Patricia J Johnson

Professor, MIMG, University of California Los Angeles

UC Profile

Research in Johnson laboratory is focused on the molecular and cellular biology of the unicellular parasite Trichomonas vaginalis. This eukaryotic microbe is responsible for the most prevalent, non-viral, sexually transmitted infection worldwide and is the most common parasite found in the US population. An estimated 275 million people worldwide have the parasite, including about 3.7 million in the United States. In 2014 the Center for Disease Control and Prevention identified trichomoniasis, the infection caused by T. vaginalis, as a Neglected Parasitic Infection in the United States. Beyond its medical importance, T. vaginalis is a fascinating organism for conducting research on the evolution of key biological processes present in all eukaryotes: from microbes to humans. Molecular data reveal T. vaginalis as one of the most divergent eukaryotes studied to date, making it an excellent system for exploring both biological diversity and extreme conservation. These basic science studies dovetail readily with medically important aspects of T. vaginalis, as its divergent, atypical properties offer possible chemotherapeutic targets and vaccine candidates. Our laboratory has focused on five aspects of trichomonad biology: organelle biogenesis & evolution, regulation of gene expression, drug resistance, host:parasite interactions and genomics. Our interdisciplinary research program merges several disciplines, including structural & cell biology, biochemistry, post-genomic bioinformatics, evolution and medical sciences. In recent years, we have primarily focused on defining and elucidating critical pathogenic mechanisms that allow T. vaginalis to establish and maintain an infection. Studies include identifying both parasite and host cell surface molecules that play critical roles in host:parasite interactions. The roles of small vesicles, called exosomes, that are secreted by the parasite, and mediate cellular communication and assist in colonization and infectivity of the host, are also being characterized. How a bacterial symbiont frequently identified in clinical isolates of T. vaginalis affects infection and a novel mechanism (called trogocytosis) human neutrophils use to kill the parasite are also being investigated.

Education and Training

The Netherland Cancer InstitutePostdoctoralMolecular Parasitology
The Rockefeller UniversityPostdoctoralBiochemistry
University of MichiganPhDCellular & Molecular Biology

Awards and Honors

  • The Helen Hay Whitney Postdoctoral Award, 1984-1987.
  • Burroughs -Wellcome Fund New Investigator Award, 1992-1995.
  • Keynote Speaker, XVIII Mexican Congress of Parasitology, 2009.
  • Plenary Speaker, 14th International Congress of Parasitology, 2018.
  • Young Investigator Award, National Foundation for Infectious Diseases, 1989.
  • American Society of Biochemistry & Molecular Biology Award in Molecular Parasitology, 2020.
  • Keynote Speaker, Annual Argentine Society of Parasitology, 2011.
  • MERIT Award from National Institute of Health (NIH), 2004-2014.
  • Elected to the National Academy of Sciences, USA, 2019.
  • Burroughs-Wellcome Fund Scholar Award, 1998-2003.
  • Elected to the American Academy of Microbiology, 2011.

