1
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Balmer EA, Wirdnam CD, Faso C. A core UPS molecular complement implicates unique endocytic compartments at the parasite-host interface in Giardia lamblia. Virulence 2023; 14:2174288. [PMID: 36730629 PMCID: PMC9928461 DOI: 10.1080/21505594.2023.2174288] [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] [Indexed: 02/04/2023] Open
Abstract
Unconventional protein secretion (UPS) plays important roles in cell physiology. In contrast to canonical secretory routes, UPS does not generally require secretory signal sequences and often bypasses secretory compartments such as the ER and the Golgi apparatus. Giardia lamblia is a protist parasite with reduced subcellular complexity which releases several proteins, some of them virulence factors, without canonical secretory signals. This implicates UPS at the parasite-host interface. No dedicated machinery nor mechanism(s) for UPS in Giardia are currently known, although speculations on the involvement of endocytic organelles called PV/PECs, have been put forth. To begin to address the question of whether PV/PECs are implicated in virulence-associated UPS and to define the composition of molecular machinery involved in protein release, we employed affinity purification and mass spectrometry, coupled to microscopy-based subcellular localization and signal correlation quantification to investigate the interactomes of 11 reported unconventionally secreted proteins, all predicted to be cytosolic. A subset of these are associated with PV/PECs. Extended and validated interactomes point to a core PV/PECs-associated UPS machinery, which includes uncharacterized and Giardia-specific coiled-coil proteins and NEK kinases. Finally, a subset of the alpha-giardin protein family was enriched in all PV/PECs-associated protein interactomes, highlighting a previously unappreciated role for these proteins at PV/PECs and in UPS. Taken together, our results provide the first characterization of a virulence-associated UPS protein complex in Giardia lamblia at PV/PECs, suggesting a novel link between these primarily endocytic and feeding organelles and UPS at the parasite-host interface.
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Affiliation(s)
- Erina A. Balmer
- Institute of Cell Biology, University of Bern, Bern, Switzerland,Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | | | - Carmen Faso
- Institute of Cell Biology, University of Bern, Bern, Switzerland,Multidisciplinary Center for Infectious Diseases, University of Bern, Bern, Switzerland,CONTACT Carmen Faso
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2
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Jamabo M, Mahlalela M, Edkins AL, Boshoff A. Tackling Sleeping Sickness: Current and Promising Therapeutics and Treatment Strategies. Int J Mol Sci 2023; 24:12529. [PMID: 37569903 PMCID: PMC10420020 DOI: 10.3390/ijms241512529] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 07/27/2023] [Accepted: 08/03/2023] [Indexed: 08/13/2023] Open
Abstract
Human African trypanosomiasis is a neglected tropical disease caused by the extracellular protozoan parasite Trypanosoma brucei, and targeted for eradication by 2030. The COVID-19 pandemic contributed to the lengthening of the proposed time frame for eliminating human African trypanosomiasis as control programs were interrupted. Armed with extensive antigenic variation and the depletion of the B cell population during an infectious cycle, attempts to develop a vaccine have remained unachievable. With the absence of a vaccine, control of the disease has relied heavily on intensive screening measures and the use of drugs. The chemotherapeutics previously available for disease management were plagued by issues such as toxicity, resistance, and difficulty in administration. The approval of the latest and first oral drug, fexinidazole, is a major chemotherapeutic achievement for the treatment of human African trypanosomiasis in the past few decades. Timely and accurate diagnosis is essential for effective treatment, while poor compliance and resistance remain outstanding challenges. Drug discovery is on-going, and herein we review the recent advances in anti-trypanosomal drug discovery, including novel potential drug targets. The numerous challenges associated with disease eradication will also be addressed.
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Affiliation(s)
- Miebaka Jamabo
- Biotechnology Innovation Centre, Rhodes University, Makhanda 6139, South Africa; (M.J.); (M.M.)
| | - Maduma Mahlalela
- Biotechnology Innovation Centre, Rhodes University, Makhanda 6139, South Africa; (M.J.); (M.M.)
| | - Adrienne L. Edkins
- Department of Biochemistry and Microbiology, Biomedical Biotechnology Research Centre (BioBRU), Rhodes University, Makhanda 6139, South Africa;
| | - Aileen Boshoff
- Biotechnology Innovation Centre, Rhodes University, Makhanda 6139, South Africa; (M.J.); (M.M.)
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3
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Kaushal RS, Naik N, Prajapati M, Rane S, Raulji H, Afu NF, Upadhyay TK, Saeed M. Leishmania species: A narrative review on surface proteins with structural aspects involved in host-pathogen interaction. Chem Biol Drug Des 2023; 102:332-356. [PMID: 36872849 DOI: 10.1111/cbdd.14227] [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: 01/13/2023] [Revised: 02/25/2023] [Accepted: 03/02/2023] [Indexed: 03/07/2023]
Abstract
In tropical and subtropical regions of the world, leishmaniasis is endemic and causes a range of clinical symptoms in people, from severe tegumentary forms (such as cutaneous, mucocutaneous, and diffuse leishmaniasis) to lethal visceral forms. The protozoan parasite of the genus Leishmania causes leishmaniasis, which is still a significant public health issue, according to the World Health Organization 2022. The public's worry about the neglected tropical disease is growing as new foci of the illness arise, which are exacerbated by alterations in behavior, changes in the environment, and an enlarged range of sand fly vectors. Leishmania research has advanced significantly during the past three decades in a few different avenues. Despite several studies on Leishmania, many issues, such as illness control, parasite resistance, parasite clearance, etc., remain unresolved. The key virulence variables that play a role in the pathogenicity-host-pathogen relationship of the parasite are comprehensively discussed in this paper. The important Leishmania virulence factors, such as Kinetoplastid Membrane Protein-11 (KMP-11), Leishmanolysin (GP63), Proteophosphoglycan (PPG), Lipophosphoglycan (LPG), Glycosylinositol Phospholipids (GIPL), and others, have an impact on the pathophysiology of the disease and enable the parasite to spread the infection. Leishmania infection may arise from virulence factors; they are treatable with medications or vaccinations more promptly and might greatly shorten the duration of treatment. Additionally, our research sought to present a modeled structure of a few putative virulence factors that might aid in the development of new chemotherapeutic approaches for the treatment of leishmaniasis. The predicted virulence protein's structure is utilized to design novel drugs, therapeutic targets, and immunizations for considerable advantage from a higher understanding of the host immune response.
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Affiliation(s)
- Radhey Shyam Kaushal
- Department of Biotechnology, Parul Institute of Applied Sciences and Centre of Research for Development, Parul University, Vadodara, 391760, Gujarat, India
| | - Nidhi Naik
- Department of Microbiology, Parul Institute of Applied Sciences, Parul University, Vadodara, 391760, Gujarat, India
| | - Maitri Prajapati
- Department of Microbiology, Parul Institute of Applied Sciences, Parul University, Vadodara, 391760, Gujarat, India
| | - Shruti Rane
- Department of Microbiology, Parul Institute of Applied Sciences, Parul University, Vadodara, 391760, Gujarat, India
| | - Himali Raulji
- Department of Microbiology, Parul Institute of Applied Sciences, Parul University, Vadodara, 391760, Gujarat, India
| | - Ngo Festus Afu
- Department of Biochemistry, Parul Institute of Applied Sciences, Parul University, Vadodara, 391760, Gujarat, India
| | - Tarun Kumar Upadhyay
- Department of Biotechnology, Parul Institute of Applied Sciences and Centre of Research for Development, Parul University, Vadodara, 391760, Gujarat, India
| | - Mohd Saeed
- Department of Biology, College of Sciences, University of Ha'il, P.O. Box 2440, Hail, 81411, Saudi Arabia
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4
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Almugadam SH, Trentini A, Maritati M, Contini C, Manfrinato MC, Cervellati C, Bellini T, Hanau S. A Calcium- and GTP-Dependent Transglutaminase in Leishmania infantum. Vet Sci 2023; 10:vetsci10030234. [PMID: 36977273 PMCID: PMC10053793 DOI: 10.3390/vetsci10030234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 03/10/2023] [Accepted: 03/15/2023] [Indexed: 03/30/2023] Open
Abstract
While human and animal leishmaniasis affect several millions of people worldwide, L. infantum is the species responsible for visceral leishmaniasis in Europe, Middle East, and America. Antileishmanial drugs present issues associated with drug toxicity and increasing parasite resistance. Therefore, the study of this parasite with a focus on new potential drug targets is extremely useful. Accordingly, we purified and characterized a transglutaminase (TGase) from L. infantum promastigotes. While Tgases are known to be involved in cell death and autophagy, it appears that these functions are very important for parasites' virulence. For the first time, we showed a Ca2+- and GTP-dependent TGase in Leishmania corresponding to a 54 kDa protein, which was purified by two chromatographic steps: DEAE-Sepharose and Heparin-Sepharose. Using polyclonal antibodies against a 50-amino-acid conserved region of the catalytic core of human TGase 2, we revealed two other bands of 66 and 75 kDa. The 54 kDa band appears to be different from the previously reported TGase, which was shown to be Ca2+- independent. Future research should address the identification of the purified enzyme sequence and, subsequently, its cloning to more comprehensively investigate its pathophysiological function and possible differences from mammal enzymes.
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Affiliation(s)
- Shawgi Hago Almugadam
- Department of Neuroscience and Rehabilitation, University of Ferrara, Via Luigi Borsari 46, 44121 Ferrara, Italy
- Faculty of Medical Laboratory Sciences, University of Khartoum, Nile Avenue, P.O. Box 321, Khartoum 51111, Sudan
| | - Alessandro Trentini
- Department of Environmental and Prevention Sciences, University of Ferrara, Via Luigi Borsari 46, 44121 Ferrara, Italy
| | - Martina Maritati
- Infectious Diseases and Dermatology, Department of Medical Sciences, University of Ferrara, Via Aldo Moro 8, 44124 Ferrara, Italy
| | - Carlo Contini
- Infectious Diseases and Dermatology, Department of Medical Sciences, University of Ferrara, Via Aldo Moro 8, 44124 Ferrara, Italy
| | - Maria Cristina Manfrinato
- Department of Neuroscience and Rehabilitation, University of Ferrara, Via Luigi Borsari 46, 44121 Ferrara, Italy
| | - Carlo Cervellati
- Department of Translational Medicine and for Romagna, University of Ferrara, Via Luigi Borsari 46, 44121 Ferrara, Italy
| | - Tiziana Bellini
- Department of Neuroscience and Rehabilitation, University of Ferrara, Via Luigi Borsari 46, 44121 Ferrara, Italy
| | - Stefania Hanau
- Department of Neuroscience and Rehabilitation, University of Ferrara, Via Luigi Borsari 46, 44121 Ferrara, Italy
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5
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Esteves S, Costa I, Luelmo S, Santarém N, Cordeiro-da-Silva A. Leishmania Vesicle-Depleted Exoproteome: What, Why, and How? Microorganisms 2022; 10:microorganisms10122435. [PMID: 36557688 PMCID: PMC9781507 DOI: 10.3390/microorganisms10122435] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 11/30/2022] [Accepted: 12/03/2022] [Indexed: 12/14/2022] Open
Abstract
Leishmaniasis, a vector-borne parasitic protozoan disease, is among the most important neglected tropical diseases. In the absence of vaccines, disease management is challenging. The available chemotherapy is suboptimal, and there are growing concerns about the emergence of drug resistance. Thus, a better understanding of parasite biology is essential to generate new strategies for disease control. In this context, in vitro parasite exoproteome characterization enabled the identification of proteins involved in parasite survival, pathogenesis, and other biologically relevant processes. After 2005, with the availability of genomic information, these studies became increasingly feasible and revealed the true complexity of the parasite exoproteome. After the discovery of Leishmania extracellular vesicles (EVs), most exoproteome studies shifted to the characterization of EVs. The non-EV portion of the exoproteome, named the vesicle-depleted exoproteome (VDE), has been mostly ignored even if it accounts for a significant portion of the total exoproteome proteins. Herein, we summarize the importance of total exoproteome studies followed by a special emphasis on the available information and the biological relevance of the VDE. Finally, we report on how VDE can be studied and disclose how it might contribute to providing biologically relevant targets for diagnosis, drug, and vaccine development.
