1
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Pinello JF, Loidl J, Seltzer ES, Cassidy-Hanley D, Kolbin D, Abdelatif A, Rey FA, An R, Newberger NJ, Bisharyan Y, Papoyan H, Byun H, Aguilar HC, Lai AL, Freed JH, Maugel T, Cole ES, Clark TG. Novel requirements for HAP2/GCS1-mediated gamete fusion in Tetrahymena. iScience 2024; 27:110146. [PMID: 38904066 PMCID: PMC11187246 DOI: 10.1016/j.isci.2024.110146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 04/29/2024] [Accepted: 05/27/2024] [Indexed: 06/22/2024] Open
Abstract
The ancestral gamete fusion protein, HAP2/GCS1, plays an essential role in fertilization in a broad range of taxa. To identify factors that may regulate HAP2/GCS1 activity, we screened mutants of the ciliate Tetrahymena thermophila for behaviors that mimic Δhap2/gcs1 knockout phenotypes in this species. Using this approach, we identified two new genes, GFU1 and GFU2, whose products are necessary for membrane pore formation following mating type recognition and adherence. GFU2 is predicted to be a single-pass transmembrane protein, while GFU1, though lacking obvious transmembrane domains, has the potential to interact directly with membrane phospholipids in the cytoplasm. Like Tetrahymena HAP2/GCS1, expression of GFU1 is required in both cells of a mating pair for efficient fusion to occur. To explain these bilateral requirements, we propose a model that invokes cooperativity between the fusion machinery on apposed membranes of mating cells and accounts for successful fertilization in Tetrahymena's multiple mating type system.
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Affiliation(s)
- Jennifer F. Pinello
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Josef Loidl
- Department of Chromosome Biology, Max Perutz Labs, University of Vienna, Vienna, Austria
| | - Ethan S. Seltzer
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Donna Cassidy-Hanley
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Daniel Kolbin
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Anhar Abdelatif
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Félix A. Rey
- Unité de Virologie Structurale, Institut Pasteur, 75724 Paris, France
- CNRS UMR 3569, 75724 Paris, France
| | - Rocky An
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Nicole J. Newberger
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Yelena Bisharyan
- Office of Technology Development, Harvard University, Cambridge, MA 02138, USA
| | - Hayk Papoyan
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Haewon Byun
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Hector C. Aguilar
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Alex L. Lai
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14850, USA
| | - Jack H. Freed
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14850, USA
| | - Timothy Maugel
- Department of Biology, Laboratory for Biological Ultrastructure, University of Maryland, College Park, MD 20742, USA
| | - Eric S. Cole
- Biology Department, St. Olaf College, Northfield, MN 55057, USA
| | - Theodore G. Clark
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
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2
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Zhong S, Zhao P, Peng X, Li HJ, Duan Q, Cheung AY. From gametes to zygote: Mechanistic advances and emerging possibilities in plant reproduction. PLANT PHYSIOLOGY 2024; 195:4-35. [PMID: 38431529 PMCID: PMC11060694 DOI: 10.1093/plphys/kiae125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 02/13/2024] [Accepted: 02/13/2024] [Indexed: 03/05/2024]
Affiliation(s)
- Sheng Zhong
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, New Cornerstone Science Laboratory, College of Life Sciences, Peking University, Beijing 100871, China
| | - Peng Zhao
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
- Hubei Hongshan Laboratory, Wuhan 430070, China
| | - Xiongbo Peng
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
- Hubei Hongshan Laboratory, Wuhan 430070, China
| | - Hong-Ju Li
- Key Laboratory of Seed Innovation, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Center for Molecular Agrobiology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Qiaohong Duan
- College of Horticulture Science and Engineering, Shandong Agricultural University, Tai’an, Shandong 271018, China
| | - Alice Y Cheung
- Department of Biochemistry and Molecular Biology, Molecular and Cellular Biology Program, Plant Biology Graduate Program, University of Massachusetts, Amherst, MA 01003, USA
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3
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Qu Z, Gong Z, Olajide JS, Wang J, Cai J. CRISPR-Cas9-based method for isolating microgametes of Eimeria tenella. Vet Parasitol 2024; 327:110131. [PMID: 38301346 DOI: 10.1016/j.vetpar.2024.110131] [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: 08/31/2023] [Revised: 01/14/2024] [Accepted: 01/16/2024] [Indexed: 02/03/2024]
Abstract
Eimeria tenella infections are known to cause severe caecal damage and death of the infected chicken. Gamogony is an essential stage in E. tenella life cycle and in the establishment of coccidiosis. Prior research had extensively explored isolation and separation of the parasite gametes - microgamete (male) and macrogamete (female). However, there is little information on the efficient, highly purified and distinctly separated male and female gametes. In this study, we generated a genome editing line expressing mCherry fluorescent protein fused with GCS1 protein in E. tenella by using Toxoplasma gondii CRISPR-Cas9 system, flow cytometry and fluorescence microscopy. This allowed precise separation of E. tenella male and female gametes in the transgenic parasite population. The separation of male and female gametes would not only build on our understanding of E. tenella transmission, but it would also facilitate development of gametocidal compounds as drug targets for E. tenella infection.
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Affiliation(s)
- Zigang Qu
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, People's Republic of China; Jiangsu Co-Innovation Center for Prevention and Control of Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu Province 225009, People's Republic of China.
| | - Zhenxing Gong
- College of Animal Science and Technology, Ningxia University, Yinchuan, Ningxia Province 750021, People's Republic of China
| | - Joshua Seun Olajide
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, People's Republic of China; Centre for Distance Learning, Obafemi Awolowo University, Ile-Ife, Nigeria
| | - Jing Wang
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, People's Republic of China
| | - Jianping Cai
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, People's Republic of China; Jiangsu Co-Innovation Center for Prevention and Control of Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu Province 225009, People's Republic of China.
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4
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Ma Y, Yan G, Zhang J, Xiong J, Miao W. Cip1, a CDK regulator, determines heterothallic mating or homothallic selfing in a protist. Proc Natl Acad Sci U S A 2024; 121:e2315531121. [PMID: 38498704 PMCID: PMC10990102 DOI: 10.1073/pnas.2315531121] [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: 09/08/2023] [Accepted: 02/20/2024] [Indexed: 03/20/2024] Open
Abstract
Mating type (sex) plays a crucial role in regulating sexual reproduction in most extant eukaryotes. One of the functions of mating types is ensuring self-incompatibility to some extent, thereby promoting genetic diversity. However, heterothallic mating is not always the best mating strategy. For example, in low-density populations or specific environments, such as parasitic ones, species may need to increase the ratio of potential mating partners. Consequently, many species allow homothallic selfing (i.e., self-fertility or intraclonal mating). Throughout the extensive evolutionary history of species, changes in environmental conditions have influenced mating strategies back and forth. However, the mechanisms through which mating-type recognition regulates sexual reproduction and the dynamics of mating strategy throughout evolution remain poorly understood. In this study, we show that the Cip1 protein is responsible for coupling sexual reproduction initiation to mating-type recognition in the protozoal eukaryote Tetrahymena thermophila. Deletion of the Cip1 protein leads to the loss of the selfing-avoidance function of mating-type recognition, resulting in selfing without mating-type recognition. Further experiments revealed that Cip1 is a regulatory subunit of the Cdk19-Cyc9 complex, which controls the initiation of sexual reproduction. These results reveal a mechanism that regulates the choice between mating and selfing. This mechanism also contributes to the debate about the ancestral state of sexual reproduction.
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Affiliation(s)
- Yang Ma
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan430072, China
| | - Guanxiong Yan
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan430072, China
| | - Jing Zhang
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan430072, China
| | - Jie Xiong
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan430072, China
- Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Chinese Academy of Sciences, Wuhan430072, China
| | - Wei Miao
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan430072, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing100049, China
- Key laboratory of Lake and Watershed Science for Water Security, Chinese Academy of Sciences, Nanjing210000, China
- Institute of Hydrobiology, Hubei Hongshan Laboratory, Wuhan430000, China
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5
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Catta-Preta CMC, Ferreira TR, Ghosh K, Paun A, Sacks D. HOP1 and HAP2 are conserved components of the meiosis-related machinery required for successful mating in Leishmania. Nat Commun 2023; 14:7159. [PMID: 37935664 PMCID: PMC10630298 DOI: 10.1038/s41467-023-42789-z] [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: 06/22/2023] [Accepted: 10/21/2023] [Indexed: 11/09/2023] Open
Abstract
Whole genome analysis of Leishmania hybrids generated experimentally in sand flies supports a meiotic mechanism of genetic exchange, with Mendelian segregation of the nuclear genome. Here, we perform functional analyses through the generation of double drug-resistant hybrids in vitro and in vivo (during sand fly infections) to assess the importance of conserved meiosis-related genes in recombination and plasmogamy. We report that HOP1 and a HAP2-paralog (HAP2-2) are essential components of the Leishmania meiosis machinery and cell-to-cell fusion mechanism, respectively, since deletion of either gene in one or both parents significantly reduces or completely abrogates mating competence. These findings significantly advance our understanding of sexual reproduction in Leishmania, with likely relevance to other trypanosomatids, by formally demonstrating the involvement of a meiotic protein homolog and a distinct fusogen that mediates non-canonical, bilateral fusion in the hybridizing cells.
