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Dohnálek V, Doležal P. Installation of LYRM proteins in early eukaryotes to regulate the metabolic capacity of the emerging mitochondrion. Open Biol 2024; 14:240021. [PMID: 38772414 DOI: 10.1098/rsob.240021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Accepted: 03/13/2024] [Indexed: 05/23/2024] Open
Abstract
Core mitochondrial processes such as the electron transport chain, protein translation and the formation of Fe-S clusters (ISC) are of prokaryotic origin and were present in the bacterial ancestor of mitochondria. In animal and fungal models, a family of small Leu-Tyr-Arg motif-containing proteins (LYRMs) uniformly regulates the function of mitochondrial complexes involved in these processes. The action of LYRMs is contingent upon their binding to the acylated form of acyl carrier protein (ACP). This study demonstrates that LYRMs are structurally and evolutionarily related proteins characterized by a core triplet of α-helices. Their widespread distribution across eukaryotes suggests that 12 specialized LYRMs were likely present in the last eukaryotic common ancestor to regulate the assembly and folding of the subunits that are conserved in bacteria but that lack LYRM homologues. The secondary reduction of mitochondria to anoxic environments has rendered the function of LYRMs and their interaction with acylated ACP dispensable. Consequently, these findings strongly suggest that early eukaryotes installed LYRMs in aerobic mitochondria as orchestrated switches, essential for regulating core metabolism and ATP production.
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Affiliation(s)
- Vít Dohnálek
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV , Vestec 252 50, Czech Republic
| | - Pavel Doležal
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV , Vestec 252 50, Czech Republic
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Motyčková A, Voleman L, Najdrová V, Arbonová L, Benda M, Dohnálek V, Janowicz N, Malych R, Šuťák R, Ettema TJG, Svärd S, Stairs CW, Doležal P. Adaptation of the late ISC pathway in the anaerobic mitochondrial organelles of Giardia intestinalis. PLoS Pathog 2023; 19:e1010773. [PMID: 37792908 PMCID: PMC10578589 DOI: 10.1371/journal.ppat.1010773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 10/16/2023] [Accepted: 09/17/2023] [Indexed: 10/06/2023] Open
Abstract
Mitochondrial metabolism is entirely dependent on the biosynthesis of the [4Fe-4S] clusters, which are part of the subunits of the respiratory chain. The mitochondrial late ISC pathway mediates the formation of these clusters from simpler [2Fe-2S] molecules and transfers them to client proteins. Here, we characterized the late ISC pathway in one of the simplest mitochondria, mitosomes, of the anaerobic protist Giardia intestinalis that lost the respiratory chain and other hallmarks of mitochondria. In addition to IscA2, Nfu1 and Grx5 we identified a novel BolA1 homologue in G. intestinalis mitosomes. It specifically interacts with Grx5 and according to the high-affinity pulldown also with other core mitosomal components. Using CRISPR/Cas9 we were able to establish full bolA1 knock out, the first cell line lacking a mitosomal protein. Despite the ISC pathway being the only metabolic role of the mitosome no significant changes in the mitosome biology could be observed as neither the number of the mitosomes or their capability to form [2Fe-2S] clusters in vitro was affected. We failed to identify natural client proteins that would require the [2Fe-2S] or [4Fe-4S] cluster within the mitosomes, with the exception of [2Fe-2S] ferredoxin, which is itself part of the ISC pathway. The overall uptake of iron into the cellular proteins remained unchanged as also observed for the grx5 knock out cell line. The pull-downs of all late ISC components were used to build the interactome of the pathway showing specific position of IscA2 due to its interaction with the outer mitosomal membrane proteins. Finally, the comparative analysis across Metamonada species suggested that the adaptation of the late ISC pathway identified in G. intestinalis occurred early in the evolution of this supergroup of eukaryotes.
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Affiliation(s)
- Alžběta Motyčková
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová Vestec, Czech Republic
| | - Luboš Voleman
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová Vestec, Czech Republic
| | - Vladimíra Najdrová
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová Vestec, Czech Republic
| | - Lenka Arbonová
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová Vestec, Czech Republic
| | - Martin Benda
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová Vestec, Czech Republic
| | - Vít Dohnálek
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová Vestec, Czech Republic
| | - Natalia Janowicz
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová Vestec, Czech Republic
| | - Ronald Malych
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová Vestec, Czech Republic
| | - Róbert Šuťák
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová Vestec, Czech Republic
| | - Thijs J G Ettema
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, The Netherlands
| | - Staffan Svärd
- Department of Cell and Molecular Biology, Biomedical Center (BMC), Uppsala University, Uppsala, Sweden
| | | | - Pavel Doležal
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová Vestec, Czech Republic
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Wu JH, Lee JC, Ho CC, Chiu PW, Sun CH. A myeloid leukemia factor homolog is involved in tolerance to stresses and stress-induced protein metabolism in Giardia lamblia. Biol Direct 2023; 18:20. [PMID: 37095576 PMCID: PMC10127389 DOI: 10.1186/s13062-023-00378-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 04/17/2023] [Indexed: 04/26/2023] Open
Abstract
BACKGROUND The eukaryotic membrane vesicles contain specific sets of proteins that determine vesicle function and shuttle with specific destination. Giardia lamblia contains unknown cytosolic vesicles that are related to the identification of a homolog of human myeloid leukemia factor (MLF) named MLF vesicles (MLFVs). Previous studies suggest that MLF also colocalized with two autophagy machineries, FYVE and ATG8-like protein, and that MLFVs are stress-induced compartments for substrates of the proteasome or autophagy in response to rapamycin, MG132, and chloroquine treatment. A mutant protein of cyclin-dependent kinase 2, CDK2m3, was used to understand whether the aberrant proteins are targeted to degradative compratments. Interestingly, MLF was upregulated by CDK2m3 and they both colocalized within the same vesicles. Autophagy is a self-digestion process that is activated to remove damaged proteins for preventing cell death in response to various stresses. Because of the absence of some autophagy machineries, the mechanism of autophagy is unclear in G. lamblia. RESULTS In this study, we tested the six autophagosome and stress inducers in mammalian cells, including MG132, rapamycin, chloroquine, nocodazole, DTT, and G418, and found that their treatment increased reactive oxygen species production and vesicle number and level of MLF, FYVE, and ATG8-like protein in G. lamblia. Five stress inducers also increased the CDK2m3 protein levels and vesicles. Using stress inducers and knockdown system for MLF, we identified that stress induction of CDK2m3 was positively regulated by MLF. An autophagosome-reducing agent, 3-methyl adenine, can reduce MLF and CDK2m3 vesicles and proteins. In addition, knockdown of MLF with CRISPR/Cas9 system reduced cell survival upon treatment with stress inducers. Our newly developed complementation system for CRISPR/Cas9 indicated that complementation of MLF restored cell survival in response to stress inducers. Furthermore, human MLF2, like Giardia MLF, can increase cyst wall protein expression and cyst formation in G. lamblia, and it can colocalize with MLFVs and interact with MLF. CONCLUSIONS Our results suggest that MLF family proteins are functionally conserved in evolution. Our results also suggest an important role of MLF in survival in stress conditions and that MLFVs share similar stress-induced characteristics with autophagy compartments.
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Affiliation(s)
- Jui-Hsuan Wu
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei, 100, Taiwan, Republic of China
| | - Jen-Chi Lee
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei, 100, Taiwan, Republic of China
| | - Chun-Che Ho
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei, 100, Taiwan, Republic of China
| | - Pei-Wei Chiu
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei, 100, Taiwan, Republic of China
| | - Chin-Hung Sun
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei, 100, Taiwan, Republic of China.