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Affiliation(s)
- Sofia Esteves
- Laboratory of Microbiology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, 4050-313 Porto, Portugal
- Institute for Research and Innovation in Health (i3S), University of Porto, 4200-135 Porto, Portugal
| | - Inês Costa
- Laboratory of Microbiology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, 4050-313 Porto, Portugal
- Institute for Research and Innovation in Health (i3S), University of Porto, 4200-135 Porto, Portugal
| | - Sara Luelmo
- Institute for Research and Innovation in Health (i3S), University of Porto, 4200-135 Porto, Portugal
| | - Nuno Santarém
- Laboratory of Microbiology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, 4050-313 Porto, Portugal
- Institute for Research and Innovation in Health (i3S), University of Porto, 4200-135 Porto, Portugal
- Correspondence: (N.S.); (A.C.-d.-S.)
| | - Anabela Cordeiro-da-Silva
- Laboratory of Microbiology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, 4050-313 Porto, Portugal
- Institute for Research and Innovation in Health (i3S), University of Porto, 4200-135 Porto, Portugal
- Correspondence: (N.S.); (A.C.-d.-S.)
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6
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Noh SH, Kim YJ, Lee MG. Autophagy-Related Pathways in Vesicular Unconventional Protein Secretion. Front Cell Dev Biol 2022; 10:892450. [PMID: 35774225 PMCID: PMC9237382 DOI: 10.3389/fcell.2022.892450] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 05/26/2022] [Indexed: 12/14/2022] Open
Abstract
Cellular proteins directed to the plasma membrane or released into the extracellular space can undergo a number of different pathways. Whereas the molecular mechanisms that underlie conventional ER-to-Golgi trafficking are well established, those associated with the unconventional protein secretion (UPS) pathways remain largely elusive. A pathway with an emerging role in UPS is autophagy. Although originally known as a degradative process for maintaining intracellular homeostasis, recent studies suggest that autophagy has diverse biological roles besides its disposal function and that it is mechanistically involved in the UPS of various secretory cargos including both leaderless soluble and Golgi-bypassing transmembrane proteins. Here, we summarize current knowledge of the autophagy-related UPS pathways, describing and comparing diverse features in the autophagy-related UPS cargos and autophagy machineries utilized in UPS. Additionally, we also suggest potential directions that further research in this field can take.
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Affiliation(s)
- Shin Hye Noh
- Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, South Korea
- *Correspondence: Shin Hye Noh, ; Min Goo Lee,
| | - Ye Jin Kim
- Department of Pharmacology, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul, South Korea
| | - Min Goo Lee
- Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, South Korea
- Department of Pharmacology, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul, South Korea
- *Correspondence: Shin Hye Noh, ; Min Goo Lee,
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7
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Tettey MD, Rojas F, Matthews KR. Extracellular release of two peptidases dominates generation of the trypanosome quorum-sensing signal. Nat Commun 2022; 13:3322. [PMID: 35680928 PMCID: PMC9184580 DOI: 10.1038/s41467-022-31057-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 05/31/2022] [Indexed: 01/22/2023] Open
Abstract
Trypanosomes causing African sleeping sickness use quorum-sensing (QS) to generate transmission-competent stumpy forms in mammalian hosts. This density-dependent process is signalled by oligopeptides that stimulate the signal transduction pathway leading to stumpy formation. Here, using mass spectrometry analysis, we identify peptidases released by trypanosomes and, for 12 peptidases, confirm their extracellular delivery. Thereafter, we determine the contribution of each peptidase to QS signal production using systematic inducible overexpression in vivo, and confirm this activity operates through the physiological QS signalling pathway. Gene knockout of the QS-active peptidases identifies two enzymes, oligopeptidase B and metallocarboxypeptidase 1, that significantly reduce QS when ablated individually. Further, combinatorial gene knockout of both peptidases confirms their dominance in the generation of the QS signal, with peptidase release of oligopeptidase B mediated via an unconventional protein secretion pathway. This work identifies how the QS signal driving trypanosome virulence and transmission is generated in mammalian hosts.
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Affiliation(s)
- Mabel Deladem Tettey
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, EH93FL, UK
| | - Federico Rojas
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, EH93FL, UK.
- Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, LA1 4AT, UK.
| | - Keith R Matthews
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, EH93FL, UK.
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8
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Lahree A, Baptista SDJS, Marques S, Perschin V, Zuzarte-Luís V, Goel M, Choudhary HH, Mishra S, Stigloher C, Zerial M, Sundaramurthy V, Mota MM. Active APPL1 sequestration by Plasmodium favors liver-stage development. Cell Rep 2022; 39:110886. [PMID: 35649358 DOI: 10.1016/j.celrep.2022.110886] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 01/10/2022] [Accepted: 05/06/2022] [Indexed: 11/03/2022] Open
Abstract
Intracellular pathogens manipulate host cells to survive and thrive. Cellular sensing and signaling pathways are among the key host machineries deregulated to favor infection. In this study, we show that liver-stage Plasmodium parasites compete with the host to sequester a host endosomal-adaptor protein (APPL1) known to regulate signaling in response to endocytosis. The enrichment of APPL1 at the parasitophorous vacuole membrane (PVM) involves an atypical Plasmodium Rab5 isoform (Rab5b). Depletion of host APPL1 alters neither the infection nor parasite development; however, upon overexpression of a GTPase-deficient host Rab5 mutant (hRab5_Q79L), the parasites are smaller and their PVM is stripped of APPL1. Infection with the GTPase-deficient Plasmodium berghei Rab5b mutant (PbRab5b_Q91L) in this case rescues the PVM APPL1 signal and parasite size. In summary, we observe a robust correlation between the level of APPL1 retention at the PVM and parasite size during exoerythrocytic development.
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Affiliation(s)
- Aparajita Lahree
- Instituto de Medicina Molecular- João Lobo Antunes (iMM-JLA), Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisboa, Portugal; Departamento de Bioengenharia, Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisboa, Portugal
| | - Sara de Jesus Santos Baptista
- Instituto de Medicina Molecular- João Lobo Antunes (iMM-JLA), Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisboa, Portugal
| | - Sofia Marques
- Instituto de Medicina Molecular- João Lobo Antunes (iMM-JLA), Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisboa, Portugal
| | - Veronika Perschin
- Imaging Core Facility, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Vanessa Zuzarte-Luís
- Instituto de Medicina Molecular- João Lobo Antunes (iMM-JLA), Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisboa, Portugal
| | - Manisha Goel
- National Centre for Biological Sciences, Tata Institute of Fundamental Research (NCBS), Bellary Road, Bangalore 560065, Karnataka, India
| | - Hadi Hasan Choudhary
- CSIR-Central Drug Research Institute Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, Uttar Pradesh, India
| | - Satish Mishra
- CSIR-Central Drug Research Institute Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, Uttar Pradesh, India
| | - Christian Stigloher
- Imaging Core Facility, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Marino Zerial
- Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG), Pfotenhauerstraße 108, 01307 Dresden, Germany
| | - Varadharajan Sundaramurthy
- National Centre for Biological Sciences, Tata Institute of Fundamental Research (NCBS), Bellary Road, Bangalore 560065, Karnataka, India
| | - Maria M Mota
- Instituto de Medicina Molecular- João Lobo Antunes (iMM-JLA), Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisboa, Portugal.
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9
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Drug discovery in leishmaniasis using protein lipidation as a target. Biophys Rev 2021; 13:1139-1146. [PMID: 35035594 PMCID: PMC8724199 DOI: 10.1007/s12551-021-00855-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 10/14/2021] [Indexed: 01/03/2023] Open
Abstract
The leishmaniases are infectious diseases caused by a number of species of obligate intracellular protozoa of the genus Leishmania with disease manifesting as cutaneous, mucocutaneous and visceral forms. Despite being endemic in more than 80 countries and its being the cause of high morbidity and mortality, leishmaniasis remains a neglected tropical disease. Chemotherapy is the frontline treatment, but drugs in current use suffer from toxic side effects, difficulties in administration and extended treatment times - moreover, resistance is emerging. New anti-leishmanial drugs are a recognised international priority. Here, we review investigations into N-myristoyltransferase (NMT) as a potential drug target. NMT catalyses the co-translational transfer of a C14 fatty acid from myristoyl-CoA onto the N-terminal glycine residue of a significant subset of proteins in eukaryotic cells. This covalent modification influences the stability and interactions of substrate proteins with lipids and partner proteins. Structure-guided development of new lead compounds emerging from high-throughput screening campaigns targeting Leishmania donovani NMT has led to the discovery of potent inhibitors which have been used to gain insights into the role of protein myristoylation in these parasites and to validate NMT as a drug target.
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10
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Balmer EA, Faso C. The Road Less Traveled? Unconventional Protein Secretion at Parasite-Host Interfaces. Front Cell Dev Biol 2021; 9:662711. [PMID: 34109175 PMCID: PMC8182054 DOI: 10.3389/fcell.2021.662711] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 04/07/2021] [Indexed: 01/01/2023] Open
Abstract
Protein secretion in eukaryotic cells is a well-studied process, which has been known for decades and is dealt with by any standard cell biology textbook. However, over the past 20 years, several studies led to the realization that protein secretion as a process might not be as uniform among different cargos as once thought. While in classic canonical secretion proteins carry a signal sequence, the secretory or surface proteome of several organisms demonstrated a lack of such signals in several secreted proteins. Other proteins were found to indeed carry a leader sequence, but simply circumvent the Golgi apparatus, which in canonical secretion is generally responsible for the modification and sorting of secretory proteins after their passage through the endoplasmic reticulum (ER). These alternative mechanisms of protein translocation to, or across, the plasma membrane were collectively termed “unconventional protein secretion” (UPS). To date, many research groups have studied UPS in their respective model organism of choice, with surprising reports on the proportion of unconventionally secreted proteins and their crucial roles for the cell and survival of the organism. Involved in processes such as immune responses and cell proliferation, and including far more different cargo proteins in different organisms than anyone had expected, unconventional secretion does not seem so unconventional after all. Alongside mammalian cells, much work on this topic has been done on protist parasites, including genera Leishmania, Trypanosoma, Plasmodium, Trichomonas, Giardia, and Entamoeba. Studies on protein secretion have mainly focused on parasite-derived virulence factors as a main source of pathogenicity for hosts. Given their need to secrete a variety of substrates, which may not be compatible with canonical secretion pathways, the study of mechanisms for alternative secretion pathways is particularly interesting in protist parasites. In this review, we provide an overview on the current status of knowledge on UPS in parasitic protists preceded by a brief overview of UPS in the mammalian cell model with a focus on IL-1β and FGF-2 as paradigmatic UPS substrates.
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Affiliation(s)
- Erina A Balmer
- Institute of Cell Biology, University of Bern, Bern, Switzerland
| | - Carmen Faso
- Institute of Cell Biology, University of Bern, Bern, Switzerland
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11
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Dong G, Wagner V, Minguez-Menendez A, Fernandez-Prada C, Olivier M. Extracellular vesicles and leishmaniasis: Current knowledge and promising avenues for future development. Mol Immunol 2021; 135:73-83. [PMID: 33873096 DOI: 10.1016/j.molimm.2021.04.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 03/23/2021] [Accepted: 04/01/2021] [Indexed: 02/09/2023]
Abstract
Extracellular vesicles (EVs) are small, membrane-bound "delivery trucks" that are present in the extracellular environment, including biological fluids. EVs are capable of inducing changes in the physiological status of neighboring cells through the transfer of key macromolecules, and are thought to play a role in a number of pathological processes. Leishmaniasis, caused by the protozoan parasite Leishmania, is an important example. The biology of Leishmania EVs has been studied in detail, and findings point to their role in exacerbation of disease and potential involvement in the perpetuation of drug resistance. Furthermore, the use of EVs for development of vaccines has been explored, as well as their potential use in a number of fields as biomarkers of disease and drug resistance. Here we discuss the latest findings on EVs, with a particular focus on Leishmania, as well as potential avenues for their future development and clinical applications.
