Cryo electron tomography with volta phase plate reveals novel structural foundations of the 96-nm axonemal repeat in the pathogen Trypanosoma brucei

eLife

Khanh Huy Bui¹  Ivo Atanasov¹  Wong H Hui²  Hui Wang³  Kent L Hill⁴  Shun Kai Yang⁵  Z Hong Zhou⁶  Simon Imhof⁶  Jiayan Zhang⁶  Hoangkim Nguyen⁶ 

[1] California NanoSystems Institute, University of California, Los Angeles, Los Angeles, United States;Department of Bioengineering, University of California, Los Angeles, Los Angeles, United States;Molecular Biology Institute, University of California, Los Angeles, Los Angeles, United States;California NanoSystems Institute, University of California, Los Angeles, Los Angeles, United States;Department of Anatomy and Cell Biology, McGill University, Montreal, United States;Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, United States;

关键词: trypanosome;    cilium;    parasite;    motility;    dynein;    axoneme;   

DOI  :  10.7554/eLife.52058

来源: DOAJ

【 摘 要 】

The 96-nm axonemal repeat includes dynein motors and accessory structures as the foundation for motility of eukaryotic flagella and cilia. However, high-resolution 3D axoneme structures are unavailable for organisms among the Excavates, which include pathogens of medical and economic importance. Here we report cryo electron tomography structures of the 96-nm repeat from Trypanosoma brucei, a protozoan parasite in the Excavate lineage that causes African trypanosomiasis. We examined bloodstream and procyclic life cycle stages, and a knockdown lacking DRC11/CMF22 of the nexin dynein regulatory complex (NDRC). Sub-tomogram averaging yields a resolution of 21.8 Å for the 96-nm repeat. We discovered several lineage-specific structures, including novel inter-doublet linkages and microtubule inner proteins (MIPs). We establish that DRC11/CMF22 is required for the NDRC proximal lobe that binds the adjacent doublet microtubule. We propose that lineage-specific elaboration of axoneme structure in T. brucei reflects adaptations to support unique motility needs in diverse host environments.

【 授权许可】

Unknown