Article | Published:

Small-molecule inhibition of a depalmitoylase enhances Toxoplasma host-cell invasion

Nature Chemical Biology volume 9, pages 651656 (2013) | Download Citation

Abstract

Although there have been numerous advances in our understanding of how apicomplexan parasites such as Toxoplasma gondii enter host cells, many of the signaling pathways and enzymes involved in the organization of invasion mediators remain poorly defined. We recently performed a forward chemical-genetic screen in T. gondii and identified compounds that markedly enhanced infectivity. Although molecular dissection of invasion has benefited from the use of small-molecule inhibitors, the mechanisms underlying induction of invasion by small-molecule enhancers have never been described. Here we identify the Toxoplasma ortholog of human APT1, palmitoyl protein thioesterase-1 (TgPPT1), as the target of one class of small-molecule enhancers. Inhibition of this uncharacterized thioesterase triggered secretion of invasion-associated organelles, increased motility and enhanced the invasive capacity of tachyzoites. We demonstrate that TgPPT1 is a bona fide depalmitoylase, thereby establishing an important role for dynamic and reversible palmitoylation in host-cell invasion by T. gondii.

  • Compound C12H12ClNO3

    7-Amino-4-chloro-3-propoxy-isocoumarin

  • Compound C12H12ClNO3

    7-Amino-4-chloro-3-isopropoxy-isocoumarin

  • Compound C12H11BrClNO3

    7-Amino-3-((1-bromopropan-2-yl)oxy)-4-chloro-isocoumarin

  • Compound C12H11ClO3

    4-Chloro-3-propoxy-isocoumarin

  • Compound C13H10ClNO3

    7-Amino-3-(but-3-yn-1-yloxy)-4-chloro-isocoumarin

  • Compound C9H8O4

    Homophthalic acid

  • Compound C9H7NO6

    Nitrohomophthalic acid

  • Compound C11H11NO6

    2-(2-Isopropoxy-2-oxoethyl)-5-nitrobenzoic acid

  • Compound C12H13NO6

    2-(2-isopropoxy-2-oxoethyl)-5-nitrobenzoic acid

  • Compound C12H12BrNO6

    2-(2-((1-Bromopropan-2-yl)oxy)-2-oxoethyl)-5-nitrobenzoic acid

  • Compound C12H10ClNO5

    4-Chloro-7-nitro-3-propoxy-isocoumarin

  • Compound C12H10ClNO5

    4-Chloro-3-isopropoxy-7-nitro-isocoumarin

  • Compound C12H9BrClNO5

    3-((1-Bromopropan-2-yl)oxy)-4-chloro-7-nitro-isocoumarin

  • Compound C13H8ClNO5

    3-(But-3-yn-1-yloxy)-4-chloro-7-nitro-isocoumarin

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Acknowledgements

We thank the Bogyo and Boothroyd labs for discussions that shaped the direction of the project; G. Ward (University of Vermont) for discussions and the GAP45 antibody; B. Martin for discussions regarding the 17-ODA metabolic labeling experiments; G. Arrizabalaga (Indiana University) and M. Treeck (Stanford University) for the TgCDPK3-HA parasite line; B. Cravatt (Scripps Research Institute) for FP-rho; T. Wandless (Stanford University) for Shield-1; and the Stanford high-throughput imaging facility for assistance with imaging the attachment and invasion assays. This work was funded by a Burroughs Wellcome Trust New Investigators in Pathogenesis Award (to M.B.), by the US National Institutes of Health grants R01-AI078947 and EB005011 (to M.B.) and RO1 AI21423 (to J.C.B.).

Author information

Affiliations

  1. Department of Pathology, Stanford University School of Medicine, Stanford, California, USA.

    • Matthew A Child
    • , Leslie O Ofori
    • , Victoria E Albrow
    • , Megan Garland
    • , Paul W Bowyer
    •  & Matthew Bogyo
  2. Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, USA.

    • Carolyn I Hall
    • , John C Boothroyd
    •  & Matthew Bogyo
  3. Department of Microbiology, Immunology and Molecular Genetics, University of California–Los Angeles, Los Angeles, California, USA.

    • Josh R Beck
    •  & Peter J Bradley
  4. Department of Chemistry, Georgia Institute of Technology, Atlanta, Georgia, USA.

    • James C Powers
  5. Department of Chemistry, Boston College, Chestnut Hill, Massachusetts, USA.

    • Eranthie Weerapana

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Contributions

M.A.C. designed and performed the majority of the experiments, analyzed the data, generated the figures and wrote the manuscript. C.I.H. performed the original high-throughput screen and various biochemical and cell biological studies. C.I.H., V.E.A. and P.W.B. characterized the enhancer phenotype. V.E.A. synthesized JCP174-IA and JCP174-alk. J.C.P. and L.O.O. synthesized JCP174, JCP222 and JCP362. J.R.B. generated the TgPPT1-HAdd parasite line under the supervision of P.J.B. M.G. contributed to the CDPK3 experiments. E.W. performed MS experiments. E.W. and J.C.B. intellectually contributed to the decision to pursue TgPPT1 as the functionally relevant target of JCP174. M.B. supervised the project, designed and analyzed experiments and wrote parts of the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Matthew Bogyo.

Supplementary information

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  1. 1.

    Supplementary Text and Figures

    Supplementary Figures 1–11 and Supplementary Tables 3 and 4.

  2. 2.

    Supplementary Note

    Supplementary Notes

Excel files

  1. 1.

    Supplementary Tables 1 and 2

    Suplementary Table 1: Mass spectrometry data of identified peptides from FP-Biotin labeling and TOP-ABPP using the JCP174-alk probe. Supplementary Table 2: List of the top 6 hits from the total list of identified targets of FP-Rho and JCP174-alk.

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DOI

https://doi.org/10.1038/nchembio.1315

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