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Affiliation(s)
- George Dong
- Infectious Diseases and Immunology in Global Health Program (IDIGH), The Research Institute of the McGill University Health Centre, Montréal, QC, Canada
| | - Victoria Wagner
- Department of Pathology and Microbiology, Faculty of Veterinary Medicine, Université de Montréal, QC, Canada; The Research Group on Infectious Diseases in Production Animals (GREMIP), Faculty of Veterinary Medicine, Université de Montréal, QC, Canada
| | | | - Christopher Fernandez-Prada
- Department of Pathology and Microbiology, Faculty of Veterinary Medicine, Université de Montréal, QC, Canada; The Research Group on Infectious Diseases in Production Animals (GREMIP), Faculty of Veterinary Medicine, Université de Montréal, QC, Canada.
| | - Martin Olivier
- Infectious Diseases and Immunology in Global Health Program (IDIGH), The Research Institute of the McGill University Health Centre, Montréal, QC, Canada; Departments of Medicine, Microbiology and Immunology, Faculty of Medicine, McGill University, Montréal, QC, Canada.
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12
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Park G, Kim BS, Kim E. A novel function of FAF1, which induces dopaminergic neuronal death through cell-to-cell transmission. Cell Commun Signal 2020; 18:133. [PMID: 32831099 PMCID: PMC7444258 DOI: 10.1186/s12964-020-00632-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 07/23/2020] [Indexed: 12/21/2022] Open
Abstract
Background Fas-associated factor 1 (FAF1) has been implicated in Parkinson’s disease (PD) and activates the cell death machinery in the cytosol. However, the presence of extracellular FAF1 has not been studied. Methods Serum-free conditioned medium (CM) from FAF1-transfected SH-SY5Y cells was concentrated and analyzed by western blotting. Exosomes were isolated from CM by ultracentrifugation and analyzed by western blotting, electron microscopy and nanoparticle tracking analysis. Soluble FAF1 from CM was immunodepleted using anti-FAF1 antibody. Transmission of secreted FAF1 was examined by transwell assay under a confocal microscope. CM-induced cell death was determined by measuring propidium iodide (PI) uptake using a flow cytometer. Results FAF1 was secreted from SH-SY5Y cells via exocytosis and brefeldin A (BFA)-resistant secretory pathways. Furthermore, FAF1 was secreted as a vesicle-free form and a genuine exosome cargo in the lumen of exosomes. In addition, FAF1 increased the number of exosomes, suggesting a regulatory role in exosome biogenesis. Extracellular FAF1 was transmitted via endocytosis to neighboring cells, where it induced cell death through apoptotic and necrotic pathways. Conclusions This study presents a novel route by which FAF1 induces neuronal death through cell-to-cell transmission. Video Abstract
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Affiliation(s)
- Gyeongrin Park
- Department of Biological Sciences, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon, 34134, South Korea
| | - Bok-Seok Kim
- Department of Biological Sciences, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon, 34134, South Korea
| | - Eunhee Kim
- Department of Biological Sciences, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon, 34134, South Korea.
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13
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Dong G, Filho AL, Olivier M. Modulation of Host-Pathogen Communication by Extracellular Vesicles (EVs) of the Protozoan Parasite Leishmania. Front Cell Infect Microbiol 2019; 9:100. [PMID: 31032233 PMCID: PMC6470181 DOI: 10.3389/fcimb.2019.00100] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 03/25/2019] [Indexed: 12/21/2022] Open
Abstract
Leishmania genus protozoan parasites have developed various strategies to overcome host cell protective mechanisms favoring their survival and propagation. Recent findings in the field propose a new player in this infectious strategy, the Leishmania exosomes. Exosomes are eukaryotic extracellular vesicles essential to cell communication in various biological contexts. In fact, there have been an increasing number of reports over the last 10 years regarding the role of protozoan parasite exosomes, Leishmania exosomes included, in their capacity to favor infection and propagation within their hosts. In this review, we will discuss the latest findings regarding Leishmania exosome function during infectious conditions with a strong focus on Leishmania-host interaction from a mammalian perspective. We also compare the immunomodulatory properties of Leishmania exosomes to other parasite exosomes, demonstrating the conserved, important role that exosomes play during parasite infection.
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Affiliation(s)
- George Dong
- Infectious Diseases and Immunity in Global Heath Program, The Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Alonso Lira Filho
- Infectious Diseases and Immunity in Global Heath Program, The Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Martin Olivier
- Infectious Diseases and Immunity in Global Heath Program, The Research Institute of the McGill University Health Centre, Montreal, QC, Canada
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14
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Kim J, Gee HY, Lee MG. Unconventional protein secretion – new insights into the pathogenesis and therapeutic targets of human diseases. J Cell Sci 2018; 131:131/12/jcs213686. [DOI: 10.1242/jcs.213686] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
ABSTRACT
Most secretory proteins travel through a well-documented conventional secretion pathway involving the endoplasmic reticulum (ER) and the Golgi complex. However, recently, it has been shown that a significant number of proteins reach the plasma membrane or extracellular space via unconventional routes. Unconventional protein secretion (UPS) can be divided into two types: (i) the extracellular secretion of cytosolic proteins that do not bear a signal peptide (i.e. leaderless proteins) and (ii) the cell-surface trafficking of signal-peptide-containing transmembrane proteins via a route that bypasses the Golgi. Understanding the UPS pathways is not only important for elucidating the mechanisms of intracellular trafficking pathways but also has important ramifications for human health, because many of the proteins that are unconventionally secreted by mammalian cells and microorganisms are associated with human diseases, ranging from common inflammatory diseases to the lethal genetic disease of cystic fibrosis. Therefore, it is timely and appropriate to summarize and analyze the mechanisms of UPS involvement in disease pathogenesis, as they may be of use for the development of new therapeutic approaches. In this Review, we discuss the intracellular trafficking pathways of UPS cargos, particularly those related to human diseases. We also outline the disease mechanisms and the therapeutic potentials of new strategies for treating UPS-associated diseases.
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Affiliation(s)
- Jiyoon Kim
- Department of Pharmacology, Brain Korea 21 PLUS Project for Medical Sciences, Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul 120-752, Korea
| | - Heon Yung Gee
- Department of Pharmacology, Brain Korea 21 PLUS Project for Medical Sciences, Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul 120-752, Korea
| | - Min Goo Lee
- Department of Pharmacology, Brain Korea 21 PLUS Project for Medical Sciences, Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul 120-752, Korea
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15
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Spears RJ, Brabham RL, Budhadev D, Keenan T, McKenna S, Walton J, Brannigan JA, Brzozowski AM, Wilkinson AJ, Plevin M, Fascione MA. Site-selective C-C modification of proteins at neutral pH using organocatalyst-mediated cross aldol ligations. Chem Sci 2018; 9:5585-5593. [PMID: 30061990 PMCID: PMC6049525 DOI: 10.1039/c8sc01617h] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 05/31/2018] [Indexed: 12/30/2022] Open
Abstract
An organocatalyst-mediated protein aldol ligation (OPAL) affords C–C linked bioconjugates at neutral pH.
The bioconjugation of proteins with small molecules has proved an invaluable strategy for probing and perturbing biological mechanisms. The general use of chemical methods for protein functionalisation can be limited however by the requirement for complicated reaction partners to be present in large excess, and harsh conditions which are incompatible with many protein scaffolds. Herein we describe a site-selective organocatalyst-mediated protein aldol ligation (OPAL) that affords stable carbon–carbon linked bioconjugates at neutral pH. OPAL enables rapid modification of proteins using simple aldehyde probes in minimal excess, and is utilised here in the affinity tagging of proteins in cell lysate. Furthermore we demonstrate that the β-hydroxy aldehyde OPAL product can be functionalised again at neutral pH in a tandem organocatalyst-mediated oxime ligation. This tandem strategy is showcased in the ‘chemical mimicry’ of a previously inaccessible natural dual post-translationally modified protein integral to the pathogenesis of the neglected tropical disease Leishmaniasis.
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Affiliation(s)
- Richard J Spears
- Department of Chemistry , University of York , York , YO10 5DD , UK .
| | - Robin L Brabham
- Department of Chemistry , University of York , York , YO10 5DD , UK .
| | - Darshita Budhadev
- Department of Chemistry , University of York , York , YO10 5DD , UK .
| | - Tessa Keenan
- Department of Chemistry , University of York , York , YO10 5DD , UK .
| | - Sophie McKenna
- Department of Chemistry , University of York , York , YO10 5DD , UK .
| | - Julia Walton
- Department of Chemistry , University of York , York , YO10 5DD , UK .
| | - James A Brannigan
- Department of Chemistry , University of York , York , YO10 5DD , UK .
| | | | | | - Michael Plevin
- Department of Biology , University of York , York , YO10 5DD , UK
| | - Martin A Fascione
- Department of Chemistry , University of York , York , YO10 5DD , UK .
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16
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Targeting Heat Shock Protein 70 as an antiviral strategy against grass carp reovirus infection. Virus Res 2018; 247:1-9. [DOI: 10.1016/j.virusres.2018.01.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Revised: 12/08/2017] [Accepted: 01/12/2018] [Indexed: 01/08/2023]
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17
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Glogger M, Subota I, Pezzarossa A, Denecke AL, Carrington M, Fenz SF, Engstler M. Facilitating trypanosome imaging. Exp Parasitol 2017; 180:13-18. [PMID: 28363776 PMCID: PMC5540225 DOI: 10.1016/j.exppara.2017.03.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 03/08/2017] [Accepted: 03/25/2017] [Indexed: 11/30/2022]
Abstract
Research on trypanosomes as a model organism has provided a substantial contribution to a detailed understanding of basic cellular processes within the last few years. At the same time, major advances in super-resolution microscopy have been achieved, facilitating the resolution of biological structures in living cells at a scale of a few nm. However, the motility of trypanosomes has prevented access to high resolution microscopy of live cells. Here, we present a hydrogel based on poly(ethylene glycol) functionalized with either norbornene or thiol moieties for UV induced thiol-ene crosslinking for the embedding and imaging of live trypanosomes. The resulting gel exhibits low autofluorescence properties, immobilizes the cells efficiently on the nanometer scale and is compatible with cell viability for up to one hour at 24 °C. We applied super-resolution imaging to the inner plasma membrane leaflet using lipid-anchored eYFP as a probe. We find specific domains within the membrane where the fluorescence either accumulates or appears diluted rather than being homogenously distributed. Based on a Ripley's analysis, the size of the domains was determined to be raccumulated=170±5 nm and rdilute>115±15 nm. We hypothesize that this structuring of the membrane is associated with the underlying cytoskeleton.
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Affiliation(s)
- Marius Glogger
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Ines Subota
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Anna Pezzarossa
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Avenida Professor Egas Moniz, 1649-028 Lisboa, Portugal
| | - Anna-Lena Denecke
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Mark Carrington
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB21QW, UK
| | - Susanne F Fenz
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, Würzburg, Germany.
| | - Markus Engstler
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, Würzburg, Germany.
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18
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Kumar M, Ranjan K, Singh V, Pathak C, Pappachan A, Singh DD. Hydrophilic Acylated Surface Protein A (HASPA) of Leishmania donovani: Expression, Purification and Biophysico-Chemical Characterization. Protein J 2017. [PMID: 28634775 DOI: 10.1007/s10930-017-9726-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Hydrophilic acylated surface proteins (HASPs) are acidic surface proteins which get localized on the surface of Leishmania parasite during infective stages through a "non-classical" pathway. In this study, we report the heterologous expression and purification of Leishmania donovani HASPA (r-LdHASPA) in E. coli system and its partial characterization. The structural aspects of the purified protein were analyzed using CD spectroscopy and modeling studies which indicate that r-LdHASPA consists of random coils. Studies in mouse macrophage RAW264.7 cell lines indicate that r-LdHASPA enhances reactive oxygen species (ROS) production. Co-immunoprecipitation (IP) studies indicate that r-LdHASPA interacts with certain macrophage proteins which however could not be identified unambiguously. The present study provides key insights into the structural and functional aspects of an important Leishmania protein, HASPA, which we believe could be useful for further research on vaccine/drug development.
