title: Evidence supporting a major promoter in the Trypanosoma cruzi rRNA gene.
abstract: Two clearly separated transcription start points (tsp) have been reported within the Trypanosoma cruzi rDNA (DNA encoding rRNA) gene spacer region. These sites are separated by 270 bp, a distance compatible with the occurrence of two core promoters. To characterize the individual participation of these two elements, a deletion analysis was carried out. Different versions of the promoter regions were assayed in a transient transfection analysis of epimastigotes, using the chloramphenicol acetyl transferase gene (cat) as a reporter. The data indicate that the so-called distal tsp-associated region (relative to the small subunit rRNA 5' terminus coding region) comprises most (80%) if not all of the observed activity. In addition, an associated locus specific repeated element showed a modest upregulating activity, since its presence stimulated the cat reporter gene by about 20%. The data here presented should be valuable in the design of expression vectors for T. cruzi, where the rRNA gene promoter has been an important functional element.
authors.affiliation: Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Apartado Postal 70-228, 04510 México D.F., Mexico.
authors.forename: Elisa
authors.initials: E
authors.lastname: Figueroa-Angulo
authors.forename: Santiago
authors.initials: S
authors.lastname: Martínez-Calvillo
authors.forename: Imelda
authors.initials: I
authors.lastname: López-Villaseñor
authors.forename: Roberto
authors.initials: R
authors.lastname: Hernández
mesh_terms: D000818:Animals; D001483:Base Sequence; D015500:Chloramphenicol O-Acetyltransferase / Q000378:metabolism; D016054:DNA, Protozoan / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics*; D015870:Gene Expression; D017125:Genes, Protozoan; D017930:Genes, Reporter; D020459:Genes, rRNA; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D016415:Sequence Alignment; D017384:Sequence Deletion; D014158:Transcription, Genetic; D014162:Transfection; D014349:Trypanosoma cruzi / Q000235:genetics*
chemical_list: D016054:DNA, Protozoan; D021903:DNA, Ribosomal Spacer; D015500:Chloramphenicol O-Acetyltransferase