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Affiliation(s)
- Carolina Moura Costa Catta-Preta
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Tiago Rodrigues Ferreira
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Kashinath Ghosh
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Andrea Paun
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - David Sacks
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
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6
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Azimi FC, Dean TT, Minari K, Basso LGM, Vance TDR, Serrão VHB. A Frame-by-Frame Glance at Membrane Fusion Mechanisms: From Viral Infections to Fertilization. Biomolecules 2023; 13:1130. [PMID: 37509166 PMCID: PMC10377500 DOI: 10.3390/biom13071130] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 07/09/2023] [Accepted: 07/12/2023] [Indexed: 07/30/2023] Open
Abstract
Viral entry and fertilization are distinct biological processes that share a common mechanism: membrane fusion. In viral entry, enveloped viruses attach to the host cell membrane, triggering a series of conformational changes in the viral fusion proteins. This results in the exposure of a hydrophobic fusion peptide, which inserts into the host membrane and brings the viral and host membranes into close proximity. Subsequent structural rearrangements in opposing membranes lead to their fusion. Similarly, membrane fusion occurs when gametes merge during the fertilization process, though the exact mechanism remains unclear. Structural biology has played a pivotal role in elucidating the molecular mechanisms underlying membrane fusion. High-resolution structures of the viral and fertilization fusion-related proteins have provided valuable insights into the conformational changes that occur during this process. Understanding these mechanisms at a molecular level is essential for the development of antiviral therapeutics and tools to influence fertility. In this review, we will highlight the biological importance of membrane fusion and how protein structures have helped visualize both common elements and subtle divergences in the mechanisms behind fusion; in addition, we will examine the new tools that recent advances in structural biology provide researchers interested in a frame-by-frame understanding of membrane fusion.
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Affiliation(s)
- Farshad C. Azimi
- Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada;
| | - Trevor T. Dean
- Pharmaceutical Sciences, University of Illinois Chicago, Chicago, IL 60612, USA;
| | - Karine Minari
- Biomolecular Cryo-Electron Microscopy Facility, University of California-Santa Cruz, Santa Cruz, CA 95064, USA;
| | - Luis G. M. Basso
- Laboratório de Ciências Físicas, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, Rio de Janeiro 28013-602, Brazil;
| | - Tyler D. R. Vance
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada;
| | - Vitor Hugo B. Serrão
- Biomolecular Cryo-Electron Microscopy Facility, University of California-Santa Cruz, Santa Cruz, CA 95064, USA;
- Department of Chemistry and Biochemistry, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
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7
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Shiba Y, Takahashi T, Ohashi Y, Ueda M, Mimuro A, Sugimoto J, Noguchi Y, Igawa T. Behavior of Male Gamete Fusogen GCS1/HAP2 and the Regulation in Arabidopsis Double Fertilization. Biomolecules 2023; 13:biom13020208. [PMID: 36830580 PMCID: PMC9953686 DOI: 10.3390/biom13020208] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 01/16/2023] [Accepted: 01/18/2023] [Indexed: 01/25/2023] Open
Abstract
In the sexual reproduction of flowering plants, two independent fertilization events occur almost simultaneously: two identical sperm cells fuse with either the egg cell or the central cell, resulting in embryo and endosperm development to produce a seed. GCS1/HAP2 is a sperm cell membrane protein essential for plasma membrane fusion with both female gametes. Other sperm membrane proteins, DMP8 and DMP9, are more important for egg cell fertilization than that of the central cell, suggesting its regulatory mechanism in GCS1/HAP2-driving gamete membrane fusion. To assess the GCS1/HAP2 regulatory cascade in the double fertilization system of flowering plants, we produced Arabidopsis transgenic lines expressing different GCS1/HAP2 variants and evaluated the fertilization in vivo. The fertilization pattern observed in GCS1_RNAi transgenic plants implied that sperm cells over the amount of GCS1/HAP2 required for fusion on their surface could facilitate membrane fusion with both female gametes. The cytological analysis of the dmp8dmp9 sperm cell arrested alone in an embryo sac supported GCS1/HAP2 distribution on the sperm surface. Furthermore, the fertilization failures with both female gametes were caused by GCS1/HAP2 secretion from the egg cell. These results provided a possible scenario of GCS1/HAP2 regulation, showing a potential scheme for capturing additional GCS1/HAP2-interacting proteins.
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Affiliation(s)
- Yuka Shiba
- Graduate School of Horticulture, Chiba University, Matsudo 648, Matsudo-shi 271-8510, Japan
| | - Taro Takahashi
- Graduate School of Horticulture, Chiba University, Matsudo 648, Matsudo-shi 271-8510, Japan
| | - Yukino Ohashi
- Graduate School of Horticulture, Chiba University, Matsudo 648, Matsudo-shi 271-8510, Japan
| | - Minako Ueda
- Graduate School of Life Sciences, Department of Ecological Developmental Adaptability Life Sciences, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan
- Suntory Rising Stars Encouragement Program in Life Sciences (SunRiSE), Sendai 980-8578, Japan
| | - Amane Mimuro
- Graduate School of Horticulture, Chiba University, Matsudo 648, Matsudo-shi 271-8510, Japan
| | - Jin Sugimoto
- Graduate School of Horticulture, Chiba University, Matsudo 648, Matsudo-shi 271-8510, Japan
| | - Yuka Noguchi
- Graduate School of Horticulture, Chiba University, Matsudo 648, Matsudo-shi 271-8510, Japan
| | - Tomoko Igawa
- Graduate School of Horticulture, Chiba University, Matsudo 648, Matsudo-shi 271-8510, Japan
- Plant Molecular Science Center, Chiba University, 1-33 Yayoi, Chiba-shi 263-8522, Japan
- Correspondence:
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8
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DMP8 and 9 regulate HAP2/GCS1 trafficking for the timely acquisition of sperm fusion competence. Proc Natl Acad Sci U S A 2022; 119:e2207608119. [PMID: 36322734 PMCID: PMC9659367 DOI: 10.1073/pnas.2207608119] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Sexual reproduction involves the fusion of two gametes of opposite sex. Although the sperm-expressed fusogen HAPLESS 2 (HAP2) or GENERATIVE CELL SPECIFIC 1 (GCS1) plays a vital role in this process in many eukaryotic organisms and an understanding of its regulation is emerging in unicellular systems [J. Zhang et al., Nat. Commun. 12, 4380 (2021); J. F. Pinello et al. Dev. Cell 56, 3380-3392.e9 (2021)], neither HAP2/GCS1 interactors nor mechanisms for delivery and activation at the fusion site are known in multicellular plants. Here, we show that Arabidopsis thaliana HAP2/GCS1 interacts with two sperm DUF679 membrane proteins (DMP8 and DMP9), which are required for the EGG CELL 1 (EC1)-induced translocation of HAP2/GCS1 from internal storage vesicle to the sperm plasma membrane to ensure successful fertilization. Our studies in Arabidopsis and tobacco provide evidence for a conserved function of DMP8/9-like proteins as HAP2/GCS1 partner in seed plants. Our data suggest that seed plants evolved a DMP8/9-dependent fusogen translocation process to achieve timely acquisition of sperm fusion competence in response to egg cell-derived signals, revealing a previously unknown critical step for successful fertilization.
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9
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Moi D, Nishio S, Li X, Valansi C, Langleib M, Brukman NG, Flyak K, Dessimoz C, de Sanctis D, Tunyasuvunakool K, Jumper J, Graña M, Romero H, Aguilar PS, Jovine L, Podbilewicz B. Discovery of archaeal fusexins homologous to eukaryotic HAP2/GCS1 gamete fusion proteins. Nat Commun 2022; 13:3880. [PMID: 35794124 PMCID: PMC9259645 DOI: 10.1038/s41467-022-31564-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 06/22/2022] [Indexed: 12/26/2022] Open
Abstract
Sexual reproduction consists of genome reduction by meiosis and subsequent gamete fusion. The presence of genes homologous to eukaryotic meiotic genes in archaea and bacteria suggests that DNA repair mechanisms evolved towards meiotic recombination. However, fusogenic proteins resembling those found in gamete fusion in eukaryotes have so far not been found in prokaryotes. Here, we identify archaeal proteins that are homologs of fusexins, a superfamily of fusogens that mediate eukaryotic gamete and somatic cell fusion, as well as virus entry. The crystal structure of a trimeric archaeal fusexin (Fusexin1 or Fsx1) reveals an archetypical fusexin architecture with unique features such as a six-helix bundle and an additional globular domain. Ectopically expressed Fusexin1 can fuse mammalian cells, and this process involves the additional globular domain and a conserved fusion loop. Furthermore, archaeal fusexin genes are found within integrated mobile elements, suggesting potential roles in cell-cell fusion and gene exchange in archaea, as well as different scenarios for the evolutionary history of fusexins.
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Affiliation(s)
- David Moi
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE-CONICET), Buenos Aires, Argentina
- Department of Computational Biology, University of Lausanne, Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Shunsuke Nishio
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - Xiaohui Li
- Department of Biology, Technion- Israel Institute of Technology, Haifa, Israel
| | - Clari Valansi
- Department of Biology, Technion- Israel Institute of Technology, Haifa, Israel
| | - Mauricio Langleib
- Unidad de Genómica Evolutiva, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
- Unidad de Bioinformática, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Nicolas G Brukman
- Department of Biology, Technion- Israel Institute of Technology, Haifa, Israel
| | - Kateryna Flyak
- Department of Biology, Technion- Israel Institute of Technology, Haifa, Israel
| | - Christophe Dessimoz
- Department of Computational Biology, University of Lausanne, Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
- Department of Genetics, Evolution and Environment, Centre for Life's Origins and Evolution, University College London, London, UK
- Department of Computer Science, University College London, London, UK
| | | | | | | | - Martin Graña
- Unidad de Bioinformática, Institut Pasteur de Montevideo, Montevideo, Uruguay.
| | - Héctor Romero
- Unidad de Genómica Evolutiva, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay.
- Centro Universitario Regional Este - CURE, Centro Interdisciplinario de Ciencia de Datos y Aprendizaje Automático - CICADA, Universidad de la República, Montevideo, Uruguay.
| | - Pablo S Aguilar
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE-CONICET), Buenos Aires, Argentina.
- Instituto de Investigaciones Biotecnológicas Universidad Nacional de San Martín (IIB-CONICET), San Martín, Buenos Aires, Argentina.
| | - Luca Jovine
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden.
