Zinc metalloprotease families in Trypansoma brucei

Summary

Principal Investigator: JOHN DONELSON
Abstract: DESCRIPTION (provided by the applicant): Proteases are critical factors enabling many protozoa and helminths to parasitize and survive in both mammalian and insect hosts. The biological properties and differential expression of related groups of zinc metalloproteases in the African trypanosome Trypanosoma brucei will be studied using the techniques of traditional gene deletion, RNA interference (RNAi), and overexpression for selected experiments. Three groups of metalloproteases, called TbMSP-A, TbMSP-B and TbMSP-C, each has about 33% amino acid identity with the major surface protease (MSP, formerly called GP63) of Leishmania, and share a common zinc binding motif. The mRNAs of all three gene families occur in bloodstream trypanosomes, whereas only the mRNA of TbMSP-B is expressed in procyclic trypanosomes. Their C-terminal amino acid sequences suggest that TbMSP-A and -B are likely associated with a cellular membrane via a glycosylphosphatidylinositol (GPI) anchor, whereas TbMSP-C may be either located in the cytoplasm or secreted. We hypothesize that those TbMSPs predicted on the basis of their sequences to traffic to the trypanosome surface, i.e., TbMSP-A and TbMSP-B, serve important functions in facilitating survival of trypanosomes in the host environment. Our preliminary data lead us to hypothesize that TbMSP-B is a surface protease under translational control in bloodstream cells, which participates in shedding of the variant surface glycoprotein (VSG) during differentiation from bloodstream to procyclic cells. Further evidence leads us to hypothesize that TbMSP-A serves a distinct proteolytic function that is not required in procyclic cells, although the exact nature of this function has yet to be identified. In this application we propose to use the techniques of immunolocalization, sub-cellular fractionation, metabolic labeling, protease characterization, and gene mutagenesis to identify the sub-cellular locations of the TbMSP-A and TbMSP-B families, to determine their biological functions, and to elucidate the molecular mechanisms regulating their differential expression.
Funding Period: 2005-07-01 - 2010-03-31
more information: NIH RePORT

Top Publications

  1. pmc Attenuation of Leishmania infantum chagasi metacyclic promastigotes by sterol depletion
    Chaoqun Yao
    Department of Veterinary Sciences and Wyoming State Veterinary Laboratory, University of Wyoming, Laramie, Wyoming, USA
    Infect Immun 81:2507-17. 2013
  2. pmc Macrophage and T-cell gene expression in a model of early infection with the protozoan Leishmania chagasi
    Nicholas A Ettinger
    Interdisciplinary Graduate Program in Molecular and Cellular Biology, University of Iowa, Iowa City, Iowa, USA
    PLoS Negl Trop Dis 2:e252. 2008
  3. pmc Leishmania infantum chagasi: a genome-based approach to identification of excreted/secreted proteins
    Sruti DebRoy
    Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA
    Exp Parasitol 126:582-91. 2010
  4. pmc Resistance of Leishmania (Viannia) braziliensis to nitric oxide: correlation with antimony therapy and TNF-alpha production
    Anselmo S Souza
    Universidade Federal de Sergipe, Aracaju, Sergipe, Brazil
    BMC Infect Dis 10:209. 2010
  5. pmc Proteomic examination of Leishmania chagasi plasma membrane proteins: Contrast between avirulent and virulent (metacyclic) parasite forms
    Chaoqun Yao
    Department of Internal Medicine, University of Iowa, Iowa City, USA
    Proteomics Clin Appl 4:4-16. 2010
  6. pmc The effects of macrophage source on the mechanism of phagocytosis and intracellular survival of Leishmania
    Chia Hung Christine Hsiao
    Molecular and Cellular Biology Program, University of Iowa, Iowa City, IA 52242, USA
    Microbes Infect 13:1033-44. 2011
  7. pmc Serial quantitative PCR assay for detection, species discrimination, and quantification of Leishmania spp. in human samples
    Jason L Weirather
    Iowa City VA Medical Center, Iowa City, Iowa, USA
    J Clin Microbiol 49:3892-904. 2011
  8. pmc Mapping of VSG similarities in Trypanosoma brucei
    Jason L Weirather
    Interdisciplinary Program in Genetics, University of Iowa, Iowa City, IA 52240, USA
    Mol Biochem Parasitol 181:141-52. 2012
  9. pmc Analysis of expressed sequence tags from the four main developmental stages of Trypanosoma congolense
    Jared R Helm
    Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
    Mol Biochem Parasitol 168:34-42. 2009
  10. pmc Differences in human macrophage receptor usage, lysosomal fusion kinetics and survival between logarithmic and metacyclic Leishmania infantum chagasi promastigotes
    Norikiyo Ueno
    Department of Microbiology, The University of Iowa, Iowa City, IA, USA
    Cell Microbiol 11:1827-41. 2009