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Fry MY, Najdrová V, Maggiolo AO, Saladi SM, Doležal P, Clemons WM. Structurally derived universal mechanism for the catalytic cycle of the tail-anchored targeting factor Get3. Nat Struct Mol Biol 2022; 29:820-830. [DOI: 10.1038/s41594-022-00798-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 05/26/2022] [Indexed: 11/09/2022]
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Hiregange DG, Rivalta A, Bose T, Breiner-Goldstein E, Samiya S, Cimicata G, Kulakova L, Zimmerman E, Bashan A, Herzberg O, Yonath A. Cryo-EM structure of the ancient eukaryotic ribosome from the human parasite Giardia lamblia. Nucleic Acids Res 2022; 50:1770-1782. [PMID: 35100413 PMCID: PMC8860606 DOI: 10.1093/nar/gkac046] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Revised: 01/12/2022] [Accepted: 01/25/2022] [Indexed: 12/13/2022] Open
Abstract
Giardiasis is a disease caused by the protist Giardia lamblia. As no human vaccines have been approved so far against it, and resistance to current drugs is spreading, new strategies for combating giardiasis need to be developed. The G. lamblia ribosome may provide a promising therapeutic target due to its distinct sequence differences from ribosomes of most eukaryotes and prokaryotes. Here, we report the cryo-electron microscopy structure of the G. lamblia (WB strain) ribosome determined at 2.75 Å resolution. The ribosomal RNA is the shortest known among eukaryotes, and lacks nearly all the eukaryote-specific ribosomal RNA expansion segments. In contrast, the ribosomal proteins are typically eukaryotic with some species-specific insertions/extensions. Most typical inter-subunit bridges are maintained except for one missing contact site. Unique structural features are located mainly at the ribosome’s periphery. These may be exploited as target sites for the design of new compounds that inhibit selectively the parasite’s ribosomal activity.
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Affiliation(s)
- Disha-Gajanan Hiregange
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Andre Rivalta
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Tanaya Bose
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Elinor Breiner-Goldstein
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Sarit Samiya
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Giuseppe Cimicata
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Liudmila Kulakova
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20742-4454, USA
| | - Ella Zimmerman
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Anat Bashan
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Osnat Herzberg
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20742-4454, USA
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742-4454, USA
| | - Ada Yonath
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
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Oxygen levels are key to understanding "Anaerobic" protozoan pathogens with micro-aerophilic lifestyles. Adv Microb Physiol 2021; 79:163-240. [PMID: 34836611 DOI: 10.1016/bs.ampbs.2021.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Publications abound on the physiology, biochemistry and molecular biology of "anaerobic" protozoal parasites as usually grown under "anaerobic" culture conditions. The media routinely used are poised at low redox potentials using techniques that remove O2 to "undetectable" levels in sealed containers. However there is growing understanding that these culture conditions do not faithfully resemble the O2 environments these organisms inhabit. Here we review for protists lacking oxidative energy metabolism, the oxygen cascade from atmospheric to intracellular concentrations and relevant methods of measurements of O2, some well-studied parasitic or symbiotic protozoan lifestyles, their homeodynamic metabolic and redox balances, organism-drug-oxygen interactions, and the present and future prospects for improved drugs and treatment regimes.
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Tůmová P, Voleman L, Klingl A, Nohýnková E, Wanner G, Doležal P. Inheritance of the reduced mitochondria of Giardia intestinalis is coupled to the flagellar maturation cycle. BMC Biol 2021; 19:193. [PMID: 34493257 PMCID: PMC8422661 DOI: 10.1186/s12915-021-01129-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 08/20/2021] [Indexed: 01/13/2023] Open
Abstract
Background The presence of mitochondria is a distinguishing feature between prokaryotic and eukaryotic cells. It is currently accepted that the evolutionary origin of mitochondria coincided with the formation of eukaryotes and from that point control of mitochondrial inheritance was required. Yet, the way the mitochondrial presence has been maintained throughout the eukaryotic cell cycle remains a matter of study. Eukaryotes control mitochondrial inheritance mainly due to the presence of the genetic component; still only little is known about the segregation of mitochondria to daughter cells during cell division. Additionally, anaerobic eukaryotic microbes evolved a variety of genomeless mitochondria-related organelles (MROs), which could be theoretically assembled de novo, providing a distinct mechanistic basis for maintenance of stable mitochondrial numbers. Here, we approach this problem by studying the structure and inheritance of the protist Giardia intestinalis MROs known as mitosomes. Results We combined 2D stimulated emission depletion (STED) microscopy and focused ion beam scanning electron microscopy (FIB/SEM) to show that mitosomes exhibit internal segmentation and conserved asymmetric structure. From a total of about forty mitosomes, a small, privileged population is harnessed to the flagellar apparatus, and their life cycle is coordinated with the maturation cycle of G. intestinalis flagella. The orchestration of mitosomal inheritance with the flagellar maturation cycle is mediated by a microtubular connecting fiber, which physically links the privileged mitosomes to both axonemes of the oldest flagella pair and guarantees faithful segregation of the mitosomes into the daughter cells. Conclusion Inheritance of privileged Giardia mitosomes is coupled to the flagellar maturation cycle. We propose that the flagellar system controls segregation of mitochondrial organelles also in other members of this supergroup (Metamonada) of eukaryotes and perhaps reflects the original strategy of early eukaryotic cells to maintain this key organelle before mitochondrial fusion-fission dynamics cycle as observed in Metazoa was established. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-021-01129-7.
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Affiliation(s)
- Pavla Tůmová
- Institute of Immunology and Microbiology, First Faculty of Medicine, Charles University, Prague, Czech Republic.
| | - Luboš Voleman
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Andreas Klingl
- Plant Development and Electron Microscopy, Department of Biology I, Biocenter of Ludwig-Maximilians University, Munich, Germany
| | - Eva Nohýnková
- Institute of Immunology and Microbiology, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Gerhard Wanner
- Department of Biology I, Biocenter of Ludwig-Maximilians University, Munich, Germany
| | - Pavel Doležal
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic.
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Pitt AS, Buchanan SK. A Biochemical and Structural Understanding of TOM Complex Interactions and Implications for Human Health and Disease. Cells 2021; 10:cells10051164. [PMID: 34064787 PMCID: PMC8150904 DOI: 10.3390/cells10051164] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 05/01/2021] [Accepted: 05/07/2021] [Indexed: 12/15/2022] Open
Abstract
The central role mitochondria play in cellular homeostasis has made its study critical to our understanding of various aspects of human health and disease. Mitochondria rely on the translocase of the outer membrane (TOM) complex for the bulk of mitochondrial protein import. In addition to its role as the major entry point for mitochondrial proteins, the TOM complex serves as an entry pathway for viral proteins. TOM complex subunits also participate in a host of interactions that have been studied extensively for their function in neurodegenerative diseases, cardiovascular diseases, innate immunity, cancer, metabolism, mitophagy and autophagy. Recent advances in our structural understanding of the TOM complex and the protein import machinery of the outer mitochondrial membrane have made structure-based therapeutics targeting outer mitochondrial membrane proteins during mitochondrial dysfunction an exciting prospect. Here, we describe advances in understanding the TOM complex, the interactome of the TOM complex subunits, the implications for the development of therapeutics, and our understanding of the structure/function relationship between components of the TOM complex and mitochondrial homeostasis.
