1
|
Sołowińska K, Holec-Gąsior L. Single Cell Expression Systems for the Production of Recombinant Proteins for Immunodiagnosis and Immunoprophylaxis of Toxoplasmosis. Microorganisms 2024; 12:1731. [PMID: 39203573 PMCID: PMC11357668 DOI: 10.3390/microorganisms12081731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2024] [Revised: 07/31/2024] [Accepted: 08/21/2024] [Indexed: 09/03/2024] Open
Abstract
Toxoplasmosis represents a significant public health and veterinary concern due to its widespread distribution, zoonotic transmission, and potential for severe health impacts in susceptible individuals and animal populations. The ability to design and produce recombinant proteins with precise antigenic properties is fundamental, as they serve as tools for accurate disease detection and effective immunization strategies, contributing to improved healthcare outcomes and disease control. Most commonly, a prokaryotic expression system is employed for the production of both single antigens and multi-epitope chimeric proteins; however, the cloning strategies, bacterial strain, vector, and expression conditions vary. Moreover, literature reports show the use of alternative microbial systems such as yeast or Leishmania tarentolae. This review provides an overview of the methods and strategies employed for the production of recombinant Toxoplasma gondii antigenic proteins for the serological detection of T. gondii infection and vaccine development.
Collapse
Affiliation(s)
| | - Lucyna Holec-Gąsior
- Department of Biotechnology and Microbiology, Faculty of Chemistry, Gdańsk University of Technology, 11/12 Narutowicza Str., 80-233 Gdańsk, Poland;
| |
Collapse
|
2
|
Namasivayam S, Sun C, Bah AB, Oberstaller J, Pierre-Louis E, Etheridge RD, Feschotte C, Pritham EJ, Kissinger JC. Massive invasion of organellar DNA drives nuclear genome evolution in Toxoplasma. Proc Natl Acad Sci U S A 2023; 120:e2308569120. [PMID: 37917792 PMCID: PMC10636329 DOI: 10.1073/pnas.2308569120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 09/26/2023] [Indexed: 11/04/2023] Open
Abstract
Toxoplasma gondii is a zoonotic protist pathogen that infects up to one third of the human population. This apicomplexan parasite contains three genome sequences: nuclear (65 Mb); plastid organellar, ptDNA (35 kb); and mitochondrial organellar, mtDNA (5.9 kb of non-repetitive sequence). We find that the nuclear genome contains a significant amount of NUMTs (nuclear integrants of mitochondrial DNA) and NUPTs (nuclear integrants of plastid DNA) that are continuously acquired and represent a significant source of intraspecific genetic variation. NUOT (nuclear DNA of organellar origin) accretion has generated 1.6% of the extant T. gondii ME49 nuclear genome-the highest fraction ever reported in any organism. NUOTs are primarily found in organisms that retain the non-homologous end-joining repair pathway. Significant movement of organellar DNA was experimentally captured via amplicon sequencing of a CRISPR-induced double-strand break in non-homologous end-joining repair competent, but not ku80 mutant, Toxoplasma parasites. Comparisons with Neospora caninum, a species that diverged from Toxoplasma ~28 mya, revealed that the movement and fixation of five NUMTs predates the split of the two genera. This unexpected level of NUMT conservation suggests evolutionary constraint for cellular function. Most NUMT insertions reside within (60%) or nearby genes (23% within 1.5 kb), and reporter assays indicate that some NUMTs have the ability to function as cis-regulatory elements modulating gene expression. Together, these findings portray a role for organellar sequence insertion in dynamically shaping the genomic architecture and likely contributing to adaptation and phenotypic changes in this important human pathogen.
Collapse
Affiliation(s)
| | - Cheng Sun
- Department of Biology, University of Texas at Arlington, Arlington, TX76019
| | - Assiatu B. Bah
- Department of Biology, University of Texas at Arlington, Arlington, TX76019
| | | | - Edwin Pierre-Louis
- Department of Cellular Biology, Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA30602
| | - Ronald Drew Etheridge
- Department of Cellular Biology, Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA30602
| | - Cedric Feschotte
- Department of Biology, University of Texas at Arlington, Arlington, TX76019
| | - Ellen J. Pritham
- Department of Biology, University of Texas at Arlington, Arlington, TX76019
| | - Jessica C. Kissinger
- Department of Genetics, Institute of Bioinformatics, Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA30602
| |
Collapse
|
3
|
Fragoso MSI, de Siqueira CM, Vitorino FNL, Vieira AZ, Martins-Duarte ÉS, Faoro H, da Cunha JPC, Ávila AR, Nardelli SC. TgKDAC4: A Unique Deacetylase of Toxoplasma' s Apicoplast. Microorganisms 2023; 11:1558. [PMID: 37375060 DOI: 10.3390/microorganisms11061558] [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: 03/02/2023] [Revised: 05/04/2023] [Accepted: 05/09/2023] [Indexed: 06/29/2023] Open
Abstract
Toxoplasma gondii is an obligate intracellular parasite of the phylum Apicomplexa and causes toxoplasmosis infections, a disease that affects a quarter of the world's population and has no effective cure. Epigenetic regulation is one of the mechanisms controlling gene expression and plays an essential role in all organisms. Lysine deacetylases (KDACs) act as epigenetic regulators affecting gene silencing in many eukaryotes. Here, we focus on TgKDAC4, an enzyme unique to apicomplexan parasites, and a class IV KDAC, the least-studied class of deacetylases so far. This enzyme shares only a portion of the specific KDAC domain with other organisms. Phylogenetic analysis from the TgKDAC4 domain shows a putative prokaryotic origin. Surprisingly, TgKDAC4 is located in the apicoplast, making it the only KDAC found in this organelle to date. Transmission electron microscopy assays confirmed the presence of TgKDAC4 in the periphery of the apicoplast. We identified possible targets or/and partners of TgKDAC4 by immunoprecipitation assays followed by mass spectrometry analysis, including TgCPN60 and TgGAPDH2, both located at the apicoplast and containing acetylation sites. Understanding how the protein works could provide new insights into the metabolism of the apicoplast, an essential organelle for parasite survival.