Scientific Experts

  • Chaoqun Yao
  • Anselmo S Souza
  • Mary E Wilson
  • John E Donelson
  • Jared R Helm
  • Jason L Weirather
  • Norikiyo Ueno
  • Chia Hung Christine Hsiao
  • Selma M B Jeronimo
  • Sruti DebRoy
  • Nicholas A Ettinger
  • Paul M Grandgenett
  • Haeok K Chang
  • Daniella R A Martins
  • Melissa A Kurtz
  • Kenneth C Moore
  • Shyam Sundar
  • Jian Q Shao
  • Kristin R Schroeder
  • Mitchell Kang
  • Sinesio Talhari
  • Albert Schriefer
  • Rashidul Haque
  • Shalini Gautam
  • Edgar M Carvalho
  • Alexandra B Keenan
  • Noboru Inoue
  • Marcelo B Soares
  • Michael A Quail
  • Nilda E Rodriguez
  • Matthew Berriman
  • Carol L Bratt
  • Christiane Hertz-Fowler
  • Mandy Sanders
  • Tatsuya Sakurai
  • Maria F Bonaldo
  • Martin Aslett
  • Patricia Storlie
  • Helen R Wilson
  • Joanna S Mehling
  • Keiko Otsu
  • Colin Thalhofer
  • Roque Almeida
  • Breck A Duerkop
  • Kenneth J Gollob
  • Shilpi Verma