Publications

  1. Molgora BM, Mukherjee SK, Baumel-Alterzon S, Santiago FM, Muratore KA, Sisk AE, Mercer F, Johnson PJ. Trichomonas vaginalis adherence phenotypes and extracellular vesicles impact parasite survival in a novel in vivo model of pathogenesis.. PLoS neglected tropical diseases, 2023.
  2. Stevens A, Muratore K, Cui Y, Johnson PJ, Zhou ZH. Atomic Structure of the Trichomonas vaginalis Double-Stranded RNA Virus 2.. mBio, 2021.
  3. Molgora BM, Rai AK, Sweredoski MJ, Moradian A, Hess S, Johnson PJ. A Novel Trichomonas vaginalis Surface Protein Modulates Parasite Attachment via Protein:Host Cell Proteoglycan Interaction.. mBio, 2021.
  4. Artuyants A, Campos TL, Rai AK, Johnson PJ, Dauros-Singorenko P, Phillips A, Simoes-Barbosa A. Extracellular vesicles produced by the protozoan parasite Trichomonas vaginalis contain a preferential cargo of tRNA-derived small RNAs.. International journal for parasitology, 2020.
  5. Lizarraga A, O'Brown ZK, Boulias K, Roach L, Greer EL, Johnson PJ, Strobl-Mazzulla PH, de Miguel N. Adenine DNA methylation, 3D genome organization, and gene expression in the parasite Trichomonas vaginalis.. Proceedings of the National Academy of Sciences of the United States of America, 2020.
  6. Rai AK, Johnson PJ. Trichomonas vaginalis extracellular vesicles are internalized by host cells using proteoglycans and caveolin-dependent endocytosis.. Proceedings of the National Academy of Sciences of the United States of America, 2019.
  7. Chen YP, Riestra AM, Rai AK, Johnson PJ. A Novel Cadherin-like Protein Mediates Adherence to and Killing of Host Cells by the Parasite Trichomonas vaginalis.. mBio, 2019.
  8. Mercer F, Johnson PJ. Trichomonas vaginalis: Pathogenesis, Symbiont Interactions, and Host Cell Immune Responses.. Trends in parasitology, 2018.
  9. Chen YP, Twu O, Johnson PJ. Trichomonas vaginalis Macrophage Migration Inhibitory Factor Mediates Parasite Survival during Nutrient Stress.. mBio, 2018.
  10. Nievas YR, Vashisht AA, Corvi MM, Metz S, Johnson PJ, Wohlschlegel JA, de Miguel N. Protein Palmitoylation Plays an Important Role in Trichomonas vaginalis Adherence.. Molecular & cellular proteomics : MCP, 2018.
  11. Mercer F, Ng SH, Brown TM, Boatman G, Johnson PJ. Neutrophils kill the parasite Trichomonas vaginalis using trogocytosis.. PLoS biology, 2018.
  12. Janssen BD, Chen YP, Molgora BM, Wang SE, Simoes-Barbosa A, Johnson PJ. CRISPR/Cas9-mediated gene modification and gene knock out in the human-infective parasite Trichomonas vaginalis.. Scientific reports, 2018.
  13. Nievas YR, Coceres VM, Midlej V, de Souza W, Benchimol M, Pereira-Neves A, Vashisht AA, Wohlschlegel JA, Johnson PJ, de Miguel N. Membrane-shed vesicles from the parasite Trichomonas vaginalis: characterization and their association with cell interaction.. Cellular and molecular life sciences : CMLS, 2017.
  14. Pachano T, Nievas YR, Lizarraga A, Johnson PJ, Strobl-Mazzulla PH, de Miguel N. Epigenetics regulates transcription and pathogenesis in the parasite Trichomonas vaginalis.. Cellular microbiology, 2017.
  15. Mercer F, Diala FG, Chen YP, Molgora BM, Ng SH, Johnson PJ. Leukocyte Lysis and Cytokine Induction by the Human Sexually Transmitted Parasite Trichomonas vaginalis.. PLoS neglected tropical diseases, 2016.
  16. Marti M, Johnson PJ. Emerging roles for extracellular vesicles in parasitic infections.. Current opinion in microbiology, 2016.
  17. Riestra AM, Gandhi S, Sweredoski MJ, Moradian A, Hess S, Urban S, Johnson PJ. A Trichomonas vaginalis Rhomboid Protease and Its Substrate Modulate Parasite Attachment and Cytolysis of Host Cells.. PLoS pathogens, 2015.
  18. Chatterjee A, Ratner DM, Ryan CM, Johnson PJ, O'Keefe BR, Secor WE, Anderson DJ, Robbins PW, Samuelson J. Anti-Retroviral Lectins Have Modest Effects on Adherence of Trichomonas vaginalis to Epithelial Cells In Vitro and on Recovery of Tritrichomonas foetus in a Mouse Vaginal Model.. PloS one, 2015.
  19. Twu O, Johnson PJ. Parasite extracellular vesicles: mediators of intercellular communication.. PLoS pathogens, 2014.
  20. Twu O, Dessí D, Vu A, Mercer F, Stevens GC, de Miguel N, Rappelli P, Cocco AR, Clubb RT, Fiori PL, Johnson PJ. Trichomonas vaginalis homolog of macrophage migration inhibitory factor induces prostate cell growth, invasiveness, and inflammatory responses.. Proceedings of the National Academy of Sciences of the United States of America, 2014.
