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Keeling PJ, Mtawali M, Trznadel M, Livingston SJ, Wakeman KC. Parallel functional reduction in the mitochondria of apicomplexan parasites. Eur J Protistol 2024; 94:126065. [PMID: 38492251 DOI: 10.1016/j.ejop.2024.126065] [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: 11/25/2023] [Revised: 02/21/2024] [Accepted: 02/22/2024] [Indexed: 03/18/2024]
Abstract
Extreme functional reduction of mitochondria has taken place in parallel in many distantly related lineages of eukaryotes, leading to a number of recurring metabolic states with variously lost electron transport chain (ETC) complexes, loss of the tricarboxylic acid (TCA) cycle, and/or loss of the mitochondrial genome. The resulting mitochondria-related organelles (MROs) are generally structurally reduced and in the most extreme cases barely recognizable features of the cell with no role in energy metabolism whatsoever (e.g., mitosomes, which generally only make iron-sulfur clusters). Recently, a wide diversity of MROs were discovered to be hiding in plain sight: in gregarine apicomplexans. This diverse group of invertebrate parasites has been known and observed for centuries, but until recent applications of culture-free genomics, their mitochondria were unremarkable. The genomics, however, showed that mitochondrial function has reduced in parallel in multiple gregarine lineages to several different endpoints, including the most reduced mitosomes. Here we review this remarkable case of parallel evolution of MROs, and some of the interesting questions this work raises.
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Affiliation(s)
- Patrick J Keeling
- Department of Botany, University of British Columbia, 3156-6270 University Blvd., Vancouver V6T 1Z4, BC, Canada.
| | - Mahara Mtawali
- Department of Botany, University of British Columbia, 3156-6270 University Blvd., Vancouver V6T 1Z4, BC, Canada
| | - Morelia Trznadel
- Department of Botany, University of British Columbia, 3156-6270 University Blvd., Vancouver V6T 1Z4, BC, Canada
| | - Samuel J Livingston
- Department of Botany, University of British Columbia, 3156-6270 University Blvd., Vancouver V6T 1Z4, BC, Canada
| | - Kevin C Wakeman
- Institute for the Advancement of Higher Education, Hokkaido University, Sapporo 060-0810, Hokkaido, Japan
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2
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Speijer D. How mitochondrial cristae illuminate the important role of oxygen during eukaryogenesis. Bioessays 2024; 46:e2300193. [PMID: 38449346 DOI: 10.1002/bies.202300193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 02/15/2024] [Accepted: 02/19/2024] [Indexed: 03/08/2024]
Abstract
Inner membranes of mitochondria are extensively folded, forming cristae. The observed overall correlation between efficient eukaryotic ATP generation and the area of internal mitochondrial inner membranes both in unicellular organisms and metazoan tissues seems to explain why they evolved. However, the crucial use of molecular oxygen (O2) as final acceptor of the electron transport chain is still not sufficiently appreciated. O2 was an essential prerequisite for cristae development during early eukaryogenesis and could be the factor allowing cristae retention upon loss of mitochondrial ATP generation. Here I analyze illuminating bacterial and unicellular eukaryotic examples. I also discuss formative influences of intracellular O2 consumption on the evolution of the last eukaryotic common ancestor (LECA). These considerations bring about an explanation for the many genes coming from other organisms than the archaeon and bacterium merging at the start of eukaryogenesis.
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Affiliation(s)
- Dave Speijer
- Medical Biochemistry, Amsterdam UMC location, University of Amsterdam, Amsterdam, The Netherlands
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3
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Butenko A, Lukeš J, Speijer D, Wideman JG. Mitochondrial genomes revisited: why do different lineages retain different genes? BMC Biol 2024; 22:15. [PMID: 38273274 PMCID: PMC10809612 DOI: 10.1186/s12915-024-01824-1] [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: 05/05/2023] [Accepted: 01/11/2024] [Indexed: 01/27/2024] Open
Abstract
The mitochondria contain their own genome derived from an alphaproteobacterial endosymbiont. From thousands of protein-coding genes originally encoded by their ancestor, only between 1 and about 70 are encoded on extant mitochondrial genomes (mitogenomes). Thanks to a dramatically increasing number of sequenced and annotated mitogenomes a coherent picture of why some genes were lost, or relocated to the nucleus, is emerging. In this review, we describe the characteristics of mitochondria-to-nucleus gene transfer and the resulting varied content of mitogenomes across eukaryotes. We introduce a 'burst-upon-drift' model to best explain nuclear-mitochondrial population genetics with flares of transfer due to genetic drift.
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Affiliation(s)
- Anzhelika Butenko
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic
- Faculty of Science, University of Ostrava, Ostrava, Czech Republic
- Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czech Republic
| | - Julius Lukeš
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic
- Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czech Republic
| | - Dave Speijer
- Medical Biochemistry, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Jeremy G Wideman
- Center for Mechanisms of Evolution, Biodesign Institute, School of Life Sciences, Arizona State University, Tempe, USA.
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4
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Speijer D. How mitochondria showcase evolutionary mechanisms and the importance of oxygen. Bioessays 2023; 45:e2300013. [PMID: 36965057 DOI: 10.1002/bies.202300013] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 03/10/2023] [Accepted: 03/14/2023] [Indexed: 03/27/2023]
Abstract
Darwinian evolution can be simply stated: natural selection of inherited variations increasing differential reproduction. However, formulated thus, links with biochemistry, cell biology, ecology, and population dynamics remain unclear. To understand interactive contributions of chance and selection, higher levels of biological organization (e.g., endosymbiosis), complexities of competing selection forces, and emerging biological novelties (such as eukaryotes or meiotic sex), we must analyze actual examples. Focusing on mitochondria, I will illuminate how biology makes sense of life's evolution, and the concepts involved. First, looking at the bacterium - mitochondrion transition: merging with an archaeon, it lost its independence, but played a decisive role in eukaryogenesis, as an extremely efficient aerobic ATP generator and internal ROS source. Second, surveying later mitochondrion adaptations and diversifications illustrates concepts such as constructive neutral evolution, dynamic interactions between endosymbionts and hosts, the contingency of life histories, and metabolic reprogramming. Without oxygen, mitochondria disappear; with (intermittent) oxygen diversification occurs in highly complex ways, especially upon (temporary) phototrophic substrate supply. These expositions show the Darwinian model to be a highly fruitful paradigm.
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Affiliation(s)
- Dave Speijer
- Department of Medical Biochemistry, Amsterdam UMC location University of Amsterdam, Amsterdam, the Netherlands
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5
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Single-Cell Genomics Reveals the Divergent Mitochondrial Genomes of Retaria (Foraminifera and Radiolaria). mBio 2023; 14:e0030223. [PMID: 36939357 PMCID: PMC10127745 DOI: 10.1128/mbio.00302-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2023] Open
Abstract
Mitochondria originated from an ancient bacterial endosymbiont that underwent reductive evolution by gene loss and endosymbiont gene transfer to the nuclear genome. The diversity of mitochondrial genomes published to date has revealed that gene loss and transfer processes are ongoing in many lineages. Most well-studied eukaryotic lineages are represented in mitochondrial genome databases, except for the superphylum Retaria-the lineage comprising Foraminifera and Radiolaria. Using single-cell approaches, we determined two complete mitochondrial genomes of Foraminifera and two nearly complete mitochondrial genomes of radiolarians. We report the complete coding content of an additional 14 foram species. We show that foraminiferan and radiolarian mitochondrial genomes contain a nearly fully overlapping but reduced mitochondrial gene complement compared to other sequenced rhizarians. In contrast to animals and fungi, many protists encode a diverse set of proteins on their mitochondrial genomes, including several ribosomal genes; however, some aerobic eukaryotic lineages (euglenids, myzozoans, and chlamydomonas-like algae) have reduced mitochondrial gene content and lack all ribosomal genes. Similar to these reduced outliers, we show that retarian mitochondrial genomes lack ribosomal protein and tRNA genes, contain truncated and divergent small and large rRNA genes, and contain only 14 or 15 protein-coding genes, including nad1, -3, -4, -4L, -5, and -7, cob, cox1, -2, and -3, and atp1, -6, and -9, with forams and radiolarians additionally carrying nad2 and nad6, respectively. In radiolarian mitogenomes, a noncanonical genetic code was identified in which all three stop codons encode amino acids. Collectively, these results add to our understanding of mitochondrial genome evolution and fill in one of the last major gaps in mitochondrial sequence databases. IMPORTANCE We present the reduced mitochondrial genomes of Retaria, the rhizarian lineage comprising the phyla Foraminifera and Radiolaria. By applying single-cell genomic approaches, we found that foraminiferan and radiolarian mitochondrial genomes contain an overlapping but reduced mitochondrial gene complement compared to other sequenced rhizarians. An alternative genetic code was identified in radiolarian mitogenomes in which all three stop codons encode amino acids. Collectively, these results shed light on the divergent nature of the mitochondrial genomes from an ecologically important group, warranting further questions into the biological underpinnings of gene content variability and genetic code variation between mitochondrial genomes.