Collapse
Affiliation(s)
| | | | - Francisca Nathália Luna Vitorino
- Special Laboratory of Cell Cycle, Center of Toxins, Immune Response and Cell Signalling (CeTICS), Instituto Butantan, São Paulo 05503-900, Brazil
| | | | - Érica Santos Martins-Duarte
- Department of Parasitology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Brazil
| | - Helisson Faoro
- Instituto Carlos Chagas, Fundação Oswaldo Cruz, Curitiba 81350-010, Brazil
| | - Júlia Pinheiro Chagas da Cunha
- Special Laboratory of Cell Cycle, Center of Toxins, Immune Response and Cell Signalling (CeTICS), Instituto Butantan, São Paulo 05503-900, Brazil
| | | | | |
Collapse
|
4
|
Down the membrane hole: Ion channels in protozoan parasites. PLoS Pathog 2022; 18:e1011004. [PMID: 36580479 PMCID: PMC9799330 DOI: 10.1371/journal.ppat.1011004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Parasitic diseases caused by protozoans are highly prevalent around the world, disproportionally affecting developing countries, where coinfection with other microorganisms is common. Control and treatment of parasitic infections are constrained by the lack of specific and effective drugs, plus the rapid emergence of resistance. Ion channels are main drug targets for numerous diseases, but their potential against protozoan parasites is still untapped. Ion channels are membrane proteins expressed in all types of cells, allowing for the flow of ions between compartments, and regulating cellular functions such as membrane potential, excitability, volume, signaling, and death. Channels and transporters reside at the interface between parasites and their hosts, controlling nutrient uptake, viability, replication, and infectivity. To understand how ion channels control protozoan parasites fate and to evaluate their suitability for therapeutics, we must deepen our knowledge of their structure, function, and modulation. However, methodological approaches commonly used in mammalian cells have proven difficult to apply in protozoans. This review focuses on ion channels described in protozoan parasites of clinical relevance, mainly apicomplexans and trypanosomatids, highlighting proteins for which molecular and functional evidence has been correlated with their physiological functions.
Collapse
|
5
|
Bacteriophage protein Gp46 is a cross-species inhibitor of nucleoid-associated HU proteins. Proc Natl Acad Sci U S A 2022; 119:2116278119. [PMID: 35193978 PMCID: PMC8892312 DOI: 10.1073/pnas.2116278119] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/14/2022] [Indexed: 11/24/2022] Open
Abstract
Histone-like protein from Escherichia coli strain U93 (HU) protein is the most abundant nucleoid-associated protein in bacteria, which plays a fundamental role in chromosomal compaction and organization. It is essential for most bacteria as well as Apicomplexans, thus an important target for the development of antimicrobial and antimalaria drugs. We report Gp46 as a phage protein HU inhibitor. It inhibits HU of Bacillus subtilis by occupying its DNA binding site, thus preventing chromosome segregation during cell division. As key residues for the interaction are highly conserved, Gp46 interacts with HUs of a broad range of pathogens, including many pathogenic bacteria and Apicomplexan parasites like Plasmodium falciparum. Thus, this cross-species property could benefit antibiotic and antimalaria drug development that targets HU. The architectural protein histone-like protein from Escherichia coli strain U93 (HU) is the most abundant bacterial DNA binding protein and highly conserved among bacteria and Apicomplexan parasites. It not only binds to double-stranded DNA (dsDNA) to maintain DNA stability but also, interacts with RNAs to regulate transcription and translation. Importantly, HU is essential to cell viability for many bacteria; hence, it is an important antibiotic target. Here, we report that Gp46 from bacteriophage SPO1 of Bacillus subtilis is an HU inhibitor whose expression prevents nucleoid segregation and causes filamentous morphology and growth defects in bacteria. We determined the solution structure of Gp46 and revealed a striking negatively charged surface. An NMR-derived structural model for the Gp46–HU complex shows that Gp46 occupies the DNA binding motif of the HU and therefore, occludes DNA binding, revealing a distinct strategy for HU inhibition. We identified the key residues responsible for the interaction that are conserved among HUs of bacteria and Apicomplexans, including clinically significant Mycobacterium tuberculosis, Acinetobacter baumannii, and Plasmodium falciparum, and confirm that Gp46 can also interact with these HUs. Our findings provide detailed insight into a mode of HU inhibition that provides a useful foundation for the development of antibacteria and antimalaria drugs.
Collapse
|
6
|
Hajj RE, Tawk L, Itani S, Hamie M, Ezzeddine J, El Sabban M, El Hajj H. Toxoplasmosis: Current and Emerging Parasite Druggable Targets. Microorganisms 2021; 9:microorganisms9122531. [PMID: 34946133 PMCID: PMC8707595 DOI: 10.3390/microorganisms9122531] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 11/10/2021] [Accepted: 11/10/2021] [Indexed: 12/19/2022] Open
Abstract
Toxoplasmosis is a prevalent disease affecting a wide range of hosts including approximately one-third of the human population. It is caused by the sporozoan parasite Toxoplasma gondii (T. gondii), which instigates a range of symptoms, manifesting as acute and chronic forms and varying from ocular to deleterious congenital or neuro-toxoplasmosis. Toxoplasmosis may cause serious health problems in fetuses, newborns, and immunocompromised patients. Recently, associations between toxoplasmosis and various neuropathies and different types of cancer were documented. In the veterinary sector, toxoplasmosis results in recurring abortions, leading to significant economic losses. Treatment of toxoplasmosis remains intricate and encompasses general antiparasitic and antibacterial drugs. The efficacy of these drugs is hindered by intolerance, side effects, and emergence of parasite resistance. Furthermore, all currently used drugs in the clinic target acute toxoplasmosis, with no or little effect on the chronic form. In this review, we will provide a comprehensive overview on the currently used and emergent drugs and their respective parasitic targets to combat toxoplasmosis. We will also abridge the repurposing of certain drugs, their targets, and highlight future druggable targets to enhance the therapeutic efficacy against toxoplasmosis, hence lessening its burden and potentially alleviating the complications of its associated diseases.
Collapse
Affiliation(s)
- Rana El Hajj
- Department of Biological Sciences, Beirut Arab University, P.O. Box 11-5020, Riad El Solh, Beirut 1107 2809, Lebanon;
| | - Lina Tawk
- Department of Medical Laboratory Sciences, Faculty of Health Sciences, University of Balamand, Beirut 1100 2807, Lebanon; (L.T.); (J.E.)
| | - Shaymaa Itani
- Department of Experimental Pathology, Microbiology and Immunology, Faculty of Medicine, American University of Beirut, P.O. Box 11-0236, Riad El-Solh, Beirut 1107 2020, Lebanon; (S.I.); (M.H.)
| | - Maguy Hamie
- Department of Experimental Pathology, Microbiology and Immunology, Faculty of Medicine, American University of Beirut, P.O. Box 11-0236, Riad El-Solh, Beirut 1107 2020, Lebanon; (S.I.); (M.H.)
| | - Jana Ezzeddine
- Department of Medical Laboratory Sciences, Faculty of Health Sciences, University of Balamand, Beirut 1100 2807, Lebanon; (L.T.); (J.E.)
| | - Marwan El Sabban
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, P.O. Box 11-0236, Riad El-Solh, Beirut 1107 2020, Lebanon;
| | - Hiba El Hajj
- Department of Experimental Pathology, Microbiology and Immunology, Faculty of Medicine, American University of Beirut, P.O. Box 11-0236, Riad El-Solh, Beirut 1107 2020, Lebanon; (S.I.); (M.H.)
