chemical_list: D018435:ATP Binding Cassette Transporter, Subfamily B; D015500:Chloramphenicol O-Acetyltransferase; D016054:DNA, Protozoan; D009687:Nuclear Proteins; D015800:Protozoan Proteins; D000097202:ATP-Binding Cassette Sub-Family B Member 4