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Füssy Z, Vinopalová M, Treitli SC, Pánek T, Smejkalová P, Čepička I, Doležal P, Hampl V. Retortamonads from vertebrate hosts share features of anaerobic metabolism and pre-adaptations to parasitism with diplomonads. Parasitol Int 2021; 82:102308. [PMID: 33626397 PMCID: PMC7985675 DOI: 10.1016/j.parint.2021.102308] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 01/26/2021] [Accepted: 02/11/2021] [Indexed: 12/17/2022]
Abstract
Although the mitochondria of extant eukaryotes share a single origin, functionally these organelles diversified to a great extent, reflecting lifestyles of the organisms that host them. In anaerobic protists of the group Metamonada, mitochondria are present in reduced forms (also termed hydrogenosomes or mitosomes) and a complete loss of mitochondrion in Monocercomonoides exilis (Metamonada:Preaxostyla) has also been reported. Within metamonads, retortamonads from the gastrointestinal tract of vertebrates form a sister group to parasitic diplomonads (e.g. Giardia and Spironucleus) and have also been hypothesized to completely lack mitochondria. We obtained transcriptomic data from Retortamonas dobelli and R. caviae and searched for enzymes of the core metabolism as well as mitochondrion- and parasitism-related proteins. Our results indicate that retortamonads have a streamlined metabolism lacking pathways for metabolites they are probably capable of obtaining from prey bacteria or their environment, reminiscent of the biochemical arrangement in other metamonads. Retortamonads were surprisingly found do encode homologs of components of Giardia's remarkable ventral disk, as well as homologs of regulatory NEK kinases and secreted lytic enzymes known for involvement in host colonization by Giardia. These can be considered pre-adaptations of these intestinal microorganisms to parasitism. Furthermore, we found traces of the mitochondrial metabolism represented by iron‑sulfur cluster assembly subunits, subunits of mitochondrial translocation and chaperone machinery and, importantly, [FeFe]‑hydrogenases and hydrogenase maturases (HydE, HydF and HydG). Altogether, our results strongly suggest that a remnant mitochondrion is still present.
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Affiliation(s)
- Zoltán Füssy
- Charles University, Faculty of Science, Department of Parasitology, BIOCEV, Vestec, Czech Republic.
| | - Martina Vinopalová
- Charles University, Faculty of Science, Department of Parasitology, BIOCEV, Vestec, Czech Republic
| | | | - Tomáš Pánek
- Charles University, Faculty of Science, Department of Zoology, Prague, Czech Republic
| | - Pavla Smejkalová
- Charles University, Faculty of Science, Department of Parasitology, BIOCEV, Vestec, Czech Republic; Charles University, Faculty of Science, Department of Parasitology, Prague, Czech Republic
| | - Ivan Čepička
- Charles University, Faculty of Science, Department of Zoology, Prague, Czech Republic
| | - Pavel Doležal
- Charles University, Faculty of Science, Department of Parasitology, BIOCEV, Vestec, Czech Republic
| | - Vladimír Hampl
- Charles University, Faculty of Science, Department of Parasitology, BIOCEV, Vestec, Czech Republic.
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Wu JH, Tung SY, Ho CC, Su LH, Gan SW, Liao JY, Cho CC, Lin BC, Chiu PW, Pan YJ, Kao YY, Liu YC, Sun CH. A myeloid leukemia factor homolog involved in encystation-induced protein metabolism in Giardia lamblia. Biochim Biophys Acta Gen Subj 2021; 1865:129859. [PMID: 33581251 DOI: 10.1016/j.bbagen.2021.129859] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 01/14/2021] [Accepted: 01/25/2021] [Indexed: 02/07/2023]
Abstract
BACKGROUND Giardia lamblia differentiates into resistant cysts as an established model for dormancy. Myeloid leukemia factor (MLF) proteins are important regulators of cell differentiation. Giardia possesses a MLF homolog which was up-regulated during encystation and localized to unknown cytosolic vesicles named MLF vesicles (MLFVs). METHODS We used double staining for visualization of potential factors with role in protein metabolism pathway and a strategy that employed a deletion mutant, CDK2m3, to test the protein degradation pathway. We also explored whether autophagy or proteasomal degradation are regulators of Giardia encystation by treatment with MG132, rapamycin, or chloroquine. RESULTS Double staining of MLF and ISCU or CWP1 revealed no overlap between their vesicles. The aberrant CDK2m3 colocalized with MLFVs and formed complexes with MLF. MG132 increased the number of CDK2m3-localized vesicles and its protein level. We further found that MLF colocalized and interacted with a FYVE protein and an ATG8-like (ATG8L) protein, which were up-regulated during encystation and their expression induced Giardia encystation. The addition of MG132, rapamycin, or chloroquine, increased their levels and the number of their vesicles, and inhibited the cyst formation. MLF and FYVE were detected in exosomes released from culture. CONCLUSIONS The MLFVs are not mitosomes or encystation-specific vesicles, but are related with degradative pathway for CDK2m3. MLF, FYVE, and ATG8L play a positive role in encystation and function in protein clearance pathway, which is important for encystation and coordinated with Exosomes. GENERAL SIGNIFICANCE MLF, FYVE, and ATG8L may be involved an encystation-induced protein metabolism during Giardia differentiation.
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Affiliation(s)
- Jui-Hsuan Wu
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei 100, Taiwan, ROC
| | - Szu-Yu Tung
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei 100, Taiwan, ROC
| | - Chun-Che Ho
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei 100, Taiwan, ROC
| | - Li-Hsin Su
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei 100, Taiwan, ROC
| | - Soo-Wah Gan
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei 100, Taiwan, ROC
| | - Jo-Yu Liao
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei 100, Taiwan, ROC
| | - Chao-Cheng Cho
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei 100, Taiwan, ROC
| | - Bo-Chi Lin
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei 100, Taiwan, ROC
| | - Pei-Wei Chiu
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei 100, Taiwan, ROC
| | - Yu-Jiao Pan
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei 100, Taiwan, ROC
| | - Yu-Yun Kao
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei 100, Taiwan, ROC
| | - Yu-Chen Liu
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei 100, Taiwan, ROC
| | - Chin-Hung Sun
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei 100, Taiwan, ROC.
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11
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Najdrová V, Stairs CW, Vinopalová M, Voleman L, Doležal P. The evolution of the Puf superfamily of proteins across the tree of eukaryotes. BMC Biol 2020; 18:77. [PMID: 32605621 PMCID: PMC7325665 DOI: 10.1186/s12915-020-00814-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 06/18/2020] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Eukaryotic gene expression is controlled by a number of RNA-binding proteins (RBP), such as the proteins from the Puf (Pumilio and FBF) superfamily (PufSF). These proteins bind to RNA via multiple Puf repeat domains, each of which specifically recognizes a single RNA base. Recently, three diversified PufSF proteins have been described in model organisms, each of which is responsible for the maturation of ribosomal RNA or the translational regulation of mRNAs; however, less is known about the role of these proteins across eukaryotic diversity. RESULTS Here, we investigated the distribution and function of PufSF RBPs in the tree of eukaryotes. We determined that the following PufSF proteins are universally conserved across eukaryotes and can be broadly classified into three groups: (i) Nop9 orthologues, which participate in the nucleolar processing of immature 18S rRNA; (ii) 'classical' Pufs, which control the translation of mRNA; and (iii) PUM3 orthologues, which are involved in the maturation of 7S rRNA. In nearly all eukaryotes, the rRNA maturation proteins, Nop9 and PUM3, are retained as a single copy, while mRNA effectors ('classical' Pufs) underwent multiple lineage-specific expansions. We propose that the variation in number of 'classical' Pufs relates to the size of the transcriptome and thus the potential mRNA targets. We further distinguished full set of PufSF proteins in divergent metamonad Giardia intestinalis and initiated their cellular and biochemical characterization. CONCLUSIONS Our data suggest that the last eukaryotic common ancestor (LECA) already contained all three types of PufSF proteins and that 'classical' Pufs then underwent lineage-specific expansions.