- Correspondence: ; Tel.: +961–1-350000 (ext. 4897)
| |
Collapse
|
7
|
Li ZH, King TP, Ayong L, Asady B, Cai X, Rahman T, Vella SA, Coppens I, Patel S, Moreno SNJ. A plastid two-pore channel essential for inter-organelle communication and growth of Toxoplasma gondii. Nat Commun 2021; 12:5802. [PMID: 34608145 PMCID: PMC8490419 DOI: 10.1038/s41467-021-25987-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 09/06/2021] [Indexed: 01/04/2023] Open
Abstract
Two-pore channels (TPCs) are a ubiquitous family of cation channels that localize to acidic organelles in animals and plants to regulate numerous Ca2+-dependent events. Little is known about TPCs in unicellular organisms despite their ancient origins. Here, we characterize a TPC from Toxoplasma gondii, the causative agent of toxoplasmosis. TgTPC is a member of a novel clad of TPCs in Apicomplexa, distinct from previously identified TPCs and only present in coccidians. We show that TgTPC localizes not to acidic organelles but to the apicoplast, a non-photosynthetic plastid found in most apicomplexan parasites. Conditional silencing of TgTPC resulted in progressive loss of apicoplast integrity, severely affecting growth and the lytic cycle. Isolation of TPC null mutants revealed a selective role for TPCs in replication independent of apicoplast loss that required conserved residues within the pore-lining region. Using a genetically-encoded Ca2+ indicator targeted to the apicoplast, we show that Ca2+ signals deriving from the ER but not from the extracellular space are selectively transmitted to the lumen. Deletion of the TgTPC gene caused reduced apicoplast Ca2+ uptake and membrane contact site formation between the apicoplast and the ER. Fundamental roles for TPCs in maintaining organelle integrity, inter-organelle communication and growth emerge.
Collapse
Affiliation(s)
- Zhu-Hong Li
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, 30602, USA
| | - Thayer P King
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, 30602, USA
| | - Lawrence Ayong
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, 30602, USA
| | - Beejan Asady
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Heath, Baltimore, MD, 21205, USA
| | - Xinjiang Cai
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Taufiq Rahman
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, USA
| | - Stephen A Vella
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, 30602, USA
| | - Isabelle Coppens
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Heath, Baltimore, MD, 21205, USA
| | - Sandip Patel
- Department of Cell and Developmental Biology, University College London, London, WC1E 6BT, UK
| | - Silvia N J Moreno
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, 30602, USA. .,Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA.
| |
Collapse
|
8
|
Xu XP, Elsheikha HM, Liu WG, Zhang ZW, Sun LX, Liang QL, Song MX, Zhu XQ. The Role of Type II Fatty Acid Synthesis Enzymes FabZ, ODSCI, and ODSCII in the Pathogenesis of Toxoplasma gondii Infection. Front Microbiol 2021; 12:703059. [PMID: 34531837 PMCID: PMC8438308 DOI: 10.3389/fmicb.2021.703059] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 07/30/2021] [Indexed: 12/02/2022] Open
Abstract
Toxoplasma gondii is an obligate intracellular protozoan parasite, which has a worldwide distribution and can infect a large number of warm-blooded animals and humans. T. gondii must colonize and proliferate inside the host cells in order to maintain its own survival by securing essential nutrients for the development of the newly generated tachyzoites. The type II fatty acid biosynthesis pathway (FASII) in the apicoplast is essential for the growth and survival of T. gondii. We investigated whether deletion of genes in the FASII pathway influences the in vitro growth and in vivo virulence of T. gondii. We focused on beta-hydroxyacyl-acyl carrier protein dehydratase (FabZ) and oxidoreductase, short chain dehydrogenase/reductase family proteins ODSCI and ODSCII. We constructed T. gondii strains deficient in FabZ, ODSCI, and ODSCII using CRISPR-Cas9 gene editing technology. The results of immunofluorescence assay, plaque assay, proliferation assay and egress assay showed that in RHΔFabZ strain the apicoplast was partly lost and the growth ability of the parasite in vitro was significantly inhibited, while for RHΔODSCI and RHΔODSCII mutant strains no similar changes were detected. RHΔFabZ exhibited reduced virulence for mice compared with RHΔODSCI and RHΔODSCII, as shown by the improved survival rate. Deletion of FabZ in the PRU strain significantly decreased the brain cyst burden in mice compared with PRUΔODSCI and PRUΔODSCII. Collectively, these findings suggest that FabZ contributes to the growth and virulence of T. gondii, while ODSCI and ODSCII do not contribute to these traits.