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He L, Tronstad KJ, Maheshwari A. Mitochondrial Dynamics during Development. NEWBORN (CLARKSVILLE, MD.) 2023; 2:19-44. [PMID: 37206581 PMCID: PMC10193651 DOI: 10.5005/jp-journals-11002-0053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Mitochondria are dynamic membrane-bound organelles in eukaryotic cells. These are important for the generation of chemical energy needed to power various cellular functions and also support metabolic, energetic, and epigenetic regulation in various cells. These organelles are also important for communication with the nucleus and other cellular structures, to maintain developmental sequences and somatic homeostasis, and for cellular adaptation to stress. Increasing information shows mitochondrial defects as an important cause of inherited disorders in different organ systems. In this article, we provide an extensive review of ontogeny, ultrastructural morphology, biogenesis, functional dynamics, important clinical manifestations of mitochondrial dysfunction, and possibilities for clinical intervention. We present information from our own clinical and laboratory research in conjunction with information collected from an extensive search in the databases PubMed, EMBASE, and Scopus.
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Affiliation(s)
- Ling He
- Department of Pediatrics and Pharmacology, Johns Hopkins University, Baltimore, United States of America
| | | | - Akhil Maheshwari
- Founding Chairman, Global Newborn Society, Clarksville, Maryland, United States of America
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7
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Reduced mitochondria provide an essential function for the cytosolic methionine cycle. Curr Biol 2022; 32:5057-5068.e5. [PMID: 36347252 PMCID: PMC9746703 DOI: 10.1016/j.cub.2022.10.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 08/15/2022] [Accepted: 10/14/2022] [Indexed: 11/09/2022]
Abstract
The loss of mitochondria in oxymonad protists has been associated with the redirection of the essential Fe-S cluster assembly to the cytosol. Yet as our knowledge of diverse free-living protists broadens, the list of functions of their mitochondrial-related organelles (MROs) expands. We revealed another such function in the closest oxymonad relative, Paratrimastix pyriformis, after we solved the proteome of its MRO with high accuracy, using localization of organelle proteins by isotope tagging (LOPIT). The newly assigned enzymes connect to the glycine cleavage system (GCS) and produce folate derivatives with one-carbon units and formate. These are likely to be used by the cytosolic methionine cycle involved in S-adenosyl methionine recycling. The data provide consistency with the presence of the GCS in MROs of free-living species and its absence in most endobionts, which typically lose the methionine cycle and, in the case of oxymonads, the mitochondria.
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Chen Z, Li J, Salas-Leiva DE, Chen M, Chen S, Li S, Wu Y, Yi Z. Group-specific functional patterns of mitochondrion-related organelles shed light on their multiple transitions from mitochondria in ciliated protists. MARINE LIFE SCIENCE & TECHNOLOGY 2022; 4:609-623. [PMID: 37078085 PMCID: PMC10077286 DOI: 10.1007/s42995-022-00147-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 09/23/2022] [Indexed: 05/03/2023]
Abstract
Adaptations of ciliates to hypoxic environments have arisen independently several times. Studies on mitochondrion-related organelle (MRO) metabolisms from distinct anaerobic ciliate groups provide evidence for understanding the transitions from mitochondria to MROs within eukaryotes. To deepen our knowledge about the evolutionary patterns of ciliate anaerobiosis, mass-culture and single-cell transcriptomes of two anaerobic species, Metopus laminarius (class Armophorea) and Plagiopyla cf. narasimhamurtii (class Plagiopylea), were sequenced and their MRO metabolic maps were compared. In addition, we carried out comparisons using publicly available predicted MRO proteomes from other ciliate classes (i.e., Armophorea, Litostomatea, Muranotrichea, Oligohymenophorea, Parablepharismea and Plagiopylea). We found that single-cell transcriptomes were similarly comparable to their mass-culture counterparts in predicting MRO metabolic pathways of ciliates. The patterns of the components of the MRO metabolic pathways might be divergent among anaerobic ciliates, even among closely related species. Notably, our findings indicate the existence of group-specific functional relics of electron transport chains (ETCs). Detailed group-specific ETC functional patterns are as follows: full oxidative phosphorylation in Oligohymenophorea and Muranotrichea; only electron-transfer machinery in Armophorea; either of these functional types in Parablepharismea; and ETC functional absence in Litostomatea and Plagiopylea. These findings suggest that adaptation of ciliates to anaerobic conditions is group-specific and has occurred multiple times. Our results also show the potential and the limitations of detecting ciliate MRO proteins using single-cell transcriptomes and improve the understanding of the multiple transitions from mitochondria to MROs within ciliates. Supplementary Information The online version contains supplementary material available at 10.1007/s42995-022-00147-w.
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Affiliation(s)
- Zhicheng Chen
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, School of Life Science, South China Normal University, Guangzhou, 510631 China
| | - Jia Li
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, School of Life Science, South China Normal University, Guangzhou, 510631 China
| | | | - Miaoying Chen
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, School of Life Science, South China Normal University, Guangzhou, 510631 China
| | - Shilong Chen
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, School of Life Science, South China Normal University, Guangzhou, 510631 China
| | - Senru Li
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, School of Life Science, South China Normal University, Guangzhou, 510631 China
| | - Yanyan Wu
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, School of Life Science, South China Normal University, Guangzhou, 510631 China
| | - Zhenzhen Yi
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, School of Life Science, South China Normal University, Guangzhou, 510631 China
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9
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Su X, Cui L, Tang Y, Wen T, Yang K, Wang Y, Zhang J, Zhu G, Yang X, Hou L, Zhu YG. Denitrification and N 2O Emission in Estuarine Sediments in Response to Ocean Acidification: From Process to Mechanism. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:14828-14839. [PMID: 36194569 DOI: 10.1021/acs.est.2c03550] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Global estuarine ecosystems are experiencing severe nitrogen pollution and ocean acidification (OA) simultaneously. Sedimentary denitrification is an important way of reactive nitrogen removal but at the same time leads to the emission of large amounts of nitrous oxide (N2O), a potent greenhouse gas. It is known that OA in estuarine regions could impact denitrification and N2O production; however, the underlying mechanism is still underexplored. Here, sediment incubation and pure culture experiments were conducted to explore the OA impacts on microbial denitrification and the associated N2O emissions in estuarine sediments. Under neutral (in situ) conditions, fungal N2O emission dominated in the sediment, while the bacterial and fungal sources had a similar role under acidification. This indicated that acidification decreased the sedimentary fungal denitrification and likely inhibited the activity of fungal denitrifiers. To explore molecular mechanisms, a denitrifying fungal strain of Penicillium janthinellum was isolated from the sediments. By using deuterium-labeled single-cell Raman spectroscopy and isobaric tags for relative and absolute quantitation proteomics, we found that acidification inhibited electron transfers in P. janthinellum and downregulated expressions of the proteins related to energy production and conservation. Two collaborative pathways of energy generation in the P. janthinellum were further revealed, that is, aerobic oxidative phosphorylation and TCA cycle and anoxic pyruvate fermentation. This indicated a distinct energy supply strategy from bacterial denitrification. Our study provides insights into fungi-mediated nitrogen cycle in acidifying aquatic ecosystems.
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Affiliation(s)
- Xiaoxuan Su
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen361021, China
- Interdisciplinary Research Center for Agriculture Green Development in Yangtze River Basin, College of Resources and Environment; Key Laboratory of Low-Carbon Green Agriculture in Southwestern China, Ministry of Agriculture and Rural Affairs, Southwest University, Chongqing400715, China
| | - Li Cui
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen361021, China
| | - Yijia Tang
- School of Life and Environmental Sciences, The University of Sydney, Biomedical Building (C81), Sydney, New South Wales2015, Australia
| | - Teng Wen
- School of Geography, Nanjing Normal University, Nanjing210023, China
- Key Laboratory of Virtual Geographic Environment, Ministry of Education, Nanjing Normal University, Nanjing210023, China
| | - Kai Yang
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen361021, China
| | - Yingmu Wang
- College of Civil Engineering, Fuzhou University, Fuzhou350116, China
| | - Jinbo Zhang
- School of Geography, Nanjing Normal University, Nanjing210023, China
- Key Laboratory of Virtual Geographic Environment, Ministry of Education, Nanjing Normal University, Nanjing210023, China
| | - Guibing Zhu
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing100085, China
| | - Xiaoru Yang
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen361021, China
| | - Lijun Hou
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai200062, China
| | - Yong-Guan Zhu
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen361021, China
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing100085, China
- University of the Chinese Academy of Sciences, Beijing100049, China
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10
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Ma J, Zhong P, Li Y, Sun Z, Sun X, Aung M, Hao L, Cheng Y, Zhu W. Hydrogenosome, Pairing Anaerobic Fungi and H2-Utilizing Microorganisms Based on Metabolic Ties to Facilitate Biomass Utilization. J Fungi (Basel) 2022; 8:jof8040338. [PMID: 35448569 PMCID: PMC9026988 DOI: 10.3390/jof8040338] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 03/21/2022] [Accepted: 03/22/2022] [Indexed: 02/04/2023] Open
Abstract
Anaerobic fungi, though low in abundance in rumen, play an important role in the degradation of forage for herbivores. When only anaerobic fungi exist in the fermentation system, the continuous accumulation of metabolites (e.g., hydrogen (H2) and formate) generated from their special metabolic organelles—the hydrogenosome—inhibits the enzymatic reactions in the hydrogenosome and reduces the activity of the anaerobic fungi. However, due to interspecific H2 transfer, H2 produced by the hydrogenosome can be used by other microorganisms to form valued bioproducts. This symbiotic interaction between anaerobic fungi and other microorganisms can be used to improve the nutritional value of animal feeds and produce value-added products that are normally in low concentrations in the fermentation system. Because of the important role in the generation and further utilization of H2, the study of the hydrogensome is increasingly becoming an important part of the development of anaerobic fungi as model organisms that can effectively improve the utilization value of roughage. Here, we summarize and discuss the classification and the process of biomass degradation of anaerobic fungi and the metabolism and function of anaerobic fungal hydrogensome, with a focus on the potential role of the hydrogensome in the efficient utilization of biomass.
