pH-dependence of the Plasmodium falciparum chloroquine resistance transporter is linked to the transport cycle
Abstract The chloroquine resistance transporter, PfCRT, of the human malaria parasite Plasmodium falciparum is sensitive to acidic pH. Consequently, PfCRT operates at 60% of its maximal drug transport activity at the pH of 5.2 of the digestive vacuole, a proteolytic organelle from which PfCRT expels...
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2023-07-01
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| Series: | Nature Communications |
| Online Access: | https://doi.org/10.1038/s41467-023-39969-2 |
| _version_ | 1797778755640360960 |
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| author | Fiona Berger Guillermo M. Gomez Cecilia P. Sanchez Britta Posch Gabrielle Planelles Farzin Sohraby Ariane Nunes-Alves Michael Lanzer |
| author_facet | Fiona Berger Guillermo M. Gomez Cecilia P. Sanchez Britta Posch Gabrielle Planelles Farzin Sohraby Ariane Nunes-Alves Michael Lanzer |
| author_sort | Fiona Berger |
| collection | DOAJ |
| description | Abstract The chloroquine resistance transporter, PfCRT, of the human malaria parasite Plasmodium falciparum is sensitive to acidic pH. Consequently, PfCRT operates at 60% of its maximal drug transport activity at the pH of 5.2 of the digestive vacuole, a proteolytic organelle from which PfCRT expels drugs interfering with heme detoxification. Here we show by alanine-scanning mutagenesis that E207 is critical for pH sensing. The E207A mutation abrogates pH-sensitivity, while preserving drug substrate specificity. Substituting E207 with Asp or His, but not other amino acids, restores pH-sensitivity. Molecular dynamics simulations and kinetics analyses suggest an allosteric binding model in which PfCRT can accept both protons and chloroquine in a partial noncompetitive manner, with increased proton concentrations decreasing drug transport. Further simulations reveal that E207 relocates from a peripheral to an engaged location during the transport cycle, forming a salt bridge with residue K80. We propose that the ionized carboxyl group of E207 acts as a hydrogen acceptor, facilitating transport cycle progression, with pH sensing as a by-product. |
| first_indexed | 2024-03-12T23:22:08Z |
| format | Article |
| id | doaj.art-4481fd0850c543e2a8b0bb81ca74a0e9 |
| institution | Directory Open Access Journal |
| issn | 2041-1723 |
| language | English |
| last_indexed | 2024-03-12T23:22:08Z |
| publishDate | 2023-07-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Nature Communications |
| spelling | doaj.art-4481fd0850c543e2a8b0bb81ca74a0e92023-07-16T11:22:41ZengNature PortfolioNature Communications2041-17232023-07-0114111610.1038/s41467-023-39969-2pH-dependence of the Plasmodium falciparum chloroquine resistance transporter is linked to the transport cycleFiona Berger0Guillermo M. Gomez1Cecilia P. Sanchez2Britta Posch3Gabrielle Planelles4Farzin Sohraby5Ariane Nunes-Alves6Michael Lanzer7Center of Infectious Diseases, Parasitology, Universitätsklinikum HeidelbergCenter of Infectious Diseases, Parasitology, Universitätsklinikum HeidelbergCenter of Infectious Diseases, Parasitology, Universitätsklinikum HeidelbergCenter of Infectious Diseases, Parasitology, Universitätsklinikum HeidelbergINSERM, Centre de Recherche des Cordeliers, Unité 1138, CNRS ERL8228, Université Pierre et Marie Curie and Université Paris-DescartesInstitute of Chemistry, Technische Universität BerlinInstitute of Chemistry, Technische Universität BerlinCenter of Infectious Diseases, Parasitology, Universitätsklinikum HeidelbergAbstract The chloroquine resistance transporter, PfCRT, of the human malaria parasite Plasmodium falciparum is sensitive to acidic pH. Consequently, PfCRT operates at 60% of its maximal drug transport activity at the pH of 5.2 of the digestive vacuole, a proteolytic organelle from which PfCRT expels drugs interfering with heme detoxification. Here we show by alanine-scanning mutagenesis that E207 is critical for pH sensing. The E207A mutation abrogates pH-sensitivity, while preserving drug substrate specificity. Substituting E207 with Asp or His, but not other amino acids, restores pH-sensitivity. Molecular dynamics simulations and kinetics analyses suggest an allosteric binding model in which PfCRT can accept both protons and chloroquine in a partial noncompetitive manner, with increased proton concentrations decreasing drug transport. Further simulations reveal that E207 relocates from a peripheral to an engaged location during the transport cycle, forming a salt bridge with residue K80. We propose that the ionized carboxyl group of E207 acts as a hydrogen acceptor, facilitating transport cycle progression, with pH sensing as a by-product.https://doi.org/10.1038/s41467-023-39969-2 |
| spellingShingle | Fiona Berger Guillermo M. Gomez Cecilia P. Sanchez Britta Posch Gabrielle Planelles Farzin Sohraby Ariane Nunes-Alves Michael Lanzer pH-dependence of the Plasmodium falciparum chloroquine resistance transporter is linked to the transport cycle Nature Communications |
| title | pH-dependence of the Plasmodium falciparum chloroquine resistance transporter is linked to the transport cycle |
| title_full | pH-dependence of the Plasmodium falciparum chloroquine resistance transporter is linked to the transport cycle |
| title_fullStr | pH-dependence of the Plasmodium falciparum chloroquine resistance transporter is linked to the transport cycle |
| title_full_unstemmed | pH-dependence of the Plasmodium falciparum chloroquine resistance transporter is linked to the transport cycle |
| title_short | pH-dependence of the Plasmodium falciparum chloroquine resistance transporter is linked to the transport cycle |
| title_sort | ph dependence of the plasmodium falciparum chloroquine resistance transporter is linked to the transport cycle |
| url | https://doi.org/10.1038/s41467-023-39969-2 |
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