Collapse
Affiliation(s)
- Xiao-Pei Xu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.,Heilongjiang Key Laboratory for Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, Harbin, China
| | - Hany M Elsheikha
- Faculty of Medicine and Health Sciences, School of Veterinary Medicine and Science, University of Nottingham, Nottingham, United Kingdom
| | - Wen-Ge Liu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Zhi-Wei Zhang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Li-Xiu Sun
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Qin-Li Liang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Ming-Xin Song
- Heilongjiang Key Laboratory for Zoonosis, College of Veterinary Medicine, Northeast Agricultural University, Harbin, China
| | - Xing-Quan Zhu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.,College of Veterinary Medicine, Shanxi Agricultural University, Taigu, China.,Key Laboratory of Veterinary Public Health of Higher Education of Yunnan Province, College of Veterinary Medicine, Yunnan Agricultural University, Kunming, China
| |
Collapse
|
9
|
Berná L, Marquez P, Cabrera A, Greif G, Francia ME, Robello C. Reevaluation of the Toxoplasma gondii and Neospora caninum genomes reveals misassembly, karyotype differences, and chromosomal rearrangements. Genome Res 2021; 31:823-833. [PMID: 33906964 PMCID: PMC8092007 DOI: 10.1101/gr.262832.120] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 12/16/2020] [Indexed: 12/14/2022]
Abstract
Neosporacaninum primarily infects cattle, causing abortions, with an estimated impact of a billion dollars on the worldwide economy annually. However, the study of its biology has been unheeded by the established paradigm that it is virtually identical to its close relative, the widely studied human pathogen Toxoplasma gondii. By revisiting the genome sequence, assembly, and annotation using third-generation sequencing technologies, here we show that the N. caninum genome was originally incorrectly assembled under the presumption of synteny with T. gondii. We show that major chromosomal rearrangements have occurred between these species. Importantly, we show that chromosomes originally named Chr VIIb and VIII are indeed fused, reducing the karyotype of both N. caninum and T. gondii to 13 chromosomes. We reannotate the N. caninum genome, revealing more than 500 new genes. We sequence and annotate the nonphotosynthetic plastid and mitochondrial genomes and show that although apicoplast genomes are virtually identical, high levels of gene fragmentation and reshuffling exist between species and strains. Our results correct assembly artifacts that are currently widely distributed in the genome database of N. caninum and T. gondii and, more importantly, highlight the mitochondria as a previously oversighted source of variability and pave the way for a change in the paradigm of synteny, encouraging rethinking the genome as basis of the comparative unique biology of these pathogens.
Collapse
Affiliation(s)
- Luisa Berná
- Laboratory of Host Pathogen Interactions-Molecular Biology Unit, Institut Pasteur de Montevideo, 11400 Montevideo, Uruguay
| | - Pablo Marquez
- Laboratory of Host Pathogen Interactions-Molecular Biology Unit, Institut Pasteur de Montevideo, 11400 Montevideo, Uruguay
| | - Andrés Cabrera
- Laboratory of Host Pathogen Interactions-Molecular Biology Unit, Institut Pasteur de Montevideo, 11400 Montevideo, Uruguay
| | - Gonzalo Greif
- Laboratory of Host Pathogen Interactions-Molecular Biology Unit, Institut Pasteur de Montevideo, 11400 Montevideo, Uruguay
| | - María E Francia
- Laboratory of Apicomplexan Biology, Institut Pasteur de Montevideo, 11400 Montevideo, Uruguay.,Departamento de Parasitología y Micología, Facultad de Medicina-Universidad de la República, 11600 Montevideo, Uruguay
| | - Carlos Robello
- Laboratory of Host Pathogen Interactions-Molecular Biology Unit, Institut Pasteur de Montevideo, 11400 Montevideo, Uruguay.,Departamento de Bioquímica, Facultad de Medicina-Universidad de la República, 11300 Montevideo, Uruguay
| |
Collapse
|
10
|
Martins-Duarte ÉS, Sheiner L, Reiff SB, de Souza W, Striepen B. Replication and partitioning of the apicoplast genome of Toxoplasma gondii is linked to the cell cycle and requires DNA polymerase and gyrase. Int J Parasitol 2021; 51:493-504. [PMID: 33581138 PMCID: PMC8113025 DOI: 10.1016/j.ijpara.2020.11.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 10/30/2020] [Accepted: 11/08/2020] [Indexed: 10/26/2022]
Abstract
Apicomplexans are the causative agents of numerous important infectious diseases including malaria and toxoplasmosis. Most of them harbour a chloroplast-like organelle called the apicoplast that is essential for the parasites' metabolism and survival. While most apicoplast proteins are nuclear encoded, the organelle also maintains its own genome, a 35 kb circle. In this study we used Toxoplasma gondii to identify and characterise essential proteins involved in apicoplast genome replication and to understand how apicoplast genome segregation unfolds over time. We demonstrated that the DNA replication enzymes Prex, DNA gyrase and DNA single stranded binding protein localise to the apicoplast. We show in knockdown experiments that apicoplast DNA Gyrase A and B, and Prex are required for apicoplast genome replication and growth of the parasite. Analysis of apicoplast genome replication by structured illumination microscopy in T. gondii tachyzoites showed that apicoplast nucleoid division and segregation initiate at the beginning of S phase and conclude during mitosis. Thus, the replication and division of the apicoplast nucleoid is highly coordinated with nuclear genome replication and mitosis. Our observations highlight essential components of apicoplast genome maintenance and shed light on the timing of this process in the context of the overall parasite cell cycle.
Collapse
Affiliation(s)
- Érica S Martins-Duarte
- Laboratório de Quimioterapia de Protozoários Egler Chiari, Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil; Núcleo de Biologia Estrutural e Bioimagens (CENABIO) - Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Biomagens (INBEB), Rio de Janeiro, RJ, Brazil.
| | - Lilach Sheiner
- Wellcome Centre for Integrative Parasitology, University of Glasgow, 120 University Place Glasgow, United Kingdom
| | - Sarah B Reiff
- Department of Cellular Biology, University of Georgia, Athens, GA, USA
| | - Wanderley de Souza
- Núcleo de Biologia Estrutural e Bioimagens (CENABIO) - Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Biomagens (INBEB), Rio de Janeiro, RJ, Brazil; Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Boris Striepen
- Department of Cellular Biology, University of Georgia, Athens, GA, USA; Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA. USA
| |
Collapse
|
11
|
Araujo-Silva CA, De Souza W, Martins-Duarte ES, Vommaro RC. HDAC inhibitors Tubastatin A and SAHA affect parasite cell division and are potential anti-Toxoplasma gondii chemotherapeutics. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2020; 15:25-35. [PMID: 33360687 PMCID: PMC7771113 DOI: 10.1016/j.ijpddr.2020.12.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 12/07/2020] [Accepted: 12/11/2020] [Indexed: 02/07/2023]
Abstract
The redirectioning of drugs in the pharmaceutical market is a well-known practice to identify new therapies for parasitic diseases. The histone deacetylase inhibitors Tubastatin A (TST) and Suberoylanilide Hydroxamic Acid (SAHA), firstly developed for cancer treatment, are effective against protozoa parasites. In this work, we aimed to demonstrate the activity of these drugs as potential agents against Toxoplasma gondii, the causative agent of toxoplasmosis. TST and SAHA were active against different genotypes of Toxoplasma gondii, such as, RH (type I), EGS (I/III) and ME49 (type II) strains. The IC₅₀ values for the RH strain were 19 ± 1 nM and 520 ± 386 nM for TST and 41 ± 3 nM and 67 ± 36 nM for SAHA, for 24 and 48 h, respectively. Both compounds were highly selective for T. gondii and their anti-proliferative effect was irreversible for 8 days. The calculated selectivity indexes (39 for TST and 30 for SAHA) make them lead compounds for the future development of anti-Toxoplasma molecules. Western blotting showed TST led to a significant increase of the nuclear histone H4 and a decrease of H3 acetylation levels. Treatment with 1 μM TST and 0.1 μM SAHA for 48 h decreased the amount of global α-tubulin. Fluorescence and electron microscopy showed that both drugs affected the endodyogeny process impairing the budding of daughter cells. The drugs led to the formation of large, rounded masses of damaged parasites with several centrosomes randomly dispersed and incorrect apicoplast division and positioning. TST-treated parasites showed a rupture of the mitochondrial membrane potential and led to a failure of the IMC assembling of new daughter cells. SAHA and TST possibly inhibit HDAC3 and other cytoplasmic or organelle targeted HDACs involved in the modification of proteins other than histones.