  21. Wexler-Cohen Y, Stevens GC, Barnoy E, van der Bliek AM, Johnson PJ. A dynamin-related protein contributes to Trichomonas vaginalis hydrogenosomal fission.. FASEB journal : official publication of the Federation of American Societies for Experimental Biology, 2013.
  22. Leitsch D, Janssen BD, Kolarich D, Johnson PJ, Duchêne M. Trichomonas vaginalis flavin reductase 1 and its role in metronidazole resistance.. Molecular microbiology, 2013.
  23. Twu O, de Miguel N, Lustig G, Stevens GC, Vashisht AA, Wohlschlegel JA, Johnson PJ. Trichomonas vaginalis exosomes deliver cargo to host cells and mediate host∶parasite interactions.. PLoS pathogens, 2013.
  24. Lustig G, Ryan CM, Secor WE, Johnson PJ. Trichomonas vaginalis contact-dependent cytolysis of epithelial cells.. Infection and immunity, 2013.
  25. de Miguel N, Riestra A, Johnson PJ. Reversible association of tetraspanin with Trichomonas vaginalis flagella upon adherence to host cells.. Cellular microbiology, 2012.
  26. Simoes-Barbosa A, Chakrabarti K, Pearson M, Benarroch D, Shuman S, Johnson PJ. Box H/ACA snoRNAs are preferred substrates for the trimethylguanosine synthase in the divergent unicellular eukaryote Trichomonas vaginalis.. RNA (New York, N.Y.), 2012.
  27. Schneider RE, Brown MT, Shiflett AM, Dyall SD, Hayes RD, Xie Y, Loo JA, Johnson PJ. The Trichomonas vaginalis hydrogenosome proteome is highly reduced relative to mitochondria, yet complex compared with mitosomes.. International journal for parasitology, 2011.
  28. Ryan CM, Mehlert A, Richardson JM, Ferguson MA, Johnson PJ. Chemical structure of Trichomonas vaginalis surface lipoglycan: a role for short galactose (β1-4/3) N-acetylglucosamine repeats in host cell interaction.. The Journal of biological chemistry, 2011.
  29. Smith AJ, Chudnovsky L, Simoes-Barbosa A, Delgadillo-Correa MG, Jonsson ZO, Wohlschlegel JA, Johnson PJ. Novel core promoter elements and a cognate transcription factor in the divergent unicellular eukaryote Trichomonas vaginalis.. Molecular and cellular biology, 2011.
  30. Ryan CM, de Miguel N, Johnson PJ. Trichomonas vaginalis: current understanding of host-parasite interactions.. Essays in biochemistry, 2011.
  31. Simoes-Barbosa A, Hirt RP, Johnson PJ. A metazoan/plant-like capping enzyme and cap modified nucleotides in the unicellular eukaryote Trichomonas vaginalis.. PLoS pathogens, 2010.
  32. de Miguel N, Lustig G, Twu O, Chattopadhyay A, Wohlschlegel JA, Johnson PJ. Proteome analysis of the surface of Trichomonas vaginalis reveals novel proteins and strain-dependent differential expression.. Molecular & cellular proteomics : MCP, 2010.
  33. Shiflett AM, Johnson PJ. Mitochondrion-related organelles in eukaryotic protists.. Annual review of microbiology, 2010.
  34. Upcroft JA, Dunn LA, Wal T, Tabrizi S, Delgadillo-Correa MG, Johnson PJ, Garland S, Siba P, Upcroft P. Metronidazole resistance in Trichomonas vaginalis from highland women in Papua New Guinea.. Sexual health, 2009.
  35. Simoes-Barbosa A, Louly C, Franco OL, Rubio MA, Alfonzo JD, Johnson PJ. The divergent eukaryote Trichomonas vaginalis has an m7G cap methyltransferase capable of a single N2 methylation.. Nucleic acids research, 2008.
  36. Okumura CY, Baum LG, Johnson PJ. Galectin-1 on cervical epithelial cells is a receptor for the sexually transmitted human parasite Trichomonas vaginalis.. Cellular microbiology, 2008.
  37. Simoes-Barbosa A, Meloni D, Wohlschlegel JA, Konarska MM, Johnson PJ. Spliceosomal snRNAs in the unicellular eukaryote Trichomonas vaginalis are structurally conserved but lack a 5'-cap structure.. RNA (New York, N.Y.), 2008.
  38. Hampl V, Silberman JD, Stechmann A, Diaz-Triviño S, Johnson PJ, Roger AJ. Genetic evidence for a mitochondriate ancestry in the 'amitochondriate' flagellate Trimastix pyriformis.. PloS one, 2008.
  39. Brown MT, Goldstone HM, Bastida-Corcuera F, Delgadillo-Correa MG, McArthur AG, Johnson PJ. A functionally divergent hydrogenosomal peptidase with protomitochondrial ancestry.. Molecular microbiology, 2007.