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Affiliation(s)
- Vladimíra Najdrová
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová 595, 252 50, Vestec, Czech Republic
| | - Courtney W Stairs
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, SE-75123, Uppsala, Sweden
| | - Martina Vinopalová
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová 595, 252 50, Vestec, Czech Republic
| | - Luboš Voleman
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová 595, 252 50, Vestec, Czech Republic
| | - Pavel Doležal
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová 595, 252 50, Vestec, Czech Republic.
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12
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Schneider A. Evolution of mitochondrial protein import – lessons from trypanosomes. Biol Chem 2020; 401:663-676. [DOI: 10.1515/hsz-2019-0444] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 03/02/2020] [Indexed: 01/02/2023]
Abstract
AbstractThe evolution of mitochondrial protein import and the systems that mediate it marks the boundary between the endosymbiotic ancestor of mitochondria and a true organelle that is under the control of the nucleus. Protein import has been studied in great detail inSaccharomyces cerevisiae. More recently, it has also been extensively investigated in the parasitic protozoanTrypanosoma brucei, making it arguably the second best studied system. A comparative analysis of the protein import complexes of yeast and trypanosomes is provided. Together with data from other systems, this allows to reconstruct the ancestral features of import complexes that were present in the last eukaryotic common ancestor (LECA) and to identify which subunits were added later in evolution. How these data can be translated into plausible scenarios is discussed, providing insights into the evolution of (i) outer membrane protein import receptors, (ii) proteins involved in biogenesis of α-helically anchored outer membrane proteins, and (iii) of the intermembrane space import and assembly system. Finally, it is shown that the unusual presequence-associated import motor of trypanosomes suggests a scenario of how the two ancestral inner membrane protein translocases present in LECA evolved into the single bifunctional one found in extant trypanosomes.
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Affiliation(s)
- André Schneider
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
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13
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von Känel C, Muñoz-Gómez SA, Oeljeklaus S, Wenger C, Warscheid B, Wideman JG, Harsman A, Schneider A. Homologue replacement in the import motor of the mitochondrial inner membrane of trypanosomes. eLife 2020; 9:52560. [PMID: 32105215 PMCID: PMC7064343 DOI: 10.7554/elife.52560] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 02/26/2020] [Indexed: 01/13/2023] Open
Abstract
Many mitochondrial proteins contain N-terminal presequences that direct them to the organelle. The main driving force for their translocation across the inner membrane is provided by the presequence translocase-associated motor (PAM) which contains the J-protein Pam18. Here, we show that in the PAM of Trypanosoma brucei the function of Pam18 has been replaced by the non-orthologous euglenozoan-specific J-protein TbPam27. TbPam27 is specifically required for the import of mitochondrial presequence-containing but not for carrier proteins. Similar to yeast Pam18, TbPam27 requires an intact J-domain to function. Surprisingly, T. brucei still contains a bona fide Pam18 orthologue that, while essential for normal growth, is not involved in protein import. Thus, during evolution of kinetoplastids, Pam18 has been replaced by TbPam27. We propose that this replacement is linked to the transition from two ancestral and functionally distinct TIM complexes, found in most eukaryotes, to the single bifunctional TIM complex present in trypanosomes.
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Affiliation(s)
- Corinne von Känel
- Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland
| | - Sergio A Muñoz-Gómez
- Center for Mechanisms of Evolution, Biodesign Institute, School of Life Sciences, Arizona State University, Tempe, United States
| | - Silke Oeljeklaus
- Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology and Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Christoph Wenger
- Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland
| | - Bettina Warscheid
- Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology and Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Jeremy G Wideman
- Center for Mechanisms of Evolution, Biodesign Institute, School of Life Sciences, Arizona State University, Tempe, United States
| | - Anke Harsman
- Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland
| | - Andre Schneider
- Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland
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14
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Vickman O, Erives A. Episodic evolution of a eukaryotic NADK repertoire of ancient provenance. PLoS One 2019; 14:e0220447. [PMID: 31369599 PMCID: PMC6675116 DOI: 10.1371/journal.pone.0220447] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 07/16/2019] [Indexed: 12/02/2022] Open
Abstract
NAD kinase (NADK) is the sole enzyme that phosphorylates nicotinamide adenine dinucleotide (NAD+/NADH) into NADP+/NADPH, which provides the chemical reducing power in anabolic (biosynthetic) pathways. While prokaryotes typically encode a single NADK, eukaryotes encode multiple NADKs. How these different NADK genes are all related to each other and those of prokaryotes is not known. Here we conduct phylogenetic analysis of NADK genes and identify major clade-defining patterns of NADK evolution. First, almost all eukaryotic NADK genes belong to one of two ancient eukaryotic sister clades corresponding to cytosolic (“cyto”) and mitochondrial (“mito”) clades. Secondly, we find that the cyto-clade NADK gene is duplicated in connection with loss of the mito-clade NADK gene in several eukaryotic clades or with acquisition of plastids in Archaeplastida. Thirdly, we find that horizontal gene transfers from proteobacteria have replaced mitochondrial NADK genes in only a few rare cases. Last, we find that the eukaryotic cyto and mito paralogs are unrelated to independent duplications that occurred in sporulating bacteria, once in mycelial Actinobacteria and once in aerobic endospore-forming Firmicutes. Altogether these findings show that the eukaryotic NADK gene repertoire is ancient and evolves episodically with major evolutionary transitions.
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Affiliation(s)
- Oliver Vickman
- Department of Biology, University of Iowa, Iowa City, IA, United States of America
| | - Albert Erives
- Department of Biology, University of Iowa, Iowa City, IA, United States of America
- * E-mail:
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15
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Development of CRISPR/Cas9-mediated gene disruption systems in Giardia lamblia. PLoS One 2019; 14:e0213594. [PMID: 30856211 PMCID: PMC6411161 DOI: 10.1371/journal.pone.0213594] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 02/25/2019] [Indexed: 12/26/2022] Open
Abstract
Giardia lamblia becomes dormant by differentiation into a water-resistant cyst that can infect a new host. Synthesis of three cyst wall proteins (CWPs) is the fundamental feature of this differentiation. Myeloid leukemia factor (MLF) proteins are involved in cell differentiation, and tumorigenesis in mammals, but little is known about its role in protozoan parasites. We developed a CRISPR/Cas9 system to understand the role of MLF in Giardia. Due to the tetraploid genome in two nuclei of Giardia, it could be hard to disrupt a gene completely in Giardia. We only generated knockdown but not knockout mutants. We found that knockdown of the mlf gene resulted in a significant decrease of cwp gene expression and cyst formation, suggesting a positive role of MLF in encystation. We further used mlf as a model gene to improve the system. The addition of an inhibitor for NHEJ, Scr7, or combining all cassettes for gRNA and Cas9 expression into one plasmid resulted in improved gene disruption efficiencies and a significant decrease in cwp gene expression. Our results provide insights into a positive role of MLF in inducing Giardia differentiation and a useful tool for studies in Giardia.
