scholarly journals Transcriptional Regulation of an Iron-Inducible Gene by Differential and Alternate Promoter Entries of Multiple Myb Proteins in the Protozoan Parasite Trichomonas vaginalis

2009 ◽  
Vol 8 (3) ◽  
pp. 362-372 ◽  
Author(s):  
Hong-Ming Hsu ◽  
Shiou-Jeng Ong ◽  
Ming-Chun Lee ◽  
Jung-Hsiang Tai

ABSTRACT Iron-inducible transcription of a malic enzyme gene (also reputed to be ap65-1) in Trichomonas vaginalis was previously shown to involve a Myb1 repressor and a Myb2 activator, each of which may preferentially select two closely spaced promoter sites, MRE-1/MRE-2r, which comprises overlapping promoter elements, and MRE-2f. In the present study, an iron-inducible ∼32-kDa Myb3 nuclear protein was demonstrated to bind only the MRE-1 element. Changes in the iron supply, which produced antagonistic effects on the levels of Myb2 and Myb3 expression, also resulted in temporal and alternate entries of Myb2 and Myb3 into the ap65-1 promoter. Repression or activation of basal and iron-inducible ap65-1 transcription was detected in transfected cells when Myb3 was, respectively, substantially knocked down or overexpressed. In the latter case, increased Myb3 promoter entry was detected with concomitant decrease in Myb2 promoter entry under specific conditions, while Myb3 promoter entry was inhibited under all test conditions in cells overexpressing Myb2. In contrast, concomitant promoter entries by Myb2 and Myb3 diminished in cells overexpressing Myb1, except that Myb3 promoter entry was slightly affected under prolonged iron depletion. Together, these results suggest that Myb2 and Myb3 may coactivate basal and iron-inducible ap65-1 transcription against Myb1 through conditional and competitive promoter entries.

2006 ◽  
Vol 5 (2) ◽  
pp. 391-399 ◽  
Author(s):  
Shiou-Jeng Ong ◽  
Hong-Ming Hsu ◽  
Hsing-Wei Liu ◽  
Chien-Hsin Chu ◽  
Jung-Hsiang Tai

ABSTRACT The transcription efficiency of an adhesion protein gene, ap65-1, in Trichomonas vaginalis varies with changes in the iron supply and with the growth stage. In the present study, two Myb recognition elements, MRE-1/MRE-2r and MRE-2f, were found to play antagonistic roles in regulating the iron-inducible activity of an ap65-1 reporter gene. Intriguingly, either of these elements was shown to be sufficient to repress basal activity, but together they were also shown to activate growth-related activity of the reporter gene in iron-depleted cells. A myb1 gene which encodes a 24-kDa protein containing a Myb-like R2R3 DNA binding domain was identified from Southwestern screening of MRE-2f-binding proteins. The Myb1 protein was detected as a major 35-kDa protein which exhibited variations in nuclear concentration with changes in the iron supply. A recombinant Myb1 protein was shown to differentially interact with MRE-1/MRE-2r and MRE-2f in vitro. Overexpression of hemagglutinin-tagged Myb1 in T. vaginalis resulted in repression or activation of ap65-1 transcription in iron-depleted cells at an early and a late stage of cell growth, respectively, while iron-inducible ap65-1 transcription was constitutively repressed. The hemagglutinin-tagged Myb1 protein was found to constantly occupy the chromosomal ap65-1 promoter at a proximal site, but it also selected two more distal sites only at the late growth stage. Together, these observations suggest that Myb1 critically regulates multifarious ap65-1 transcription, possibly via differential selection of multiple promoter sites upon environmental changes.


Author(s):  
Fatemeh Rahmani ◽  
Yahya Ehteshaminia ◽  
Hamid Mohammadi ◽  
Seif Ali Mahdavi

Introduction: Trichomoniasis is the most common non-viral sexually transmitted infection in the world, caused by the protozoan parasite Trichomonas vaginalis, which infects the urogenital tract of men and women. Approximately, 250 million new cases of Trichomonas vaginalis Infection are reported worldwide each year. Trichomoniasis is also considered an important HIV co-infection. The infection is often asymptomatic but can be accompanied by symptoms such as severe inflammation, itching and irritation, foamy discharge, and malodorous smell mucus, but the signs and symptoms of the disease are not sufficient for specific diagnosis. Material and Methods: In this study, the websites of PubMed, Google Scholar, SID, and Margiran were searched and related articles were reviewed. Results: Only screening and the use of highly sensitive and specific diagnostic methods can identify asymptomatic individuals. Today, the most common way to diagnose the infection is to use wet slide, Pap smear and culture methods that do not have high sensitivity and specificity. Also, due to the increase in infection and its complications, finding an efficient, rapid, and easy test to detect the parasite and differentiate Trichomoniasis vaginitis from other sexually transmitted diseases is considered important and necessary. Conclusion: Nowadays, there are several diagnostic methods that differentiate trichomoniasis infection from other sexually transmitted infections with high accuracy and sensitivity. Of course, existing diagnostic methods mostly use women's urine and vaginal samples for diagnosis, and methods that specifically diagnose the infection in men are more limited.