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Affiliation(s)
- Jing Ma
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China; (J.M.); (P.Z.); (Y.L.); (Z.S.); (X.S.); (M.A.); (W.Z.)
| | - Pei Zhong
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China; (J.M.); (P.Z.); (Y.L.); (Z.S.); (X.S.); (M.A.); (W.Z.)
| | - Yuqi Li
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China; (J.M.); (P.Z.); (Y.L.); (Z.S.); (X.S.); (M.A.); (W.Z.)
| | - Zhanying Sun
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China; (J.M.); (P.Z.); (Y.L.); (Z.S.); (X.S.); (M.A.); (W.Z.)
| | - Xiaoni Sun
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China; (J.M.); (P.Z.); (Y.L.); (Z.S.); (X.S.); (M.A.); (W.Z.)
| | - Min Aung
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China; (J.M.); (P.Z.); (Y.L.); (Z.S.); (X.S.); (M.A.); (W.Z.)
- Department of Animal Nutrition, University of Veterinary Science, Nay Pyi Taw 15013, Myanmar
| | - Lizhuang Hao
- Key Laboratory of Plateau Grazing Animal Nutrition and Feed Science of Qinghai Province, State Key Laboratory of Plateau Ecology and Agriculture, Qinghai Plateau Yak Research Center, Qinghai Academy of Science and Veterinary Medicine of Qinghai University, Xining 810016, China;
| | - Yanfen Cheng
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China; (J.M.); (P.Z.); (Y.L.); (Z.S.); (X.S.); (M.A.); (W.Z.)
- Correspondence: ; Tel.: +86-25-8439-5523
| | - Weiyun Zhu
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China; (J.M.); (P.Z.); (Y.L.); (Z.S.); (X.S.); (M.A.); (W.Z.)
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11
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Rotterová J, Edgcomb VP, Čepička I, Beinart R. Anaerobic Ciliates as a Model Group for Studying Symbioses in Oxygen-depleted Environments. J Eukaryot Microbiol 2022; 69:e12912. [PMID: 35325496 DOI: 10.1111/jeu.12912] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Anaerobiosis has independently evolved in multiple lineages of ciliates, allowing them to colonize a variety of anoxic and oxygen-depleted habitats. Anaerobic ciliates commonly form symbiotic relationships with various prokaryotes, including methanogenic archaea and members of several bacterial groups. The hypothesized functions of these ecto- and endosymbionts include the symbiont utilizing the ciliate's fermentative end-products to increase host's anaerobic metabolic efficiency, or the symbiont directly providing the host with energy by denitrification or photosynthesis. The host, in turn, may protect the symbiont from competition, the environment, and predation. Despite rapid advances in sampling, molecular, and microscopy methods, as well as the associated broadening of the known diversity of anaerobic ciliates, many aspects of these ciliate symbioses, including host-specificity and co-evolution, remain largely unexplored. Nevertheless, with the number of comparative genomic and transcriptomic analyses targeting anaerobic ciliates and their symbionts on the rise, insights into the nature of these symbioses and the evolution of the ciliate transition to obligate anaerobiosis continue to deepen. This review summarizes the current body of knowledge regarding the complex nature of symbioses in anaerobic ciliates, the diversity of these symbionts, their role in the evolution of ciliate anaerobiosis and their significance in ecosystem-level processes.
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Affiliation(s)
- Johana Rotterová
- Graduate School of Oceanography, University of Rhode Island, Narragansett, Rhode Island, USA.,Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Virginia P Edgcomb
- Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
| | - Ivan Čepička
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Roxanne Beinart
- Graduate School of Oceanography, University of Rhode Island, Narragansett, Rhode Island, USA
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12
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Záhonová K, Treitli SC, Le T, Škodová-Sveráková I, Hanousková P, Čepička I, Tachezy J, Hampl V. Anaerobic derivates of mitochondria and peroxisomes in the free-living amoeba Pelomyxa schiedti revealed by single-cell genomics. BMC Biol 2022; 20:56. [PMID: 35227266 PMCID: PMC8887013 DOI: 10.1186/s12915-022-01247-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 02/03/2022] [Indexed: 01/15/2023] Open
Abstract
Background Mitochondria and peroxisomes are the two organelles that are most affected during adaptation to microoxic or anoxic environments. Mitochondria are known to transform into anaerobic mitochondria, hydrogenosomes, mitosomes, and various transition stages in between, collectively called mitochondrion-related organelles (MROs), which vary in enzymatic capacity. Anaerobic peroxisomes were identified only recently, and their putatively most conserved function seems to be the metabolism of inositol. The group Archamoebae includes anaerobes bearing both anaerobic peroxisomes and MROs, specifically hydrogenosomes in free-living Mastigamoeba balamuthi and mitosomes in the human pathogen Entamoeba histolytica, while the organelles within the third lineage represented by Pelomyxa remain uncharacterized. Results We generated high-quality genome and transcriptome drafts from Pelomyxa schiedti using single-cell omics. These data provided clear evidence for anaerobic derivates of mitochondria and peroxisomes in this species, and corresponding vesicles were tentatively identified in electron micrographs. In silico reconstructed MRO metabolism harbors respiratory complex II, electron-transferring flavoprotein, a partial TCA cycle running presumably in the reductive direction, pyruvate:ferredoxin oxidoreductase, [FeFe]-hydrogenases, a glycine cleavage system, a sulfate activation pathway, and an expanded set of NIF enzymes for iron-sulfur cluster assembly. When expressed in the heterologous system of yeast, some of these candidates localized into mitochondria, supporting their involvement in the MRO metabolism. The putative functions of P. schiedti peroxisomes could be pyridoxal 5′-phosphate biosynthesis, amino acid and carbohydrate metabolism, and hydrolase activities. Unexpectedly, out of 67 predicted peroxisomal enzymes, only four were also reported in M. balamuthi, namely peroxisomal processing peptidase, nudix hydrolase, inositol 2-dehydrogenase, and d-lactate dehydrogenase. Localizations in yeast corroborated peroxisomal functions of the latter two. Conclusions This study revealed the presence and partially annotated the function of anaerobic derivates of mitochondria and peroxisomes in P. schiedti using single-cell genomics, localizations in yeast heterologous systems, and transmission electron microscopy. The MRO metabolism resembles that of M. balamuthi and most likely reflects the state in the common ancestor of Archamoebae. The peroxisomal metabolism is strikingly richer in P. schiedti. The presence of myo-inositol 2-dehydrogenase in the predicted peroxisomal proteome corroborates the situation in other Archamoebae, but future experimental evidence is needed to verify additional functions of this organelle. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-022-01247-w.
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Affiliation(s)
- Kristína Záhonová
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic. .,Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic.
| | | | - Tien Le
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Ingrid Škodová-Sveráková
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic.,Department of Biochemistry, Faculty of Natural Sciences, Comenius University, Bratislava, Slovakia
| | - Pavla Hanousková
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Ivan Čepička
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Jan Tachezy
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Vladimír Hampl
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic.
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13
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Stairs CW, Táborský P, Salomaki ED, Kolisko M, Pánek T, Eme L, Hradilová M, Vlček Č, Jerlström-Hultqvist J, Roger AJ, Čepička I. Anaeramoebae are a divergent lineage of eukaryotes that shed light on the transition from anaerobic mitochondria to hydrogenosomes. Curr Biol 2021; 31:5605-5612.e5. [PMID: 34710348 DOI: 10.1016/j.cub.2021.10.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 07/07/2021] [Accepted: 10/05/2021] [Indexed: 01/02/2023]
Abstract
Discoveries of diverse microbial eukaryotes and their inclusion in comprehensive phylogenomic analyses have crucially re-shaped the eukaryotic tree of life in the 21st century.1 At the deepest level, eukaryotic diversity comprises 9-10 "supergroups." One of these supergroups, the Metamonada, is particularly important to our understanding of the evolutionary dynamics of eukaryotic cells, including the remodeling of mitochondrial function. All metamonads thrive in low-oxygen environments and lack classical aerobic mitochondria, instead possessing mitochondrion-related organelles (MROs) with metabolisms that are adapted to low-oxygen conditions. These MROs lack an organellar genome, do not participate in the Krebs cycle and oxidative phosphorylation,2 and often synthesize ATP by substrate-level phosphorylation coupled to hydrogen production.3,4 The events that occurred during the transition from an oxygen-respiring mitochondrion to a functionally streamlined MRO early in metamonad evolution remain largely unknown. Here, we report transcriptomes of two recently described, enigmatic, anaerobic protists from the genus Anaeramoeba.5 Using phylogenomic analysis, we show that these species represent a divergent, phylum-level lineage in the tree of metamonads, emerging as a sister group of the Parabasalia and reordering the deep branching order of the metamonad tree. Metabolic reconstructions of the Anaeramoeba MROs reveal many "classical" mitochondrial features previously not seen in metamonads, including a disulfide relay import system, propionate production, and amino acid metabolism. Our findings suggest that the cenancestor of Metamonada likely had MROs with more classical mitochondrial features than previously anticipated and demonstrate how discoveries of novel lineages of high taxonomic rank continue to transform our understanding of early eukaryote evolution.
