1
|
Zhou ZH, Stevens A, Kashyap S, Crofut E, Wang S, Muratore K, Johnson P. Structures of Native Doublet Microtubules from Trichomonas vaginalis Reveal Parasite-Specific Proteins as Potential Drug Targets. RESEARCH SQUARE 2024:rs.3.rs-4632384. [PMID: 39281863 PMCID: PMC11398567 DOI: 10.21203/rs.3.rs-4632384/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/18/2024]
Abstract
Doublet microtubules (DMTs) are flagellar components required for the protist Trichomonas vaginalis (Tv) to swim through the human genitourinary tract to cause trichomoniasis, the most common non-viral sexually transmitted disease. Lack of DMT structures has prevented structure-guided drug design to manage Tv infection. Here, we determined the cryo-EM structure of native Tv-DMTs, identifying 29 unique proteins, including 18 microtubule inner proteins and 9 microtubule outer proteins. While the A-tubule is simplistic compared to DMTs of other organisms, the B-tubule features specialized, parasite-specific proteins, such as TvFAP40 and TvFAP35 that form filaments near the inner and outer junctions, respectively, to stabilize DMTs and enable Tv locomotion. Notably, a small molecule, assigned as IP6, is coordinated within a pocket of TvFAP40 and has characteristics of a drug molecule. This first atomic model of the Tv-DMT highlights the diversity of eukaryotic motility machinery and provides a structural framework to inform rational design of therapeutics.
Collapse
|
2
|
Verdan R, Patricio B, Weismuller G, Miranda K, de Souza W, Benchimol M, Gadelha AP. Characterization of a new extra-axonemal structure in the Giardia intestinalis flagella. J Struct Biol 2024; 216:108064. [PMID: 38280689 DOI: 10.1016/j.jsb.2024.108064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 01/05/2024] [Accepted: 01/18/2024] [Indexed: 01/29/2024]
Abstract
The inner structure of the flagella of Giardia intestinalis is similar to that of other organisms, consisting of nine pairs of outer microtubules and a central pair containing radial spokes. Although the 9+2 axonemal structure is conserved, it is not clear whether subregions, including the transition zone, are present in the flagella of this parasite. Giardia axonemes originate from basal bodies and have a lengthy cytosolic portion before becoming active flagella. The region of the emergence of the flagellum is not accompanied by any membrane specialization, as seen in other protozoa. Although Giardia is an intriguing model of study, few works focused on the ultrastructural analysis of the flagella of this parasite. Here, we analyzed the externalization region of the G. intestinalis flagella using ultra-high resolution scanning microscopy (with electrons and ions), atomic force microscopy in liquid medium, freeze fracture, and electron tomography. Our data show that this region possesses a distinctive morphological feature - it extends outward and takes on a ring-like shape. When the plasma membrane is removed, a structure surrounding the axoneme becomes visible in this region. This new extra-axonemal structure is observed in all pairs of flagella of trophozoites and remains attached to the axoneme even when the interconnections between the axonemal microtubules are disrupted. High-resolution scanning electron microscopy provided insights into the arrangement of this structure, contributing to the characterization of the externalization region of the flagella of this parasite.
Collapse
Affiliation(s)
- Raphael Verdan
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Beatriz Patricio
- Instituto Biomédico, Universidade Federal do Estado Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Gilberto Weismuller
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Kildare Miranda
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil; Centro Nacional de Biologia Estrutural e Bioimagem e Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil; Centro Multiusuário para Análise de Fenômenos Biomédicos, Universidade do Estado do Amazonas, Manaus, Brazil
| | - Wanderley de Souza
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil; Centro Nacional de Biologia Estrutural e Bioimagem e Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil; Centro Multiusuário para Análise de Fenômenos Biomédicos, Universidade do Estado do Amazonas, Manaus, Brazil
| | - Marlene Benchimol
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil; Centro Nacional de Biologia Estrutural e Bioimagem e Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil; Universidade do Grande Rio (UNIGRANRIO), Rio de Janeiro, RJ, Brazil
| | - Ana Paula Gadelha
- Universidade do Grande Rio (UNIGRANRIO), Rio de Janeiro, RJ, Brazil; Diretoria de Metrologia Científica e Industrial, Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMETRO), Rio de Janeiro, Rio de Janeiro, Brazil.