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16
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Faso C, Hehl AB. A cytonaut's guide to protein trafficking in Giardia lamblia. ADVANCES IN PARASITOLOGY 2019; 106:105-127. [PMID: 31630756 DOI: 10.1016/bs.apar.2019.08.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Over the past years, the subcellular organization of the Excavata member Giardia lamblia (syn. duodenalis, intestinalis) has been investigated in considerable detail. There are several reasons for this endeavour which go beyond this parasite's medical importance and are mostly concerned with its reduced subcellular complexity and debated evolutionary status. One may say that simplification has emerged as a paradigm for the evolution of Giardia's subcellular architecture. However, a complete appreciation of the evolutionary and ecological significance of this phenomenon is far from complete. In this chapter, we present and discuss the most recent data on the main trafficking pathways in G. lamblia which include endo- and exo-cytosis, organellar import and function. We provide perspectives on open questions concerning organelle replication and inheritance and include a technical outlook on methods and approaches to genetic manipulations in G. lamblia. A better understanding of G. lamblia subcellular organization at the morphological and molecular level complements any effort aimed at elucidating this parasitic species' evolutionary status and could provide us with the basis for novel strategies to interfere with parasite transmission and/or pathogenesis.
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Affiliation(s)
- Carmen Faso
- Laboratory of Molecular Parasitology, Institute of Parasitology, University of Zurich (ZH), Zürich, Switzerland
| | - Adrian B Hehl
- Laboratory of Molecular Parasitology, Institute of Parasitology, University of Zurich (ZH), Zürich, Switzerland.
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17
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Pyrihová E, Motycková A, Voleman L, Wandyszewska N, Fišer R, Seydlová G, Roger A, Kolísko M, Doležal P. A Single Tim Translocase in the Mitosomes of Giardia intestinalis Illustrates Convergence of Protein Import Machines in Anaerobic Eukaryotes. Genome Biol Evol 2018; 10:2813-2822. [PMID: 30265292 PMCID: PMC6200312 DOI: 10.1093/gbe/evy215] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/27/2018] [Indexed: 11/14/2022] Open
Abstract
Mitochondria have evolved diverse forms across eukaryotic diversity in adaptation to anoxia. Mitosomes are the simplest and the least well-studied type of anaerobic mitochondria. Transport of proteins via TIM complexes, composed of three proteins of the Tim17 protein family (Tim17/22/23), is one of the key unifying aspects of mitochondria and mitochondria-derived organelles. However, multiple experimental and bioinformatic attempts have so far failed to identify the nature of TIM in mitosomes of the anaerobic metamonad protist, Giardia intestinalis, one of the few experimental models for mitosome biology. Here, we present the identification of a single G. intestinalis Tim17 protein (GiTim17), made possible only by the implementation of a metamonad-specific hidden Markov model. While very divergent in primary sequence and in predicted membrane topology, experimental data suggest that GiTim17 is an inner membrane mitosomal protein, forming a disulphide-linked dimer. We suggest that the peculiar GiTim17 sequence reflects adaptation to the unusual, detergent resistant, inner mitosomal membrane. Specific pull-down experiments indicate interaction of GiTim17 with mitosomal Tim44, the tethering component of the import motor complex. Analysis of TIM complexes across eukaryote diversity suggests that a "single Tim" translocase is a convergent adaptation of mitosomes in anaerobic protists, with Tim22 and Tim17 (but not Tim23), providing the protein backbone.
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Affiliation(s)
- Eva Pyrihová
- Department of Parasitology, Faculty of Science, Charles University, Vestec, Czech Republic
| | - Alžbeta Motycková
- Department of Parasitology, Faculty of Science, Charles University, Vestec, Czech Republic
| | - Luboš Voleman
- Department of Parasitology, Faculty of Science, Charles University, Vestec, Czech Republic
| | - Natalia Wandyszewska
- Department of Parasitology, Faculty of Science, Charles University, Vestec, Czech Republic
| | - Radovan Fišer
- Department of Genetics and Microbiology, Charles University, Praha 2, Czech Republic
| | - Gabriela Seydlová
- Department of Genetics and Microbiology, Charles University, Praha 2, Czech Republic
| | - Andrew Roger
- Centre for Comparative Genomics and Evolutionary Bioinformatics, Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Canada
| | - Martin Kolísko
- Centre for Comparative Genomics and Evolutionary Bioinformatics, Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Canada.,Biology Centre CAS, České Budějovice, Czech Republic
| | - Pavel Doležal
- Department of Parasitology, Faculty of Science, Charles University, Vestec, Czech Republic
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18
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Santos HJ, Makiuchi T, Nozaki T. Reinventing an Organelle: The Reduced Mitochondrion in Parasitic Protists. Trends Parasitol 2018; 34:1038-1055. [PMID: 30201278 DOI: 10.1016/j.pt.2018.08.008] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 08/10/2018] [Accepted: 08/10/2018] [Indexed: 12/18/2022]
Abstract
Mitochondria originated from the endosymbiotic event commencing from the engulfment of an ancestral α-proteobacterium by the first eukaryotic ancestor. Establishment of niches has led to various adaptations among eukaryotes. In anaerobic parasitic protists, the mitochondria have undergone modifications by combining features shared from the aerobic mitochondria with lineage-specific components and mechanisms; a diversified class of organelles emerged and are generally called mitochondrion-related organelles (MROs). In this review we summarize and discuss the recent advances in the knowledge of MROs from parasitic protists, particularly the themes such as metabolic functions, contribution to parasitism, dynamics, protein targeting, and novel lineage- specific proteins, with emphasis on the diversity among these organelles.
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Affiliation(s)
- Herbert J Santos
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Takashi Makiuchi
- Department of Infectious Diseases, Tokai University School of Medicine, 143 Shimokasuya, Isehara, Kanagawa 259-1193, Japan
| | - Tomoyoshi Nozaki
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
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19
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Membrane-Associated Proteins in Giardia lamblia. Genes (Basel) 2018; 9:genes9080404. [PMID: 30103435 PMCID: PMC6115752 DOI: 10.3390/genes9080404] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 08/03/2018] [Accepted: 08/07/2018] [Indexed: 01/01/2023] Open
Abstract
The manner in which membrane-associated proteins interact with the membrane defines their subcellular fate and function. This interaction relies on the characteristics of the proteins, their journey after synthesis, and their interaction with other proteins or enzymes. Understanding these properties may help to define the function of a protein and also the role of an organelle. In the case of microorganisms like protozoa parasites, it may help to understand singular features that will eventually lead to the design of parasite-specific drugs. The protozoa parasite Giardia lamblia is an example of a widespread parasite that has been infecting humans and animals from ancestral times, adjusting itself to the changes of the environment inside and outside the host. Several membrane-associated proteins have been posted in the genome database GiardiaDB, although only a few of them have been characterized. This review discusses the data regarding membrane-associated proteins in relationship with lipids and specific organelles and their implication in the discovery of anti-giardial therapies.