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Affiliation(s)
- Courtney W Stairs
- Department of Biology, Lund University, Sölvegatan 35, 223 62 Lund, Sweden.
| | - Petr Táborský
- Department of Zoology, Faculty of Science, Charles University, Viničná 7, 128 44 Prague, Czech Republic
| | - Eric D Salomaki
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, 370 05 České Budějovice, Czech Republic
| | - Martin Kolisko
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, 370 05 České Budějovice, Czech Republic
| | - Tomáš Pánek
- Department of Zoology, Faculty of Science, Charles University, Viničná 7, 128 44 Prague, Czech Republic
| | - Laura Eme
- Université Paris-Saclay, CNRS, AgroParisTech, Ecologie Systématique Evolution, 91400 Orsay, France
| | - Miluše Hradilová
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Vídeňská 1083, 142 20 Prague, Czech Republic
| | - Čestmír Vlček
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Vídeňská 1083, 142 20 Prague, Czech Republic
| | - Jon Jerlström-Hultqvist
- Department of Biochemistry and Molecular Biology, Dalhousie University, 5850 College St. Halifax, NS B3H 4R2, Canada
| | - Andrew J Roger
- Department of Biochemistry and Molecular Biology, Dalhousie University, 5850 College St. Halifax, NS B3H 4R2, Canada
| | - Ivan Čepička
- Department of Zoology, Faculty of Science, Charles University, Viničná 7, 128 44 Prague, Czech Republic.
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14
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Mathur V, Wakeman KC, Keeling PJ. Parallel functional reduction in the mitochondria of apicomplexan parasites. Curr Biol 2021; 31:2920-2928.e4. [PMID: 33974849 DOI: 10.1016/j.cub.2021.04.028] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 02/18/2021] [Accepted: 04/12/2021] [Indexed: 12/20/2022]
Abstract
Gregarines are an early-diverging lineage of apicomplexan parasites that hold many clues into the origin and evolution of the group, a remarkable transition from free-living phototrophic algae into obligate parasites of animals.1 Using single-cell transcriptomics targeting understudied lineages to complement available sequencing data, we characterized the mitochondrial metabolic repertoire across the tree of apicomplexans. In contrast to the large suite of proteins involved in aerobic respiration in well-studied parasites like Toxoplasma or Plasmodium,2 we find that gregarine trophozoites have significantly reduced energy metabolism: most lack respiratory complexes III and IV, and some lack the electron transport chains (ETCs) and tricarboxylic acid (TCA) cycle entirely. Phylogenomic analyses show that these reductions took place several times in parallel, resulting in a functional range from fully aerobic organelles to extremely reduced "mitosomes" restricted to Fe-S cluster biosynthesis. The mitochondrial genome has also been lost repeatedly: in species with severe functional reduction simply by gene loss but in one species with a complete ETC by relocating cox1 to the nuclear genome. Severe functional reduction of mitochondria is generally associated with structural reduction, resulting in small, nondescript mitochondrial-related organelles (MROs).3 By contrast, gregarines retain distinctive mitochondria with tubular cristae, even the most functionally reduced cases that also lack genes associated with cristae formation. Overall, the parallel, severe reduction of gregarine mitochondria expands the diversity of organisms that contain MROs and further emphasizes the role of parallel transitions in apicomplexan evolution.
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Affiliation(s)
- Varsha Mathur
- Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
| | - Kevin C Wakeman
- Institute for the Advancement of Higher Education, Hokkaido University, Sapporo 060-0810, Hokkaido, Japan
| | - Patrick J Keeling
- Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
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15
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Salomaki ED, Terpis KX, Rueckert S, Kotyk M, Varadínová ZK, Čepička I, Lane CE, Kolisko M. Gregarine single-cell transcriptomics reveals differential mitochondrial remodeling and adaptation in apicomplexans. BMC Biol 2021; 19:77. [PMID: 33863338 PMCID: PMC8051059 DOI: 10.1186/s12915-021-01007-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 03/19/2021] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Apicomplexa is a diverse phylum comprising unicellular endobiotic animal parasites and contains some of the most well-studied microbial eukaryotes including the devastating human pathogens Plasmodium falciparum and Cryptosporidium hominis. In contrast, data on the invertebrate-infecting gregarines remains sparse and their evolutionary relationship to other apicomplexans remains obscure. Most apicomplexans retain a highly modified plastid, while their mitochondria remain metabolically conserved. Cryptosporidium spp. inhabit an anaerobic host-gut environment and represent the known exception, having completely lost their plastid while retaining an extremely reduced mitochondrion that has lost its genome. Recent advances in single-cell sequencing have enabled the first broad genome-scale explorations of gregarines, providing evidence of differential plastid retention throughout the group. However, little is known about the retention and metabolic capacity of gregarine mitochondria. RESULTS Here, we sequenced transcriptomes from five species of gregarines isolated from cockroaches. We combined these data with those from other apicomplexans, performed detailed phylogenomic analyses, and characterized their mitochondrial metabolism. Our results support the placement of Cryptosporidium as the earliest diverging lineage of apicomplexans, which impacts our interpretation of evolutionary events within the phylum. By mapping in silico predictions of core mitochondrial pathways onto our phylogeny, we identified convergently reduced mitochondria. These data show that the electron transport chain has been independently lost three times across the phylum, twice within gregarines. CONCLUSIONS Apicomplexan lineages show variable functional restructuring of mitochondrial metabolism that appears to have been driven by adaptations to parasitism and anaerobiosis. Our findings indicate that apicomplexans are rife with convergent adaptations, with shared features including morphology, energy metabolism, and intracellularity.
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Affiliation(s)
- Eric D Salomaki
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Kristina X Terpis
- Department of Biological Sciences, University of Rhode Island, Kingston, RI, USA
| | - Sonja Rueckert
- School of Applied Sciences, Edinburgh Napier University, Edinburgh, Scotland, UK
| | - Michael Kotyk
- Department of Zoology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | | | - Ivan Čepička
- Department of Zoology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Christopher E Lane
- Department of Biological Sciences, University of Rhode Island, Kingston, RI, USA.
| | - Martin Kolisko
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic.
- Department of Molecular Biology and Genetics, University of South Bohemia, České Budějovice, Czech Republic.
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16
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Graf JS, Schorn S, Kitzinger K, Ahmerkamp S, Woehle C, Huettel B, Schubert CJ, Kuypers MMM, Milucka J. Anaerobic endosymbiont generates energy for ciliate host by denitrification. Nature 2021; 591:445-450. [PMID: 33658719 PMCID: PMC7969357 DOI: 10.1038/s41586-021-03297-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 01/27/2021] [Indexed: 11/27/2022]
Abstract
Mitochondria are specialized eukaryotic organelles that have a dedicated function in oxygen respiration and energy production. They evolved about 2 billion years ago from a free-living bacterial ancestor (probably an alphaproteobacterium), in a process known as endosymbiosis1,2. Many unicellular eukaryotes have since adapted to life in anoxic habitats and their mitochondria have undergone further reductive evolution3. As a result, obligate anaerobic eukaryotes with mitochondrial remnants derive their energy mostly from fermentation4. Here we describe 'Candidatus Azoamicus ciliaticola', which is an obligate endosymbiont of an anaerobic ciliate and has a dedicated role in respiration and providing energy for its eukaryotic host. 'Candidatus A. ciliaticola' contains a highly reduced 0.29-Mb genome that encodes core genes for central information processing, the electron transport chain, a truncated tricarboxylic acid cycle, ATP generation and iron-sulfur cluster biosynthesis. The genome encodes a respiratory denitrification pathway instead of aerobic terminal oxidases, which enables its host to breathe nitrate instead of oxygen. 'Candidatus A. ciliaticola' and its ciliate host represent an example of a symbiosis that is based on the transfer of energy in the form of ATP, rather than nutrition. This discovery raises the possibility that eukaryotes with mitochondrial remnants may secondarily acquire energy-providing endosymbionts to complement or replace functions of their mitochondria.
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Affiliation(s)
- Jon S Graf
- Max Planck Institute for Marine Microbiology, Bremen, Germany.
| | - Sina Schorn
- Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Katharina Kitzinger
- Max Planck Institute for Marine Microbiology, Bremen, Germany
- Division of Microbial Ecology, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | | | - Christian Woehle
- Max Planck Genome Centre Cologne, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Bruno Huettel
- Max Planck Genome Centre Cologne, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Carsten J Schubert
- Surface Waters - Research and Management, Eawag, Kastanienbaum, Switzerland
| | | | - Jana Milucka
- Max Planck Institute for Marine Microbiology, Bremen, Germany.
