KHARON1 Mediates Flagellar Targeting of a Glucose Transporter in Leishmania mexicana and Is Critical for Viability of Infectious Intracellular Amastigotes |
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Authors: | Khoa D Tran Dayana Rodriguez-Contreras Danielle P Vieira Phillip A Yates Larry David Wandy Beatty Johannes Elferich Scott M Landfear |
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Institution: | From the Departments of ‡Molecular Microbiology and Immunology.;§Biochemistry and Molecular Biology, and ;¶Proteomics Shared Resource, Oregon Health & Science University, Portland, Oregon 97239 and ;the ‖Molecular Microbiology Imaging Facility, Washington University School of Medicine, St. Louis, Missouri 63110 |
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Abstract: | The LmxGT1 glucose transporter is selectively targeted to the flagellum of the kinetoplastid parasite Leishmania mexicana, but the mechanism for targeting this and other flagella-specific membrane proteins among the Kinetoplastida is unknown. To address the mechanism of flagellar targeting, we employed in vivo cross-linking, tandem affinity purification, and mass spectrometry to identify a novel protein, KHARON1 (KH1), which is important for the flagellar trafficking of LmxGT1. Kh1 null mutant parasites are strongly impaired in flagellar targeting of LmxGT1, and trafficking of the permease was arrested in the flagellar pocket. Immunolocalization revealed that KH1 is located at the base of the flagellum, within the flagellar pocket, where it associates with the proximal segment of the flagellar axoneme. We propose that KH1 mediates transit of LmxGT1 from the flagellar pocket into the flagellar membrane via interaction with the proximal portion of the flagellar axoneme. KH1 represents the first component involved in flagellar trafficking of integral membrane proteins among parasitic protozoa. Of considerable interest, Kh1 null mutants are strongly compromised for growth as amastigotes within host macrophages. Thus, KH1 is also important for the disease causing stage of the parasite life cycle. |
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Keywords: | Glucose Transport Leishmania Mass Spectrometry (MS) Pathogenesis Protein Targeting Flagellar Membrane Protein Targeting TAP Tagging Amastigote Viability Glucose Transporter |
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