Collapse
Affiliation(s)
- Carlla Assis Araujo-Silva
- Laboratório de Ultraestrutura Celular Hertha Meyer - Universidade Federal do Rio de Janeiro - Instituto de Biofísica Carlos Chagas Filho, Av. Carlos Chagas Filho, 373 -Cidade Universitária, Rio de Janeiro - RJ, 21941-170, Brazil; Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens, Universidade Federal do Rio de Janeiro, Brazil
| | - Wanderley De Souza
- Laboratório de Ultraestrutura Celular Hertha Meyer - Universidade Federal do Rio de Janeiro - Instituto de Biofísica Carlos Chagas Filho, Av. Carlos Chagas Filho, 373 -Cidade Universitária, Rio de Janeiro - RJ, 21941-170, Brazil; Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens, Universidade Federal do Rio de Janeiro, Brazil
| | - Erica S Martins-Duarte
- Laboratório de Quimioterapia de Protozoários Egler Chiari, Departamento de Parasitologia - ICB - Universidade Federal de Minas Gerais - Avenida Presidente Antônio Carlos, 6.627 -Pampulha - Belo Horizonte, MG, 31270-901, Brazil.
| | - Rossiane C Vommaro
- Laboratório de Ultraestrutura Celular Hertha Meyer - Universidade Federal do Rio de Janeiro - Instituto de Biofísica Carlos Chagas Filho, Av. Carlos Chagas Filho, 373 -Cidade Universitária, Rio de Janeiro - RJ, 21941-170, Brazil; Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens, Universidade Federal do Rio de Janeiro, Brazil.
| |
Collapse
|
12
|
García-Sánchez M, Jiménez-Pelayo L, Horcajo P, Regidor-Cerrillo J, Collantes-Fernández E, Ortega-Mora LM. Gene Expression Profiling of Neospora caninum in Bovine Macrophages Reveals Differences Between Isolates Associated With Key Parasite Functions. Front Cell Infect Microbiol 2019; 9:354. [PMID: 31681630 PMCID: PMC6803445 DOI: 10.3389/fcimb.2019.00354] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 10/01/2019] [Indexed: 12/19/2022] Open
Abstract
Intraspecific differences in biological traits between Neospora caninum isolates have been widely described and associated with variations in virulence. However, the molecular basis underlying these differences has been poorly studied. We demonstrated previously that Nc-Spain7 and Nc-Spain1H, high- and low-virulence isolates, respectively, show different invasion, proliferation and survival capabilities in bovine macrophages (boMØs), a key cell in the immune response against Neospora, and modulate the cell immune response in different ways. Here, we demonstrate that these differences are related to specific tachyzoite gene expression profiles. Specifically, the low-virulence Nc-Spain1H isolate showed enhanced expression of genes encoding for surface antigens and genes related to the bradyzoite stage. Among the primary up-regulated genes in Nc-Spain7, genes involved in parasite growth and redox homeostasis are particularly noteworthy because of their correlation with the enhanced proliferation and survival rates of Nc-Spain7 in boMØs relative to Nc-Spain1H. Genes potentially implicated in induction of proinflammatory immune responses were found to be up-regulated in the low-virulence isolate, whereas the high-virulence isolate showed enhanced expression of genes that may be involved in immune evasion. These results represent a further step in understanding the parasite effector molecules that may be associated to virulence and thus to disease traits as abortion and transmission.
Collapse
Affiliation(s)
- Marta García-Sánchez
- Saluvet, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Madrid, Spain
| | - Laura Jiménez-Pelayo
- Saluvet, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Madrid, Spain
| | - Pilar Horcajo
- Saluvet, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Madrid, Spain
| | - Javier Regidor-Cerrillo
- Saluvet, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Madrid, Spain.,Saluvet-Innova, Faculty of Veterinary Sciences, Complutense University of Madrid, Madrid, Spain
| | - Esther Collantes-Fernández
- Saluvet, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Madrid, Spain
| | - Luis Miguel Ortega-Mora
- Saluvet, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Madrid, Spain
| |
Collapse
|
13
|
Host Cell Metabolism Contributes to Delayed-Death Kinetics of Apicoplast Inhibitors in Toxoplasma gondii. Antimicrob Agents Chemother 2019; 63:AAC.01646-18. [PMID: 30455243 PMCID: PMC6355570 DOI: 10.1128/aac.01646-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Accepted: 11/08/2018] [Indexed: 01/24/2023] Open
Abstract
Toxoplasma gondii and related human parasites contain an essential plastid organelle called the apicoplast. Clinically used antibiotics and other inhibitors that disrupt apicoplast biogenesis cause a mysterious “delayed-death” phenotype in which parasite growth is unaffected during the first lytic cycle of inhibitor treatment but is severely inhibited in the second lytic cycle even after drug removal. Toxoplasma gondii and related human parasites contain an essential plastid organelle called the apicoplast. Clinically used antibiotics and other inhibitors that disrupt apicoplast biogenesis cause a mysterious “delayed-death” phenotype in which parasite growth is unaffected during the first lytic cycle of inhibitor treatment but is severely inhibited in the second lytic cycle even after drug removal. Critical to understanding the complex downstream cellular effects of these drug classes are the timing of apicoplast loss during inhibitor treatment and how it relates to this peculiar growth phenotype. Here we show that, upon treatment with diverse classes of apicoplast inhibitors, newly replicated T. gondii parasites in the first lytic cycle initially form apicoplasts with defects in protein import or genome replication and eventually fail to inherit the apicoplast altogether. Despite the accumulation of parasites with defective or missing apicoplasts, growth is unaffected during the first lytic cycle, as previously observed. Strikingly, concomitant inhibition of host cell isoprenoid biosynthesis results in growth inhibition in the first lytic cycle and unmasks the apicoplast defects. These results suggest that defects in and even the complete loss of the apicoplast in T. gondii are partially rescued by scavenging of host cell metabolites, leading to death that is delayed. Our findings uncover host cell interactions that can alleviate apicoplast inhibition and highlight key differences in delayed-death inhibitors between T. gondii and Plasmodium falciparum.