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20
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Giardia lamblia : Identification of peroxisomal-like proteins. Exp Parasitol 2018; 191:36-43. [DOI: 10.1016/j.exppara.2018.06.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 06/04/2018] [Accepted: 06/14/2018] [Indexed: 11/18/2022]
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21
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Štáfková J, Rada P, Meloni D, Žárský V, Smutná T, Zimmann N, Harant K, Pompach P, Hrdý I, Tachezy J. Dynamic secretome of Trichomonas vaginalis: Case study of β-amylases. Mol Cell Proteomics 2018; 17:304-320. [PMID: 29233912 PMCID: PMC5795393 DOI: 10.1074/mcp.ra117.000434] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2017] [Indexed: 11/06/2022] Open
Abstract
The secretion of virulence factors by parasitic protists into the host environment plays a fundamental role in multifactorial host-parasite interactions. Several effector proteins are known to be secreted by Trichomonas vaginalis, a human parasite of the urogenital tract. However, a comprehensive profiling of the T. vaginalis secretome remains elusive, as do the mechanisms of protein secretion. In this study, we used high-resolution label-free quantitative MS to analyze the T. vaginalis secretome, considering that secretion is a time- and temperature-dependent process, to define the cutoff for secreted proteins. In total, we identified 2 072 extracellular proteins, 89 of which displayed significant quantitative increases over time at 37 °C. These 89 bona fide secreted proteins were sorted into 13 functional categories. Approximately half of the secreted proteins were predicted to possess transmembrane helixes. These proteins mainly include putative adhesins and leishmaniolysin-like metallopeptidases. The other half of the soluble proteins include several novel potential virulence factors, such as DNaseII, pore-forming proteins, and β-amylases. Interestingly, current bioinformatic tools predicted the secretory signal in only 18% of the identified T. vaginalis-secreted proteins. Therefore, we used β-amylases as a model to investigate the T. vaginalis secretory pathway. We demonstrated that two β-amylases (BA1 and BA2) are transported via the classical endoplasmic reticulum-to-Golgi pathways, and in the case of BA1, we showed that the protein is glycosylated with multiple N-linked glycans of Hex5HexNAc2 structure. The secretion was inhibited by brefeldin A but not by FLI-06. Another two β-amylases (BA3 and BA4), which are encoded in the T. vaginalis genome but absent from the secretome, were targeted to the lysosomal compartment. Collectively, under defined in vitro conditions, our analysis provides a comprehensive set of constitutively secreted proteins that can serve as a reference for future comparative studies, and it provides the first information about the classical secretory pathway in this parasite.
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Affiliation(s)
| | - Petr Rada
- From the ‡Department of Parasitology
| | | | | | | | | | | | - Petr Pompach
- §Institute of Biotechnology CAS, v. v. i., BIOCEV, Vestec, Czech Republic
- ¶Department of Biochemistry, Charles University, Faculty of Science, BIOCEV, Vestec, Czech Republic
| | - Ivan Hrdý
- From the ‡Department of Parasitology
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22
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Nosala C, Hagen KD, Dawson SC. 'Disc-o-Fever': Getting Down with Giardia's Groovy Microtubule Organelle. Trends Cell Biol 2017; 28:99-112. [PMID: 29153830 DOI: 10.1016/j.tcb.2017.10.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2017] [Revised: 10/14/2017] [Accepted: 10/25/2017] [Indexed: 11/29/2022]
Abstract
Protists have evolved a myriad of highly specialized cytoskeletal organelles that expand known functional capacities of microtubule (MT) polymers. One such innovation - the ventral disc - is a cup-shaped MT organelle that the parasite Giardia uses to attach to the small intestine of its host. The molecular mechanisms underlying the generation of suction-based forces by overall conformational changes of the disc remain unclear. The elaborate disc architecture is defined by novel proteins and complexes that decorate almost all disc MT protofilaments, and vary in composition and conformation along the length of the MTs. Future genetic, biochemical, and functional analyses of disc-associated proteins will be central toward understanding not only disc architecture and assembly, but also the overall disc conformational dynamics that promote attachment.
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Affiliation(s)
- Christopher Nosala
- Department of Microbiology and Molecular Genetics, One Shields Avenue, UC Davis, Davis, CA 95616, USA
| | - Kari D Hagen
- Department of Microbiology and Molecular Genetics, One Shields Avenue, UC Davis, Davis, CA 95616, USA
| | - Scott C Dawson
- Department of Microbiology and Molecular Genetics, One Shields Avenue, UC Davis, Davis, CA 95616, USA.
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23
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Fukasawa Y, Oda T, Tomii K, Imai K. Origin and Evolutionary Alteration of the Mitochondrial Import System in Eukaryotic Lineages. Mol Biol Evol 2017; 34:1574-1586. [PMID: 28369657 PMCID: PMC5455965 DOI: 10.1093/molbev/msx096] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Protein transport systems are fundamentally important for maintaining mitochondrial function. Nevertheless, mitochondrial protein translocases such as the kinetoplastid ATOM complex have recently been shown to vary in eukaryotic lineages. Various evolutionary hypotheses have been formulated to explain this diversity. To resolve any contradiction, estimating the primitive state and clarifying changes from that state are necessary. Here, we present more likely primitive models of mitochondrial translocases, specifically the translocase of the outer membrane (TOM) and translocase of the inner membrane (TIM) complexes, using scrutinized phylogenetic profiles. We then analyzed the translocases’ evolution in eukaryotic lineages. Based on those results, we propose a novel evolutionary scenario for diversification of the mitochondrial transport system. Our results indicate that presequence transport machinery was mostly established in the last eukaryotic common ancestor, and that primitive translocases already had a pathway for transporting presequence-containing proteins. Moreover, secondary changes including convergent and migrational gains of a presequence receptor in TOM and TIM complexes, respectively, likely resulted from constrained evolution. The nature of a targeting signal can constrain alteration to the protein transport complex.
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Affiliation(s)
- Yoshinori Fukasawa
- Artificial Intelligence Research Center, National Institute of Advanced Science and Technology (AIST), Tokyo, Japan
| | - Toshiyuki Oda
- Artificial Intelligence Research Center, National Institute of Advanced Science and Technology (AIST), Tokyo, Japan
| | - Kentaro Tomii
- Artificial Intelligence Research Center, National Institute of Advanced Science and Technology (AIST), Tokyo, Japan.,Biotechnology Research Institute for Drug Discovery, National Institute of Advanced Science and Technology (AIST), Tokyo, Japan
| | - Kenichiro Imai
- Artificial Intelligence Research Center, National Institute of Advanced Science and Technology (AIST), Tokyo, Japan.,Biotechnology Research Institute for Drug Discovery, National Institute of Advanced Science and Technology (AIST), Tokyo, Japan
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24
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Touz MC, Zamponi N. Sorting without a Golgi complex. Traffic 2017; 18:637-645. [DOI: 10.1111/tra.12500] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 07/01/2017] [Accepted: 07/06/2017] [Indexed: 12/22/2022]
Affiliation(s)
- Maria C. Touz
- Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC - CONICET; Universidad Nacional de Córdoba; Córdoba Argentina
| | - Nahuel Zamponi
- Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC - CONICET; Universidad Nacional de Córdoba; Córdoba Argentina
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25
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Giardia intestinalis mitosomes undergo synchronized fission but not fusion and are constitutively associated with the endoplasmic reticulum. BMC Biol 2017; 15:27. [PMID: 28372543 DOI: 10.1186/s12915-017-0361-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 03/01/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Mitochondria of opisthokonts undergo permanent fission and fusion throughout the cell cycle. Here, we investigated the dynamics of the mitosomes, the simplest forms of mitochondria, in the anaerobic protist parasite Giardia intestinalis, a member of the Excavata supergroup of eukaryotes. The mitosomes have abandoned typical mitochondrial traits such as the mitochondrial genome and aerobic respiration and their single role known to date is the formation of iron-sulfur clusters. RESULTS In live experiments, no fusion events were observed between the mitosomes in G. intestinalis. Moreover, the organelles were highly prone to becoming heterogeneous. This suggests that fusion is either much less frequent or even absent in mitosome dynamics. Unlike in mitochondria, division of the mitosomes was absolutely synchronized and limited to mitosis. The association of the nuclear and the mitosomal division persisted during the encystation of the parasite. During the segregation of the divided mitosomes, the subset of the organelles between two G. intestinalis nuclei had a prominent role. Surprisingly, the sole dynamin-related protein of the parasite seemed not to be involved in mitosomal division. However, throughout the cell cycle, mitosomes associated with the endoplasmic reticulum (ER), although none of the known ER-tethering complexes was present. Instead, the ER-mitosome interface was occupied by the lipid metabolism enzyme long-chain acyl-CoA synthetase 4. CONCLUSIONS This study provides the first report on the dynamics of mitosomes. We show that together with the loss of metabolic complexity of mitochondria, mitosomes of G. intestinalis have uniquely streamlined their dynamics by harmonizing their division with mitosis. We propose that this might be a strategy of G. intestinalis to maintain a stable number of organelles during cell propagation. The lack of mitosomal fusion may also be related to the secondary reduction of the organelles. However, as there are currently no reports on mitochondrial fusion in the whole Excavata supergroup, it is possible that the absence of mitochondrial fusion is an ancestral trait common to all excavates.