Detail Information

Publications19

  1. pmc Attenuation of Leishmania infantum chagasi metacyclic promastigotes by sterol depletion
    Chaoqun Yao
    Department of Veterinary Sciences and Wyoming State Veterinary Laboratory, University of Wyoming, Laramie, Wyoming, USA
    Infect Immun 81:2507-17. 2013
    ..These data support the hypothesis that plasma membrane sterols are important for the virulence of Leishmania protozoa at least in part through retention of membrane virulence proteins...
  2. pmc Macrophage and T-cell gene expression in a model of early infection with the protozoan Leishmania chagasi
    Nicholas A Ettinger
    Interdisciplinary Graduate Program in Molecular and Cellular Biology, University of Iowa, Iowa City, Iowa, USA
    PLoS Negl Trop Dis 2:e252. 2008
    ..This local microenvironment at the site of parasite inoculation may determine the initial course of immune T-cell development...
  3. pmc Leishmania infantum chagasi: a genome-based approach to identification of excreted/secreted proteins
    Sruti DebRoy
    Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA
    Exp Parasitol 126:582-91. 2010
    ..We found both amastigote-specific and promastigote-specific released proteins. The ES proteins of Lic are candidates for future studies of parasite virulence determinants and host protective immunity...
  4. pmc Resistance of Leishmania (Viannia) braziliensis to nitric oxide: correlation with antimony therapy and TNF-alpha production
    Anselmo S Souza
    Universidade Federal de Sergipe, Aracaju, Sergipe, Brazil
    BMC Infect Dis 10:209. 2010
    ..The aim of this study is to investigate if there is an association between the resistance of L. (V.) braziliensis to NO and nonresponsiveness to antimony therapy and cytokine production...
  5. pmc Proteomic examination of Leishmania chagasi plasma membrane proteins: Contrast between avirulent and virulent (metacyclic) parasite forms
    Chaoqun Yao
    Department of Internal Medicine, University of Iowa, Iowa City, USA
    Proteomics Clin Appl 4:4-16. 2010
    ..We hypothesized that proteins important for promastigote virulence might be uniquely represented in the plasma membrane of metacyclic, but not procyclic, promastigotes...
  6. pmc The effects of macrophage source on the mechanism of phagocytosis and intracellular survival of Leishmania
    Chia Hung Christine Hsiao
    Molecular and Cellular Biology Program, University of Iowa, Iowa City, IA 52242, USA
    Microbes Infect 13:1033-44. 2011
    ..We hypothesize that the mechanism of phagocytosis differs between primary versus immortalized human macrophage cells, with corresponding differences in the subsequent intracellular fate of the parasite...
  7. pmc Serial quantitative PCR assay for detection, species discrimination, and quantification of Leishmania spp. in human samples
    Jason L Weirather
    Iowa City VA Medical Center, Iowa City, Iowa, USA
    J Clin Microbiol 49:3892-904. 2011
    ..Thus, serial qPCR is useful for leishmania detection and species determination and for absolute quantification when compared to a standard curve from the same Leishmania species...
  8. pmc Mapping of VSG similarities in Trypanosoma brucei
    Jason L Weirather
    Interdisciplinary Program in Genetics, University of Iowa, Iowa City, IA 52240, USA
    Mol Biochem Parasitol 181:141-52. 2012
    ..These data suggest that mosaic gene formation is a major contributor to the overall VSG diversity, even though gene recombinational events between members of different N-terminal types occur only rarely...
  9. pmc Analysis of expressed sequence tags from the four main developmental stages of Trypanosoma congolense
    Jared R Helm
    Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
    Mol Biochem Parasitol 168:34-42. 2009
    ..The T. congolense EST databases are available at: http://www.sanger.ac.uk/Projects/T_congolense/EST_index.shtml. The sequence data have been submitted to EMBL under the following accession numbers: FN263376-FN292969...
  10. pmc Differences in human macrophage receptor usage, lysosomal fusion kinetics and survival between logarithmic and metacyclic Leishmania infantum chagasi promastigotes
    Norikiyo Ueno
    Department of Microbiology, The University of Iowa, Iowa City, IA, USA
    Cell Microbiol 11:1827-41. 2009
    ..The relatively quiescent entry of virulent Leishmania spp. into macrophages may be accounted for by the ability of metacyclic promastigotes to selectively bypass deleterious entry pathways...
  11. pmc Differential expression of a protease gene family in African trypanosomes
    Jared R Helm
    Department of Biochemistry, University of Iowa, 4 339 Bowen Science Bldg, Iowa City, IA 52242, USA
    Mol Biochem Parasitol 163:8-18. 2009
    ..Thus, the 23-bp element of this protease gene affects both the level of RNA and its translation...
  12. pmc Different trans RNA splicing events in bloodstream and procyclic Trypanosoma brucei
    Jared R Helm
    Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA
    Mol Biochem Parasitol 159:134-7. 2008
    ..These alternative SL addition sites may be aberrant or they might be utilized to expand the number of gene products from individual genes. Future experiments on endogenous genes will be necessary to examine the latter possibility...
  13. pmc The major surface protease (MSP or GP63) in the intracellular amastigote stage of Leishmania chagasi
    Chia Hung Christine Hsiao
    Molecular Biology Program, University of Iowa, Iowa City, IA 52242, USA
    Mol Biochem Parasitol 157:148-59. 2008
    ..We hypothesize that MSP plays different roles in the extracellular versus intracellular forms of Leishmania spp...
  14. pmc A function for a specific zinc metalloprotease of African trypanosomes
    Paul M Grandgenett
    Interdepartmental Genetics Program, University of Iowa, Iowa City, Iowa, USA
    PLoS Pathog 3:1432-45. 2007
    ..Inhibitors of cysteine proteases did not affect this result. These findings demonstrate that removal of 60% of the VSG during differentiation from bloodstream to procyclic form is due to the synergistic activities of GPI-PLC and TbMSP-B...
  15. pmc Leishmania chagasi: homogenous metacyclic promastigotes isolated by buoyant density are highly virulent in a mouse model
    Chaoqun Yao
    Department of Internal Medicine, University of Iowa, IA 52242, USA
    Exp Parasitol 118:129-33. 2008
    ..These metacyclic L. chagasi expressed both the virulence-associated 59-kDa, and the constitutively expressed 63-kDa, isoforms of MSP...
  16. pmc Internal and surface-localized major surface proteases of Leishmania spp. and their differential release from promastigotes
    Chaoqun Yao
    Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA
    Eukaryot Cell 6:1905-12. 2007
    ..We present a model in which these different MSP pools are released under distinct life cycle-specific conditions...
  17. pmc Leishmania chagasi: a tetracycline-inducible cell line driven by T7 RNA polymerase
    Chaoqun Yao
    Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA
    Exp Parasitol 116:205-13. 2007
    ..that allows the exogenous T7RNAP-driven gene expression to be tetracycline-inducible; and may provide a useful tool for addressing protein function by manipulating expression levels of Leishmania endogenous genes...
  18. pmc Oxidant generation by single infected monocytes after short-term fluorescence labeling of a protozoan parasite
    Haeok K Chang
    Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA
    Infect Immun 75:1017-24. 2007
    ..The parasite must balance these positive and negative survival effects in order to initiate a viable infection...
  19. pmc Leishmania chagasi T-cell antigens identified through a double library screen
    Daniella R A Martins
    Department of Internal Medicine, University of Iowa, SW34 GH, 200 Hawkins Drive, Iowa City, IA 52242, USA
    Infect Immun 74:6940-8. 2006
    ..Humans naturally infected with L. chagasi mounted both cellular and antibody responses to these proteins. Preparations containing multiple antigens may be optimal for immunodiagnosis and protective vaccines...