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10
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Plattner H. Ciliate Research. From Myth to Trendsetting Science. J Eukaryot Microbiol 2022; 69:e12926. [PMID: 35608570 DOI: 10.1111/jeu.12926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 05/18/2022] [Accepted: 05/18/2022] [Indexed: 11/28/2022]
Abstract
This special issue of the Journal of Eukaryotic Microbiology (JEM) summarizes achievements obtained by generations of researchers with ciliates in widely different disciplines. In fact, ciliates range among the first cells seen under the microscope centuries ago. Their beauty made them an object of scientia amabilis and their manifold reactions made them attractive for college experiments and finally challenged causal analyses at the cellular level. Some of this work was honored by a Nobel Prize. Some observations yielded a baseline for additional novel discoveries, occasionally facilitated by specific properties of some ciliates. This also offers some advantage in the exploration of closely related parasites (malaria). Articles contributed here by colleagues from all over the world encompass a broad spectrum of ciliate life, from genetics to evolution, from molecular cell biology to ecology, from intercellular signaling to epigenetics etc. This introductory chapter, largely based on my personal perception, aims at integrating work presented in this special issue of JEM into a broader historical context up to current research.
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11
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Plattner H. Membrane Traffic and Ca 2+ -Signals in Ciliates. J Eukaryot Microbiol 2022; 69:e12895. [PMID: 35156735 DOI: 10.1111/jeu.12895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 02/01/2022] [Accepted: 02/01/2022] [Indexed: 11/30/2022]
Abstract
A Paramecium cell has as many types of membrane interactions as mammalian cells, as established with monoclonal antibodies by R. Allen and A. Fok. Since then, we have identified key-players, such as SNARE-proteins, Ca2+ -regulating proteins, including Ca2+ -channels, Ca2+ -pumps, Ca2+ -binding proteins of different affinity etc. at the molecular level, probed their function and localized them at the light and electron microscopy level. SNARE-proteins, in conjunction with a synaptotagmin-like Ca2+ -sensor protein, mediate membrane fusion. This interaction is additionally regulated by monomeric GTPases whose spectrum in Tetrahymena and Paramecium has been established by A. Turkewitz. As known from mammalian cells, GTPases are activated on membranes in conjunction with lumenal acidification by an H+ -ATPase. For these complex molecules we found in Paramecium an unsurpassed number of 17 a-subunit paralogs which connect the polymeric head and basis part, V1 and V0. (This multitude may reflect different local functional requirements.) Together with plasmalemmal Ca2+ -influx-channels, locally enriched intracellular InsP3 -type (InsP3 R, mainly in osmoregulatory system) and ryanodine receptor-like Ca2+ -release channels (ryanodine receptor-like proteins, RyR-LP), this complexity mediates Ca2+ signals for most flexible local membrane-to-membrane interactions. As we found, the latter channel types miss a substantial portion of the N-terminal part. Caffeine and 4-chloro-meta-cresol (the agent used to probe mutations of RyRs in man during surgery in malignant insomnia patients) initiate trichocyst exocytosis by activating Ca2+ -release channels type CRC-IV in the peripheral part of alveolar sacs. This is superimposed by Ca2+ -influx, i.e. a mechanism called "store-operated Ca2+ -entry" (SOCE). For the majority of key players, we have mapped paralogs throughout the Paramecium cell, with features in common or at variance in the different organelles participating in vesicle trafficking. Local values of free Ca2+ -concentration, [Ca2+ ]i , and their change, e.g. upon exocytosis stimulation, have been registered by flurochromes and chelator effects. In parallel we have registered release of Ca2+ from alveolar sacs by quenched-flow analysis combined with cryofixation and x-ray microanalysis.
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12
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Brukman NG, Li X, Podbilewicz B. Fusexins, HAP2/GCS1 and Evolution of Gamete Fusion. Front Cell Dev Biol 2022; 9:824024. [PMID: 35083224 PMCID: PMC8784728 DOI: 10.3389/fcell.2021.824024] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Accepted: 12/21/2021] [Indexed: 12/14/2022] Open
Abstract
Gamete fusion is the climax of fertilization in all sexually reproductive organisms, from unicellular fungi to humans. Similarly to other cell-cell fusion events, gamete fusion is mediated by specialized proteins, named fusogens, that overcome the energetic barriers during this process. In recent years, HAPLESS 2/GENERATIVE CELL-SPECIFIC 1 (HAP2/GCS1) was identified as the fusogen mediating sperm-egg fusion in flowering plants and protists, being both essential and sufficient for the membrane merger in some species. The identification of HAP2/GCS1 in invertebrates, opens the possibility that a similar fusogen may be used in vertebrate fertilization. HAP2/GCS1 proteins share a similar structure with two distinct families of exoplasmic fusogens: the somatic Fusion Family (FF) proteins discovered in nematodes, and class II viral glycoproteins (e.g., rubella and dengue viruses). Altogether, these fusogens form the Fusexin superfamily. While some attributes are shared among fusexins, for example the overall structure and the possibility of assembly into trimers, some other characteristics seem to be specific, such as the presence or not of hydrophobic loops or helices at the distal tip of the protein. Intriguingly, HAP2/GCS1 or other fusexins have neither been identified in vertebrates nor in fungi, raising the question of whether these genes were lost during evolution and were replaced by other fusion machinery or a significant divergence makes their identification difficult. Here, we discuss the biology of HAP2/GCS1, its involvement in gamete fusion and the structural, mechanistic and evolutionary relationships with other fusexins.
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Affiliation(s)
- Nicolas G Brukman
- Department of Biology, Technion- Israel Institute of Technology, Haifa, Israel
| | - Xiaohui Li
- Department of Biology, Technion- Israel Institute of Technology, Haifa, Israel
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13
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Pinello JF, Clark TG. HAP2-Mediated Gamete Fusion: Lessons From the World of Unicellular Eukaryotes. Front Cell Dev Biol 2022; 9:807313. [PMID: 35071241 PMCID: PMC8777248 DOI: 10.3389/fcell.2021.807313] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 11/15/2021] [Indexed: 01/29/2023] Open
Abstract
Most, if not all the cellular requirements for fertilization and sexual reproduction arose early in evolution and are retained in extant lineages of single-celled organisms including a number of important model organism species. In recent years, work in two such species, the green alga, Chlamydomonas reinhardtii, and the free-living ciliate, Tetrahymena thermophila, have lent important new insights into the role of HAP2/GCS1 as a catalyst for gamete fusion in organisms ranging from protists to flowering plants and insects. Here we summarize the current state of knowledge around how mating types from these algal and ciliate systems recognize, adhere and fuse to one another, current gaps in our understanding of HAP2-mediated gamete fusion, and opportunities for applying what we know in practical terms, especially for the control of protozoan parasites.
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Affiliation(s)
- Jennifer F. Pinello
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, United States
| | - Theodore G. Clark
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY, United States
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14
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Louradour I, Ferreira TR, Duge E, Karunaweera N, Paun A, Sacks D. Stress conditions promote Leishmania hybridization in vitro marked by expression of the ancestral gamete fusogen HAP2 as revealed by single-cell RNA-seq. eLife 2022; 11:73488. [PMID: 34994687 PMCID: PMC8794473 DOI: 10.7554/elife.73488] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 01/06/2022] [Indexed: 12/18/2022] Open
Abstract
Leishmania are protozoan parasites transmitted by the bite of sand fly vectors producing a wide spectrum of diseases in their mammalian hosts. These diverse clinical outcomes are directly associated with parasite strain and species diversity. Although Leishmania reproduction is mainly clonal, a cryptic sexual cycle capable of producing hybrid genotypes has been inferred from population genetic studies and directly demonstrated by laboratory crosses. Experimentally, mating competence has been largely confined to promastigotes developing in the sand fly midgut. The ability to hybridize culture promastigotes in vitro has been limited so far to low-efficiency crosses between two Leishmania tropica strains, L747 and MA37, that mate with high efficiency in flies. Here, we show that exposure of promastigote cultures to DNA damage stress produces a remarkably enhanced efficiency of in vitro hybridization of the L. tropica strains and extends to other species, including Leishmania donovani, Leishmania infantum, and Leishmania braziliensis, a capacity to generate intra- and interspecific hybrids. Whole-genome sequencing and total DNA content analyses indicate that the hybrids are in each case full genome, mostly tetraploid hybrids. Single-cell RNA sequencing of the L747 and MA37 parental lines highlights the transcriptome heterogeneity of culture promastigotes and reveals discrete clusters that emerge post-irradiation in which genes potentially involved in genetic exchange are expressed, including the ancestral gamete fusogen HAP2. By generating reporter constructs for HAP2, we could select for promastigotes that could either hybridize or not in vitro. Overall, this work reveals that there are specific populations involved in Leishmania hybridization associated with a discernible transcriptomic signature, and that stress facilitated in vitro hybridization can be a transformative approach to generate large numbers of hybrid genotypes between diverse species and strains.
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Affiliation(s)
- Isabelle Louradour
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, United States
| | - Tiago Rodrigues Ferreira
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, United States
| | - Emma Duge
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, United States
| | - Nadira Karunaweera
- Department of Parasitology, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka
| | - Andrea Paun
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, United States
| | - David Sacks
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, United States
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15
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Pinello JF, Liu Y, Snell WJ. MAR1 links membrane adhesion to membrane merger during cell-cell fusion in Chlamydomonas. Dev Cell 2021; 56:3380-3392.e9. [PMID: 34813735 DOI: 10.1016/j.devcel.2021.10.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Revised: 09/22/2021] [Accepted: 10/28/2021] [Indexed: 01/17/2023]
Abstract
Union of two gametes to form a zygote is a defining event in the life of sexual eukaryotes, yet the mechanisms that underlie cell-cell fusion during fertilization remain poorly characterized. Here, in studies of fertilization in the green alga, Chlamydomonas, we report identification of a membrane protein on minus gametes, Minus Adhesion Receptor 1 (MAR1), that is essential for the membrane attachment with plus gametes that immediately precedes lipid bilayer merger. We show that MAR1 forms a receptor pair with previously identified receptor FUS1 on plus gametes, whose ectodomain architecture we find is identical to a sperm adhesion protein conserved throughout plant lineages. Strikingly, before fusion, MAR1 is biochemically and functionally associated with the ancient, evolutionarily conserved eukaryotic Class II fusion protein HAP2 on minus gametes. Thus, the integral membrane protein MAR1 provides a molecular link between membrane adhesion and bilayer merger during fertilization in Chlamydomonas.
