Characterization of an iron-responsive promoter in the protozoan pathogen Trichomonas vaginalis.
Iron has been shown to regulate transcription in the protozoan pathogen Trichomonas vaginalis. In this study, a DNA transfection system was developed to monitor ap65-1 promoter activity in response to changing iron supply. In conjunction with electrophoretic mobility shift assay, iron-induced transcription of the ap65-1 gene was shown to be regulated by multiple closely spaced DNA elements spanning an iron-responsive region (-110/-54), including an iron-responsive DNA element ((-98)AGATAACGA(-90)), which overlaps with a 3'-MYB-like protein binding sequence ((-95)TAACGATAT(-87)), and three nearby T-rich sequences ((-110)ATTTTT(-105), (-78)ATTATT(-73), and (-59)ATTTTT(-54)). 5'- and 3'-flanking sequences of the iron-responsive region were shown to regulate basal transcription. A distal DNA regulatory region was shown to enhance both basal and iron-induced transcription. These findings delineate the DNA regulatory elements and nuclear proteins involving in iron-induced transcription of the ap65-1 gene, which provide useful tools for the future study of transcriptional regulation in T. vaginalis.
Tsai
Chu-Dang
CD
Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan 114, Republic of China.
Liu
Hsing-Wei
HW
Tai
Jung-Hsiang
JH
D000818:Animals; D001483:Base Sequence; D015815:Cell Adhesion Molecules; D002467:Cell Nucleus / Q000378:metabolism; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism; D017353:Gene Deletion; D005786:Gene Expression Regulation; D007501:Iron / Q000378:metabolism*; D008156:Luciferases / Q000378:metabolism; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009154:Mutation; D010957:Plasmids / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D015800:Protozoan Proteins / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic; D014162:Transfection; D014246:Trichomonas vaginalis / Q000235:genetics* / Q000378:metabolism*
C096723:AP65-1 protein, Trichomonas vaginalis; D015815:Cell Adhesion Molecules; D015800:Protozoan Proteins; D004247:DNA; D007501:Iron; D008156:Luciferases