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Affiliation(s)
- Manoj Kumar
- Department of Bioinformatics and Structural Biology, Indian Institute of Advanced Research, Gandhinagar, Gujarat, 382007, India
| | - Kishu Ranjan
- Department of Cell Biology, Indian Institute of Advanced Research, Gandhinagar, Gujarat, 382007, India
| | - Vijay Singh
- Department of Bioinformatics and Structural Biology, Indian Institute of Advanced Research, Gandhinagar, Gujarat, 382007, India
| | - Chandramani Pathak
- Department of Cell Biology, Indian Institute of Advanced Research, Gandhinagar, Gujarat, 382007, India
| | - Anju Pappachan
- Department of Bioinformatics and Structural Biology, Indian Institute of Advanced Research, Gandhinagar, Gujarat, 382007, India
| | - Desh Deepak Singh
- Department of Bioinformatics and Structural Biology, Indian Institute of Advanced Research, Gandhinagar, Gujarat, 382007, India.
- Department of Biotechnology, Panjab University, Chandigarh, 160014, India.
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19
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Shibata T, Hadano J, Kawasaki D, Dong X, Kawabata SI. Drosophila TG-A transglutaminase is secreted via an unconventional Golgi-independent mechanism involving exosomes and two types of fatty acylations. J Biol Chem 2017; 292:10723-10734. [PMID: 28476891 DOI: 10.1074/jbc.m117.779710] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 04/26/2017] [Indexed: 01/07/2023] Open
Abstract
Transglutaminases (TGs) play essential intracellular and extracellular roles by covalently cross-linking many proteins. Drosophila TG is encoded by one gene and has two alternative splicing-derived isoforms, TG-A and TG-B, which contain distinct N-terminal 46- and 38-amino acid sequences, respectively. The TGs identified to date do not have a typical endoplasmic reticulum (ER)-signal peptide, and the molecular mechanisms of their secretion under physiologic conditions are unclear. Immunocytochemistry revealed that TG-A localizes to multivesicular-like structures, whereas TG-B localizes to the cytosol. We also found that TG-A, but not TG-B, was modified concomitantly by N-myristoylation and S-palmitoylation, and N-myristoylation was a pre-requisite for S-palmitoylation. Moreover, TG-A, but not TG-B, was secreted in response to calcium signaling induced by Ca2+ ionophores and uracil, a pathogenic bacteria-derived substance. Brefeldin A and monensin, inhibitors of the ER/Golgi-mediated conventional pathway, did not suppress TG-A secretion, whereas inhibition of S-palmitoylation by 2-bromopalmitate blocked TG-A secretion. Ultracentrifugation, electron microscopy analyses, and treatments with inhibitors of multivesicular body formation revealed that TG-A was secreted via exosomes together with co-transfected mammalian CD63, an exosomal marker, and the secreted TG-A was taken up by other cells. The 8-residue N-terminal fragment of TG-A containing the fatty acylation sites was both necessary and sufficient for the exosome-dependent secretion of TG-A. In conclusion, TG-A is secreted through an unconventional ER/Golgi-independent pathway involving two types of fatty acylations and exosomes.
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Affiliation(s)
- Toshio Shibata
- From the Department of Biology, Faculty of Science.,Institute for Advanced Study, and
| | - Jinki Hadano
- the Graduate School of Systems Life Sciences, Kyushu University, Fukuoka 819-0395, Japan
| | - Daichi Kawasaki
- the Graduate School of Systems Life Sciences, Kyushu University, Fukuoka 819-0395, Japan
| | - Xiaoqing Dong
- the Graduate School of Systems Life Sciences, Kyushu University, Fukuoka 819-0395, Japan
| | - Shun-Ichiro Kawabata
- From the Department of Biology, Faculty of Science, .,the Graduate School of Systems Life Sciences, Kyushu University, Fukuoka 819-0395, Japan
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20
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Brown RWB, Sharma AI, Engman DM. Dynamic protein S-palmitoylation mediates parasite life cycle progression and diverse mechanisms of virulence. Crit Rev Biochem Mol Biol 2017; 52:145-162. [PMID: 28228066 PMCID: PMC5560270 DOI: 10.1080/10409238.2017.1287161] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Eukaryotic parasites possess complex life cycles and utilize an assortment of molecular mechanisms to overcome physical barriers, suppress and/or bypass the host immune response, including invading host cells where they can replicate in a protected intracellular niche. Protein S-palmitoylation is a dynamic post-translational modification in which the fatty acid palmitate is covalently linked to cysteine residues on proteins by the enzyme palmitoyl acyltransferase (PAT) and can be removed by lysosomal palmitoyl-protein thioesterase (PPT) or cytosolic acyl-protein thioesterase (APT). In addition to anchoring proteins to intracellular membranes, functions of dynamic palmitoylation include - targeting proteins to specific intracellular compartments via trafficking pathways, regulating the cycling of proteins between membranes, modulating protein function and regulating protein stability. Recent studies in the eukaryotic parasites - Plasmodium falciparum, Toxoplasma gondii, Trypanosoma brucei, Cryptococcus neoformans and Giardia lamblia - have identified large families of PATs and palmitoylated proteins. Many palmitoylated proteins are important for diverse aspects of pathogenesis, including differentiation into infective life cycle stages, biogenesis and tethering of secretory organelles, assembling the machinery powering motility and targeting virulence factors to the plasma membrane. This review aims to summarize our current knowledge of palmitoylation in eukaryotic parasites, highlighting five exemplary mechanisms of parasite virulence dependent on palmitoylation.
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Affiliation(s)
- Robert W B Brown
- a Department of Pathology and Laboratory Medicine , Cedars-Sinai Medical Center , Los Angeles , CA , USA
| | - Aabha I Sharma
- b Departments of Pathology and Microbiology-Immunology , Northwestern University , Chicago , IL , USA
| | - David M Engman
- a Department of Pathology and Laboratory Medicine , Cedars-Sinai Medical Center , Los Angeles , CA , USA
- b Departments of Pathology and Microbiology-Immunology , Northwestern University , Chicago , IL , USA
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21
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Audagnotto M, Dal Peraro M. Protein post-translational modifications: In silico prediction tools and molecular modeling. Comput Struct Biotechnol J 2017; 15:307-319. [PMID: 28458782 PMCID: PMC5397102 DOI: 10.1016/j.csbj.2017.03.004] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Revised: 03/17/2017] [Accepted: 03/21/2017] [Indexed: 02/09/2023] Open
Abstract
Post-translational modifications (PTMs) occur in almost all proteins and play an important role in numerous biological processes by significantly affecting proteins' structure and dynamics. Several computational approaches have been developed to study PTMs (e.g., phosphorylation, sumoylation or palmitoylation) showing the importance of these techniques in predicting modified sites that can be further investigated with experimental approaches. In this review, we summarize some of the available online platforms and their contribution in the study of PTMs. Moreover, we discuss the emerging capabilities of molecular modeling and simulation that are able to complement these bioinformatics methods, providing deeper molecular insights into the biological function of post-translational modified proteins.
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Affiliation(s)
- Martina Audagnotto
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Matteo Dal Peraro
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
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22
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Doehl JSP, Sádlová J, Aslan H, Pružinová K, Metangmo S, Votýpka J, Kamhawi S, Volf P, Smith DF. Leishmania HASP and SHERP Genes Are Required for In Vivo Differentiation, Parasite Transmission and Virulence Attenuation in the Host. PLoS Pathog 2017; 13:e1006130. [PMID: 28095465 PMCID: PMC5271408 DOI: 10.1371/journal.ppat.1006130] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Revised: 01/27/2017] [Accepted: 12/15/2016] [Indexed: 12/15/2022] Open
Abstract
Differentiation of extracellular Leishmania promastigotes within their sand fly vector, termed metacyclogenesis, is considered to be essential for parasites to regain mammalian host infectivity. Metacyclogenesis is accompanied by changes in the local parasite environment, including secretion of complex glycoconjugates within the promastigote secretory gel and colonization and degradation of the sand fly stomodeal valve. Deletion of the stage-regulated HASP and SHERP genes on chromosome 23 of Leishmania major is known to stall metacyclogenesis in the sand fly but not in in vitro culture. Here, parasite mutants deficient in specific genes within the HASP/SHERP chromosomal region have been used to investigate their role in metacyclogenesis, parasite transmission and establishment of infection. Metacyclogenesis was stalled in HASP/SHERP mutants in vivo and, although still capable of osmotaxis, these mutants failed to secrete promastigote secretory gel, correlating with a lack of parasite accumulation in the thoracic midgut and failure to colonise the stomodeal valve. These defects prevented parasite transmission to a new mammalian host. Sand fly midgut homogenates modulated parasite behaviour in vitro, suggesting a role for molecular interactions between parasite and vector in Leishmania development within the sand fly. For the first time, stage-regulated expression of the small HASPA proteins in Leishmania (Leishmania) has been demonstrated: HASPA2 is expressed only in extracellular promastigotes and HASPA1 only in intracellular amastigotes. Despite its lack of expression in amastigotes, replacement of HASPA2 into the null locus background delays onset of pathology in BALB/c mice. This HASPA2-dependent effect is reversed by HASPA1 gene addition, suggesting that the HASPAs may have a role in host immunomodulation.
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Affiliation(s)
- Johannes S. P. Doehl
- Centre for Immunology and Infection, Department of Biology, University of York, York, United Kingdom
| | - Jovana Sádlová
- Department of Parasitology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Hamide Aslan
- Vector Molecular Biology Section, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Kateřina Pružinová
- Department of Parasitology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Sonia Metangmo
- Vector Molecular Biology Section, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Jan Votýpka
- Department of Parasitology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Shaden Kamhawi
- Vector Molecular Biology Section, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Petr Volf
- Department of Parasitology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Deborah F. Smith
- Centre for Immunology and Infection, Department of Biology, University of York, York, United Kingdom
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23
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Sanchez MA, Tran KD, Valli J, Hobbs S, Johnson E, Gluenz E, Landfear SM. KHARON Is an Essential Cytoskeletal Protein Involved in the Trafficking of Flagellar Membrane Proteins and Cell Division in African Trypanosomes. J Biol Chem 2016; 291:19760-73. [PMID: 27489106 DOI: 10.1074/jbc.m116.739235] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Indexed: 11/06/2022] Open
Abstract
African trypanosomes and related kinetoplastid parasites selectively traffic specific membrane proteins to the flagellar membrane, but the mechanisms for this trafficking are poorly understood. We show here that KHARON, a protein originally identified in Leishmania parasites, interacts with a putative trypanosome calcium channel and is required for its targeting to the flagellar membrane. KHARON is located at the base of the flagellar axoneme, where it likely mediates targeting of flagellar membrane proteins, but is also on the subpellicular microtubules and the mitotic spindle. Hence, KHARON is probably a multifunctional protein that associates with several components of the trypanosome cytoskeleton. RNA interference-mediated knockdown of KHARON mRNA results in failure of the calcium channel to enter the flagellar membrane, detachment of the flagellum from the cell body, and disruption of mitotic spindles. Furthermore, knockdown of KHARON mRNA induces a lethal failure of cytokinesis in both bloodstream (mammalian host) and procyclic (insect vector) life cycle stages, and KHARON is thus critical for parasite viability.
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Affiliation(s)
- Marco A Sanchez
- From the Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, Oregon 97239 and
| | - Khoa D Tran
- From the Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, Oregon 97239 and
| | - Jessica Valli
- the Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom
| | - Sam Hobbs
- From the Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, Oregon 97239 and
| | - Errin Johnson
- the Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom
| | - Eva Gluenz
- the Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom
| | - Scott M Landfear
- From the Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, Oregon 97239 and
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24
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Atayde VD, Hassani K, da Silva Lira Filho A, Borges AR, Adhikari A, Martel C, Olivier M. Leishmania exosomes and other virulence factors: Impact on innate immune response and macrophage functions. Cell Immunol 2016; 309:7-18. [PMID: 27499212 DOI: 10.1016/j.cellimm.2016.07.013] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 07/14/2016] [Accepted: 07/25/2016] [Indexed: 12/23/2022]
Abstract
Leishmania parasites are the causative agents of the leishmaniases, a collection of vector-borne diseases that range from simple cutaneous to fatal visceral forms. Employing potent immune modulation mechanisms, Leishmania is able to render the host macrophage inactive and persist inside its phagolysosome. In the last few years, the role of exosomes in Leishmania-host interactions has been increasingly investigated. For instance, it was reported that Leishmania exosome release is augmented following temperature shift, a condition mimicking parasite's entry into its mammalian host. Leishmania exosomes were found to strongly affect macrophage cell signaling and functions, similarly to whole parasites. Importantly, these vesicles were shown to be pro-inflammatory, capable to recruit neutrophils at their inoculation site exacerbating the pathology. In this review, we provide the most recent insights on the role of exosomes and other virulence factors, especially the surface protease GP63, in Leishmania-host interactions, deepening our knowledge on leishmaniasis and paving the way for the development of new therapeutics.