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Affiliation(s)
- Jennifer F Pinello
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Yanjie Liu
- Department of Cell Biology, University of Texas Southwestern Medical Center, 6000 Harry Hines Boulevard, Dallas, TX 75390-9039, USA
| | - William J Snell
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA.
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16
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Using a Hand-Held Gene Gun for Genetic Transformation of Tetrahymena thermophila. Methods Mol Biol 2021. [PMID: 34542863 DOI: 10.1007/978-1-0716-1661-1_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Biolistic bombardment is widely used as a means of delivering vector-coated microparticles into microorganisms, cultured cells, and tissues. The first particle delivery system contained a helium propulsion unit (the gun) mounted in a vacuum-controlled chamber. In contrast, the hand-held gene gun does not operate within a chamber. It is completely hand-held, easy, and efficient to use, and it requires minimal space on the laboratory bench top. This chapter describes protocols for using a hand-held gene gun to deliver transformation vectors for overexpression of genes or gene replacement into the macronucleus of Tetrahymena thermophila. The protocols provide helpful information for preparing Tetrahymena for biolistic bombardment, preparation of vector-coated microcarriers, and basic gene gun operating procedures.
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17
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Zhang J, Pinello JF, Fernández I, Baquero E, Fedry J, Rey FA, Snell WJ. Species-specific gamete recognition initiates fusion-driving trimer formation by conserved fusogen HAP2. Nat Commun 2021; 12:4380. [PMID: 34282138 PMCID: PMC8289870 DOI: 10.1038/s41467-021-24613-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 06/15/2021] [Indexed: 12/02/2022] Open
Abstract
Recognition and fusion between gametes during fertilization is an ancient process. Protein HAP2, recognized as the primordial eukaryotic gamete fusogen, is a structural homolog of viral class II fusion proteins. The mechanisms that regulate HAP2 function, and whether virus-fusion-like conformational changes are involved, however, have not been investigated. We report here that fusion between plus and minus gametes of the green alga Chlamydomonas indeed requires an obligate conformational rearrangement of HAP2 on minus gametes from a labile, prefusion form into the stable homotrimers observed in structural studies. Activation of HAP2 to undergo its fusogenic conformational change occurs only upon species-specific adhesion between the two gamete membranes. Following a molecular mechanism akin to fusion of enveloped viruses, the membrane insertion capacity of the fusion loop is required to couple formation of trimers to gamete fusion. Thus, species-specific membrane attachment is the gateway to fusion-driving HAP2 rearrangement into stable trimers. HAP2 is essential for gamete fusion during fertilization and is conserved among eukaryotes. Here the authors show that species-specific adhesion between Chlamydomonas plus and minus gametes initiates HAP2 to undergo a fusogenic conformational change into homotrimers via a molecular mechanism akin to that of enveloped viruses.
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Affiliation(s)
- Jun Zhang
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
| | - Jennifer F Pinello
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
| | - Ignacio Fernández
- Unité de Virologie Structurale, Virology Department and CNRS UMR 3569, Institut Pasteur, Paris, France
| | - Eduard Baquero
- Unité de Virologie Structurale, Virology Department and CNRS UMR 3569, Institut Pasteur, Paris, France
| | - Juliette Fedry
- Unité de Virologie Structurale, Virology Department and CNRS UMR 3569, Institut Pasteur, Paris, France
| | - Félix A Rey
- Unité de Virologie Structurale, Virology Department and CNRS UMR 3569, Institut Pasteur, Paris, France
| | - William J Snell
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA.
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18
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Peacock L, Kay C, Farren C, Bailey M, Carrington M, Gibson W. Sequential production of gametes during meiosis in trypanosomes. Commun Biol 2021; 4:555. [PMID: 33976359 PMCID: PMC8113336 DOI: 10.1038/s42003-021-02058-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 03/24/2021] [Indexed: 02/03/2023] Open
Abstract
Meiosis is a core feature of eukaryotes that occurs in all major groups, including the early diverging excavates. In this group, meiosis and production of haploid gametes have been described in the pathogenic protist, Trypanosoma brucei, and mating occurs in the salivary glands of the insect vector, the tsetse fly. Here, we searched for intermediate meiotic stages among trypanosomes from tsetse salivary glands. Many different cell types were recovered, including trypanosomes in Meiosis I and gametes. Significantly, we found trypanosomes containing three nuclei with a 1:2:1 ratio of DNA contents. Some of these cells were undergoing cytokinesis, yielding a mononucleate gamete and a binucleate cell with a nuclear DNA content ratio of 1:2. This cell subsequently produced three more gametes in two further rounds of division. Expression of the cell fusion protein HAP2 (GCS1) was not confined to gametes, but also extended to meiotic intermediates. We propose a model whereby the two nuclei resulting from Meiosis I undergo asynchronous Meiosis II divisions with sequential production of haploid gametes.
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Affiliation(s)
- Lori Peacock
- School of Biological Sciences University of Bristol, Bristol, UK
- Bristol Veterinary School, University of Bristol, Bristol, UK
| | - Chris Kay
- School of Biological Sciences University of Bristol, Bristol, UK
| | - Chloe Farren
- School of Biological Sciences University of Bristol, Bristol, UK
| | - Mick Bailey
- Bristol Veterinary School, University of Bristol, Bristol, UK
| | - Mark Carrington
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Wendy Gibson
- School of Biological Sciences University of Bristol, Bristol, UK.
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19
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Gibson W. The sexual side of parasitic protists. Mol Biochem Parasitol 2021; 243:111371. [PMID: 33872659 DOI: 10.1016/j.molbiopara.2021.111371] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 03/26/2021] [Accepted: 04/13/2021] [Indexed: 01/09/2023]
Abstract
Much of the vast evolutionary landscape occupied by Eukaryotes is dominated by protists. Though parasitism has arisen in many lineages, there are three main groups of parasitic protists of relevance to human and livestock health: the Apicomplexa, including the malaria parasite Plasmodium and coccidian pathogens of livestock such as Eimeria; the excavate flagellates, encompassing a diverse range of protist pathogens including trypanosomes, Leishmania, Giardia and Trichomonas; and the Amoebozoa, including pathogenic amoebae such as Entamoeba. These three groups represent separate, deep branches of the eukaryote tree, underlining their divergent evolutionary histories. Here, I explore what is known about sex in these three main groups of parasitic protists.
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Affiliation(s)
- Wendy Gibson
- School of Biological Sciences, Life Sciences Building, University of Bristol, Bristol, BS8 1TQ, United Kingdom.
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20
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Hofstatter PG, Ribeiro GM, Porfírio‐Sousa AL, Lahr DJG. The Sexual Ancestor of all Eukaryotes: A Defense of the “Meiosis Toolkit”. Bioessays 2020; 42:e2000037. [DOI: 10.1002/bies.202000037] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 05/08/2020] [Indexed: 12/16/2022]
Affiliation(s)
- Paulo G. Hofstatter
- Universidade de São Paulo Instituto de Biociencias, Rua do Matão, travessa 14, A101. São Paulo, CEP.: 05508‐090, Brazil
| | - Giulia M. Ribeiro
- Universidade de São Paulo Instituto de Biociencias, Rua do Matão, travessa 14, A101. São Paulo, CEP.: 05508‐090, Brazil
| | - Alfredo L. Porfírio‐Sousa
- Universidade de São Paulo Instituto de Biociencias, Rua do Matão, travessa 14, A101. São Paulo, CEP.: 05508‐090, Brazil
| | - Daniel J. G. Lahr
- Universidade de São Paulo Instituto de Biociencias, Rua do Matão, travessa 14, A101. São Paulo, CEP.: 05508‐090, Brazil
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21
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Ma Y, Yan G, Han X, Zhang J, Xiong J, Miao W. Sexual cell cycle initiation is regulated by CDK19 and CYC9 in Tetrahymena thermophila. J Cell Sci 2020; 133:jcs235721. [PMID: 32041901 DOI: 10.1242/jcs.235721] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 01/27/2020] [Indexed: 01/31/2023] Open
Abstract
To investigate the mechanisms underlying initiation of the sexual cell cycle in eukaryotes, we have focused on cyclins and cyclin-dependent kinases (CDKs) in the well-studied model ciliate, Tetrahymena thermophila We identified two genes, CDK19 and CYC9, which are highly co-expressed with the mating-associated factors MTA, MTB and HAP2. Both CDK19 and CYC9 were found to be essential for mating in T. thermophila Subcellular localization experiments suggested that these proteins are located at the oral area, including the conjugation junction area, and that CDK19 or CYC9 knockout prevents mating. We found that CDK19 and CYC9 form a complex, and also identified several additional subunits, which may have regulatory or constitutive functions. RNA sequencing analyses and cytological experiments showed that mating is abnormal in both ΔCDK19 and ΔCYC9, mainly at the entry to the co-stimulation stage. These results indicate that the CDK19-CYC9 complex initiates the sexual cell cycle in T. thermophila.
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Affiliation(s)
- Yang Ma
- State Key Laboratory of Freshwater Ecology and Biotechnology, Wuhan 430072, China
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guanxiong Yan
- State Key Laboratory of Freshwater Ecology and Biotechnology, Wuhan 430072, China
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaojie Han
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- College of Fisheries and Life Science, Dalian Ocean University, Dalian 116023, China
| | - Jing Zhang
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Jie Xiong
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Wei Miao
- State Key Laboratory of Freshwater Ecology and Biotechnology, Wuhan 430072, China
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- CAS Center for Excellence in Animal Evolution and Genetics, Kunming 650223, China
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22
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Bloomfield G. The molecular foundations of zygosis. Cell Mol Life Sci 2020; 77:323-330. [PMID: 31203379 PMCID: PMC11105095 DOI: 10.1007/s00018-019-03187-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 05/27/2019] [Accepted: 06/06/2019] [Indexed: 10/26/2022]
Abstract
Zygosis is the generation of new biological individuals by the sexual fusion of gamete cells. Our current understanding of eukaryotic phylogeny indicates that sex is ancestral to all extant eukaryotes. Although sexual development is extremely diverse, common molecular elements have been retained. HAP2-GCS1, a protein that promotes the fusion of gamete cell membranes that is related in structure to certain viral fusogens, is conserved in many eukaryotic lineages, even though gametes vary considerably in form and behaviour between species. Similarly, although zygotes have dramatically different forms and fates in different organisms, diverse eukaryotes share a common developmental programme in which homeodomain-containing transcription factors play a central role. These common mechanistic elements suggest possible common evolutionary histories that, if correct, would have profound implications for our understanding of eukaryogenesis.
