Flagellum couples cell shape to motility in Trypanosoma brucei
| Autor: | Wah Chiu, Michael F. Schmid, Matthew T. Dougherty, Xiaoduo Dong, Chwee Teck Lim, Cynthia Y. He, Muyuan Chen, Stella Y. Sun, Yasaman Nematbakhsh, Jason T. Kaelber, Jian Shi |
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| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Trypanosoma brucei brucei Cell Motility cell motility Flagellum Trypanosoma brucei Cytoplast flagellum 03 medical and health sciences 0302 clinical medicine parasitic diseases medicine Cytoskeleton Cell shape Multidisciplinary biology Chemistry Cryoelectron Microscopy Biological Sciences biology.organism_classification cryo-electron tomography Cell biology Biophysics and Computational Biology 030104 developmental biology medicine.anatomical_structure PNAS Plus Flagella Cryo-electron tomography cell deformation 030217 neurology & neurosurgery |
| Zdroj: | Proceedings of the National Academy of Sciences of the United States of America |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.1722618115 |
| Popis: | Significance Trypanosoma brucei is a highly invasive pathogen capable of penetrating deeply into host tissues. To understand how flagellar motility facilitates cell penetration, we used cryo-electron tomography (cryo-ET) to visualize two genetically anucleate mutants with different flagellar motility behaviors. We found that the T. brucei cell body is highly deformable as defined by changes in cytoskeletal twist and spacing, in response to flagellar beating and environmental conditions. Based on the cryo-ET models, we proposed a mechanism of how flagellum motility is coupled to cell shape changes, which may facilitate penetration through size-limiting barriers. In the unicellular parasite Trypanosoma brucei, the causative agent of human African sleeping sickness, complex swimming behavior is driven by a flagellum laterally attached to the long and slender cell body. Using microfluidic assays, we demonstrated that T. brucei can penetrate through an orifice smaller than its maximum diameter. Efficient motility and penetration depend on active flagellar beating. To understand how active beating of the flagellum affects the cell body, we genetically engineered T. brucei to produce anucleate cytoplasts (zoids and minis) with different flagellar attachment configurations and different swimming behaviors. We used cryo-electron tomography (cryo-ET) to visualize zoids and minis vitrified in different motility states. We showed that flagellar wave patterns reflective of their motility states are coupled to cytoskeleton deformation. Based on these observations, we propose a mechanism for how flagellum beating can deform the cell body via a flexible connection between the flagellar axoneme and the cell body. This mechanism may be critical for T. brucei to disseminate in its host through size-limiting barriers. |
| Databáze: | OpenAIRE |
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