The long term objectives of this research are to understand the basic properties that are critical for the expression of genes in the parasite Trichomonas vaginalis, to examine the role of altered gene expression in metronidazole resistant parasites and to determine the mechanism underlying drug resistance. T. vaginalis is one of the most common parasites encountered by Americans. Isolates of this parasite that are refractory to treatment with metronidazole, the only drug licensed for therapy, are frequently reported. Our previous research has provided evidence that drug resistant strains have altered transcription of genes encoding proteins that are necessary for activation of this prodrug to its cytotoxic form. Investigation of the mechanisms that govern transcription in T. vaginalis and how these mechanisms can be altered to give rise to drug resistance has lead to our discovery of a highly conserved, essential promoter element (Inr) that is necessary for transcription of all T. vaginalis protein-coding genes. We propose to define the role of this element and its interacting proteins in initiation of transcription. Possible novel mechanisms used for the translation of T. vaginalis proteins will also be examined. As our studies focus on properties of the parasite that distinguish it from its human host, the information gained may lead to identification of novel, therapeutic targets. We propose to extend our research on gene expression and drug resistance by (1) characterizing a protein that specifically binds to the essential Inr promoter element by purifying the protein and cloning the gene encoding this protein, (2) examining the role of the unusual 5' untranslated regions of mRNAs in expression of T. vaginalis genes and (3) determining whether altered gene expression is responsible for drug resistance in trichomonads. These studies will greatly enhance our understanding of gene expression in early-evolving eukaryotes. Moreover, a better understanding of the basic properties underlying gene expression in trichomonads will provide insights into the evolution of gene regulatory mechanisms in parasitic protists, as well as biochemical mechanisms that give rise to drug resistance.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI030537-09
Application #
6373212
Study Section
Special Emphasis Panel (ZRG1-BM-2 (06))
Program Officer
Gottlieb, Michael
Project Start
1991-09-01
Project End
2004-07-31
Budget Start
2001-08-01
Budget End
2002-07-31
Support Year
9
Fiscal Year
2001
Total Cost
$259,812
Indirect Cost
Name
University of California Los Angeles
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
119132785
City
Los Angeles
State
CA
Country
United States
Zip Code
90095
Simoes-Barbosa, Augusto; Chakrabarti, Kausik; Pearson, Michael et al. (2012) Box H/ACA snoRNAs are preferred substrates for the trimethylguanosine synthase in the divergent unicellular eukaryote Trichomonas vaginalis. RNA 18:1656-65
Smith, Alias J; Chudnovsky, Lorissa; Simoes-Barbosa, Augusto et al. (2011) Novel core promoter elements and a cognate transcription factor in the divergent unicellular eukaryote Trichomonas vaginalis. Mol Cell Biol 31:1444-58
Smith, Alias; Johnson, Patricia (2011) Gene expression in the unicellular eukaryote Trichomonas vaginalis. Res Microbiol 162:646-54
Simoes-Barbosa, Augusto; Hirt, Robert P; Johnson, Patricia J (2010) A metazoan/plant-like capping enzyme and cap modified nucleotides in the unicellular eukaryote Trichomonas vaginalis. PLoS Pathog 6:e1000999
Simoes-Barbosa, Augusto; Louly, Camila; Franco, Octavio L et al. (2008) The divergent eukaryote Trichomonas vaginalis has an m7G cap methyltransferase capable of a single N2 methylation. Nucleic Acids Res 36:6848-58
Simoes-Barbosa, Augusto; Meloni, Dionigia; Wohlschlegel, James A et al. (2008) Spliceosomal snRNAs in the unicellular eukaryote Trichomonas vaginalis are structurally conserved but lack a 5'-cap structure. RNA 14:1617-31
Lau, Audrey O T; Smith, Alias J; Brown, Mark T et al. (2006) Trichomonas vaginalis initiator binding protein (IBP39) and RNA polymerase II large subunit carboxy terminal domain interaction. Mol Biochem Parasitol 150:56-62
Vanacova, Stepanka; Yan, Weihong; Carlton, Jane M et al. (2005) Spliceosomal introns in the deep-branching eukaryote Trichomonas vaginalis. Proc Natl Acad Sci U S A 102:4430-5
Land, Kirkwood M; Delgadillo-Correa, Maria G; Tachezy, Jan et al. (2004) Targeted gene replacement of a ferredoxin gene in Trichomonas vaginalis does not lead to metronidazole resistance. Mol Microbiol 51:115-22
Schumacher, Maria A; Lau, Audrey O T; Johnson, Patricia J (2003) Structural basis of core promoter recognition in a primitive eukaryote. Cell 115:413-24

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