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23
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Akematsu T, Sánchez-Fernández R, Kosta F, Holzer E, Loidl J. The Transmembrane Protein Semi1 Positions Gamete Nuclei for Reciprocal Fertilization in Tetrahymena. iScience 2019; 23:100749. [PMID: 31884169 PMCID: PMC6941865 DOI: 10.1016/j.isci.2019.100749] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 11/01/2019] [Accepted: 11/25/2019] [Indexed: 11/01/2022] Open
Abstract
During sexual reproduction in the ciliate, Tetrahymena thermophila, cells of complementary mating type pair ("conjugate") undergo simultaneous meiosis and fertilize each other. In both mating partners only one of the four meiotic products is "selected" to escape autophagy, and this nucleus divides mitotically to produce two pronuclei. The migrating pronucleus of one cell translocates to the mating partner and fuses with its stationary pronucleus and vice versa. Selection of the designated gametic nucleus was thought to depend on its position within the cell because it always attaches to the junction with the partner cell. Here we show that a transmembrane protein, Semi1, is crucial for attachment. Loss of Semi1 causes failure to attach and consequent infertility. However, a nucleus is selected and gives rise to pronuclei regardless of Semi1 expression, indicating that attachment of a nucleus to the junction is not a precondition for selection but follows the selection process.
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Affiliation(s)
- Takahiko Akematsu
- Department of Chromosome Biology, University of Vienna, Dr. Bohr-Gasse 9, Vienna 1030, Austria.
| | | | - Felix Kosta
- Department of Chromosome Biology, University of Vienna, Dr. Bohr-Gasse 9, Vienna 1030, Austria
| | - Elisabeth Holzer
- Department of Chromosome Biology, University of Vienna, Dr. Bohr-Gasse 9, Vienna 1030, Austria
| | - Josef Loidl
- Department of Chromosome Biology, University of Vienna, Dr. Bohr-Gasse 9, Vienna 1030, Austria
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24
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Lobov AA, Maltseva AL, Mikhailova NA, Granovitch AI. The Molecular Mechanisms of Gametic Incompatibility in Invertebrates. Acta Naturae 2019; 11:4-15. [PMID: 31720011 PMCID: PMC6826153 DOI: 10.32607/20758251-2019-11-3-4-15] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 09/09/2019] [Indexed: 12/02/2022] Open
Abstract
Fertilization (gamete fusion followed by zygote formation) is a multistage process. Each stage is mediated by ligand-receptor recognition of gamete interaction molecules. This recognition includes the movement of sperm in the gradient of egg chemoattractants, destruction of the egg envelope by acrosomal proteins, etc. Gametic incompatibility is one of the mechanisms of reproductive isolation. It is based on species-specific molecular interactions that prevent heterospecific fertilization. Although gametic incompatibility may occur in any sexually reproducing organism, it has been studied only in a few model species. Gamete interactions in different taxa involve generally similar processes, but they often employ non-homologous molecules. Gamete recognition proteins evolve rapidly, like immunity proteins, and include many taxon-specific families. In fact, recently appeared proteins particularly contribute to reproductive isolation via gametic incompatibility. Thus, we can assume a multiple, independent origin of this type of reproductive isolation throughout animal evolution. Gametic incompatibility can be achieved at any fertilization stage and entails different consequences at different taxonomic levels and ranges, from complete incompatibility between closely related species to partial incompatibility between distantly related taxa.
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Affiliation(s)
- A. A. Lobov
- Department of Invertebrate Zoology, Faculty of Biology, St Petersburg State University, Universitetskaya Emb. 7/9, St. Petersburg, 199034, Russia
- Laboratory of Regenerative Biomedicine, Institute of Cytology of the Russian Academy of Sciences, Tikhoretsky Ave. 4, St. Petersburg, 194064, Russia
| | - A. L. Maltseva
- Department of Invertebrate Zoology, Faculty of Biology, St Petersburg State University, Universitetskaya Emb. 7/9, St. Petersburg, 199034, Russia
| | - N. A. Mikhailova
- Centre of Cell Technologies, Institute of Cytology of the Russian Academy of Sciences, Tikhoretsky Ave. 4, St. Petersburg, 194064, Russia
| | - A. I. Granovitch
- Department of Invertebrate Zoology, Faculty of Biology, St Petersburg State University, Universitetskaya Emb. 7/9, St. Petersburg, 199034, Russia
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25
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Cole ES, Dmytrenko O, Chmelik CJ, Li M, Christensen TA, Macon EP, Nilsson HJ, Blower RJ, Reuter TG, Beckman JP, Remmers BC, Smith CL, O'Toole E, Ozzello C, Morgan G, Giddings T. Restoration of cellular integrity following "ballistic" pronuclear exchange during Tetrahymena conjugation. Dev Biol 2018; 444:33-40. [PMID: 30268714 DOI: 10.1016/j.ydbio.2018.09.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 09/22/2018] [Accepted: 09/25/2018] [Indexed: 11/15/2022]
Abstract
During sexual reproduction or conjugation, ciliates form a specialized cell adhesion zone for the purpose of exchanging gametic pronuclei. Hundreds of individual membrane fusion events transform the adhesion zone into a perforated membrane curtain, the mating junction. Pronuclei from each mating partner are propelled through this fenestrated membrane junction by a web of short, cris-crossing microtubules. Pronuclear passage results in the formation of two breaches in the membrane junction. Following pronuclear exchange and karyogamy (fertilization), cells seal these twin membrane breaches thereby re-establishing cellular independence. This would seem like a straightforward problem: simply grow membrane in from the edges of each breach in a fashion similar to how animal cells "grow" their cytokinetic furrows or how plant cells construct a cell wall during mitosis. Serial section electron microscopy and 3-D electron tomography reveal that the actual mechanism is less straightforward. Each of the two membrane breaches transforms into a bowed membrane assembly platform. The resulting membrane protrusions continue to grow into the cytoplasm of the mating partner, traverse the cytoplasm in anti-parallel directions and make contact with the plasma membrane that flanks the mating junction. This investigation reveals the details of a novel, developmentally-induced mechanism of membrane disruption and restoration associated with pronuclear exchange and fertilization in the ciliate, Tetrahymena thermophila.
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Affiliation(s)
- Eric S Cole
- Biology Department, St. Olaf College, Northfield, MN, USA.
| | | | - Carl J Chmelik
- Biology Department, St. Olaf College, Northfield, MN, USA
| | - Mark Li
- Biology Department, St. Olaf College, Northfield, MN, USA
| | | | - Elaine P Macon
- Biology Department, St. Olaf College, Northfield, MN, USA
| | | | - Ruth J Blower
- Biology Department, St. Olaf College, Northfield, MN, USA
| | | | - John P Beckman
- Biology Department, St. Olaf College, Northfield, MN, USA
| | | | - Claire L Smith
- Biology Department, St. Olaf College, Northfield, MN, USA
| | - Eileen O'Toole
- The Boulder Laboratory for 3D Electron Microscopy of Cells, Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO, USA
| | - Courtney Ozzello
- The Boulder Laboratory for 3D Electron Microscopy of Cells, Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO, USA
| | - Garry Morgan
- The Boulder Laboratory for 3D Electron Microscopy of Cells, Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO, USA
| | - Thomas Giddings
- The Boulder Laboratory for 3D Electron Microscopy of Cells, Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO, USA
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Baquero E, Fedry J, Legrand P, Krey T, Rey FA. Species-Specific Functional Regions of the Green Alga Gamete Fusion Protein HAP2 Revealed by Structural Studies. Structure 2018; 27:113-124.e4. [PMID: 30416037 PMCID: PMC6327110 DOI: 10.1016/j.str.2018.09.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 08/28/2018] [Accepted: 09/28/2018] [Indexed: 12/25/2022]
Abstract
The cellular fusion protein HAP2, which is structurally homologous to viral class II fusion proteins, drives gamete fusion across several eukaryotic kingdoms. Gamete fusion is a highly controlled process in eukaryotes, and is allowed only between same species gametes. In spite of a conserved architecture, HAP2 displays several species-specific functional regions that were not resolved in the available X-ray structure of the green alga Chlamydomonas reinhardtii HAP2 ectodomain. Here we present an X-ray structure resolving these regions, showing a target membrane interaction surface made by three amphipathic helices in a horseshoe-shaped arrangement. HAP2 from green algae also features additional species-specific motifs inserted in regions that in viral class II proteins are critical for the fusogenic conformational change. Such insertions include a cystine ladder-like module evocative of EGF-like motifs responsible for extracellular protein-protein interactions in animals, and a mucin-like region. These features suggest potential HAP2 interaction sites involved in gamete fusion control. Unprecedented organization of amphipathic α helices in the algal HAP2 fusion loops An inserted EGF-like motif suggests a potential algal-specific fusion control site An adjacent mucin-like region potentially modulates algal-specific interactions Inter-chain stem/domain II interactions stabilize the post-fusion hairpin conformation
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Affiliation(s)
- Eduard Baquero
- Institut Pasteur, Unité de Virologie Structurale, 25-28 Rue du Docteur Roux, 75724 Paris Cedex 15, France; CNRS UMR 3569, 25-28 Rue du Docteur Roux, 75724 Paris Cedex 15, France
| | - Juliette Fedry
- Institut Pasteur, Unité de Virologie Structurale, 25-28 Rue du Docteur Roux, 75724 Paris Cedex 15, France; CNRS UMR 3569, 25-28 Rue du Docteur Roux, 75724 Paris Cedex 15, France
| | - Pierre Legrand
- Synchrotron SOLEIL, L'Orme des Merisiers, 91192 Gif-sur-Yvette, France
| | - Thomas Krey
- Institut Pasteur, Unité de Virologie Structurale, 25-28 Rue du Docteur Roux, 75724 Paris Cedex 15, France; CNRS UMR 3569, 25-28 Rue du Docteur Roux, 75724 Paris Cedex 15, France
| | - Felix A Rey
- Institut Pasteur, Unité de Virologie Structurale, 25-28 Rue du Docteur Roux, 75724 Paris Cedex 15, France; CNRS UMR 3569, 25-28 Rue du Docteur Roux, 75724 Paris Cedex 15, France.