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Affiliation(s)
- Vanessa Diniz Atayde
- Departments of Medicine, Microbiology and Immunology, McGill University, 3775 University Street, Montréal, QC H3A 2B4, Canada; Infectious Diseases and Immunity in Global Heath Program, The Research Institute of the McGill University Health Centre, 1001 Boulevard Décarie, Montréal, QC H4A 3J1, Canada
| | - Kasra Hassani
- Departments of Medicine, Microbiology and Immunology, McGill University, 3775 University Street, Montréal, QC H3A 2B4, Canada; Infectious Diseases and Immunity in Global Heath Program, The Research Institute of the McGill University Health Centre, 1001 Boulevard Décarie, Montréal, QC H4A 3J1, Canada
| | - Alonso da Silva Lira Filho
- Departments of Medicine, Microbiology and Immunology, McGill University, 3775 University Street, Montréal, QC H3A 2B4, Canada; Infectious Diseases and Immunity in Global Heath Program, The Research Institute of the McGill University Health Centre, 1001 Boulevard Décarie, Montréal, QC H4A 3J1, Canada
| | - Andrezza Raposo Borges
- Departments of Medicine, Microbiology and Immunology, McGill University, 3775 University Street, Montréal, QC H3A 2B4, Canada; Infectious Diseases and Immunity in Global Heath Program, The Research Institute of the McGill University Health Centre, 1001 Boulevard Décarie, Montréal, QC H4A 3J1, Canada
| | - Anupam Adhikari
- Departments of Medicine, Microbiology and Immunology, McGill University, 3775 University Street, Montréal, QC H3A 2B4, Canada; Infectious Diseases and Immunity in Global Heath Program, The Research Institute of the McGill University Health Centre, 1001 Boulevard Décarie, Montréal, QC H4A 3J1, Canada
| | - Caroline Martel
- Departments of Medicine, Microbiology and Immunology, McGill University, 3775 University Street, Montréal, QC H3A 2B4, Canada; Infectious Diseases and Immunity in Global Heath Program, The Research Institute of the McGill University Health Centre, 1001 Boulevard Décarie, Montréal, QC H4A 3J1, Canada
| | - Martin Olivier
- Departments of Medicine, Microbiology and Immunology, McGill University, 3775 University Street, Montréal, QC H3A 2B4, Canada; Infectious Diseases and Immunity in Global Heath Program, The Research Institute of the McGill University Health Centre, 1001 Boulevard Décarie, Montréal, QC H4A 3J1, Canada.
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MacLean L, Price H, O'Toole P. Exploring the Leishmania Hydrophilic Acylated Surface Protein B (HASPB) Export Pathway by Live Cell Imaging Methods. Methods Mol Biol 2016; 1459:191-203. [PMID: 27665560 DOI: 10.1007/978-1-4939-3804-9_13] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Leishmania major is a human-infective protozoan parasite transmitted by the bite of the female phlebotomine sand fly. The L. major hydrophilic acylated surface protein B (HASPB) is only expressed in infective parasite stages suggesting a role in parasite virulence. HASPB is a "nonclassically" secreted protein that lacks a conventional signal peptide, reaching the cell surface by an alternative route to the classical ER-Golgi pathway. Instead HASPB trafficking to and exposure on the parasite plasma membrane requires dual N-terminal acylation. Here, we use live cell imaging methods to further explore this pathway allowing visualization of key events in real time at the individual cell level. These methods include live cell imaging using fluorescent reporters to determine the subcellular localization of wild type and acylation site mutation HASPB18-GFP fusion proteins, fluorescence recovery after photobleaching (FRAP) to analyze the dynamics of HASPB in live cells, and live antibody staining to detect surface exposure of HASPB by confocal microscopy.
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Affiliation(s)
- Lorna MacLean
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK.
| | - Helen Price
- Centre for Applied Entomology and Parasitology, School of Life Sciences, Keele University, Keele, Staffordshire, ST5 5BG, UK
| | - Peter O'Toole
- Technology Facility, Department of Biology, University of York, York, YO10 5DD, UK
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26
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Landfear SM, Tran KD, Sanchez MA. Flagellar membrane proteins in kinetoplastid parasites. IUBMB Life 2015; 67:668-76. [PMID: 26599841 DOI: 10.1002/iub.1411] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 08/06/2015] [Indexed: 11/06/2022]
Abstract
All kinetoplastid parasites, including protozoa such as Leishmania species, Trypanosoma brucei, and Trypanosoma cruzi that cause devastating diseases in humans and animals, are flagellated throughout their life cycles. Although flagella were originally thought of primarily as motility organelles, flagellar functions in other critical processes, especially in sensing and signal transduction, have become more fully appreciated in the recent past. The flagellar membrane is a highly specialized subdomain of the surface membrane, and flagellar membrane proteins are likely to be critical components for all the biologically important roles of flagella. In this review, we summarize recent discoveries relevant to flagellar membrane proteins in these parasites, including the identification of such proteins, investigation of their biological functions, and mechanisms of selective trafficking to the flagellar membrane. Prospects for future investigations and current unsolved problems are highlighted.
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Affiliation(s)
- Scott M Landfear
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, OR, USA
| | - Khoa D Tran
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, OR, USA
| | - Marco A Sanchez
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, OR, USA
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27
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Thavayogarajah T, Gangopadhyay P, Rahlfs S, Becker K, Lingelbach K, Przyborski JM, Holder AA. Alternative Protein Secretion in the Malaria Parasite Plasmodium falciparum. PLoS One 2015; 10:e0125191. [PMID: 25909331 PMCID: PMC4409355 DOI: 10.1371/journal.pone.0125191] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 03/11/2015] [Indexed: 12/13/2022] Open
Abstract
Plasmodium falciparum invades human red blood cells, residing in a parasitophorous vacuole (PV), with a parasitophorous vacuole membrane (PVM) separating the PV from the host cell cytoplasm. Here we have investigated the role of N-myristoylation and two other N-terminal motifs, a cysteine potential S-palmitoylation site and a stretch of basic residues, as the driving force for protein targeting to the parasite plasma membrane (PPM) and subsequent translocation across this membrane. Plasmodium falciparum adenylate kinase 2 (Pf AK2) contains these three motifs, and was previously proposed to be targeted beyond the parasite to the PVM, despite the absence of a signal peptide for entry into the classical secretory pathway. Biochemical and microscopy analyses of PfAK2 variants tagged with green fluorescent protein (GFP) showed that these three motifs are involved in targeting the protein to the PPM and translocation across the PPM to the PV. It was shown that the N-terminal 37 amino acids of PfAK2 alone are sufficient to target and translocate GFP across the PPM. As a control we examined the N-myristoylated P. falciparum ADP-ribosylation factor 1 (PfARF1). PfARF1 was found to co-localise with a Golgi marker. To determine whether or not the putative palmitoylation and the cluster of lysine residues from the N-terminus of PfAK2 would modulate the subcellular localization of PfARF1, a chimeric fusion protein containing the N-terminus of PfARF1 and the two additional PfAK2 motifs was analysed. This chimeric protein was targeted to the PPM, but not translocated across the membrane into the PV, indicating that other features of the N-terminus of PfAK2 also play a role in the secretion process.
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Affiliation(s)
- Thuvaraka Thavayogarajah
- Division of Parasitology, Faculty of Biology, Philipps-University Marburg, Karl-von-Frisch Straße 8, 35043 Marburg, Germany
| | - Preetish Gangopadhyay
- Division of Parasitology, Faculty of Biology, Philipps-University Marburg, Karl-von-Frisch Straße 8, 35043 Marburg, Germany
| | - Stefan Rahlfs
- Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus Liebig University Giessen, 35392 Giessen, Germany
| | - Katja Becker
- Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus Liebig University Giessen, 35392 Giessen, Germany
| | - Klaus Lingelbach
- Division of Parasitology, Faculty of Biology, Philipps-University Marburg, Karl-von-Frisch Straße 8, 35043 Marburg, Germany
| | - Jude M. Przyborski
- Division of Parasitology, Faculty of Biology, Philipps-University Marburg, Karl-von-Frisch Straße 8, 35043 Marburg, Germany
- * E-mail: (AAH); (JMP)
| | - Anthony A. Holder
- The Francis Crick Institute Mill Hill Laboratory, The Ridgeway, Mill Hill, London NW7 1AA, United Kingdom
- * E-mail: (AAH); (JMP)
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28
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Wright MH, Paape D, Storck EM, Serwa RA, Smith DF, Tate EW. Global analysis of protein N-myristoylation and exploration of N-myristoyltransferase as a drug target in the neglected human pathogen Leishmania donovani. ACTA ACUST UNITED AC 2015; 22:342-54. [PMID: 25728269 PMCID: PMC4372256 DOI: 10.1016/j.chembiol.2015.01.003] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 12/16/2014] [Accepted: 01/13/2015] [Indexed: 10/26/2022]
Abstract
N-Myristoyltransferase (NMT) modulates protein function through the attachment of the lipid myristate to the N terminus of target proteins, and is a promising drug target in eukaryotic parasites such as Leishmania donovani. Only a small number of NMT substrates have been characterized in Leishmania, and a global picture of N-myristoylation is lacking. Here, we use metabolic tagging with an alkyne-functionalized myristic acid mimetic in live parasites followed by downstream click chemistry and analysis to identify lipidated proteins in both the promastigote (extracellular) and amastigote (intracellular) life stages. Quantitative chemical proteomics is used to profile target engagement by NMT inhibitors, and to define the complement of N-myristoylated proteins. Our results provide new insight into the multiple pathways modulated by NMT and the pleiotropic effects of NMT inhibition. This work constitutes the first global experimental analysis of protein lipidation in Leishmania, and reveals the extent of NMT-related biology yet to be explored for this neglected human pathogen.
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Affiliation(s)
- Megan H Wright
- Department of Chemistry, Imperial College London, London SW7 2AZ, UK.
| | - Daniel Paape
- Centre for Immunology and Infection, Department of Biology, University of York, York YO10 5DD, UK
| | | | - Remigiusz A Serwa
- Department of Chemistry, Imperial College London, London SW7 2AZ, UK
| | - Deborah F Smith
- Centre for Immunology and Infection, Department of Biology, University of York, York YO10 5DD, UK
| | - Edward W Tate
- Department of Chemistry, Imperial College London, London SW7 2AZ, UK.
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29
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Goldston AM, Sharma AI, Paul KS, Engman DM. Acylation in trypanosomatids: an essential process and potential drug target. Trends Parasitol 2014; 30:350-60. [PMID: 24954795 DOI: 10.1016/j.pt.2014.05.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 05/06/2014] [Accepted: 05/06/2014] [Indexed: 12/11/2022]
Abstract
Fatty acylation--the addition of fatty acid moieties such as myristate and palmitate to proteins--is essential for the survival, growth, and infectivity of the trypanosomatids: Trypanosoma brucei, Trypanosoma cruzi, and Leishmania. Myristoylation and palmitoylation are critical for parasite growth, targeting and localization, and the intrinsic function of some proteins. The trypanosomatids possess a single N-myristoyltransferase (NMT) and multiple palmitoyl acyltransferases, and these enzymes and their protein targets are only now being characterized. Global inhibition of either process leads to cell death in trypanosomatids, and genetic ablation of NMT compromises virulence. Moreover, NMT inhibitors effectively cure T. brucei infection in rodents. Thus, protein acylation represents an attractive target for the development of new trypanocidal drugs.