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26
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Leger MM, Kolisko M, Kamikawa R, Stairs CW, Kume K, Čepička I, Silberman JD, Andersson JO, Xu F, Yabuki A, Eme L, Zhang Q, Takishita K, Inagaki Y, Simpson AGB, Hashimoto T, Roger AJ. Organelles that illuminate the origins of Trichomonas hydrogenosomes and Giardia mitosomes. Nat Ecol Evol 2017; 1:0092. [PMID: 28474007 PMCID: PMC5411260 DOI: 10.1038/s41559-017-0092] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Michelle M Leger
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Canada
| | - Martin Kolisko
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Canada
| | - Ryoma Kamikawa
- Graduate School of Human and Environmental Studies, Graduate School of Global Environmental Studies, Kyoto University, Kyoto, Japan
| | - Courtney W Stairs
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Canada
| | - Keitaro Kume
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Ivan Čepička
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Jeffrey D Silberman
- Department of Biological Sciences, University of Arkansas, Fayetteville, USA
| | - Jan O Andersson
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Feifei Xu
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Akinori Yabuki
- Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Kanagawa, Japan
| | - Laura Eme
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Canada
| | - Qianqian Zhang
- Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong, People's Republic of China
| | - Kiyotaka Takishita
- Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Kanagawa, Japan
| | - Yuji Inagaki
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan.,Center for Computational Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | | | - Tetsuo Hashimoto
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan.,Center for Computational Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Andrew J Roger
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Canada
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27
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Rout S, Zumthor JP, Schraner EM, Faso C, Hehl AB. An Interactome-Centered Protein Discovery Approach Reveals Novel Components Involved in Mitosome Function and Homeostasis in Giardia lamblia. PLoS Pathog 2016; 12:e1006036. [PMID: 27926928 PMCID: PMC5142787 DOI: 10.1371/journal.ppat.1006036] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 11/01/2016] [Indexed: 12/23/2022] Open
Abstract
Protozoan parasites of the genus Giardia are highly prevalent globally, and infect a wide range of vertebrate hosts including humans, with proliferation and pathology restricted to the small intestine. This narrow ecological specialization entailed extensive structural and functional adaptations during host-parasite co-evolution. An example is the streamlined mitosomal proteome with iron-sulphur protein maturation as the only biochemical pathway clearly associated with this organelle. Here, we applied techniques in microscopy and protein biochemistry to investigate the mitosomal membrane proteome in association to mitosome homeostasis. Live cell imaging revealed a highly immobilized array of 30–40 physically distinct mitosome organelles in trophozoites. We provide direct evidence for the single giardial dynamin-related protein as a contributor to mitosomal morphogenesis and homeostasis. To overcome inherent limitations that have hitherto severely hampered the characterization of these unique organelles we applied a novel interaction-based proteome discovery strategy using forward and reverse protein co-immunoprecipitation. This allowed generation of organelle proteome data strictly in a protein-protein interaction context. We built an initial Tom40-centered outer membrane interactome by co-immunoprecipitation experiments, identifying small GTPases, factors with dual mitosome and endoplasmic reticulum (ER) distribution, as well as novel matrix proteins. Through iterative expansion of this protein-protein interaction network, we were able to i) significantly extend this interaction-based mitosomal proteome to include other membrane-associated proteins with possible roles in mitosome morphogenesis and connection to other subcellular compartments, and ii) identify novel matrix proteins which may shed light on mitosome-associated metabolic functions other than Fe-S cluster biogenesis. Functional analysis also revealed conceptual conservation of protein translocation despite the massive divergence and reduction of protein import machinery in Giardia mitosomes. Organelles with endosymbiotic origin are present in virtually all extant eukaryotes and have undergone considerable remodeling during > 1 billion years of evolution. Highly diverged organelles such as mitosomes or plastids in some parasitic protozoa are the product of extensive secondary reduction. They are sufficiently unique to generate interest as targets for pharmacological intervention, in addition to providing a rich ground for evolutionary cell biologists. The so-called mitochondria-related organelles (MROs) comprise mitosomes and hydrogenosomes, with the former having lost any role in energy metabolism along with the organelle genome. The mitosomes of the intestinal pathogen Giardia lamblia are the most highly reduced MROs known and have proven difficult to investigate because of their extreme divergence and their unique biophysical properties. Here, we implemented a novel strategy aimed at systematic analysis of the organelle proteome by iterative expansion of a protein-protein interaction network. We combined serial forward and reverse co-immunoprecipitations with mass spectrometry analysis, data mining, and validation by subcellular localization and/or functional analysis to generate an interactome network centered on a giardial Tom40 homolog. This iterative ab initio proteome reconstruction provided protein-protein interaction data in addition to identifying novel organelle proteins and functions. Building on this data we generated information on organelle replication, mitosome morphogenesis and organelle dynamics in living cells.
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Affiliation(s)
- Samuel Rout
- Institute of Parasitology, University of Zurich (ZH), Zurich, Switzerland
| | - Jon Paulin Zumthor
- Institute of Parasitology, University of Zurich (ZH), Zurich, Switzerland
| | | | - Carmen Faso
- Institute of Parasitology, University of Zurich (ZH), Zurich, Switzerland
- * E-mail: (ABH); (CF)
| | - Adrian B. Hehl
- Institute of Parasitology, University of Zurich (ZH), Zurich, Switzerland
- * E-mail: (ABH); (CF)
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Abstract
Background The Tim17 family of proteins plays a fundamental role in the biogenesis of mitochondria. Three Tim17 family proteins, Tim17, Tim22, and Tim23, are the central components of the widely conserved multi-subunit protein translocases, TIM23 and TIM22, which mediate protein transport across and into the inner mitochondrial membrane, respectively. In addition, several Tim17 family proteins occupy the inner and outer membranes of plastids. Results We have performed comprehensive sequence analyses on 5631 proteomes from all domains of life deposited in the Uniprot database. The analyses showed that the Tim17 family of proteins is much more diverse than previously thought and involves at least ten functionally and phylogenetically distinct groups of proteins. As previously shown, mitochondrial inner membrane accommodates prototypical Tim17, Tim22 and Tim23 and two Tim17 proteins, TIMMDC1 and NDUFA11, which participate in the assembly of complex I of the respiratory chain. In addition, we have identified Romo1/Mgr2 as Tim17 family member. The protein has been shown to control lateral release of substrates fromTIM23 complex in yeast and to participate in the production of reactive oxygen species in mammalian cells. Two peroxisomal proteins, Pmp24 and Tmem135, of so far unknown function also belong to Tim17 protein family. Additionally, a new group of Tim17 family proteins carrying a C-terminal coiled-coil domain has been identified predominantly in fungi. Conclusions We have mapped the distribution of Tim17 family members in the eukaryotic supergroups and found that the mitochondrial Tim17, Tim22 and Tim23 proteins, as well as the peroxisomal Tim17 family proteins, were all likely to be present in the last eukaryotic common ancestor (LECA). Thus, kinetoplastid mitochondria previously identified as carrying a single Tim17protein family homologue are likely to be the outcome of a secondary reduction. The eukaryotic cell has modified mitochondrial Tim17 family proteins to mediate different functions in multiple cellular compartments including mitochondria, plastids and peroxisomes. Concerning the origin of Tim17 protein family, our analyses do not support the affiliation of the protein family and the component of bacterial amino acid permease. Thus, it is likely that Tim17 protein family is exclusive to eukaryotes. Reviewers The article was reviewed by Michael Gray, Martijn Huynen and Kira Makarova. Electronic supplementary material The online version of this article (doi:10.1186/s13062-016-0157-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Vojtěch Žárský
- Department of Parasitology, Faculty of Science, Charles University in Prague, Prumyslova 595, 252 42, Vestec, Czech Republic
| | - Pavel Doležal
- Department of Parasitology, Faculty of Science, Charles University in Prague, Prumyslova 595, 252 42, Vestec, Czech Republic.