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27
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Abstract
Sex has consequences—indeed, where would we be without it? Yet for all its importance, remarkably little is known about how sex evolved, why it has persisted, or even what mechanisms allow sperm–egg fusion to occur. Fortunately, answers to these questions are beginning to emerge with studies of hapless 2/generative cell specific1 (HAP2/GCS1), a molecular machine that promotes gamete fusion in organisms ranging from protists to flowering plants and insects. In studies by Fedry and colleagues, key structural features of the HAP2 protein are revealed for the first time, lending new insights into its mode of action and reinforcing its relationship to viral proteins that accomplish a similar task and may be intimately linked to the origins of cell–cell fusion events (including sexual reproduction) across evolutionary time. Close structural relationships between proteins that mediate gamete fusion and class II viral fusogens support older theoretical arguments that sexual reproduction in eukaryotes arose with the horizontal transfer of a viral gene to a primordial cell early in the course of evolution.
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Affiliation(s)
- Theodore Clark
- Department of Microbiology and Immunology, Cornell University, Ithaca, New York, United States of America
- * E-mail:
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28
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Fedry J, Forcina J, Legrand P, Péhau-Arnaudet G, Haouz A, Johnson M, Rey FA, Krey T. Evolutionary diversification of the HAP2 membrane insertion motifs to drive gamete fusion across eukaryotes. PLoS Biol 2018; 16:e2006357. [PMID: 30102690 PMCID: PMC6089408 DOI: 10.1371/journal.pbio.2006357] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Accepted: 07/09/2018] [Indexed: 12/20/2022] Open
Abstract
HAPLESS2 (HAP2) is a broadly conserved, gamete-expressed transmembrane protein that was shown recently to be structurally homologous to viral class II fusion proteins, which initiate fusion with host cells via insertion of fusion loops into the host membrane. However, the functional conformation of the HAP2 fusion loops has remained unknown, as the reported X-ray structure of Chlamydomonas reinhardtii HAP2 lacked this critical region. Here, we report a structure-guided alignment that reveals diversification of the proposed HAP2 fusion loops. Representative crystal structures show that in flowering plants, HAP2 has a single prominent fusion loop projecting an amphipathic helix at its apex, while in trypanosomes, three small nonpolar loops of HAP2 are poised to interact with the target membrane. A detailed structure-function analysis of the Arabidopsis HAP2 amphipathic fusion helix defines key residues that are essential for membrane insertion and for gamete fusion. Our study suggests that HAP2 may have evolved multiple modes of membrane insertion to accommodate the diversity of membrane environments it has encountered during eukaryotic evolution. The fusion of gamete plasma membranes is the fundamental cellular event that brings two parental cells together to form a new individual, yet we know surprisingly little about this process at the molecular level. HAPLESS 2 (HAP2) is a conserved sperm plasma membrane protein that is essential for gamete fusion in a diverse array of eukaryotes. It was recently shown to share a common ancestor with viral proteins that drive fusion of the viral envelope with host membranes, but its mechanism of action remained elusive, since the reported structure did not resolve the proposed membrane interaction surface. Here, we report two new HAP2 structures revealing that HAP2 has evolved diverse membrane interaction surfaces. In the flowering plants, HAP2 uses an amphipathic helix that presents nonpolar residues to the target membrane; in trypanosomes, the membrane interaction surface comprises three shallow nonpolar loops.
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Affiliation(s)
- Juliette Fedry
- Unité de Virologie Structurale, Institut Pasteur, Paris, France
- CNRS UMR 3569, Paris, France
- Universite Paris Descartes Sorbonne Paris Cité, Institut Pasteur, Paris, France
- Institute of Virology, Hannover Medical School, Hannover, Germany
| | - Jennifer Forcina
- Brown University, Department of Molecular Biology, Cell Biology, and Biochemistry, Providence, Rhode Island, United States of America
| | - Pierre Legrand
- Synchrotron SOLEIL, L'Orme des Merisiers, Gif-sur-Yvette, France
| | | | - Ahmed Haouz
- Protéopôle, CNRS UMR 3528, Institut Pasteur, Paris, France
| | - Mark Johnson
- Brown University, Department of Molecular Biology, Cell Biology, and Biochemistry, Providence, Rhode Island, United States of America
- * E-mail: (MJ); (FAR); (TK)
| | - Felix A. Rey
- Unité de Virologie Structurale, Institut Pasteur, Paris, France
- CNRS UMR 3569, Paris, France
- * E-mail: (MJ); (FAR); (TK)
| | - Thomas Krey
- Unité de Virologie Structurale, Institut Pasteur, Paris, France
- CNRS UMR 3569, Paris, France
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research (DZIF), Hannover, Germany
- * E-mail: (MJ); (FAR); (TK)
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The AFF-1 exoplasmic fusogen is required for endocytic scission and seamless tube elongation. Nat Commun 2018; 9:1741. [PMID: 29717108 PMCID: PMC5931541 DOI: 10.1038/s41467-018-04091-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 04/03/2018] [Indexed: 12/28/2022] Open
Abstract
Many membranes must merge during cellular trafficking, but fusion and fission events initiating at exoplasmic (non-cytosolic) membrane surfaces are not well understood. Here we show that the C. elegans cell-cell fusogen anchor-cell fusion failure 1 (AFF-1) is required for membrane trafficking events during development of a seamless unicellular tube. EGF-Ras-ERK signaling upregulates AFF-1 expression in the excretory duct tube to promote tube auto-fusion and subsequent lumen elongation. AFF-1 is required for scission of basal endocytic compartments and for apically directed exocytosis to extend the apical membrane. Lumen elongation also requires the transcytosis factor Rab11, but occurs independently of dynamin and clathrin. These results support a transcytosis model of seamless tube lumen growth and show that cell-cell fusogens also can play roles in intracellular membrane trafficking events.
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30
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Wood FC, Heidari A, Tekle YI. Genetic Evidence for Sexuality in Cochliopodium (Amoebozoa). J Hered 2018; 108:769-779. [PMID: 29036297 PMCID: PMC5892394 DOI: 10.1093/jhered/esx078] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2017] [Accepted: 09/18/2017] [Indexed: 12/18/2022] Open
Abstract
Microbial eukaryotes, including amoeboids, display diverse and complex life cycles that may or may not involve sexual reproduction. A recent comprehensive gene inventory study concluded that the Amoebozoa are ancestrally sexual. However, the detection of sex genes in some lineages known for their potentially sexual life cycle was very low. Particularly, the genus Cochliopodium, known to undergo a process of cell fusion, karyogamy, and subsequent fission previously described as parasexual, had no meiosis genes detected. This is likely due to low data representation, given the extensive nuclear fusion observed in the genus. In this study, we generate large amounts of transcriptome data for 2 species of Cochliopodium, known for their high frequency of cellular and nuclear fusion, in order to study the genetic basis of the complex life cycle observed in the genus. We inventory 60 sex-related genes, including 11 meiosis-specific genes, and 31 genes involved in fusion and karyogamy. We find a much higher detection of sex-related genes, including 5 meiosis-specific genes not previously detected in Cochliopodium, in this large transcriptome data. The expressed genes form a near-complete recombination machinery, indicating that Cochliopodium is an actively recombining sexual lineage. We also find 9 fusion-related genes in Cochliopodium, although no conserved fusion-specific genes were detected in the transcriptomes. Cochliopodium thus likely uses lineage specific genes for the fusion and depolyploidization processes. Our results demonstrate that Cochliopodium possess the genetic toolkit for recombination, while the mechanism involving fusion and genome reduction remains to be elucidated.
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Affiliation(s)
- Fiona C Wood
- Department of Biology, Spelman College, 350 Spelman Lane Southwest, Atlanta, GA 30314
| | - Alireza Heidari
- Department of Biology, Spelman College, 350 Spelman Lane Southwest, Atlanta, GA 30314
| | - Yonas I Tekle
- Department of Biology, Spelman College, 350 Spelman Lane Southwest, Atlanta, GA 30314
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31
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Abstract
Cell-cell fusion is essential for fertilization and organ development. Dedicated proteins known as fusogens are responsible for mediating membrane fusion. However, until recently, these proteins either remained unidentified or were poorly understood at the mechanistic level. Here, we review how fusogens surmount multiple energy barriers to mediate cell-cell fusion. We describe how early preparatory steps bring membranes to a distance of ∼10 nm, while fusogens act in the final approach between membranes. The mechanical force exerted by cell fusogens and the accompanying lipidic rearrangements constitute the hallmarks of cell-cell fusion. Finally, we discuss the relationship between viral and eukaryotic fusogens, highlight a classification scheme regrouping a superfamily of fusogens called Fusexins, and propose new questions and avenues of enquiry.