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Affiliation(s)
- Amanda M Goldston
- Departments of Pathology and Microbiology-Immunology, Northwestern University, Chicago, Illinois, USA
| | - Aabha I Sharma
- Departments of Pathology and Microbiology-Immunology, Northwestern University, Chicago, Illinois, USA
| | - Kimberly S Paul
- Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, USA
| | - David M Engman
- Departments of Pathology and Microbiology-Immunology, Northwestern University, Chicago, Illinois, USA.
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30
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MacLean L, Myburgh E, Rodgers J, Price HP. Imaging African trypanosomes. Parasite Immunol 2014; 35:283-94. [PMID: 23790101 PMCID: PMC3992894 DOI: 10.1111/pim.12046] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 06/18/2013] [Indexed: 12/18/2022]
Abstract
Trypanosoma brucei are extracellular kinetoplastid parasites transmitted by the blood-sucking tsetse fly. They are responsible for the fatal disease human African trypanosomiasis (HAT), also known as sleeping sickness. In late-stage infection, trypanosomes cross the blood–brain barrier (BBB) and invade the central nervous system (CNS) invariably leading to coma and death if untreated. There is no available vaccine and current late-stage HAT chemotherapy consists of either melarsoprol, which is highly toxic causing up to 8% of deaths, or nifurtimox–eflornithine combination therapy (NECT), which is costly and difficult to administer. There is therefore an urgent need to identify new late-stage HAT drug candidates. Here, we review how current imaging tools, ranging from fluorescent confocal microscopy of live immobilized cells in culture to whole-animal imaging, are providing insight into T. brucei biology, parasite-host interplay, trypanosome CNS invasion and disease progression. We also consider how imaging tools can be used for candidate drug screening purposes that could lead to new chemotherapies.
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Affiliation(s)
- L MacLean
- Centre for Immunology and Infection, Department of Biology/Hull York Medical School, University of York, Heslington, York, UK.
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31
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Tate EW, Bell AS, Rackham MD, Wright MH. N-Myristoyltransferase as a potential drug target in malaria and leishmaniasis. Parasitology 2014; 141:37-49. [PMID: 23611109 DOI: 10.1017/s0031182013000450] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Infections caused by protozoan parasites are among the most widespread and intractable transmissible diseases affecting the developing world, with malaria and leishmaniasis being the most costly in terms of morbidity and mortality. Although new drugs are urgently required against both diseases in the face of ever-rising resistance to frontline therapies, very few candidates passing through development pipelines possess a known and novel mode of action. Set in the context of drugs currently in use and under development, we present the evidence for N-myristoyltransferase (NMT), an enzyme that N-terminally lipidates a wide range of specific target proteins through post-translational modification, as a potential drug target in malaria and the leishmaniases. We discuss the limitations of current knowledge regarding the downstream targets of this enzyme in protozoa, and our recent progress towards potent cell-active NMT inhibitors against the most clinically-relevant species of parasite. Finally, we outline the next steps required in terms of both tools to understand N-myristoylation in protozoan parasites, and the generation of potential development candidates based on the output of our recently-reported high-throughput screens.
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Affiliation(s)
- Edward W Tate
- Department of Chemistry, Institute of Chemical Biology, Imperial College London, London SW7 2AZ, UK
| | - Andrew S Bell
- Department of Chemistry, Institute of Chemical Biology, Imperial College London, London SW7 2AZ, UK
| | - Mark D Rackham
- Department of Chemistry, Institute of Chemical Biology, Imperial College London, London SW7 2AZ, UK
| | - Megan H Wright
- Department of Chemistry, Institute of Chemical Biology, Imperial College London, London SW7 2AZ, UK
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32
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Lefebvre M, Tetaud E, Thonnus M, Salin B, Boissier F, Blancard C, Sauvanet C, Metzler C, Espiau B, Sahin A, Merlin G. LdFlabarin, a new BAR domain membrane protein of Leishmania flagellum. PLoS One 2013; 8:e76380. [PMID: 24086735 PMCID: PMC3785460 DOI: 10.1371/journal.pone.0076380] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Accepted: 08/23/2013] [Indexed: 11/18/2022] Open
Abstract
During the Leishmania life cycle, the flagellum undergoes successive assembly and disassembly of hundreds of proteins. Understanding these processes necessitates the study of individual components. Here, we investigated LdFlabarin, an uncharacterized L. donovani flagellar protein. The gene is conserved within the Leishmania genus and orthologous genes only exist in the Trypanosoma genus. LdFlabarin associates with the flagellar plasma membrane, extending from the base to the tip of the flagellum as a helicoidal structure. Site-directed mutagenesis, deletions and chimera constructs showed that LdFlabarin flagellar addressing necessitates three determinants: an N-terminal potential acylation site and a central BAR domain for membrane targeting and the C-terminal domain for flagellar specificity. In vitro, the protein spontaneously associates with liposomes, triggering tubule formation, which suggests a structural/morphogenetic function. LdFlabarin is the first characterized Leishmania BAR domain protein, and the first flagellum-specific BAR domain protein.
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Affiliation(s)
- Michèle Lefebvre
- CNRS UMR 5290, Montpellier, France
- Université Montpellier 1, Montpellier, France
- Centre Hospitalier Universitaire La Colombière, Montpellier, France
- IRD 224, Montpellier, France
| | - Emmanuel Tetaud
- CNRS UMR 5095, Institut de Biochimie Génétique et Cellulaire, Bordeaux, France
- Université Bordeaux Segalen, Bordeaux, France
| | - Magali Thonnus
- CNRS UMR 5234, Bordeaux, France
- Université Bordeaux Segalen, Bordeaux, France
| | - Bénédicte Salin
- CNRS UMR 5095, Institut de Biochimie Génétique et Cellulaire, Bordeaux, France
- Université Bordeaux Segalen, Bordeaux, France
| | - Fanny Boissier
- CNRS UMR 5095, Institut de Biochimie Génétique et Cellulaire, Bordeaux, France
- Université Bordeaux Segalen, Bordeaux, France
| | - Corinne Blancard
- CNRS UMR 5095, Institut de Biochimie Génétique et Cellulaire, Bordeaux, France
- Université Bordeaux Segalen, Bordeaux, France
| | - Cécile Sauvanet
- CNRS UMR 5095, Institut de Biochimie Génétique et Cellulaire, Bordeaux, France
- Université Bordeaux Segalen, Bordeaux, France
| | | | - Benoît Espiau
- CNRS-EPHE USR 3278, Papetoai, Moorea, Polynésie Française
| | - Annelise Sahin
- CNRS UMR 5234, Bordeaux, France
- Université Bordeaux Segalen, Bordeaux, France
| | - Gilles Merlin
- CNRS UMR 5290, Montpellier, France
- Université Montpellier 1, Montpellier, France
- Centre Hospitalier Universitaire La Colombière, Montpellier, France
- IRD 224, Montpellier, France
- * E-mail:
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33
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Price HP, Paape D, Hodgkinson MR, Farrant K, Doehl J, Stark M, Smith DF. The Leishmania major BBSome subunit BBS1 is essential for parasite virulence in the mammalian host. Mol Microbiol 2013; 90:597-611. [PMID: 23998526 PMCID: PMC3916885 DOI: 10.1111/mmi.12383] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/27/2013] [Indexed: 12/17/2022]
Abstract
Bardet-Biedl syndrome (BBS) is a human genetic disorder with a spectrum of symptoms caused by primary cilium dysfunction. The disease is caused by mutations in one of at least 17 identified genes, of which seven encode subunits of the BBSome, a protein complex required for specific trafficking events to and from the primary cilium. The molecular mechanisms associated with BBSome function remain to be fully elucidated. Here, we generated null and complemented mutants of the BBSome subunit BBS1 in the protozoan parasite, Leishmania. In the absence of BBS1, extracellular parasites have no apparent defects in growth, flagellum assembly, motility or differentiation in vitro but there is accumulation of vacuole-like structures close to the flagellar pocket. Infectivity of these parasites for macrophages in vitro is reduced compared with wild-type controls but the null parasites retain the ability to differentiate to the intracellular amastigote stage. However, infectivity of BBS1 null parasites is severely compromised in a BALB/c mouse footpad model. We hypothesize that the absence of BBS1 in Leishmania leads to defects in specific trafficking events that affect parasite persistence in the host. This is the first report of an association between the BBSome complex and pathogen infectivity.
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Affiliation(s)
- Helen P Price
- Centre for Immunology and Infection, Department of Biology, University of York, Heslington, York, YO10 5YW, UK
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34
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Tran KD, Rodriguez-Contreras D, Vieira DP, Yates PA, David L, Beatty W, Elferich J, Landfear SM. KHARON1 mediates flagellar targeting of a glucose transporter in Leishmania mexicana and is critical for viability of infectious intracellular amastigotes. J Biol Chem 2013; 288:22721-33. [PMID: 23766511 PMCID: PMC3829357 DOI: 10.1074/jbc.m113.483461] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 06/12/2012] [Indexed: 01/05/2023] Open
Abstract
The LmxGT1 glucose transporter is selectively targeted to the flagellum of the kinetoplastid parasite Leishmania mexicana, but the mechanism for targeting this and other flagella-specific membrane proteins among the Kinetoplastida is unknown. To address the mechanism of flagellar targeting, we employed in vivo cross-linking, tandem affinity purification, and mass spectrometry to identify a novel protein, KHARON1 (KH1), which is important for the flagellar trafficking of LmxGT1. Kh1 null mutant parasites are strongly impaired in flagellar targeting of LmxGT1, and trafficking of the permease was arrested in the flagellar pocket. Immunolocalization revealed that KH1 is located at the base of the flagellum, within the flagellar pocket, where it associates with the proximal segment of the flagellar axoneme. We propose that KH1 mediates transit of LmxGT1 from the flagellar pocket into the flagellar membrane via interaction with the proximal portion of the flagellar axoneme. KH1 represents the first component involved in flagellar trafficking of integral membrane proteins among parasitic protozoa. Of considerable interest, Kh1 null mutants are strongly compromised for growth as amastigotes within host macrophages. Thus, KH1 is also important for the disease causing stage of the parasite life cycle.
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Affiliation(s)
- Khoa D. Tran
- From the Departments of Molecular Microbiology and Immunology
| | | | | | | | - Larry David
- Proteomics Shared Resource, Oregon Health & Science University, Portland, Oregon 97239 and
| | - Wandy Beatty
- the Molecular Microbiology Imaging Facility, Washington University School of Medicine, St. Louis, Missouri 63110
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35
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Traverso JA, Pulido A, Rodríguez-García MI, Alché JD. Thiol-based redox regulation in sexual plant reproduction: new insights and perspectives. FRONTIERS IN PLANT SCIENCE 2013; 4:465. [PMID: 24294217 PMCID: PMC3827552 DOI: 10.3389/fpls.2013.00465] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 10/28/2013] [Indexed: 05/19/2023]
Abstract
The success of sexual reproduction in plants involves (i) the proper formation of the plant gametophytes (pollen and embryo sac) containing the gametes, (ii) the accomplishment of specific interactions between pollen grains and the stigma, which subsequently lead to (iii) the fusion of the gametes and eventually to (iv) the seed setting. Owing to the lack of mobility, plants have developed specific regulatory mechanisms to control all developmental events underlying the sexual plant reproduction according to environmental challenges. Over the last decade, redox regulation and signaling have come into sight as crucial mechanisms able to manage critical stages during sexual plant reproduction. This regulation involves a complex redox network which includes reactive oxygen species (ROS), reactive nitrogen species (RNS), glutathione and other classic buffer molecules or antioxidant proteins, and some thiol/disulphide-containing proteins belonging to the thioredoxin superfamily, like glutaredoxins (GRXs) or thioredoxins (TRXs). These proteins participate as critical elements not only in the switch between the mitotic to the meiotic cycle but also at further developmental stages of microsporogenesis. They are also implicated in the regulation of pollen rejection as the result of self-incompatibility. In addition, they display precise space-temporal patterns of expression and are present in specific localizations like the stigmatic papillae or the mature pollen, although their functions and subcellular localizations are not clear yet. In this review we summarize insights and perspectives about the presence of thiol/disulphide-containing proteins in plant reproduction, taking into account the general context of the cell redox network.