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17
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Gawryluk RMR, Stairs CW. Diversity of electron transport chains in anaerobic protists. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1862:148334. [PMID: 33159845 DOI: 10.1016/j.bbabio.2020.148334] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/21/2020] [Accepted: 10/30/2020] [Indexed: 01/06/2023]
Abstract
Eukaryotic microbes (protists) that occupy low-oxygen environments often have drastically different mitochondrial metabolism compared to their aerobic relatives. A common theme among many anaerobic protists is the serial loss of components of the electron transport chain (ETC). Here, we discuss the diversity of the ETC across the tree of eukaryotes and review hypotheses for how ETCs are modified, and ultimately lost, in protists. We find that while protists have converged to some of the same metabolism as anaerobic animals, there are clear protist-specific strategies to thrive without oxygen.
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Affiliation(s)
- Ryan M R Gawryluk
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
| | - Courtney W Stairs
- Department of Biology, Lund University, Sölvegatan 35, 223 62 Lund, Sweden; Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, SE-75123 Uppsala, Sweden.
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18
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Hirakata Y, Hatamoto M, Oshiki M, Watari T, Araki N, Yamaguchi T. Food selectivity of anaerobic protists and direct evidence for methane production using carbon from prey bacteria by endosymbiotic methanogen. ISME JOURNAL 2020; 14:1873-1885. [PMID: 32341474 DOI: 10.1038/s41396-020-0660-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 04/05/2020] [Accepted: 04/07/2020] [Indexed: 01/28/2023]
Abstract
Anaerobic protists are major predators of prokaryotes in anaerobic ecosystems. However, little is known about the predation behavior of anaerobic protists because almost none have been cultured. In particular, these characteristics of anaerobic protists in the phyla Metamonada and Cercozoa have not been reported previously. In this study, we isolated three anaerobic protists, Cyclidium sp., Trichomitus sp., and Paracercomonas sp., from anaerobic granular sludge in an up-flow anaerobic sludge blanket reactor used to treat domestic sewage. Ingestion and digestion of food bacteria by anaerobic protists with or without endosymbiotic methanogens were demonstrated using tracer experiments with green fluorescent protein and a stable carbon isotope. These tracer experiments also demonstrated that Cyclidium sp. supplied CO2 and hydrogen to endosymbiotic methanogens. While Cyclidium sp. and Trichomitus sp. ingested both Gram-negative and -positive bacteria, Paracercomonas sp. could only take up Gram-negative bacteria. Archaeal cells such as Methanobacterium beijingense and Methanospirillum hungatei did not support the growth of these protists. Metabolite patterns of all three protists differed and were influenced by food bacterial species. These reported growth rates, ingestion rates, food selectivity, and metabolite patterns provide important insights into the ecological roles of these protists in anaerobic ecosystems.
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Affiliation(s)
- Yuga Hirakata
- Department of Science of Technology Innovation, Nagaoka University of Technology, Nagaoka, Niigata, Japan
| | - Masashi Hatamoto
- Department of Civil and Environmental Systems Engineering, Nagaoka University of Technology, Nagaoka, Niigata, Japan.
| | - Mamoru Oshiki
- Department of Civil Engineering, Nagaoka College, National Institute of Technology, Nagaoka, Niigata, Japan
| | - Takahiro Watari
- Department of Civil and Environmental Systems Engineering, Nagaoka University of Technology, Nagaoka, Niigata, Japan
| | - Nobuo Araki
- Department of Civil Engineering, Nagaoka College, National Institute of Technology, Nagaoka, Niigata, Japan
| | - Takashi Yamaguchi
- Department of Science of Technology Innovation, Nagaoka University of Technology, Nagaoka, Niigata, Japan.,Department of Civil and Environmental Systems Engineering, Nagaoka University of Technology, Nagaoka, Niigata, Japan
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19
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Rotterová J, Salomaki E, Pánek T, Bourland W, Žihala D, Táborský P, Edgcomb VP, Beinart RA, Kolísko M, Čepička I. Genomics of New Ciliate Lineages Provides Insight into the Evolution of Obligate Anaerobiosis. Curr Biol 2020; 30:2037-2050.e6. [PMID: 32330419 DOI: 10.1016/j.cub.2020.03.064] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Revised: 03/10/2020] [Accepted: 03/24/2020] [Indexed: 02/07/2023]
Abstract
Oxygen plays a crucial role in energetic metabolism of most eukaryotes. Yet adaptations to low-oxygen concentrations leading to anaerobiosis have independently arisen in many eukaryotic lineages, resulting in a broad spectrum of reduced and modified mitochondrion-related organelles (MROs). In this study, we present the discovery of two new class-level lineages of free-living marine anaerobic ciliates, Muranotrichea, cl. nov. and Parablepharismea, cl. nov., that, together with the class Armophorea, form a major clade of obligate anaerobes (APM ciliates) within the Spirotrichea, Armophorea, and Litostomatea (SAL) group. To deepen our understanding of the evolution of anaerobiosis in ciliates, we predicted the mitochondrial metabolism of cultured representatives from all three classes in the APM clade by using transcriptomic and metagenomic data and performed phylogenomic analyses to assess their evolutionary relationships. The predicted mitochondrial metabolism of representatives from the APM ciliates reveals functional adaptations of metabolic pathways that were present in their last common ancestor and likely led to the successful colonization and diversification of the group in various anoxic environments. Furthermore, we discuss the possible relationship of Parablepharismea to the uncultured deep-sea class Cariacotrichea on the basis of single-gene analyses. Like most anaerobic ciliates, all studied species of the APM clade host symbionts, which we propose to be a significant accelerating factor in the transitions to an obligately anaerobic lifestyle. Our results provide an insight into the evolutionary mechanisms of early transitions to anaerobiosis and shed light on fine-scale adaptations in MROs over a relatively short evolutionary time frame.
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Affiliation(s)
- Johana Rotterová
- Department of Zoology, Faculty of Science, Charles University, Prague 128 43, Czech Republic.
| | - Eric Salomaki
- Institute of Parasitology, Biology Centre Czech Academy of Sciences, České Budějovice 370 05, Czech Republic
| | - Tomáš Pánek
- Department of Zoology, Faculty of Science, Charles University, Prague 128 43, Czech Republic
| | - William Bourland
- Department of Biological Sciences, Boise State University, Boise, ID 83725-1515, USA
| | - David Žihala
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava 710 00, Czech Republic
| | - Petr Táborský
- Institute of Parasitology, Biology Centre Czech Academy of Sciences, České Budějovice 370 05, Czech Republic
| | - Virginia P Edgcomb
- Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | - Roxanne A Beinart
- Graduate School of Oceanography, University of Rhode Island, Narragansett, RI 02882, USA
| | - Martin Kolísko
- Institute of Parasitology, Biology Centre Czech Academy of Sciences, České Budějovice 370 05, Czech Republic; Department of Molecular Biology and Genetics, Faculty of Science, University of South Bohemia, 370 05 České Budějovice, Czech Republic
| | - Ivan Čepička
- Department of Zoology, Faculty of Science, Charles University, Prague 128 43, Czech Republic
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20
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Gray MW, Burger G, Derelle R, Klimeš V, Leger MM, Sarrasin M, Vlček Č, Roger AJ, Eliáš M, Lang BF. The draft nuclear genome sequence and predicted mitochondrial proteome of Andalucia godoyi, a protist with the most gene-rich and bacteria-like mitochondrial genome. BMC Biol 2020; 18:22. [PMID: 32122349 PMCID: PMC7050145 DOI: 10.1186/s12915-020-0741-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 01/21/2020] [Indexed: 01/02/2023] Open
Abstract
Background Comparative analyses have indicated that the mitochondrion of the last eukaryotic common ancestor likely possessed all the key core structures and functions that are widely conserved throughout the domain Eucarya. To date, such studies have largely focused on animals, fungi, and land plants (primarily multicellular eukaryotes); relatively few mitochondrial proteomes from protists (primarily unicellular eukaryotic microbes) have been examined. To gauge the full extent of mitochondrial structural and functional complexity and to identify potential evolutionary trends in mitochondrial proteomes, more comprehensive explorations of phylogenetically diverse mitochondrial proteomes are required. In this regard, a key group is the jakobids, a clade of protists belonging to the eukaryotic supergroup Discoba, distinguished by having the most gene-rich and most bacteria-like mitochondrial genomes discovered to date. Results In this study, we assembled the draft nuclear genome sequence for the jakobid Andalucia godoyi and used a comprehensive in silico approach to infer the nucleus-encoded portion of the mitochondrial proteome of this protist, identifying 864 candidate mitochondrial proteins. The A. godoyi mitochondrial proteome has a complexity that parallels that of other eukaryotes, while exhibiting an unusually large number of ancestral features that have been lost particularly in opisthokont (animal and fungal) mitochondria. Notably, we find no evidence that the A. godoyi nuclear genome has or had a gene encoding a single-subunit, T3/T7 bacteriophage-like RNA polymerase, which functions as the mitochondrial transcriptase in all eukaryotes except the jakobids. Conclusions As genome and mitochondrial proteome data have become more widely available, a strikingly punctuate phylogenetic distribution of different mitochondrial components has been revealed, emphasizing that the pathways of mitochondrial proteome evolution are likely complex and lineage-specific. Unraveling this complexity will require comprehensive comparative analyses of mitochondrial proteomes from a phylogenetically broad range of eukaryotes, especially protists. The systematic in silico approach described here offers a valuable adjunct to direct proteomic analysis (e.g., via mass spectrometry), particularly in cases where the latter approach is constrained by sample limitation or other practical considerations.
