Trichomonas vaginalis has two fibronectin-like iron-regulated genes

Backgound Trichomonas vaginalis, a protozoan parasite: of the human urogeni tal tract, interacts with fibronectin (FN), a glycoprotein of the extracell ular matrix. We, therefore, attempted to identify genes of this eukaryote e ncoding FN-binding proteins. Methods. A cDNA clone, Cl, representing an incomplete gene was obtained fro m an expression library based on its FN-binding ability and was characteriz ed. The full-length 378-bp gene encoding a 14.8-kDa protein of 125 amino ac ids was obtained. Results. The amino acid sequences revealed homology with the type III-14 re peat of the heparin-binding domain at the carboxyl terminal end of FN. This fibronectin-like protein gene, flp1, was single copy in all the T. vaginal is isolates examined. Levels of flp1 transcript were elevated in cells grow n under low-iron conditions. Another low-iron-regulated gene,flp2, with 70 and 67.5% identity to flp1 at the nucleotide and amino acid levels, respect ively, was recovered from the trichomonad genome. Both flp1 and flp2 had co nsensus Inr promoter-like elements immediately adjacent to the start codon. flp2 also contained an additional Inr element followed by an ATG 24-bp wit hin the gene. Conclusions. Unlike fly2, the flp1 gene had AU-rich destabilizing elements in the 3 ' -untranslated region (UTR). (C) 2001 IMSS. Published by Elsevier Science Inc.