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Affiliation(s)
- Jose A. Traverso
- Estación Experimental del Zaidín, Consejo Superior de Investigaciones CientíficasGranada, Spain
| | - Amada Pulido
- Departamento de Fisiología Vegetal, Universidad de GranadaGranada, Spain
| | | | - Juan D. Alché
- Estación Experimental del Zaidín, Consejo Superior de Investigaciones CientíficasGranada, Spain
- *Correspondence: Juan D. Alché, Plant Reproductive Biology Group, Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín, Spanish Council for Scientific Research, Profesor Albareda 1, 18008 Granada, Spain e-mail:
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36
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Rabouille C, Malhotra V, Nickel W. Diversity in unconventional protein secretion. J Cell Sci 2012; 125:5251-5. [DOI: 10.1242/jcs.103630] [Citation(s) in RCA: 208] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Catherine Rabouille
- Hubrecht Institute for, Developmental Biology and Stem Cell Research, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Vivek Malhotra
- Centre for Genomic Regulation, C/ Dr. Aiguader 88, 08003 Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys 23, 08010 Barcelona, Spain
| | - Walter Nickel
- Heidelberg University Biochemistry Center, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
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37
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Abstract
SIGNIFICANCE Cysteine residues of proteins participate in the catalysis of biochemical reactions, are crucial for redox reactions, and influence protein structure by the formation of disulfide bonds. Covalent posttranslational modifications (PTMs) of cysteine residues are important mediators of redox regulation and signaling by coupling protein activity to the cellular redox state, and moreover influence stability, function, and localization of proteins. A diverse group of protozoan and metazoan parasites are a major cause of diseases in humans, such as malaria, African trypanosomiasis, leishmaniasis, toxoplasmosis, filariasis, and schistosomiasis. RECENT ADVANCES Human parasites undergo dramatic morphological and metabolic changes while they pass complex life cycles and adapt to changing environments in host and vector. These processes are in part regulated by PTMs of parasitic proteins. In human parasites, posttranslational cysteine modifications are involved in crucial cellular events such as signal transduction (S-glutathionylation and S-nitrosylation), redox regulation of proteins (S-glutathionylation and S-nitrosylation), protein trafficking and subcellular localization (palmitoylation and prenylation), as well as invasion into and egress from host cells (palmitoylation). This review focuses on the occurrence and mechanisms of these cysteine modifications in parasites. CRITICAL ISSUES Studies on cysteine modifications in human parasites are so far largely based on in vitro experiments. FUTURE DIRECTIONS The in vivo regulation of cysteine modifications and their role in parasite development will be of great interest in order to understand redox signaling in parasites.
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Affiliation(s)
- Esther Jortzik
- Interdisciplinary Research Center, Justus Liebig University, Giessen, Germany
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38
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Tran KD, Rodriguez-Contreras D, Shinde U, Landfear SM. Both sequence and context are important for flagellar targeting of a glucose transporter. J Cell Sci 2012; 125:3293-8. [PMID: 22467850 DOI: 10.1242/jcs.103028] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Many of the cilia- and flagella-specific integral membrane proteins identified to date function to sense the extracellular milieu, and there is considerable interest in defining pathways for targeting such proteins to these sensory organelles. The flagellar glucose transporter of Leishmania mexicana, LmxGT1, is targeted selectively to the flagellar membrane, whereas two other isoforms, LmxGT2 and LmxGT3, are targeted to the pellicular plasma membrane of the cell body. To define the flagellar targeting signal, deletions and point mutations were generated in the N-terminal hydrophilic domain of LmxGT1, which mediates flagellar localization. Three amino acids, N95-P96-M97, serve critical roles in flagellar targeting, resulting in strong mistargeting phenotypes when mutagenized. However, to facilitate flagellar targeting of other non-flagellar membrane proteins, it was necessary to attach a larger region surrounding the NPM motif containing amino acids 81-113. Molecular modeling suggests that this region might present the critical NPM residues at the surface of the N-terminal domain. It is likely that the NPM motif is recognized by currently unknown protein-binding partners that mediate flagellar targeting of membrane-associated proteins.
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Affiliation(s)
- Khoa D Tran
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR 97239, USA
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Lambertz U, Silverman JM, Nandan D, McMaster WR, Clos J, Foster LJ, Reiner NE. Secreted virulence factors and immune evasion in visceral leishmaniasis. J Leukoc Biol 2012; 91:887-99. [PMID: 22442494 DOI: 10.1189/jlb.0611326] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Evasion or subversion of host immune responses is a well-established paradigm in infection with visceralizing leishmania. In this review, we summarize current findings supporting a model in which leishmania target host regulatory molecules and pathways, such as the PTP SHP-1 and the PI3K/Akt signaling cascade, to prevent effective macrophage activation. Furthermore, we describe how virulence factors, secreted by leishmania, interfere with macrophage intracellular signaling. Finally, we discuss mechanisms of secretion and provide evidence that leishmania use a remarkably adept, exosome-based secretion mechanism to export and deliver effector molecules to host cells. In addition to representing a novel mechanism for trafficking of virulence factors across membranes, recent findings indicate that leishmania exosomes may have potential as vaccine candidates.
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Affiliation(s)
- Ulrike Lambertz
- Department of Medicine Division of Infectious Diseases and the Experimental Medicine Program, University of British Columbia, Vancouver, Canada
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Acylation-dependent and-independent membrane targeting and distinct functions of small myristoylated proteins (SMPs) in Leishmania major. Int J Parasitol 2012; 42:239-47. [DOI: 10.1016/j.ijpara.2011.12.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Revised: 12/21/2011] [Accepted: 12/22/2011] [Indexed: 11/20/2022]
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Maclean LM, O'Toole PJ, Stark M, Marrison J, Seelenmeyer C, Nickel W, Smith DF. Trafficking and release of Leishmania metacyclic HASPB on macrophage invasion. Cell Microbiol 2012; 14:740-61. [PMID: 22256896 PMCID: PMC3491706 DOI: 10.1111/j.1462-5822.2012.01756.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Proteins of the Leishmania hydrophilic acylated surface protein B (HASPB) family are only expressed in infective parasites (both extra- and intracellular stages) and, together with the peripheral membrane protein SHERP (small hydrophilic endoplasmic reticulum-associated protein), are essential for parasite differentiation (metacyclogenesis) in the sand fly vector. HASPB is a ‘non-classically’ secreted protein, requiring N-terminal acylation for trafficking to and exposure on the plasma membrane. Here, we use live cell imaging methods to further explore this pathway to the membrane and flagellum. Unlike HASPB trafficking in transfected mammalian cells, we find no evidence for a phosphorylation-regulated recycling pathway in metacyclic parasites. Once at the plasma membrane, HASPB18–GFP (green fluorescent protein) can undergo bidirectional movement within the inner leaflet of the membrane and on the flagellum. Transfer of fluorescent protein between the flagellum and the plasma membrane is compromised, however, suggesting the presence of a diffusion barrier at the base of the Leishmania flagellum. Full-length HASPB is released from the metacyclic parasite surface on to macrophages during phagocytosis but while expression is maintained in intracellular amastigotes, HASPB cannot be detected on the external surface in these cells. Thus HASPB may be a dual function protein that is shed by the infective metacyclic but retained internally once Leishmania are taken up by macrophages.
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Affiliation(s)
- Lorna M Maclean
- Centre for Immunology and Infection, Department of Biology/Hull York Medical School, University of York, York YO10 5DD, UK
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Zhang O, Xu W, Balakrishna Pillai A, Zhang K. Developmentally regulated sphingolipid degradation in Leishmania major. PLoS One 2012; 7:e31059. [PMID: 22299050 PMCID: PMC3267774 DOI: 10.1371/journal.pone.0031059] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Accepted: 01/01/2012] [Indexed: 12/22/2022] Open
Abstract
Leishmania parasites alternate between extracellular promastigotes in sandflies and intracellular amastigotes in mammals. These protozoans acquire sphingolipids (SLs) through de novo synthesis (to produce inositol phosphorylceramide) and salvage (to obtain sphingomyelin from the host). A single ISCL (Inositol phosphoSphingolipid phospholipase C-Like) enzyme is responsible for the degradation of both inositol phosphorylceramide (the IPC hydrolase or IPCase activity) and sphingomyelin (the SMase activity). Recent studies of a L. major ISCL-null mutant (iscl−) indicate that SL degradation is required for promastigote survival in stationary phase, especially under acidic pH. ISCL is also essential for L. major proliferation in mammals. To further understand the role of ISCL in Leishmania growth and virulence, we introduced a sole IPCase or a sole SMase into the iscl− mutant. Results showed that restoration of IPCase only complemented the acid resistance defect in iscl− promastigotes and improved their survival in macrophages, but failed to recover virulence in mice. In contrast, a sole SMase fully restored parasite infectivity in mice but was unable to reverse the promastigote defects in iscl−. These findings suggest that SL degradation in Leishmania possesses separate roles in different stages: while the IPCase activity is important for promastigote survival and acid tolerance, the SMase activity is required for amastigote proliferation in mammals. Consistent with these findings, ISCL was preferentially expressed in stationary phase promastigotes and amastigotes. Together, our results indicate that SL degradation by Leishmania is critical for parasites to establish and sustain infection in the mammalian host.
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Affiliation(s)
- Ou Zhang
- Department of Biological Sciences, Texas Tech University, Lubbock, Texas, United States of America
| | - Wei Xu
- Department of Biological Sciences, Texas Tech University, Lubbock, Texas, United States of America
| | | | - Kai Zhang
- Department of Biological Sciences, Texas Tech University, Lubbock, Texas, United States of America
- * E-mail:
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Bonzon-Kulichenko E, Martínez-Martínez S, Trevisan-Herraz M, Navarro P, Redondo JM, Vázquez J. Quantitative in-depth analysis of the dynamic secretome of activated Jurkat T-cells. J Proteomics 2011; 75:561-71. [DOI: 10.1016/j.jprot.2011.08.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Revised: 07/22/2011] [Accepted: 08/24/2011] [Indexed: 10/17/2022]
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Ritzerfeld J, Remmele S, Wang T, Temmerman K, Brügger B, Wegehingel S, Tournaviti S, Strating JRPM, Wieland FT, Neumann B, Ellenberg J, Lawerenz C, Hesser J, Erfle H, Pepperkok R, Nickel W. Phenotypic profiling of the human genome reveals gene products involved in plasma membrane targeting of SRC kinases. Genome Res 2011; 21:1955-68. [PMID: 21795383 DOI: 10.1101/gr.116087.110] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
SRC proteins are non-receptor tyrosine kinases that play key roles in regulating signal transduction by a diverse set of cell surface receptors. They contain N-terminal SH4 domains that are modified by fatty acylation and are functioning as membrane anchors. Acylated SH4 domains are both necessary and sufficient to mediate specific targeting of SRC kinases to the inner leaflet of plasma membranes. Intracellular transport of SRC kinases to the plasma membrane depends on microdomains into which SRC kinases partition upon palmitoylation. In the present study, we established a live-cell imaging screening system to identify gene products involved in plasma membrane targeting of SRC kinases. Based on siRNA arrays and a human model cell line expressing two kinds of SH4 reporter molecules, we conducted a genome-wide analysis of SH4-dependent protein targeting using an automated microscopy platform. We identified and validated 54 gene products whose down-regulation causes intracellular retention of SH4 reporter molecules. To detect and quantify this phenotype, we developed a software-based image analysis tool. Among the identified gene products, we found factors involved in lipid metabolism, intracellular transport, and cellular signaling processes. Furthermore, we identified proteins that are either associated with SRC kinases or are related to various known functions of SRC kinases such as other kinases and phosphatases potentially involved in SRC-mediated signal transduction. Finally, we identified gene products whose function is less defined or entirely unknown. Our findings provide a major resource for future studies unraveling the molecular mechanisms that underlie proper targeting of SRC kinases to the inner leaflet of plasma membranes.