Author(s):  
Fatemeh Rahmani ◽  
Yahya Ehteshaminia ◽  
Hamid Mohammadi ◽  
Seif Ali Mahdavi

Introduction: Trichomonas vaginalis is a protozoan parasite that infects the urogenital tract of men and women and causes trichomoniasis, a common sexually transmitted disease in both men and women. The infection is often asymptomatic, but it can be accompanied by symptoms such as severe inflammation, itching and burning, foamy discharge and foul-smelling mucus. In one year, 250 million cases of Trichomonas vaginalis were reported worldwide. Material and Methods: In this study, the websites of PubMed, Google Scholar, SID, and Margiran were searched and related articles were reviewed.    Results: Today, the most common treatment for this disease is the use of metronidazole. However, its side effects, which include hematological and neurotoxic effects, cannot be ignored. Because of these side effects, researchers are looking for a suitable replacement for metronidazole in the treatment of trichomoniasis. Researchers' desire to use  herbs can be due to various reasons such as fewer side effects, better patient acceptance, recommendation of traditional medicine, lower prices of herbs and also compatibility with the normal physiological function of the human body. Conclusion: Considering the inhibitory effects of medicinal plants on the growth and proliferation of Trichomonas vaginalis in vitro, it can be concluded that the use of these plants can have many applications in the treatment of trichomoniasis. As a result, by studying more about their advantages and disadvantages, it is possible to make a drug that has higher therapeutic effects with fewer side effects.


Parasitology ◽  
2019 ◽  
Vol 146 (9) ◽  
pp. 1206-1216 ◽  
Author(s):  
Victor Midlej ◽  
Felipe Rubim ◽  
Wilmer Villarreal ◽  
Érica S. Martins-Duarte ◽  
Maribel Navarro ◽  
...  

AbstractTrichomonas vaginalis is a protozoan parasite that causes trichomoniasis in humans, the most prevalent non-viral sexually transmitted disease (STD). Imidazole compounds are used for the treatment of trichomoniasis, and metronidazole is the most commonly prescribed. However, these compounds can lead to parasite resistance and unwanted side effects. Therefore, there is a need for an alternative treatment for this disease. Here, we explored the potential of clotrimazole (CTZ) and zinc compounds, as well as CTZ complexed with zinc salts ([1] acetate [Zn(CTZ)2(Ac)2] and [2] a chloride [Zn(CTZ)2Cl2] complexes) against T. vaginalis. We synthesized the zinc complexed CTZ compounds and determined their concentration values that inhibited parasite growth by 50% (IC50). We used scanning and transmission electron microscopy to visualize the ultrastructural alterations induced by CTZ and their zinc complexes. The incubation of the parasites with [Zn(CTZ)2(Ac)2] complex inhibited their growth, yielding an IC50 of 4.9 µm. Moreover, there were changes in the shape of treated parasites, including the formation of surface projections that subsequently detached from the cell, in addition to changes in the hydrogenosomes, endoplasmic reticulum and Golgi complex. We found [Zn(CTZ)2(Ac)2] to be a highly effective compound against T. vaginalis in vitro, suggesting its potential utility as an alternative chemotherapy for trichomoniasis.


2001 ◽  
Vol 45 (6) ◽  
pp. 1743-1745 ◽  
Author(s):  
Graham H. Coombs ◽  
Jeremy C. Mottram

ABSTRACT Methionine γ-lyase, the enzyme which catalyzes the single-step conversion of methionine to α-ketobutyrate, ammonia, and methanethiol, is highly active in many anaerobic pathogenic microorganisms but has no counterpart in mammals. This study tested the hypothesis that this pathogen-specific enzyme can be exploited as a drug target by prodrugs that are exclusively activated by it. Trifluoromethionine was confirmed as such a prodrug and shown to be highly toxic in vitro to the anaerobic protozoan parasiteTrichomonas vaginalis, to anaerobic bacteria containing methionine γ-lyase, and to Escherichia coli expressing the trichomonad gene. The compound also has exceptional activity against the parasite growing in vivo, with a single dose preventing lesion formation in five of the six mice challenged. These findings suggest that trifluoromethionine represents a lead compound for a novel class of anti-infective drugs with potential as chemotherapeutic agents against a range of prokaryotic and eukaryotic anaerobic pathogens.


1992 ◽  
Vol 132 (2) ◽  
pp. 162 ◽  
Author(s):  
P. C. Goswami ◽  
M. Hill ◽  
R. Higashikubo ◽  
W. D. Wright ◽  
J. L. Roti Roti

2020 ◽  
Vol 50 (14) ◽  
pp. 1145-1155
Author(s):  
Anastasiia Artuyants ◽  
Tulio L. Campos ◽  
Anand K. Rai ◽  
Patricia J. Johnson ◽  
Priscila Dauros-Singorenko ◽  
...  

1991 ◽  
Vol 279 (3) ◽  
pp. 675-682 ◽  
Author(s):  
B C Lockwood ◽  
G H Coombs

Methionine gamma-lyase (EC 4.4.1.11) was purified to homogeneity from the anaerobic protozoan parasite Trichomonas vaginalis by a series of f.p.l.c. procedures. The enzyme catalyses alpha gamma- and alpha beta-elimination reactions of a number of derivatives of methionine and cysteine. It also catalyses gamma-replacement reactions of the thiomethyl group of methionine, homocysteine and ethionine to yield the corresponding S-substituted homocysteine derivative. The enzyme is pyridoxal 5′-phosphate-dependent, has a native molecular mass of approx. 160 kDa and consists of four apparently identical subunits of molecular mass 43-45 kDa. The absorption spectrum of the enzyme is typical of those obtained for other pyridoxal 5′-phosphate-dependent enzymes, and the holoenzyme can be resolved to the apoenzyme by incubation with hydroxylamine and reconstituted by addition of the cofactor. The enzyme activity is significantly affected by carbonyl and thiol reagents, is competitively inhibited by a number of substrate analogues and is completely inactivated by the suicide inhibitor DL-propargylglycine. The T. vaginalis enzyme is similar, in terms of activity and properties, to the enzymes found in a number of species of bacteria that metabolize methionine under anaerobic conditions. It is suggested that methionine catabolism may be of particular importance to the survival of T. vaginalis under microaerophilic conditions in its host.


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