tvcp12: a novel Trichomonas vaginalis cathepsin L-like cysteine proteinase-encoding gene

Abstract

Trichomonas vaginalis is the causative agent of trichomoniasis, one of the most common sexually transmitted diseases in humans. This protozoan has multiple proteinases that are mainly of the cysteine proteinase (CP) type, some of which are known to be involved in the parasite's virulence. Here, a novel T. vaginalis CP-encoding gene, tvcp12, was identified and characterized. tvcp12 is 948 bp long and encodes a predicted 34·4 kDa protein that has the characteristics of the papain-like CP family. TvCP12 does not appear to have a signal peptide, suggesting that this is a cytoplasmic CP. By Southern blot assays, the tvcp12 gene was found as a single copy in the T. vaginalis genome. Remarkably, Northern blot experiments showed a single transcript band of ∼1·3 kb in the mRNA obtained from parasites grown in low iron conditions and no transcript was observed in the mRNA from parasites grown in high iron conditions. By RT-PCR assays, a 270 bp band was amplified from the cDNA of parasites grown in low iron medium, which was very faint when cDNA from parasites grown in high iron conditions was used. Transcripts of the 3′ region obtained in both iron conditions presented differences in their poly(A) tail length. These data suggest that tvcp12 is another gene that is negatively regulated by iron and that the length of the poly(A) tail may be one of the factors involved in the iron-modulated protein expression.

Identification of Trichomonas vaginalis Cysteine Proteases That Induce Apoptosis in Human Vaginal Epithelial Cells

“…Garber et al (24) reported the cloning of a cDNA from a GT 11 library representing a portion of a secreted 60-kDa CP, whereas Leon-Sicairos et al (25,26) reported the cloning of three CPs, including an apparently intracellular CP, tvcp12. Although the approach used by Mallinson et al (7) to clone T. vaginalis CPs did not allow the investigators to identify the CPs as being secreted, our MALDI-TOF MS (Fig.…”

“…The other two are partial, although near fulllength. Subsequently, additional CPs were cloned by Garber et al (24) (accession number X70823) and Leon-Sicairos et al (25,26; accession numbers AY371180, AY371181, and AY463679).…”

Trichomoniasis

“…Ranging from 20 to 110 kDa (63), several of the lowermolecular-mass proteinases are released from the cell (63,64,81), although a recent report suggests that one cysteine proteinase is probably cytoplasmic since it lacks a signal peptide (60).…”

TvMP50 is an Immunogenic Metalloproteinase during Male Trichomoniasis

“…We used the following primer pairs to amplify the 1320-bp mp50 gene: forward, 5Ј-CCGGATCCATGTCAGGTGAC-GAATTC-3Ј (BamHI recognition site is underlined) and reverse, 5Ј-CCAAGCTTTCAAAGTACTCTTGAAGC-3Ј (HindIII recognition site underlined). In addition, a 112-bp fragment of the ␤-tubulin gene was used as a loading control (20). The amplified products were analyzed on 1% agarose gels and visualized by ethidium bromide staining.…”