| |
Collapse
|
3
|
Ortiz SFDN, Verdan R, Fortes FDSDA, Benchimol M. Trichomonas vaginalis: Monolayer and Cluster Formation-Ultrastructural Aspects Using High-Resolution Scanning Electron Microscopy. Pathogens 2023; 12:1381. [PMID: 38133266 PMCID: PMC10747464 DOI: 10.3390/pathogens12121381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 11/12/2023] [Accepted: 11/20/2023] [Indexed: 12/23/2023] Open
Abstract
Trichomonas vaginalis is an extracellular protozoan parasite that causes human trichomoniasis, a sexually transmitted infection (STI) that affects approximately 270 million people worldwide. The phenomenon of T. vaginalis adhesion to inert substrates has been described in several reports. Still, very few studies on cluster formation have been conducted, and more detailed analyses of the contact regions between the parasites' membranes in these aggregate formations have not been carried out. The present study aims to show that T. vaginalis forms a tight monolayer, similar to an epithelium, with parasites firmly adhered to the culture flask bottom by interdigitations and in the absence of host cells. In addition, we analyzed and compared the formation of the clusters, focusing on parasite aggregates that float in the culture flasks. We employed various imaging techniques, including high-resolution scanning electron microscopy, transmission electron microscopy, cytochemistry, TEM tomography, and dye injection. We analyzed whether the monolayer behaves as an epithelium, analyzing cell junctions, cell communication, and ultrastructural aspects, and concluded that monolayer formation differs from cluster formation in many aspects. The monolayers form strong adhesion, whereas the clusters have fragile attachments. We did not find fusion or the passage of molecules between neighbor-attached cells; there is no need for different strains to form filopodia, cytonemes, and extracellular vesicles during cluster and monolayer formation.
Collapse
Affiliation(s)
- Sharmila Fiama das Neves Ortiz
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Centro de Pesquisa em Medicina de Precisão, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-901, Brazil; (S.F.d.N.O.); (R.V.)
| | - Raphael Verdan
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Centro de Pesquisa em Medicina de Precisão, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-901, Brazil; (S.F.d.N.O.); (R.V.)
| | - Fabio da Silva de Azevedo Fortes
- BIOTRANS-CAXIAS Campus, Universidade do Grande Rio, UNIGRANRIO, Rio de Janeiro 96200-000, Brazil;
- Laboratório de Terapia e Fisiologia Celular e Molecular, Departamento de Biologia, Faculdade de Ciências Biológicas e Saúde, Universidade do Estado do Rio de Janeiro, Rio de Janeiro 23070-200, Brazil
| | - Marlene Benchimol
- BIOTRANS-CAXIAS Campus, Universidade do Grande Rio, UNIGRANRIO, Rio de Janeiro 96200-000, Brazil;
- Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens e Centro Nacional de Biologia Estrutural e Bioimagens, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-901, Brazil
| |
Collapse
|
4
|
Wang X, Chen J, Zheng J. The state of the art of extracellular vesicle research in protozoan infection. Front Genet 2022; 13:941561. [PMID: 36035188 PMCID: PMC9417467 DOI: 10.3389/fgene.2022.941561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 07/25/2022] [Indexed: 11/25/2022] Open
Abstract
Protozoan diseases seriously affect the health of human beings, livestock and poultry and lead to high economic and medical costs. Extracellular vesicles (EVs) are membranous structures formed through biological processes that play important roles in immune regulation. Studies have shown that parasites transmit information to hosts through EVs to modulate host immune responses. The major roles played by EVs released from parasites involve facilitating parasitization of the host. In this review, we discuss relevant recently obtained data on EVs secreted by different kinds of protozoa, including their molecular mechanisms, and discuss the roles played by EVs in the occurrence and development of parasitic diseases.
Collapse
Affiliation(s)
- Xinlei Wang
- Department of Clinical Laboratory, The Second Hospital of Jilin University, Jilin University, Changchun, China
| | - Jie Chen
- Institute of Theoretical Chemistry, Jilin University, Changchun, China
| | - Jingtong Zheng
- Department of Pathogenobiology, College of Basic Medical Sciences, Jilin University, Changchun, China
- *Correspondence: Jingtong Zheng,
| |
Collapse
|