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Affiliation(s)
- Michael W Gray
- Department of Biochemistry and Molecular Biology and Centre for Comparative Genomics and Evolutionary Bioinformatics, Sir Charles Tupper Medical Building, Dalhousie University, 5850 College Street, Halifax, Nova Scotia, B3H 4R2, Canada.
| | - Gertraud Burger
- Département de Biochimie and Robert-Cedergren Center for Bioinformatics and Genomics, Université de Montréal, Montréal, QC, Canada
| | - Romain Derelle
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Vladimír Klimeš
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Michelle M Leger
- Department of Biochemistry and Molecular Biology and Centre for Comparative Genomics and Evolutionary Bioinformatics, Sir Charles Tupper Medical Building, Dalhousie University, 5850 College Street, Halifax, Nova Scotia, B3H 4R2, Canada.,Institute of Evolutionary Biology (CSIC-UPF), Barcelona, Spain
| | - Matt Sarrasin
- Département de Biochimie and Robert-Cedergren Center for Bioinformatics and Genomics, Université de Montréal, Montréal, QC, Canada
| | - Čestmír Vlček
- Current address: Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Andrew J Roger
- Department of Biochemistry and Molecular Biology and Centre for Comparative Genomics and Evolutionary Bioinformatics, Sir Charles Tupper Medical Building, Dalhousie University, 5850 College Street, Halifax, Nova Scotia, B3H 4R2, Canada
| | - Marek Eliáš
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - B Franz Lang
- Département de Biochimie and Robert-Cedergren Center for Bioinformatics and Genomics, Université de Montréal, Montréal, QC, Canada
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21
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Feng JM, Jiang CQ, Sun ZY, Hua CJ, Wen JF, Miao W, Xiong J. Single-cell transcriptome sequencing of rumen ciliates provides insight into their molecular adaptations to the anaerobic and carbohydrate-rich rumen microenvironment. Mol Phylogenet Evol 2019; 143:106687. [PMID: 31740334 DOI: 10.1016/j.ympev.2019.106687] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 11/11/2019] [Accepted: 11/13/2019] [Indexed: 01/26/2023]
Abstract
Rumen ciliates are a specialized group of ciliates exclusively found in the anaerobic, carbohydrate-rich rumen microenvironment. However, the molecular and mechanistic basis of the physiological and behavioral adaptation of ciliates to the rumen microenvironment is undefined. We used single-cell transcriptome sequencing to explore the adaptive evolution of three rumen ciliates: two entodiniomorphids, Entodinium furca and Diplodinium dentatum; and one vestibuliferid, Isotricha intestinalis. We found that all three species are members of monophyletic orders within the class Litostomatea, with E. furca and D. dentatum in Entodiniomorphida and I. intestinalis in Vestibuliferida. The two entodiniomorphids might use H2-producing mitochondria and the vestibuliferid might use anaerobic mitochondria to survive under strictly anaerobic conditions. Moreover, carbohydrate-active enzyme (CAZyme) genes were identified in all three species, including cellulases, hemicellulases, and pectinases. The evidence that all three species have acquired prokaryote-derived genes by horizontal gene transfer (HGT) to digest plant biomass includes a significant enrichment of gene ontology categories such as cell wall macromolecule catabolic process and carbohydrate catabolic process and the identification of genes in common between CAZyme and HGT groups. These findings suggest that HGT might be an important mechanism in the adaptive evolution of ciliates to the rumen microenvironment.
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Affiliation(s)
- Jin-Mei Feng
- Department of Pathogenic Biology, School of Medicine, Jianghan University, Wuhan 430056, China
| | - Chuan-Qi Jiang
- Shenzhen Institute of Guangdong Ocean University, Shenzhen 518120, China; Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, Shenzhen 518120, China; Shenzhen Dapeng New District Science and Technology Innovation Service Center, Shenzhen 518119, China; Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Zong-Yi Sun
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Cong-Jie Hua
- Department of Pathogenic Biology, School of Medicine, Jianghan University, Wuhan 430056, China
| | - Jian-Fan Wen
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223, China
| | - Wei Miao
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; State Key Laboratory of Freshwater Ecology and Biotechnology of China, Wuhan 430072, China; CAS Center for Excellence in Animal Evolution and Genetics, Kunming 650223, China.
| | - Jie Xiong
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
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22
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Should I stay or should I go? Retention and loss of components in vestigial endosymbiotic organelles. Curr Opin Genet Dev 2019; 58-59:33-39. [PMID: 31466038 DOI: 10.1016/j.gde.2019.07.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 06/21/2019] [Accepted: 07/19/2019] [Indexed: 01/28/2023]
Abstract
Our knowledge on the variability of the reduced forms of endosymbiotic organelles - mitochondria and plastids - is expanding rapidly, thanks to growing interest in peculiar microbial eukaryotes, along with the availability of the methods used in modern genomics and transcriptomics. The aim of this work is to highlight the most recent advances in understanding these organelles' diversity, physiology and evolution. We also outline the known mechanisms behind the convergence of traits between organelles which have undergone reduction independently, the importance of the earliest evolutionary events in determining the vestigial organelles' eventual fate, and a proposed classification of nonphotosynthetic plastids.
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23
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Zimorski V, Mentel M, Tielens AGM, Martin WF. Energy metabolism in anaerobic eukaryotes and Earth's late oxygenation. Free Radic Biol Med 2019; 140:279-294. [PMID: 30935869 PMCID: PMC6856725 DOI: 10.1016/j.freeradbiomed.2019.03.030] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 03/21/2019] [Accepted: 03/26/2019] [Indexed: 01/09/2023]
Abstract
Eukaryotes arose about 1.6 billion years ago, at a time when oxygen levels were still very low on Earth, both in the atmosphere and in the ocean. According to newer geochemical data, oxygen rose to approximately its present atmospheric levels very late in evolution, perhaps as late as the origin of land plants (only about 450 million years ago). It is therefore natural that many lineages of eukaryotes harbor, and use, enzymes for oxygen-independent energy metabolism. This paper provides a concise overview of anaerobic energy metabolism in eukaryotes with a focus on anaerobic energy metabolism in mitochondria. We also address the widespread assumption that oxygen improves the overall energetic state of a cell. While it is true that ATP yield from glucose or amino acids is increased in the presence of oxygen, it is also true that the synthesis of biomass costs thirteen times more energy per cell in the presence of oxygen than in anoxic conditions. This is because in the reaction of cellular biomass with O2, the equilibrium lies very far on the side of CO2. The absence of oxygen offers energetic benefits of the same magnitude as the presence of oxygen. Anaerobic and low oxygen environments are ancient. During evolution, some eukaryotes have specialized to life in permanently oxic environments (life on land), other eukaryotes have remained specialized to low oxygen habitats. We suggest that the Km of mitochondrial cytochrome c oxidase of 0.1-10 μM for O2, which corresponds to about 0.04%-4% (avg. 0.4%) of present atmospheric O2 levels, reflects environmental O2 concentrations that existed at the time that the eukaryotes arose.
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Affiliation(s)
- Verena Zimorski
- Institute of Molecular Evolution, Heinrich-Heine-University, 40225, Düsseldorf, Germany.
| | - Marek Mentel
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, 851 04, Bratislava, Slovakia.
| | - Aloysius G M Tielens
- Department of Medical Microbiology and Infectious Diseases, Erasmus Medical Center Rotterdam, The Netherlands; Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
| | - William F Martin
- Institute of Molecular Evolution, Heinrich-Heine-University, 40225, Düsseldorf, Germany.
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24
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Zhang D, Zou H, Hua CJ, Li WX, Mahboob S, Al-Ghanim KA, Al-Misned F, Jakovlić I, Wang GT. Mitochondrial Architecture Rearrangements Produce Asymmetrical Nonadaptive Mutational Pressures That Subvert the Phylogenetic Reconstruction in Isopoda. Genome Biol Evol 2019; 11:1797-1812. [PMID: 31192351 PMCID: PMC6601869 DOI: 10.1093/gbe/evz121] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/08/2019] [Indexed: 01/04/2023] Open
Abstract
The phylogeny of Isopoda, a speciose order of crustaceans, remains unresolved, with different data sets (morphological, nuclear, mitochondrial) often producing starkly incongruent phylogenetic hypotheses. We hypothesized that extreme diversity in their life histories might be causing compositional heterogeneity/heterotachy in their mitochondrial genomes, and compromising the phylogenetic reconstruction. We tested the effects of different data sets (mitochondrial, nuclear, nucleotides, amino acids, concatenated genes, individual genes, gene orders), phylogenetic algorithms (assuming data homogeneity, heterogeneity, and heterotachy), and partitioning; and found that almost all of them produced unique topologies. As we also found that mitogenomes of Asellota and two Cymothoida families (Cymothoidae and Corallanidae) possess inversed base (GC) skew patterns in comparison to other isopods, we concluded that inverted skews cause long-branch attraction phylogenetic artifacts between these taxa. These asymmetrical skews are most likely driven by multiple independent inversions of origin of replication (i.e., nonadaptive mutational pressures). Although the PhyloBayes CAT-GTR algorithm managed to attenuate some of these artifacts (and outperform partitioning), mitochondrial data have limited applicability for reconstructing the phylogeny of Isopoda. Regardless of this, our analyses allowed us to propose solutions to some unresolved phylogenetic debates, and support Asellota are the most likely candidate for the basal isopod branch. As our findings show that architectural rearrangements might produce major compositional biases even on relatively short evolutionary timescales, the implications are that proving the suitability of data via composition skew analyses should be a prerequisite for every study that aims to use mitochondrial data for phylogenetic reconstruction, even among closely related taxa.
