title: Flagellar pocket restructuring through the Leishmania life cycle involves a discrete flagellum attachment zone.
abstract: Leishmania promastigote parasites have a flagellum, which protrudes from the flagellar pocket at the cell anterior, yet, surprisingly, have homologs of many flagellum attachment zone (FAZ) proteins--proteins used in the related Trypanosoma species to laterally attach the flagellum to the cell body from the flagellar pocket to the cell posterior. Here, we use seven Leishmania mexicana cell lines that expressed eYFP fusions of FAZ protein homologs to show that the Leishmania flagellar pocket includes a FAZ structure. Electron tomography revealed a precisely defined 3D organisation for both the flagellar pocket and FAZ, with striking similarities to those of Trypanosoma brucei. Expression of two T. brucei FAZ proteins in L. mexicana showed that T. brucei FAZ proteins can assemble into the Leishmania FAZ structure. Leishmania therefore have a previously unrecognised FAZ structure, which we show undergoes major structural reorganisation in the transition from the promastigote (sandfly vector) to amastigote (in mammalian macrophages). Morphogenesis of the Leishmania flagellar pocket, a structure important for pathogenicity, is therefore intimately associated with a FAZ; a finding with implications for understanding shape changes involving component modules during evolution.
authors.affiliation: Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, Dresden 01307, Germany Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE, UK richard.wheeler@path.ox.ac.uk jack.sunter@path.ox.ac.uk.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Wheeler
authors.affiliation: Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE, UK richard.wheeler@path.ox.ac.uk jack.sunter@path.ox.ac.uk.
authors.forename: Jack D
authors.initials: JD
authors.lastname: Sunter
authors.affiliation: Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE, UK.
authors.forename: Keith
authors.initials: K
authors.lastname: Gull
mesh_terms: D054468:Axoneme / Q000378:metabolism / Q000648:ultrastructure; D005407:Flagella / Q000378:metabolism* / Q000648:ultrastructure; D007894:Leishmania mexicana / Q000502:physiology / Q000648:ultrastructure*; D021381:Protein Transport; D015800:Protozoan Proteins / Q000378:metabolism*; D014346:Trypanosoma brucei brucei / Q000648:ultrastructure
chemical_list: D015800:Protozoan Proteins
keywords: Amastigote; Electron tomography; Flagellum attachment zone; Leishmania; Life cycle differentiation; Trypanosoma brucei