Trichomonas vaginalis has two fibronectin-like iron-regulated genes.
BACKGROUND
Trichomonas vaginalis, a protozoan parasite of the human urogenital tract, interacts with fibronectin (FN), a glycoprotein of the extracellular matrix. We, therefore, attempted to identify genes of this eukaryote encoding FN-binding proteins.


METHODS
A cDNA clone, C1, representing an incomplete gene was obtained from an expression library based on its FN-binding ability and was characterized. The full-length 378-bp gene encoding a 14.8-kDa protein of 125 amino acids was obtained.


RESULTS
The amino acid sequences revealed homology with the type III-14 repeat 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. vaginalis isolates examined. Levels of flp1 transcript were elevated in cells grown 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, respectively, was recovered from the trichomonad genome. Both flp1 and flp2 had consensus Inr promoter-like elements immediately adjacent to the start codon. flp2 also contained an additional Inr element followed by an ATG 24-bp within the gene.


CONCLUSIONS
Unlike flp2, the flp1 gene had AU-rich destabilizing elements in the 3'-untranslated region (UTR).
Crouch
M V
MV
Department of Microbiology, University of Texas Health Science Center at San Antonio (UTHSCSA), San Antonio, TX 78229-3900, USA.
Alderete
J F
JF
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018076:DNA, Complementary; D005353:Fibronectins / Q000235:genetics*; D005786:Gene Expression Regulation / Q000502:physiology*; D017125:Genes, Protozoan; D007501:Iron / Q000502:physiology*; D008969:Molecular Sequence Data; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D014246:Trichomonas vaginalis / Q000235:genetics*
D018076:DNA, Complementary; D005353:Fibronectins; D015800:Protozoan Proteins; C432106:flp1 protein, Trichomonas vaginalis; C432105:flp2 protein, Trichomonas vaginalis; D007501:Iron