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Pyrih J, Pyrihová E, Kolísko M, Stojanovová D, Basu S, Harant K, Haindrich AC, Doležal P, Lukeš J, Roger A, Tachezy J. Minimal cytosolic iron-sulfur cluster assembly machinery of Giardia intestinalis is partially associated with mitosomes. Mol Microbiol 2016; 102:701-714. [PMID: 27582265 DOI: 10.1111/mmi.13487] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/21/2016] [Indexed: 01/10/2023]
Abstract
Iron-sulfur (Fe-S) clusters are essential cofactors that enable proteins to transport electrons, sense signals, or catalyze chemical reactions. The maturation of dozens of Fe-S proteins in various compartments of every eukaryotic cell is driven by several assembly pathways. The ubiquitous cytosolic Fe-S cluster assembly (CIA) pathway, typically composed of eight highly conserved proteins, depends on mitochondrial Fe-S cluster assembly (ISC) machinery. Giardia intestinalis contains one of the smallest eukaryotic genomes and the mitosome, an extremely reduced mitochondrion. Because the only pathway known to be retained within this organelle is the synthesis of Fe-S clusters mediated by ISC machinery, a likely function of the mitosome is to cooperate with the CIA pathway. We investigated the cellular localization of CIA components in G. intestinalis and the origin and distribution of CIA-related components and Tah18-like proteins in other Metamonada. We show that orthologs of Tah18 and Dre2 are missing in these eukaryotes. In Giardia, all CIA components are exclusively cytosolic, with the important exception of Cia2 and two Nbp35 paralogs, which are present in the mitosomes. We propose that the dual localization of Cia2 and Nbp35 proteins in Giardia might represent a novel connection between the ISC and the CIA pathways.
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Affiliation(s)
- Jan Pyrih
- Department of Parasitology, Charles University in Prague, Vestec, 252 42, Czech Republic
| | - Eva Pyrihová
- Department of Parasitology, Charles University in Prague, Vestec, 252 42, Czech Republic
| | - Martin Kolísko
- Centre for Comparative Genomics and Evolutionary Bioinformatics, Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, B3H 4R2, Canada
| | - Darja Stojanovová
- Department of Parasitology, Charles University in Prague, Vestec, 252 42, Czech Republic
| | - Somsuvro Basu
- Institute of Parasitology, Biology Centre, České Budějovice, Budweis, 37005, Czech Republic
| | - Karel Harant
- Department of Parasitology, Charles University in Prague, Vestec, 252 42, Czech Republic
| | - Alexander C Haindrich
- Institute of Parasitology, Biology Centre, České Budějovice, Budweis, 37005, Czech Republic.,Faculty of Sciences, University of South Bohemia, České Budějovice, Budweis, 37005, Czech Republic
| | - Pavel Doležal
- Department of Parasitology, Charles University in Prague, Vestec, 252 42, Czech Republic
| | - Julius Lukeš
- Institute of Parasitology, Biology Centre, České Budějovice, Budweis, 37005, Czech Republic.,Faculty of Sciences, University of South Bohemia, České Budějovice, Budweis, 37005, Czech Republic.,Canadian Institute for Advanced Research, Toronto, ON, M5G 1Z8, Canada
| | - Andrew Roger
- Centre for Comparative Genomics and Evolutionary Bioinformatics, Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, B3H 4R2, Canada.,Canadian Institute for Advanced Research, Toronto, ON, M5G 1Z8, Canada
| | - Jan Tachezy
- Department of Parasitology, Charles University in Prague, Vestec, 252 42, Czech Republic
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Einarsson E, Ma'ayeh S, Svärd SG. An up-date on Giardia and giardiasis. Curr Opin Microbiol 2016; 34:47-52. [PMID: 27501461 DOI: 10.1016/j.mib.2016.07.019] [Citation(s) in RCA: 218] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 07/27/2016] [Accepted: 07/27/2016] [Indexed: 12/11/2022]
Abstract
Giardia intestinalis is a non-invasive protozoan parasite infecting the upper small intestine causing acute, watery diarrhea or giardiasis in 280 million people annually. Asymptomatic infections are equally common and recent data have suggested that infections even can be protective against other diarrheal diseases. Most symptomatic infections resolve spontaneously but infections can lead to chronic disease and treatment failures are becoming more common world-wide. Giardia infections can also result in irritable bowel syndrome (IBS) and food allergies after resolution. Until recently not much was known about the mechanism of giardiasis or the cause of post-giardiasis syndromes and treatment failures, but here we will describe the recent progress in these areas.
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Affiliation(s)
- Elin Einarsson
- Department of Cell and Molecular Biology, BMC, Box 596, Uppsala University, SE-751 24 Uppsala, Sweden
| | - Showgy Ma'ayeh
- Department of Cell and Molecular Biology, BMC, Box 596, Uppsala University, SE-751 24 Uppsala, Sweden
| | - Staffan G Svärd
- Department of Cell and Molecular Biology, BMC, Box 596, Uppsala University, SE-751 24 Uppsala, Sweden.
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Emery SJ, Lacey E, Haynes PA. Quantitative proteomics in Giardia duodenalis —Achievements and challenges. Mol Biochem Parasitol 2016; 208:96-112. [DOI: 10.1016/j.molbiopara.2016.07.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 07/13/2016] [Accepted: 07/16/2016] [Indexed: 12/31/2022]
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32
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Abstract
Mitochondrion-related organelles (MROs) have arisen independently in a wide range of anaerobic protist lineages. Only a few of these organelles and their functions have been investigated in detail, and most of what is known about MROs comes from studies of parasitic organisms such as the parabasalid Trichomonas vaginalis. Here, we describe the MRO of a free-living anaerobic jakobid excavate, Stygiella incarcerata. We report an RNAseq-based reconstruction of S. incarcerata’s MRO proteome, with an associated biochemical map of the pathways predicted to be present in this organelle. The pyruvate metabolism and oxidative stress response pathways are strikingly similar to those found in the MROs of other anaerobic protists, such as Pygsuia and Trichomonas. This elegant example of convergent evolution is suggestive of an anaerobic biochemical ‘module’ of prokaryotic origins that has been laterally transferred among eukaryotes, enabling them to adapt rapidly to anaerobiosis. We also identified genes corresponding to a variety of mitochondrial processes not found in Trichomonas, including intermembrane space components of the mitochondrial protein import apparatus, and enzymes involved in amino acid metabolism and cardiolipin biosynthesis. In this respect, the MROs of S. incarcerata more closely resemble those of the much more distantly related free-living organisms Pygsuia biforma and Cantina marsupialis, likely reflecting these organisms’ shared lifestyle as free-living anaerobes.
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Affiliation(s)
- Michelle M Leger
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada
| | - Laura Eme
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada
| | - Laura A Hug
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada
| | - Andrew J Roger
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada
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