  40. Carlton JM, Hirt RP, Silva JC, Delcher AL, Schatz M, Zhao Q, Wortman JR, Bidwell SL, Alsmark UC, Besteiro S, Sicheritz-Ponten T, Noel CJ, Dacks JB, Foster PG, Simillion C, Van de Peer Y, Miranda-Saavedra D, Barton GJ, Westrop GD, Müller S, Dessi D, Fiori PL, Ren Q, Paulsen I, Zhang H, Bastida-Corcuera FD, Simoes-Barbosa A, Brown MT, Hayes RD, Mukherjee M, Okumura CY, Schneider R, Smith AJ, Vanacova S, Villalvazo M, Haas BJ, Pertea M, Feldblyum TV, Utterback TR, Shu CL, Osoegawa K, de Jong PJ, Hrdy I, Horvathova L, Zubacova Z, Dolezal P, Malik SB, Logsdon JM, Henze K, Gupta A, Wang CC, Dunne RL, Upcroft JA, Upcroft P, White O, Salzberg SL, Tang P, Chiu CH, Lee YS, Embley TM, Coombs GH, Mottram JC, Tachezy J, Fraser-Liggett CM, Johnson PJ. Draft genome sequence of the sexually transmitted pathogen Trichomonas vaginalis.. Science (New York, N.Y.), 2007.
  41. Mukherjee M, Brown MT, McArthur AG, Johnson PJ. Proteins of the glycine decarboxylase complex in the hydrogenosome of Trichomonas vaginalis.. Eukaryotic cell, 2006.
  42. Mukherjee M, Sievers SA, Brown MT, Johnson PJ. Identification and biochemical characterization of serine hydroxymethyl transferase in the hydrogenosome of Trichomonas vaginalis.. Eukaryotic cell, 2006.
  43. Lau AO, Smith AJ, Brown MT, Johnson PJ. Trichomonas vaginalis initiator binding protein (IBP39) and RNA polymerase II large subunit carboxy terminal domain interaction.. Molecular and biochemical parasitology, 2006.
  44. Upcroft JA, Delgadillo-Correa MG, Dunne RL, Sturm AW, Johnson PJ, Upcroft P. Genotyping Trichomonas vaginalis.. International journal for parasitology, 2006.
  45. Bastida-Corcuera FD, Okumura CY, Colocoussi A, Johnson PJ. Trichomonas vaginalis lipophosphoglycan mutants have reduced adherence and cytotoxicity to human ectocervical cells.. Eukaryotic cell, 2005.
  46. Vanácová S, Yan W, Carlton JM, Johnson PJ. Spliceosomal introns in the deep-branching eukaryote Trichomonas vaginalis.. Proceedings of the National Academy of Sciences of the United States of America, 2005.
  47. Dyall SD, Yan W, Delgadillo-Correa MG, Lunceford A, Loo JA, Clarke CF, Johnson PJ. Non-mitochondrial complex I proteins in a hydrogenosomal oxidoreductase complex.. Nature, 2004.
  48. Silva JC, Bastida F, Bidwell SL, Johnson PJ, Carlton JM. A potentially functional mariner transposable element in the protist Trichomonas vaginalis.. Molecular biology and evolution, 2004.
  49. Sutak R, Dolezal P, Fiumera HL, Hrdy I, Dancis A, Delgadillo-Correa M, Johnson PJ, Müller M, Tachezy J. Mitochondrial-type assembly of FeS centers in the hydrogenosomes of the amitochondriate eukaryote Trichomonas vaginalis.. Proceedings of the National Academy of Sciences of the United States of America, 2004.
  50. Dyall SD, Brown MT, Johnson PJ. Ancient invasions: from endosymbionts to organelles.. Science (New York, N.Y.), 2004.
  51. Silberman JD, Collins AG, Gershwin LA, Johnson PJ, Roger AJ. Ellobiopsids of the genus Thalassomyces are alveolates.. The Journal of eukaryotic microbiology, 2004.
  52. Land KM, Delgadillo-Correa MG, Tachezy J, Vanacova S, Hsieh CL, Sutak R, Johnson PJ. Targeted gene replacement of a ferredoxin gene in Trichomonas vaginalis does not lead to metronidazole resistance.. Molecular microbiology, 2004.
  53. Schumacher MA, Lau AO, Johnson PJ. Structural basis of core promoter recognition in a primitive eukaryote.. Cell, 2003.
  54. Lau AO, Liston DR, Vanacova S, Johnson PJ. Trichomonas vaginalis initiator binding protein, IBP39, contains a novel DNA binding motif.. Molecular and biochemical parasitology, 2003.
  55. Dyall SD, Lester DC, Schneider RE, Delgadillo-Correa MG, Plümper E, Martinez A, Koehler CM, Johnson PJ. Trichomonas vaginalis Hmp35, a putative pore-forming hydrogenosomal membrane protein, can form a complex in yeast mitochondria.. The Journal of biological chemistry, 2003.
  56. Ortiz D, Johnson PJ. Tetracycline-inducible gene expression in Trichomonas vaginalis.. Molecular and biochemical parasitology, 2003.
  57. Vanacova S, Liston DR, Tachezy J, Johnson PJ. Molecular biology of the amitochondriate parasites, Giardia intestinalis, Entamoeba histolytica and Trichomonas vaginalis.. International journal for parasitology, 2003.
  58. Land KM, Delgadillo MG, Johnson PJ. In vivo expression of ferredoxin in a drug resistant trichomonad increases metronidazole susceptibility.. Molecular and biochemical parasitology, 2002.
  59. Johnson PJ. Spliceosomal introns in a deep-branching eukaryote: the splice of life.. Proceedings of the National Academy of Sciences of the United States of America, 2002.