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Affiliation(s)
- Javier M Hernández
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, D-44227 Dortmund, Germany
| | - Benjamin Podbilewicz
- Department of Biology, Technion - Israel Institute of Technology, Haifa 32000, Israel
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32
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Camacho-Nuez M, Hernández-Silva DJ, Castañeda-Ortiz EJ, Paredes-Martínez ME, Rocha-Martínez MK, Alvarez-Sánchez ME, Mercado-Curiel RF, Aguilar-Tipacamu G, Mosqueda J. Hap2, a novel gene in Babesia bigemina is expressed in tick stages, and specific antibodies block zygote formation. Parasit Vectors 2017; 10:568. [PMID: 29132437 PMCID: PMC5683354 DOI: 10.1186/s13071-017-2510-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 10/30/2017] [Indexed: 12/18/2022] Open
Abstract
Background Bovine babesiosis is a tick-borne disease caused by the protozoan parasites of the genus Babesia. In their host vector, Babesia spp. undergo sexual reproduction. Therefore, the development of sexual stages and the subsequent formation of the zygote are essential for the parasite to invade the intestinal cells of the vector tick and continue its life-cycle. HAP2/GCS1 is a protein identified in plants, protozoan parasites and other organisms that has an important role during membrane fusion in fertilization processes. The identification and characterization of HAP-2 protein in Babesia would be very significant to understand the biology of the parasite and to develop a transmission-blocking vaccine in the future. Results To isolate and sequence the hap2 gene DNA from an infected bovine with Babesia bigemina was purified. The hap2 gene was amplified, cloned and sequenced. The sequences of hap2 from four geographically different strains showed high conservation at the amino acid level, including the typical structure with a signal peptide and the HAP2/GSC domain. Antisera anti-HAP2 against the conserved extracellular region of the HAP2 amino acid sequence were obtained from rabbits. The expression of hap2 in the host and vector tissues was analyzed by using semi-quantitative RT-PCR, and the protein was examined by western blot and immunofluorescence. Based on the RT-PCR and WB results, HAP2 is expressed in both, sexual stages induced in vitro, and in infected ticks as well. We did not detect any expression in asexual erythrocytic stages of B. bigemina, relevantly anti-HAP2 specific antibodies were able to block zygotes formation in vitro. Conclusion Babesia bigemina HAP2 is expressed only in tick-infecting stages, and specific antibodies block zygote formation. Further studies regarding the function of HAP2 during tick infection may provide new insights into the molecular mechanisms of sexual reproduction of the parasite. Electronic supplementary material The online version of this article (10.1186/s13071-017-2510-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Minerva Camacho-Nuez
- Posgrado en Ciencias Genómicas, Universidad Autónoma de la Ciudad de México, San Lorenzo, esquina Roberto Gayol, Colonia del Valle Sur, Delegación Benito Juárez, C.P. 03100, Mexico D.F, Mexico
| | - Diego Josimar Hernández-Silva
- Facultad de Ciencias Naturales, Universidad Autónoma de Querétaro, Av. de las Ciencias s/n Col Juriquilla, C.P, 76230, Queretaro, Mexico
| | - Elizabeth Jacqueline Castañeda-Ortiz
- Posgrado en Ciencias Genómicas, Universidad Autónoma de la Ciudad de México, San Lorenzo, esquina Roberto Gayol, Colonia del Valle Sur, Delegación Benito Juárez, C.P. 03100, Mexico D.F, Mexico
| | - María Elena Paredes-Martínez
- Posgrado en Ciencias Genómicas, Universidad Autónoma de la Ciudad de México, San Lorenzo, esquina Roberto Gayol, Colonia del Valle Sur, Delegación Benito Juárez, C.P. 03100, Mexico D.F, Mexico.,Facultad de Ciencias Naturales, Universidad Autónoma de Querétaro, Av. de las Ciencias s/n Col Juriquilla, C.P, 76230, Queretaro, Mexico
| | - Marisol Karina Rocha-Martínez
- Posgrado en Ciencias Genómicas, Universidad Autónoma de la Ciudad de México, San Lorenzo, esquina Roberto Gayol, Colonia del Valle Sur, Delegación Benito Juárez, C.P. 03100, Mexico D.F, Mexico
| | - María Elizbeth Alvarez-Sánchez
- Posgrado en Ciencias Genómicas, Universidad Autónoma de la Ciudad de México, San Lorenzo, esquina Roberto Gayol, Colonia del Valle Sur, Delegación Benito Juárez, C.P. 03100, Mexico D.F, Mexico
| | | | - Gabriela Aguilar-Tipacamu
- Facultad de Ciencias Naturales, Universidad Autónoma de Querétaro, Av. de las Ciencias s/n Col Juriquilla, C.P, 76230, Queretaro, Mexico
| | - Juan Mosqueda
- Facultad de Ciencias Naturales, Universidad Autónoma de Querétaro, Av. de las Ciencias s/n Col Juriquilla, C.P, 76230, Queretaro, Mexico.
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33
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The Ancient Gamete Fusogen HAP2 Is a Eukaryotic Class II Fusion Protein. Cell 2017; 168:904-915.e10. [PMID: 28235200 PMCID: PMC5332557 DOI: 10.1016/j.cell.2017.01.024] [Citation(s) in RCA: 120] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 01/03/2017] [Accepted: 01/19/2017] [Indexed: 02/01/2023]
Abstract
Sexual reproduction is almost universal in eukaryotic life and involves the fusion of male and female haploid gametes into a diploid cell. The sperm-restricted single-pass transmembrane protein HAP2-GCS1 has been postulated to function in membrane merger. Its presence in the major eukaryotic taxa—animals, plants, and protists (including important human pathogens like Plasmodium)—suggests that many eukaryotic organisms share a common gamete fusion mechanism. Here, we report combined bioinformatic, biochemical, mutational, and X-ray crystallographic studies on the unicellular alga Chlamydomonas reinhardtii HAP2 that reveal homology to class II viral membrane fusion proteins. We further show that targeting the segment corresponding to the fusion loop by mutagenesis or by antibodies blocks gamete fusion. These results demonstrate that HAP2 is the gamete fusogen and suggest a mechanism of action akin to viral fusion, indicating a way to block Plasmodium transmission and highlighting the impact of virus-cell genetic exchanges on the evolution of eukaryotic life. The primordial gamete fusogen HAP2 exhibits homology to class II viral fusion proteins HAP2 inserts into the target gamete membrane via a hydrophobic fusion loop HAP2 links virus entry into target cells and the origins of sexual reproduction HAP2 is a sex-specific target for blocking fertilization in multiple kingdoms
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34
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Structure-Function Studies Link Class II Viral Fusogens with the Ancestral Gamete Fusion Protein HAP2. Curr Biol 2017; 27:651-660. [PMID: 28238660 DOI: 10.1016/j.cub.2017.01.049] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 12/31/2016] [Accepted: 01/24/2017] [Indexed: 11/24/2022]
Abstract
The conserved transmembrane protein, HAP2/GCS1, has been linked to fertility in a wide range of taxa and is hypothesized to be an ancient gamete fusogen. Using template-based structural homology modeling, we now show that the ectodomain of HAP2 orthologs from Tetrahymena thermophila and other species adopt a protein fold remarkably similar to the dengue virus E glycoprotein and related class II viral fusogens. To test the functional significance of this predicted structure, we developed a flow-cytometry-based assay that measures cytosolic exchange across the conjugation junction to rapidly probe the effects of HAP2 mutations in the Tetrahymena system. Using this assay, alterations to a region in and around a predicted "fusion loop" in T. thermophila HAP2 were found to abrogate membrane pore formation in mating cells. Consistent with this, a synthetic peptide corresponding to the HAP2 fusion loop was found to interact directly with model membranes in a variety of biophysical assays. These results raise interesting questions regarding the evolutionary relationships of class II membrane fusogens and harken back to a long-held argument that eukaryotic sex arose as the byproduct of selection for the horizontal transfer of a "selfish" genetic element from cell to cell via membrane fusion.
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35
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Valansi C, Moi D, Leikina E, Matveev E, Graña M, Chernomordik LV, Romero H, Aguilar PS, Podbilewicz B. Arabidopsis HAP2/GCS1 is a gamete fusion protein homologous to somatic and viral fusogens. J Cell Biol 2017; 216:571-581. [PMID: 28137780 PMCID: PMC5350521 DOI: 10.1083/jcb.201610093] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 12/27/2016] [Accepted: 01/18/2017] [Indexed: 01/08/2023] Open
Abstract
Cell-cell fusion is inherent to sexual reproduction. Loss of HAPLESS 2/GENERATIVE CELL SPECIFIC 1 (HAP2/GCS1) proteins results in gamete fusion failure in diverse organisms, but their exact role is unclear. In this study, we show that Arabidopsis thaliana HAP2/GCS1 is sufficient to promote mammalian cell-cell fusion. Hemifusion and complete fusion depend on HAP2/GCS1 presence in both fusing cells. Furthermore, expression of HAP2 on the surface of pseudotyped vesicular stomatitis virus results in homotypic virus-cell fusion. We demonstrate that the Caenorhabditis elegans Epithelial Fusion Failure 1 (EFF-1) somatic cell fusogen can replace HAP2/GCS1 in one of the fusing membranes, indicating that HAP2/GCS1 and EFF-1 share a similar fusion mechanism. Structural modeling of the HAP2/GCS1 protein family predicts that they are homologous to EFF-1 and viral class II fusion proteins (e.g., Zika virus). We name this superfamily Fusexins: fusion proteins essential for sexual reproduction and exoplasmic merger of plasma membranes. We suggest a common origin and evolution of sexual reproduction, enveloped virus entry into cells, and somatic cell fusion.