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Affiliation(s)
- Julia Ritzerfeld
- Heidelberg University Biochemistry Center, 69120 Heidelberg, Germany
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Maric D, McGwire BS, Buchanan KT, Olson CL, Emmer BT, Epting CL, Engman DM. Molecular determinants of ciliary membrane localization of Trypanosoma cruzi flagellar calcium-binding protein. J Biol Chem 2011; 286:33109-17. [PMID: 21784841 DOI: 10.1074/jbc.m111.240895] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The flagellar calcium-binding protein (FCaBP) of Trypanosoma cruzi is localized to the flagellar membrane in all life cycle stages of the parasite. Myristoylation and palmitoylation of the N terminus of FCaBP are necessary for flagellar membrane targeting. Not all dually acylated proteins in T. cruzi are flagellar, however. Other determinants of FCaBP therefore likely contribute to flagellar specificity. We generated T. cruzi transfectants expressing the N-terminal 24 or 12 amino acids of FCaBP fused to GFP. Analysis of these mutants revealed that although amino acids 1-12 are sufficient for dual acylation and membrane binding, amino acids 13-24 are required for flagellar specificity and lipid raft association. Mutagenesis of several conserved lysine residues in the latter peptide demonstrated that these residues are essential for flagellar targeting and lipid raft association. Finally, FCaBP was expressed in the protozoan Leishmania amazonensis, which lacks FCaBP. The flagellar localization and membrane association of FCaBP in L. amazonensis suggest that the mechanisms for flagellar targeting, including a specific palmitoyl acyltransferase, are conserved in this organism.
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Affiliation(s)
- Danijela Maric
- Department of Pathology, Northwestern University, Chicago, Illinois 60611, USA
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Gibbons TF, Storey SM, Williams CV, McIntosh A, Mitchel DM, Parr RD, Schroeder ME, Schroeder F, Ball JM. Rotavirus NSP4: Cell type-dependent transport kinetics to the exofacial plasma membrane and release from intact infected cells. Virol J 2011; 8:278. [PMID: 21645398 PMCID: PMC3129587 DOI: 10.1186/1743-422x-8-278] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Accepted: 06/06/2011] [Indexed: 11/10/2022] Open
Abstract
Background Rotavirus NSP4 localizes to multiple intracellular sites and is multifunctional, contributing to RV morphogenesis, replication and pathogenesis. One function of NSP4 is the induction of early secretory diarrhea by binding surface receptors to initiate signaling events. The aims of this study were to determine the transport kinetics of NSP4 to the exofacial plasma membrane (PM), the subsequent release from intact infected cells, and rebinding to naïve and/or neighboring cells in two cell types. Methods Transport kinetics was evaluated using surface-specific biotinylation/streptavidin pull-downs and exofacial exposure of NSP4 was confirmed by antibody binding to intact cells, and fluorescent resonant energy transfer. Transfected cells similarly were monitored to discern NSP4 movement in the absence of infection or other viral proteins. Endoglycosidase H digestions, preparation of CY3- or CY5- labeled F(ab)2 fragments, confocal imaging, and determination of preferential polarized transport employed standard laboratory techniques. Mock-infected, mock-biotinylated and non-specific antibodies served as controls. Results Only full-length (FL), endoglycosidase-sensitive NSP4 was detected on the exofacial surface of two cell types, whereas the corresponding cell lysates showed multiple glycosylated forms. The C-terminus of FL NSP4 was detected on exofacial-membrane surfaces at different times in different cell types prior to its release into culture media. Transport to the PM was rapid and distinct yet FL NSP4 was secreted from both cell types at a time similar to the release of virus. NSP4-containing, clarified media from both cells bound surface molecules of naïve cells, and imaging showed secreted NSP4 from one or more infected cells bound neighboring cell membranes in culture. Preferential sorting to apical or basolateral membranes also was distinct in different polarized cells. Conclusions The intracellular transport of NSP4 to the PM, translocation across the PM, exposure of the C-terminus on the cell surface and subsequent secretion occurs via an unusual, complex and likely cell-dependent process. The exofacial exposure of the C-terminus poses several questions and suggests an atypical mechanism by which NSP4 traverses the PM and interacts with membrane lipids. Mechanistic details of the unconventional trafficking of NSP4, interactions with host-cell specific molecules and subsequent release require additional study.
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Affiliation(s)
- Thomas F Gibbons
- Department of Pathobiology Texas A&M University, TVMC, College Station, TX 77843-4467, USA
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Sádlová J, Price HP, Smith BA, Votýpka J, Volf P, Smith DF. The stage-regulated HASPB and SHERP proteins are essential for differentiation of the protozoan parasite Leishmania major in its sand fly vector, Phlebotomus papatasi. Cell Microbiol 2011; 12:1765-79. [PMID: 20636473 PMCID: PMC3015063 DOI: 10.1111/j.1462-5822.2010.01507.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The stage-regulated HASPB and SHERP proteins of Leishmania major are predominantly expressed in cultured metacyclic parasites that are competent for macrophage uptake and survival. The role of these proteins in parasite development in the sand fly vector has not been explored, however. Here, we confirm that expression of HASPB is detected only in vector metacyclic stages, correlating with the expression of metacyclic-specific lipophosphoglycan and providing the first definitive protein marker for this infective sand fly stage. Similarly, SHERP is expressed in vector metacyclics but is also detected at low levels in the preceding short promastigote stage. Using genetically modified parasites lacking or complemented for the LmcDNA16 locus on chromosome 23 that contains the HASP and SHERP genes, we further show that the presence of this locus is essential for parasite differentiation to the metacyclic stage in Phlebotomus papatasi. While wild-type and complemented parasites transform normally in late-stage infections, generating metacyclic promastigotes and colonizing the sand fly stomodeal valve, null parasites accumulate at the earlier elongated nectomonad stage of development within the abdominal and thoracic midgut of the sand fly. Complementation with HASPB or SHERP alone suggests that HASPB is the dominant effector molecule in this process.
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Affiliation(s)
- Jovana Sádlová
- Department of Parasitology, Faculty of Science, Charles University, Prague CZ 128 44, Czech Republic
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Global analysis of protein palmitoylation in African trypanosomes. EUKARYOTIC CELL 2010; 10:455-63. [PMID: 21193548 DOI: 10.1128/ec.00248-10] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Many eukaryotic proteins are posttranslationally modified by the esterification of cysteine thiols to long-chain fatty acids. This modification, protein palmitoylation, is catalyzed by a large family of palmitoyl acyltransferases that share an Asp-His-His-Cys Cys-rich domain but differ in their subcellular localizations and substrate specificities. In Trypanosoma brucei, the flagellated protozoan parasite that causes African sleeping sickness, protein palmitoylation has been observed for a few proteins, but the extent and consequences of this modification are largely unknown. We undertook the present study to investigate T. brucei protein palmitoylation at both the enzyme and substrate levels. Treatment of parasites with an inhibitor of total protein palmitoylation caused potent growth inhibition, yet there was no effect on growth by the separate, selective inhibition of each of the 12 individual T. brucei palmitoyl acyltransferases. This suggested either that T. brucei evolved functional redundancy for the palmitoylation of essential palmitoyl proteins or that palmitoylation of some proteins is catalyzed by a noncanonical transferase. To identify the palmitoylated proteins in T. brucei, we performed acyl biotin exchange chemistry on parasite lysates, followed by streptavidin chromatography, two-dimensional liquid chromatography-tandem mass spectrometry protein identification, and QSpec statistical analysis. A total of 124 palmitoylated proteins were identified, with an estimated false discovery rate of 1.0%. This palmitoyl proteome includes all of the known palmitoyl proteins in procyclic-stage T. brucei as well as several proteins whose homologues are palmitoylated in other organisms. Their sequences demonstrate the variety of substrate motifs that support palmitoylation, and their identities illustrate the range of cellular processes affected by palmitoylation in these important pathogens.
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Millington OR, Myburgh E, Mottram JC, Alexander J. Imaging of the host/parasite interplay in cutaneous leishmaniasis. Exp Parasitol 2010; 126:310-7. [PMID: 20501336 PMCID: PMC3427850 DOI: 10.1016/j.exppara.2010.05.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2009] [Revised: 05/17/2010] [Accepted: 05/19/2010] [Indexed: 11/19/2022]
Abstract
An understanding of host-parasite interplay is essential for the development of therapeutics and vaccines. Immunoparasitologists have learned a great deal from 'conventional'in vitro and in vivo approaches, but recent developments in imaging technologies have provided us (immunologists and parasitologists) with the ability to ask new and exciting questions about the dynamic nature of the parasite-immune system interface. These studies are providing us with new insights into the mechanisms involved in the initiation of a Leishmania infection and the consequent induction and regulation of the immune response. Here, we review some of the recent developments and discuss how these observations can be further developed to understand the immunology of cutaneous Leishmania infection in vivo.
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Depledge DP, MacLean LM, Hodgkinson MR, Smith BA, Jackson AP, Ma S, Uliana SRB, Smith DF. Leishmania-specific surface antigens show sub-genus sequence variation and immune recognition. PLoS Negl Trop Dis 2010; 4:e829. [PMID: 20927190 PMCID: PMC2946902 DOI: 10.1371/journal.pntd.0000829] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Accepted: 08/31/2010] [Indexed: 11/25/2022] Open
Abstract
Background A family of hydrophilic acylated surface (HASP) proteins, containing extensive and variant amino acid repeats, is expressed at the plasma membrane in infective extracellular (metacyclic) and intracellular (amastigote) stages of Old World Leishmania species. While HASPs are antigenic in the host and can induce protective immune responses, the biological functions of these Leishmania-specific proteins remain unresolved. Previous genome analysis has suggested that parasites of the sub-genus Leishmania (Viannia) have lost HASP genes from their genomes. Methods/Principal Findings We have used molecular and cellular methods to analyse HASP expression in New World Leishmania mexicana complex species and show that, unlike in L. major, these proteins are expressed predominantly following differentiation into amastigotes within macrophages. Further genome analysis has revealed that the L. (Viannia) species, L. (V.) braziliensis, does express HASP-like proteins of low amino acid similarity but with similar biochemical characteristics, from genes present on a region of chromosome 23 that is syntenic with the HASP/SHERP locus in Old World Leishmania species and the L. (L.) mexicana complex. A related gene is also present in Leptomonas seymouri and this may represent the ancestral copy of these Leishmania-genus specific sequences. The L. braziliensis HASP-like proteins (named the orthologous (o) HASPs) are predominantly expressed on the plasma membrane in amastigotes and are recognised by immune sera taken from 4 out of 6 leishmaniasis patients tested in an endemic region of Brazil. Analysis of the repetitive domains of the oHASPs has shown considerable genetic variation in parasite isolates taken from the same patients, suggesting that antigenic change may play a role in immune recognition of this protein family. Conclusions/Significance These findings confirm that antigenic hydrophilic acylated proteins are expressed from genes in the same chromosomal region in species across the genus Leishmania. These proteins are surface-exposed on amastigotes (although L. (L.) major parasites also express HASPB on the metacyclic plasma membrane). The central repetitive domains of the HASPs are highly variant in their amino acid sequences, both within and between species, consistent with a role in immune recognition in the host. Single-celled Leishmania parasites, transmitted by sand flies, infect humans and other mammals in many tropical and sub-tropical regions, giving rise to a spectrum of diseases called the leishmaniases. Species of parasite within the Leishmania genus can be divided into two groups (referred to as sub-genera) that are separated by up to 100 million years of evolution yet are highly related at the genome level. Our research is focused on identifying gene differences between these sub-genera that may identify proteins that impact on the transmission and pathogenicity of different Leishmania species. Here we report the presence of a highly-variant genomic locus (OHL) that was previously described as absent in parasites of the L. (Viannia) subgenus (on the basis of lack of key genes) but is present and well-characterised (as the LmcDNA16 locus) in all members of the alternative subgenus, L. (Leishmania). We demonstrate that the proteins encoded within the LmcDNA16 and OHL loci are similar in their structure and surface localisation in mammalian-infective amastigotes, despite significant differences in their DNA sequences. Most importantly, we demonstrate that the OHL locus proteins, like the HASP proteins from the LmcDNA16 locus, contain highly variable amino acid repeats that are antigenic in man and may therefore contribute to future vaccine development.
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Affiliation(s)
- Daniel P Depledge
- Centre for Immunology and Infection, Department of Biology, Hull York Medical School, University of York, York, United Kingdom
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