Collapse
|
14
|
Biddau M, Bouchut A, Major J, Saveria T, Tottey J, Oka O, van-Lith M, Jennings KE, Ovciarikova J, DeRocher A, Striepen B, Waller RF, Parsons M, Sheiner L. Two essential Thioredoxins mediate apicoplast biogenesis, protein import, and gene expression in Toxoplasma gondii. PLoS Pathog 2018; 14:e1006836. [PMID: 29470517 PMCID: PMC5823475 DOI: 10.1371/journal.ppat.1006836] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 12/21/2017] [Indexed: 11/19/2022] Open
Abstract
Apicomplexan parasites are global killers, being the causative agents of diseases like toxoplasmosis and malaria. These parasites are known to be hypersensitive to redox imbalance, yet little is understood about the cellular roles of their various redox regulators. The apicoplast, an essential plastid organelle, is a verified apicomplexan drug target. Nuclear-encoded apicoplast proteins traffic through the ER and multiple apicoplast sub-compartments to their place of function. We propose that thioredoxins contribute to the control of protein trafficking and of protein function within these apicoplast compartments. We studied the role of two Toxoplasma gondiiapicoplast thioredoxins (TgATrx), both essential for parasite survival. By describing the cellular phenotypes of the conditional depletion of either of these redox regulated enzymes we show that each of them contributes to a different apicoplast biogenesis pathway. We provide evidence for TgATrx1’s involvement in ER to apicoplast trafficking and TgATrx2 in the control of apicoplast gene expression components. Substrate pull-down further recognizes gene expression factors that interact with TgATrx2. We use genetic complementation to demonstrate that the function of both TgATrxs is dependent on their disulphide exchange activity. Finally, TgATrx2 is divergent from human thioredoxins. We demonstrate its activity in vitro thus providing scope for drug screening. Our study represents the first functional characterization of thioredoxins in Toxoplasma, highlights the importance of redox regulation of apicoplast functions and provides new tools to study redox biology in these parasites. To survive, apicomplexan parasites must adjust to the redox insults they experience. These parasites undergo redox stresses induced by the host cell within which they live, by the host immune system, and by their own metabolic activities. Yet the myriad of cellular processes that are affected by redox changes and that may take part in maintaining the redox balance within the parasite are largely understudied. Thioredoxins are enzymes that link the redox state of subcellular environments to the functional state or the cellular trafficking of their substrate proteins. In this work, we identify two pathways that are controlled by two thioredoxins in the apicomplexan Toxoplasma gondii, and demonstrate that both are essential for parasite survival. We show that each of these enzymes contributes to the function of the apicomplexan plastid, the apicoplast, a unique parasite organelle with importance for drug discovery efforts. We thus highlight that part of the apicomplexan sensitivity to redox imbalance is specifically related to the apicoplast, and point at the importance of thioredoxins in mediating apicoplast biogenesis. Finally, our work raises the potential of apicoplast thioredoxins as new drug targets.
Collapse
Affiliation(s)
- Marco Biddau
- Wellcome Centre for Molecular Parasitology, University of Glasgow, 120 University Place Glasgow, United Kingdom
| | - Anne Bouchut
- Center for Infectious Disease Research, Seattle, WA, United States of America
| | - Jack Major
- Wellcome Centre for Molecular Parasitology, University of Glasgow, 120 University Place Glasgow, United Kingdom
| | - Tracy Saveria
- Center for Infectious Disease Research, Seattle, WA, United States of America
| | - Julie Tottey
- Wellcome Centre for Molecular Parasitology, University of Glasgow, 120 University Place Glasgow, United Kingdom
| | - Ojore Oka
- Institute of Molecular Cell and Systems Biology, Wolfson Link Building, University of Glasgow, Glasgow, United Kingdom
| | - Marcel van-Lith
- Institute of Molecular Cell and Systems Biology, Wolfson Link Building, University of Glasgow, Glasgow, United Kingdom
| | - Katherine Elizabeth Jennings
- Center for Tropical & Emerging Global Diseases, University of Georgia, Brooks Dr. Athens, GA, United States of America
| | - Jana Ovciarikova
- Wellcome Centre for Molecular Parasitology, University of Glasgow, 120 University Place Glasgow, United Kingdom
| | - Amy DeRocher
- Center for Infectious Disease Research, Seattle, WA, United States of America
| | - Boris Striepen
- Center for Tropical & Emerging Global Diseases, University of Georgia, Brooks Dr. Athens, GA, United States of America
| | | | - Marilyn Parsons
- Center for Infectious Disease Research, Seattle, WA, United States of America
- Department of Global Health, University of Washington, Seattle, WA, United States of America
| | - Lilach Sheiner
- Wellcome Centre for Molecular Parasitology, University of Glasgow, 120 University Place Glasgow, United Kingdom
- * E-mail:
| |
Collapse
|
15
|
Abstract
Mechanisms by which 3'-phosphorylated phosphoinositides (3'-PIPs) regulate the development of apicomplexan parasites Plasmodium falciparum and Toxoplasma gondii are poorly understood. The catabolic process of autophagy, which is dependent on autophagy-related proteins (ATGs), is one of the major targets of 3'-PIPs in yeast and mammals. In the present study, we identified autophagy-related protein ATG18 as an effector of 3'-PIPs in these parasites. Pfalciparum ATG18 (PfATG18) and Tgondii ATG18 (TgATG18) interact with 3'-PIPs but exhibited differences in their specificity of interaction with the ligand PIP. The conditional knockdown of Tgondii or Pfalciparum ATG18 (Tg/PfATG18) impaired replication of parasites and resulted in their delayed death. Intriguingly, ATG18 depletion resulted in the loss of the apicomplexan parasite-specific nonphotosynthetic plastid-like organelle apicoplast, which harbors the machinery for biosynthesis of key metabolites, and the interaction of ATG18 to phosphatidylinositol 3-phosphate (PI3P) was critical for apicoplast inheritance. Furthermore, ATG18 regulates membrane association and apicoplast localization of ATG8. These findings provide insights into a novel noncanonical role of ATG18 in apicoplast inheritance. This function of ATG18 in organelle biogenesis is unprecedented in any organism and may be conserved across most apicomplexan parasites.IMPORTANCE Typically, autophagy is a catabolic process utilized by cells for their survival upon encountering nutrient-limiting conditions. The autophagy machinery is very tightly regulated, and autophagy-related genes (ATGs) play a pivotal role in this process. In the present study, we report a novel noncanonical function of autophagy-related protein ATG18 in inheritance of the nonphotosynthetic plastid-like organelle apicoplast in apicomplexan parasites Plasmodium and Toxoplasma ATG18 depletion in these parasites resulted in "delayed death," which was the result of loss of apicoplast and impaired parasite division. Pf/TgATG18 interact with 3'-phosphorylated PIPs, which guide their cellular localization in the parasite, which is essential for their function.