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Affiliation(s)
- Dong Zhang
- Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, P.R. China
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, P.R. China
- University of Chinese Academy of Sciences, Beijing, P.R. China
| | - Hong Zou
- Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, P.R. China
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, P.R. China
| | - Cong-Jie Hua
- Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, P.R. China
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, P.R. China
| | - Wen-Xiang Li
- Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, P.R. China
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, P.R. China
| | - Shahid Mahboob
- Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia
- Department of Zoology, GC University, Faisalabad, Pakistan
| | | | - Fahad Al-Misned
- Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia
| | | | - Gui-Tang Wang
- Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, P.R. China
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, P.R. China
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25
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Sinha S, Manoj N. Molecular evolution of proteins mediating mitochondrial fission-fusion dynamics. FEBS Lett 2019; 593:703-718. [PMID: 30861107 DOI: 10.1002/1873-3468.13356] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 03/02/2019] [Accepted: 03/07/2019] [Indexed: 01/24/2023]
Abstract
Eukaryotes employ a subset of dynamins to mediate mitochondrial fusion and fission dynamics. Here we report the molecular evolution and diversification of the dynamin-related mitochondrial proteins that drive the fission (Drp1) and the fusion processes (mitofusin and OPA1). We demonstrate that the three paralogs emerged concurrently in an early mitochondriate eukaryotic ancestor. Furthermore, multiple independent duplication events from an ancestral bifunctional fission protein gave rise to specialized fission proteins. The evolutionary history of these proteins is marked by transformations that include independent gain and loss events occurring at the levels of entire genes, specific functional domains, and intronic regions. The domain level variations primarily comprise loss-gain of lineage specific domains that are present in the terminal regions of the sequences.
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Affiliation(s)
- Sansrity Sinha
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, India
| | - Narayanan Manoj
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, India
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26
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Roger AJ, Muñoz-Gómez SA, Kamikawa R. The Origin and Diversification of Mitochondria. Curr Biol 2018; 27:R1177-R1192. [PMID: 29112874 DOI: 10.1016/j.cub.2017.09.015] [Citation(s) in RCA: 559] [Impact Index Per Article: 93.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Mitochondria are best known for their role in the generation of ATP by aerobic respiration. Yet, research in the past half century has shown that they perform a much larger suite of functions and that these functions can vary substantially among diverse eukaryotic lineages. Despite this diversity, all mitochondria derive from a common ancestral organelle that originated from the integration of an endosymbiotic alphaproteobacterium into a host cell related to Asgard Archaea. The transition from endosymbiotic bacterium to permanent organelle entailed a massive number of evolutionary changes including the origins of hundreds of new genes and a protein import system, insertion of membrane transporters, integration of metabolism and reproduction, genome reduction, endosymbiotic gene transfer, lateral gene transfer and the retargeting of proteins. These changes occurred incrementally as the endosymbiont and the host became integrated. Although many insights into this transition have been gained, controversy persists regarding the nature of the original endosymbiont, its initial interactions with the host and the timing of its integration relative to the origin of other features of eukaryote cells. Since the establishment of the organelle, proteins have been gained, lost, transferred and retargeted as mitochondria have specialized into the spectrum of functional types seen across the eukaryotic tree of life.
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Affiliation(s)
- Andrew J Roger
- Centre for Comparative Genomics and Evolutionary Bioinformatics, Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada.
| | - Sergio A Muñoz-Gómez
- Centre for Comparative Genomics and Evolutionary Bioinformatics, Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Ryoma Kamikawa
- Graduate School of Human and Environmental Studies, Graduate School of Global Environmental Studies, Kyoto University, Japan
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27
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Stairs CW, Eme L, Muñoz-Gómez SA, Cohen A, Dellaire G, Shepherd JN, Fawcett JP, Roger AJ. Microbial eukaryotes have adapted to hypoxia by horizontal acquisitions of a gene involved in rhodoquinone biosynthesis. eLife 2018; 7:34292. [PMID: 29697049 PMCID: PMC5953543 DOI: 10.7554/elife.34292] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 04/25/2018] [Indexed: 01/01/2023] Open
Abstract
Under hypoxic conditions, some organisms use an electron transport chain consisting of only complex I and II (CII) to generate the proton gradient essential for ATP production. In these cases, CII functions as a fumarate reductase that accepts electrons from a low electron potential quinol, rhodoquinol (RQ). To clarify the origins of RQ-mediated fumarate reduction in eukaryotes, we investigated the origin and function of rquA, a gene encoding an RQ biosynthetic enzyme. RquA is very patchily distributed across eukaryotes and bacteria adapted to hypoxia. Phylogenetic analyses suggest lateral gene transfer (LGT) of rquA from bacteria to eukaryotes occurred at least twice and the gene was transferred multiple times amongst protists. We demonstrate that RquA functions in the mitochondrion-related organelles of the anaerobic protist Pygsuia and is correlated with the presence of RQ. These analyses reveal the role of gene transfer in the evolutionary remodeling of mitochondria in adaptation to hypoxia.
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Affiliation(s)
- Courtney W Stairs
- Centre for Comparative Genomics and Evolutionary Bioinformatics (CGEB), Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Canada
| | - Laura Eme
- Centre for Comparative Genomics and Evolutionary Bioinformatics (CGEB), Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Canada
| | - Sergio A Muñoz-Gómez
- Centre for Comparative Genomics and Evolutionary Bioinformatics (CGEB), Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Canada
| | - Alejandro Cohen
- Proteomics Core Facility, Life Sciences Research Institute, Dalhousie University, Halifax, Canada
| | - Graham Dellaire
- Department of Pathology, Dalhousie University, Halifax, Canada.,Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Canada
| | - Jennifer N Shepherd
- Department of Chemistry and Biochemistry, Gonzaga University, Spokane, United States
| | - James P Fawcett
- Proteomics Core Facility, Life Sciences Research Institute, Dalhousie University, Halifax, Canada.,Department of Pharmacology, Dalhousie University, Halifax, Canada.,Department of Surgery, Dalhousie University, Halifax, Canada
| | - Andrew J Roger
- Centre for Comparative Genomics and Evolutionary Bioinformatics (CGEB), Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Canada
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28
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Ngo CN, Braithwaite KS, Bass D, Young AJ, Croft BJ. Phytocercomonas venanatans, a New Species of Cercozoa Associated with Chlorotic Streak of Sugarcane. PHYTOPATHOLOGY 2018; 108:479-486. [PMID: 29256830 DOI: 10.1094/phyto-07-17-0237-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Chlorotic streak is a global disease of commercial sugarcane (Saccharum spp. hybrids). The disease is transmitted by wet soil, water, as well as in diseased planting material. Although first recognized almost 90 years ago and despite significant research effort, the identity of the causal agent has been elusive. Metagenomic high throughput sequencing (HTS) facilitated the discovery of novel protistan ribosomal and nuclear genes in chlorotic streak-infected sugarcane. These sequences suggest a possible causal agent belonging to the order Cercomonadida (Rhizaria, phylum Cercozoa). An organism with morphological features similar to cercomonads (=Cercomonadida) was isolated into pure axenic culture from internal stalk tissues of infected sugarcane. The isolated organism contained DNA sequences identical to those identified in infected plants by HTS. The DNA sequences and the morphology of the organism did not match any known species. Here we present a new genus and species, Phytocercomonas venanatans, which is associated with chlorotic streak of sugarcane. Amplicon sequencing also supports that P. venanatans is associated with this disease. This is the first reported member from Cercomonadida showing a probable pathogenic association with higher plants.