Collapse
|
16
|
Burroughs AM, Kaur G, Zhang D, Aravind L. Novel clades of the HU/IHF superfamily point to unexpected roles in the eukaryotic centrosome, chromosome partitioning, and biologic conflicts. Cell Cycle 2017; 16:1093-1103. [PMID: 28441108 PMCID: PMC5499826 DOI: 10.1080/15384101.2017.1315494] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
The HU superfamily of proteins, with a unique DNA-binding mode, has been extensively studied as the primary chromosome-packaging protein of the bacterial superkingdom. Representatives also play a role in DNA-structuring during recombination events and in eukaryotic organellar genome maintenance. However, beyond these well-studied roles, little is understood of the functional diversification of this large superfamily. Using sensitive sequence and structure analysis methods we identify multiple novel clades of the HU superfamily. We present evidence that a novel eukaryotic clade prototyped by the human CCDC81 protein acquired roles beyond DNA-binding, likely in protein-protein interaction in centrosome organization and as a potential cargo-binding protein in conjunction with Dynein-VII. We also show that these eukaryotic versions were acquired via an early lateral transfer from bacteroidetes, where we predict a role in chromosome partition. This likely happened before the last eukaryotic common ancestor, pointing to potential endosymbiont contributions beyond that of the mitochondrial progenitor. Further, we show that the dramatic lineage-specific expansion of this domain in the bacteroidetes lineage primarily is linked to a functional shift related to potential recognition and preemption of genome invasive entities such as mobile elements. Remarkably, the CCDC81 clade has undergone a similar massive lineage-specific expansion within the archosaurian lineage in birds, suggesting a possible use of the HU superfamily in a similar capacity in recognition of non-self molecules even in this case.
Collapse
Affiliation(s)
- A Maxwell Burroughs
- a National Center for Biotechnology Information , National Library of Medicine, National Institutes of Health , Bethesda , MD , USA
| | - Gurmeet Kaur
- a National Center for Biotechnology Information , National Library of Medicine, National Institutes of Health , Bethesda , MD , USA
| | - Dapeng Zhang
- a National Center for Biotechnology Information , National Library of Medicine, National Institutes of Health , Bethesda , MD , USA
| | - L Aravind
- a National Center for Biotechnology Information , National Library of Medicine, National Institutes of Health , Bethesda , MD , USA
| |
Collapse
|
17
|
Sheiner L, Fellows JD, Ovciarikova J, Brooks CF, Agrawal S, Holmes ZC, Bietz I, Flinner N, Heiny S, Mirus O, Przyborski JM, Striepen B. Toxoplasma gondii Toc75 Functions in Import of Stromal but not Peripheral Apicoplast Proteins. Traffic 2015; 16:1254-69. [PMID: 26381927 DOI: 10.1111/tra.12333] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Revised: 09/14/2015] [Accepted: 09/14/2015] [Indexed: 01/09/2023]
Abstract
Apicomplexa are unicellular parasites causing important human and animal diseases, including malaria and toxoplasmosis. Most of these pathogens possess a relict but essential plastid, the apicoplast. The apicoplast was acquired by secondary endosymbiosis between a red alga and a flagellated eukaryotic protist. As a result the apicoplast is surrounded by four membranes. This complex structure necessitates a system of transport signals and translocons allowing nuclear encoded proteins to find their way to specific apicoplast sub-compartments. Previous studies identified translocons traversing two of the four apicoplast membranes. Here we provide functional support for the role of an apicomplexan Toc75 homolog in apicoplast protein transport. We identify two apicomplexan genes encoding Toc75 and Sam50, both members of the Omp85 protein family. We localize the respective proteins to the apicoplast and the mitochondrion of Toxoplasma and Plasmodium. We show that the Toxoplasma Toc75 is essential for parasite growth and that its depletion results in a rapid defect in the import of apicoplast stromal proteins while the import of proteins of the outer compartments is affected only as the secondary consequence of organelle loss. These observations along with the homology to Toc75 suggest a potential role in transport through the second innermost membrane.