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Affiliation(s)
- Chuong N Ngo
- First and second authors: Sugar Research Australia, Indooroopilly, QLD, 4068, Australia; third author: Division of Genomics and Microbial Diversity, Department of Life Sciences, Natural History Museum, London, SW7 5BD, United Kingdom and Centre for Environment, Fisheries and Aquaculture Science (Cefas), Barrack Road, The Nothe, Weymouth, Dorset DT4 8UB, United Kingdom; fourth author: Centre for Crop Health, University of Southern Queensland, Toowoomba, QLD, 4350, Australia; and fifth author: Sugar Research Australia, Woodford, QLD 4514, Australia
| | - Kathryn S Braithwaite
- First and second authors: Sugar Research Australia, Indooroopilly, QLD, 4068, Australia; third author: Division of Genomics and Microbial Diversity, Department of Life Sciences, Natural History Museum, London, SW7 5BD, United Kingdom and Centre for Environment, Fisheries and Aquaculture Science (Cefas), Barrack Road, The Nothe, Weymouth, Dorset DT4 8UB, United Kingdom; fourth author: Centre for Crop Health, University of Southern Queensland, Toowoomba, QLD, 4350, Australia; and fifth author: Sugar Research Australia, Woodford, QLD 4514, Australia
| | - David Bass
- First and second authors: Sugar Research Australia, Indooroopilly, QLD, 4068, Australia; third author: Division of Genomics and Microbial Diversity, Department of Life Sciences, Natural History Museum, London, SW7 5BD, United Kingdom and Centre for Environment, Fisheries and Aquaculture Science (Cefas), Barrack Road, The Nothe, Weymouth, Dorset DT4 8UB, United Kingdom; fourth author: Centre for Crop Health, University of Southern Queensland, Toowoomba, QLD, 4350, Australia; and fifth author: Sugar Research Australia, Woodford, QLD 4514, Australia
| | - Anthony J Young
- First and second authors: Sugar Research Australia, Indooroopilly, QLD, 4068, Australia; third author: Division of Genomics and Microbial Diversity, Department of Life Sciences, Natural History Museum, London, SW7 5BD, United Kingdom and Centre for Environment, Fisheries and Aquaculture Science (Cefas), Barrack Road, The Nothe, Weymouth, Dorset DT4 8UB, United Kingdom; fourth author: Centre for Crop Health, University of Southern Queensland, Toowoomba, QLD, 4350, Australia; and fifth author: Sugar Research Australia, Woodford, QLD 4514, Australia
| | - Barry J Croft
- First and second authors: Sugar Research Australia, Indooroopilly, QLD, 4068, Australia; third author: Division of Genomics and Microbial Diversity, Department of Life Sciences, Natural History Museum, London, SW7 5BD, United Kingdom and Centre for Environment, Fisheries and Aquaculture Science (Cefas), Barrack Road, The Nothe, Weymouth, Dorset DT4 8UB, United Kingdom; fourth author: Centre for Crop Health, University of Southern Queensland, Toowoomba, QLD, 4350, Australia; and fifth author: Sugar Research Australia, Woodford, QLD 4514, Australia
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29
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Kosman DJ. The teleos of metallo-reduction and metallo-oxidation in eukaryotic iron and copper trafficking. Metallomics 2018; 10:370-377. [PMID: 29484341 DOI: 10.1039/c8mt00015h] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Eukaryotic cells, whether free-living or organismal, rely on metallo-reductases to process environmental ferric iron and cupric copper prior to uptake. In addition, some free-living eukaryotes (e.g. fungi and algae) couple ferri-reduction to ferro-oxidation, a process catalyzed by a small cohort of multi-copper oxidases; in these organisms, the ferric iron product is a ligand for cell iron uptake via a ferric iron permease. In addition to their support of iron uptake in lower eukaryotes, ferroxidases support ferrous iron efflux in Chordata; in this process the release of the ferrous iron from the efflux transporter is catalyzed by its ferroxidation. Last, ferroxidases also catalyze the oxidation of cuprous copper and, as metallo-oxidases, mirror the dual activity of the metallo-reductases. This Perspective examines the teleos of the yin-yang of this redox cycling of iron and copper in their metabolism.
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Affiliation(s)
- Daniel J Kosman
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, The University at Buffalo, Farber Hall Room 140, 3435 Main St., Buffalo, NY 14214-3000, USA.
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30
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The challenges of integrating two genomes in one cell. Curr Opin Microbiol 2017; 41:89-94. [PMID: 29277086 DOI: 10.1016/j.mib.2017.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 11/26/2017] [Accepted: 12/10/2017] [Indexed: 11/22/2022]
Abstract
Mutualistic bacteria and mitochondria have small genomes that harbor host-essential genes. A major question is why a distinct bacterial or mitochondrial genome is needed to encode these functions. The dual location of genes demand two sets of information processing systems, coordination of gene expression and elaborate transport systems. A simpler solution would be to harbor all genes in a single genome. Functional gene transfers to the host nuclear genome is uncommon in mutualistic bacteria and lost gene functions are rather rescued by co-symbiotic bacteria. Recent findings suggest that the mitochondrial genome is retained to avoid conflicting signals between protein targeting pathways in the cell. However, if the selective pressure for oxygenic respiration is lost, the mitochondrial genome will start to deteriorate and soon be lost.
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31
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Comparative biochemistry of cytochrome c oxidase in animals. Comp Biochem Physiol B Biochem Mol Biol 2017; 224:170-184. [PMID: 29180239 DOI: 10.1016/j.cbpb.2017.11.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 11/06/2017] [Accepted: 11/07/2017] [Indexed: 12/19/2022]
Abstract
Cytochrome c oxidase (COX), the terminal enzyme of the electron transport system, is central to aerobic metabolism of animals. Many aspects of its structure and function are highly conserved, yet, paradoxically, it is also an important model for studying the evolution of the metabolic phenotype. In this review, part of a special issue honouring Peter Hochachka, we consider the biology of COX from the perspective of comparative and evolutionary biochemistry. The approach is to consider what is known about the enzyme in the context of conventional biochemistry, but focus on how evolutionary researchers have used this background to explore the role of the enzyme in biochemical adaptation of animals. In synthesizing the conventional and evolutionary biochemistry, we hope to identify synergies and future research opportunities. COX represents a rare opportunity for researchers to design studies that span the breadth of biology: molecular genetics, protein biochemistry, enzymology, metabolic physiology, organismal performance, evolutionary biology, and phylogeography.
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32
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Táborský P, Pánek T, Čepička I. Anaeramoebidae fam. nov., a Novel Lineage of Anaerobic Amoebae and Amoeboflagellates of Uncertain Phylogenetic Position. Protist 2017; 168:495-526. [DOI: 10.1016/j.protis.2017.07.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 07/17/2017] [Accepted: 07/27/2017] [Indexed: 12/18/2022]
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33
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Takishita K, Chikaraishi Y, Tanifuji G, Ohkouchi N, Hashimoto T, Fujikura K, Roger AJ. Microbial Eukaryotes that Lack Sterols. J Eukaryot Microbiol 2017; 64:897-900. [PMID: 28509379 DOI: 10.1111/jeu.12426] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 05/08/2017] [Accepted: 05/09/2017] [Indexed: 11/29/2022]
Abstract
It is widely held that sterols are key cyclic triterpenoid lipids in eukaryotic cell membranes and are synthesized through oxygen-dependent multienzyme pathways. However, there are known exceptions-ciliated protozoans, such as Tetrahymena, along with diverse low-oxygen-adapted eukaryotes produce, instead of sterols, the cyclic triterpenoid lipid tetrahymanol that does not require molecular oxygen for its biosynthesis. Here, we report that a number of anaerobic microbial eukaryotes (protists) utilize neither sterols nor tetrahymanol in their membranes. The lack of detectable sterol-like compounds in their membranes may provide an opportunity to reconsider the physiological function of sterols and sterol-like lipids in eukaryotes.
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Affiliation(s)
- Kiyotaka Takishita
- Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Kanagawa, 237-0061, Japan
| | - Yoshito Chikaraishi
- Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Kanagawa, 237-0061, Japan.,Institute of Low Temperature Science, Hokkaido University, Sapporo, Hokkaido, 060-0819, Japan
| | - Goro Tanifuji
- Department of Zoology, National Museum of Nature and Science, Tsukuba, Ibaraki, 305-0005, Japan
| | - Naohiko Ohkouchi
- Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Kanagawa, 237-0061, Japan
| | - Tetsuo Hashimoto
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8577, Japan
| | - Katsunori Fujikura
- Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Kanagawa, 237-0061, Japan
| | - Andrew J Roger
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, B3H 1X5, Canada
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34
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Björkholm P, Ernst AM, Hagström E, Andersson SGE. Why mitochondria need a genome revisited. FEBS Lett 2016; 591:65-75. [PMID: 27928819 DOI: 10.1002/1873-3468.12510] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 11/15/2016] [Accepted: 11/21/2016] [Indexed: 01/13/2023]
Abstract
In this paper, we experimentally address the debate about why functional transfer of mitochondrial genes to the nucleus has been halted in some organismal groups and why cytosolic expression of mitochondrial proteins has proven remarkably difficult. By expressing all 13 human mitochondrial-encoded genes with strong mitochondrial-targeting sequences in the cytosol of human cells, we show that all proteins, except ATP8, are transported to the endoplasmic reticulum (ER). These results confirm and extend previous findings based on three mitochondrial genes lacking mitochondrial-targeting sequences that also were relocated to the ER during cytosolic expression. We conclude that subcellular protein targeting constitutes a major barrier to functional transfer of mitochondrial genes to the nuclear genome.
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Affiliation(s)
- Patrik Björkholm
- Department of Molecular Evolution, Cell and Molecular Biology, Uppsala University, Sweden
| | - Andreas M Ernst
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - Erik Hagström
- Department of Molecular Evolution, Cell and Molecular Biology, Uppsala University, Sweden
| | - Siv G E Andersson
- Department of Molecular Evolution, Cell and Molecular Biology, Uppsala University, Sweden
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Abstract
Mitochondria in the protist Brevimastigomonas motovehiculus are in the process of dismantling their mitochondrial electron transport chain complexes as they adapt to anaerobic environments. Novel protein interactions suggest a highly complicated process rather than the simple removal of unnecessary genes.
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Affiliation(s)
- Mark van der Giezen
- Biocatalysis Centre, University of Exeter, Stocker Road, Exeter EX4 4QD, UK.
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