Collapse
Affiliation(s)
- Lilach Sheiner
- Center for Tropical and Emerging Global Diseases & Department of Cellular Biology, University of Georgia, 500 D.W. Brooks Drive, Athens, GA, 30602, USA.,Wellcome Trust Centre For Molecular Parasitology, Institute of Infection, Immunity & Inflammation, College of Medical, Veterinary & Life Sciences, Sir Graeme Davies Building, University of Glasgow, 120 University Place, Glasgow, G12 8TA, UK
| | - Justin D Fellows
- Center for Tropical and Emerging Global Diseases & Department of Cellular Biology, University of Georgia, 500 D.W. Brooks Drive, Athens, GA, 30602, USA
| | - Jana Ovciarikova
- Wellcome Trust Centre For Molecular Parasitology, Institute of Infection, Immunity & Inflammation, College of Medical, Veterinary & Life Sciences, Sir Graeme Davies Building, University of Glasgow, 120 University Place, Glasgow, G12 8TA, UK
| | - Carrie F Brooks
- Center for Tropical and Emerging Global Diseases & Department of Cellular Biology, University of Georgia, 500 D.W. Brooks Drive, Athens, GA, 30602, USA
| | - Swati Agrawal
- Center for Tropical and Emerging Global Diseases & Department of Cellular Biology, University of Georgia, 500 D.W. Brooks Drive, Athens, GA, 30602, USA
| | - Zachary C Holmes
- Center for Tropical and Emerging Global Diseases & Department of Cellular Biology, University of Georgia, 500 D.W. Brooks Drive, Athens, GA, 30602, USA
| | - Irine Bietz
- Department of Parasitology, Faculty of Biology, Philipps University Marburg, Marburg, Germany
| | - Nadine Flinner
- Molecular Cell Biology of Plants, Biocenter N200, 3. OG, Max-von-Laue-Str. 9, 60438, Frankfurt, Germany
| | - Sabrina Heiny
- Department of Parasitology, Faculty of Biology, Philipps University Marburg, Marburg, Germany
| | - Oliver Mirus
- Molecular Cell Biology of Plants, Biocenter N200, 3. OG, Max-von-Laue-Str. 9, 60438, Frankfurt, Germany
| | - Jude M Przyborski
- Department of Parasitology, Faculty of Biology, Philipps University Marburg, Marburg, Germany
| | - Boris Striepen
- Center for Tropical and Emerging Global Diseases & Department of Cellular Biology, University of Georgia, 500 D.W. Brooks Drive, Athens, GA, 30602, USA
| |
Collapse
|
18
|
Maciel B, Moura R, Carvalho F, Costa E, Albuquerque G. Identification and genetic characterization of a new Brazilian genotype of Toxoplasma gondii from sheep intended for human consumption. Parasitol Int 2014; 63:567-70. [DOI: 10.1016/j.parint.2014.03.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 02/14/2014] [Accepted: 03/04/2014] [Indexed: 11/28/2022]
|
19
|
Farrell A, Coleman BI, Benenati B, Brown KM, Blader IJ, Marth GT, Gubbels MJ. Whole genome profiling of spontaneous and chemically induced mutations in Toxoplasma gondii. BMC Genomics 2014; 15:354. [PMID: 24885922 PMCID: PMC4035079 DOI: 10.1186/1471-2164-15-354] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Accepted: 05/02/2014] [Indexed: 12/18/2022] Open
Abstract
Background Next generation sequencing is helping to overcome limitations in organisms less accessible to classical or reverse genetic methods by facilitating whole genome mutational analysis studies. One traditionally intractable group, the Apicomplexa, contains several important pathogenic protozoan parasites, including the Plasmodium species that cause malaria. Here we apply whole genome analysis methods to the relatively accessible model apicomplexan, Toxoplasma gondii, to optimize forward genetic methods for chemical mutagenesis using N-ethyl-N-nitrosourea (ENU) and ethylmethane sulfonate (EMS) at varying dosages. Results By comparing three different lab-strains we show that spontaneously generated mutations reflect genome composition, without nucleotide bias. However, the single nucleotide variations (SNVs) are not distributed randomly over the genome; most of these mutations reside either in non-coding sequence or are silent with respect to protein coding. This is in contrast to the random genomic distribution of mutations induced by chemical mutagenesis. Additionally, we report a genome wide transition vs transversion ratio (ti/tv) of 0.91 for spontaneous mutations in Toxoplasma, with a slightly higher rate of 1.20 and 1.06 for variants induced by ENU and EMS respectively. We also show that in the Toxoplasma system, surprisingly, both ENU and EMS have a proclivity for inducing mutations at A/T base pairs (78.6% and 69.6%, respectively). Conclusions The number of SNVs between related laboratory strains is relatively low and managed by purifying selection away from changes to amino acid sequence. From an experimental mutagenesis point of view, both ENU (24.7%) and EMS (29.1%) are more likely to generate variation within exons than would naturally accumulate over time in culture (19.1%), demonstrating the utility of these approaches for yielding proportionally greater changes to the amino acid sequence. These results will not only direct the methods of future chemical mutagenesis in Toxoplasma, but also aid in designing forward genetic approaches in less accessible pathogenic protozoa as well. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-354) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Marc-Jan Gubbels
- Department of Biology, Boston College, Higgins Hall 355, 140 Commonwealth Avenue, Chestnut Hill, MA 02467, USA.
| |
Collapse
|
20
|
Abstract
Toxoplasma gondii and Plasmodium falciparum are important human pathogens. These parasites and many of their apicomplexan relatives undergo a complex developmental process in the cells of their hosts, which includes genome replication, cell division and the assembly of new invasive stages. Apicomplexan cell cycle progression is both globally and locally regulated. Global regulation is carried out throughout the cytoplasm by diffusible factors that include cell cycle-specific kinases, cyclins and transcription factors. Local regulation acts on individual nuclei and daughter cells that are developing inside the mother cell. We propose that the centrosome is a master regulator that physically tethers cellular components and that provides spatial and temporal control of apicomplexan cell division.
Collapse
Affiliation(s)
- Maria E Francia
- Department of Cellular Biology, University of Georgia, Athens, Georgia 30602, USA
| | - Boris Striepen
- 1] Department of Cellular Biology, University of Georgia, Athens, Georgia 30602, USA. [2] Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia 30602, USA
| |
Collapse
|
21
|
Jacot D, Daher W, Soldati-Favre D. Toxoplasma gondii myosin F, an essential motor for centrosomes positioning and apicoplast inheritance. EMBO J 2013; 32:1702-16. [PMID: 23695356 DOI: 10.1038/emboj.2013.113] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 04/22/2013] [Indexed: 11/09/2022] Open
Abstract
Members of the Apicomplexa phylum possess an organelle surrounded by four membranes, originating from the secondary endosymbiosis of a red alga. This so-called apicoplast hosts essential metabolic pathways. We report here that apicoplast inheritance is an actin-based process. Concordantly, parasites depleted in either profilin or actin depolymerizing factor, or parasites overexpressing the FH2 domain of formin 2, result in loss of the apicoplast. The class XXII myosin F (MyoF) is conserved across the phylum and localizes in the vicinity of the Toxoplasma gondii apicoplast during division. Conditional knockdown of TgMyoF severely affects apicoplast turnover, leading to parasite death. This recapitulates the phenotype observed upon perturbation of actin dynamics that led to the accumulation of the apicoplast and secretory organelles in enlarged residual bodies. To further dissect the mode of action of this motor, we conditionally stabilized the tail of MyoF, which forms an inactive heterodimer with endogenous TgMyoF. This dominant negative mutant reveals a central role of this motor in the positioning of the two centrosomes prior to daughter cell formation and in apicoplast segregation.
Collapse
Affiliation(s)
- Damien Jacot
- Department of Microbiology and Molecular Medicine, CMU, University of Geneva, Geneva, Switzerland
| | | | | |
Collapse
|