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Affiliation(s)
- Clari Valansi
- Department of Biology, Technion- Israel Institute of Technology, Haifa 32000, Israel
| | - David Moi
- Laboratorio de Biología Celular de Membranas, Instituto de Investigaciones Biotecnologicas "Dr. Rodolfo A. Ugalde," Universidad Nacional de San Martin, Buenos Aires, CP1650, Argentina
| | - Evgenia Leikina
- Section on Membrane Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892
| | - Elena Matveev
- Department of Biology, Technion- Israel Institute of Technology, Haifa 32000, Israel
| | - Martín Graña
- Unidad de Bioinformática, Institut Pasteur Montevideo, Montevideo 11400, Uruguay
| | - Leonid V Chernomordik
- Section on Membrane Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892
| | - Héctor Romero
- Laboratorio de Organización y Evolución del Genoma, Unidad de Genómica Evolutiva, Departamento Ecología y Evolución, Facultad de Ciencias/Centro Universitario Regional del Este, Universidad de la República, Montevideo 11400, Uruguay
| | - Pablo S Aguilar
- Laboratorio de Biología Celular de Membranas, Instituto de Investigaciones Biotecnologicas "Dr. Rodolfo A. Ugalde," Universidad Nacional de San Martin, Buenos Aires, CP1650, Argentina
| | - Benjamin Podbilewicz
- Department of Biology, Technion- Israel Institute of Technology, Haifa 32000, Israel
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36
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Abstract
Compared with the animal kingdom, fertilization is particularly complex in flowering plants (angiosperms). Sperm cells of angiosperms have lost their motility and require transportation as a passive cargo by the pollen tube cell to the egg apparatus (egg cell and accessory synergid cells). Sperm cell release from the pollen tube occurs after intensive communication between the pollen tube cell and the receptive synergid, culminating in the lysis of both interaction partners. Following release of the two sperm cells, they interact and fuse with two dimorphic female gametes (the egg and the central cell) forming the major seed components embryo and endosperm, respectively. This process is known as double fertilization. Here, we review the current understanding of the processes of sperm cell reception, gamete interaction, their pre-fertilization activation and fusion, as well as the mechanisms plants use to prevent the fusion of egg cells with multiple sperm cells. The role of Ca(2+) is highlighted in these various processes and comparisons are drawn between fertilization mechanisms in flowering plants and other eukaryotes, including mammals.
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Affiliation(s)
- Thomas Dresselhaus
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, 93040 Regensburg, Germany.
| | - Stefanie Sprunck
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, 93040 Regensburg, Germany
| | - Gary M Wessel
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, Rhode Island 02912, USA
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37
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Lehtonen J, Kokko H, Parker GA. What do isogamous organisms teach us about sex and the two sexes? Philos Trans R Soc Lond B Biol Sci 2016; 371:20150532. [PMID: 27619696 PMCID: PMC5031617 DOI: 10.1098/rstb.2015.0532] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/24/2016] [Indexed: 11/12/2022] Open
Abstract
Isogamy is a reproductive system where all gametes are morphologically similar, especially in terms of size. Its importance goes beyond specific cases: to this day non-anisogamous systems are common outside of multicellular animals and plants, they can be found in all eukaryotic super-groups, and anisogamous organisms appear to have isogamous ancestors. Furthermore, because maleness is synonymous with the production of small gametes, an explanation for the initial origin of males and females is synonymous with understanding the transition from isogamy to anisogamy. As we show here, this transition may also be crucial for understanding why sex itself remains common even in taxa with high costs of male production (the twofold cost of sex). The transition to anisogamy implies the origin of male and female sexes, kickstarts the subsequent evolution of sex roles, and has a major impact on the costliness of sexual reproduction. Finally, we combine some of the consequences of isogamy and anisogamy in a thought experiment on the maintenance of sexual reproduction. We ask what happens if there is a less than twofold benefit to sex (not an unlikely scenario as large short-term benefits have proved difficult to find), and argue that this could lead to a situation where lineages that evolve anisogamy-and thus the highest costs of sex-end up being associated with constraints that make invasion by asexual reproduction unlikely (the 'anisogamy gateway' hypothesis).This article is part of the themed issue 'Weird sex: the underappreciated diversity of sexual reproduction'.
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Affiliation(s)
- Jussi Lehtonen
- Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Hanna Kokko
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Geoff A Parker
- Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
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Cold ER, Vasta GR, Robledo JAF. Transient Expression of Plasmodium berghei MSP8 and HAP2 in the Marine Protozoan Parasite Perkinsus marinus. J Parasitol 2016; 103:118-122. [PMID: 27723436 DOI: 10.1645/16-88] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Perkinsus marinus is a protozoan parasite of molluscs that can be propagated in vitro in a defined culture medium, in the absence of host cells. We previously reported that P. marinus trophozoites can be transfected with high efficiency by electroporation using a plasmid based on MOE, a highly expressed gene, and proposed its potential use as a "pseudoparasite." This is a novel gene expression platform for parasites of medical relevance for which the choice of the surrogate organism is based on phylogenetic affinity to the parasite of interest, while taking advantage of the whole engineered surrogate organism as a vaccination adjuvant. Here we improved the original transfection plasmid by incorporating a multicloning site, an enterokinase recognition sequence upstream of GFP, and a His-tag and demonstrate its potential suitability for the heterologous expression of Plasmodium sp. genes relevant to the development of anti-malarial vaccines. Plasmodium berghei HAP2 and MSP8, currently considered candidate genes for a malaria vaccine, were cloned into p[MOE]:GFP, and the constructs were used to transfect P. marinus trophozoites. Within 48 hr of transfection we observed fluorescent cells indicating that the P. berghei genes fused to GFP were expressed. The expression appeared to be transient for both P. berghei genes, as florescence of the transfectants diminished gradually over time. Although this heterologous expression system will require optimization for integration and constitutive expression of Plasmodium genes, our results represent attainment of proof for the "pseudoparasite" concept we previously proposed, as we show that the engineered P. marinus system has the potential to become a surrogate system suitable for expression of Plasmodium spp. genes of interest, which could eventually be used as a malaria vaccine delivery platform. The aim of the present study was to test the ability of marine protozoan parasite P. marinus to express genes of P. berghei .
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Affiliation(s)
- Emma R Cold
- Bigelow Laboratory for Ocean Sciences, East Boothbay, Maine 04544
| | - Gerardo R Vasta
- Bigelow Laboratory for Ocean Sciences, East Boothbay, Maine 04544
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Maruyama D, Ohtsu M, Higashiyama T. Cell fusion and nuclear fusion in plants. Semin Cell Dev Biol 2016; 60:127-135. [PMID: 27473789 DOI: 10.1016/j.semcdb.2016.07.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 07/25/2016] [Accepted: 07/26/2016] [Indexed: 10/21/2022]
Abstract
Eukaryotic cells are surrounded by a plasma membrane and have a large nucleus containing the genomic DNA, which is enclosed by a nuclear envelope consisting of the outer and inner nuclear membranes. Although these membranes maintain the identity of cells, they sometimes fuse to each other, such as to produce a zygote during sexual reproduction or to give rise to other characteristically polyploid tissues. Recent studies have demonstrated that the mechanisms of plasma membrane or nuclear membrane fusion in plants are shared to some extent with those of yeasts and animals, despite the unique features of plant cells including thick cell walls and intercellular connections. Here, we summarize the key factors in the fusion of these membranes during plant reproduction, and also focus on "non-gametic cell fusion," which was thought to be rare in plant tissue, in which each cell is separated by a cell wall.
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Affiliation(s)
- Daisuke Maruyama
- Kihara Institute for Biological Research, Yokohama City University, 641-12 Maioka-cho, Totsuka-ku, Yokohama, Kanagawa 244-0813, Japan.
| | - Mina Ohtsu
- Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602, Japan
| | - Tetsuya Higashiyama
- Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602, Japan; Institute of Transformative Bio-Molecules (ITbM), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602, Japan; JST ERATO Higashiyama Live-Holonics Project, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602, Japan
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Soulavie F, Sundaram MV. Auto-fusion and the shaping of neurons and tubes. Semin Cell Dev Biol 2016; 60:136-145. [PMID: 27436685 DOI: 10.1016/j.semcdb.2016.07.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 07/15/2016] [Accepted: 07/15/2016] [Indexed: 12/14/2022]
Abstract
Cells adopt specific shapes that are necessary for specific functions. For example, some neurons extend elaborate arborized dendrites that can contact multiple targets. Epithelial and endothelial cells can form tiny seamless unicellular tubes with an intracellular lumen. Recent advances showed that cells can auto-fuse to acquire those specific shapes. During auto-fusion, a cell merges two parts of its own plasma membrane. In contrast to cell-cell fusion or macropinocytic fission, which result in the merging or formation of two separate membrane bound compartments, auto-fusion preserves one compartment, but changes its shape. The discovery of auto-fusion in C. elegans was enabled by identification of specific protein fusogens, EFF-1 and AFF-1, that mediate cell-cell fusion. Phenotypic characterization of eff-1 and aff-1 mutants revealed that fusogen-mediated fusion of two parts of the same cell can be used to sculpt dendritic arbors, reconnect two parts of an axon after injury, or form a hollow unicellular tube. Similar auto-fusion events recently were detected in vertebrate cells, suggesting that auto-fusion could be a widely used mechanism for shaping neurons and tubes.
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Affiliation(s)
- Fabien Soulavie
- Department of Genetics, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA 19104,United States
| | - Meera V Sundaram
- Department of Genetics, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA 19104,United States.
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Okamoto M, Yamada L, Fujisaki Y, Bloomfield G, Yoshida K, Kuwayama H, Sawada H, Mori T, Urushihara H. Two HAP2-GCS1 homologs responsible for gamete interactions in the cellular slime mold with multiple mating types: Implication for common mechanisms of sexual reproduction shared by plants and protozoa and for male-female differentiation. Dev Biol 2016; 415:6-13. [PMID: 27189178 PMCID: PMC4910948 DOI: 10.1016/j.ydbio.2016.05.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 04/23/2016] [Accepted: 05/13/2016] [Indexed: 11/28/2022]
Abstract
Fertilization is a central event in sexual reproduction, and understanding its molecular mechanisms has both basic and applicative biological importance. Recent studies have uncovered the molecules that mediate this process in a variety of organisms, making it intriguing to consider conservation and evolution of the mechanisms of sexual reproduction across phyla. The social amoeba Dictyostelium discoideum undergoes sexual maturation and forms gametes under dark and humid conditions. It exhibits three mating types, type-I, -II, and -III, for the heterothallic mating system. Based on proteome analyses of the gamete membranes, we detected expression of two homologs of the plant fertilization protein HAP2-GCS1. When their coding genes were disrupted in type-I and type-II strains, sexual potency was completely lost, whereas disruption in the type-III strain did not affect mating behavior, suggesting that the latter acts as female in complex organisms. Our results demonstrate the highly conserved function of HAP2-GCS1 in gamete interactions and suggest the presence of additional allo-recognition mechanisms in D. discoideum gametes. Two HAP2-GCS1 homologs are expressed in Dictyostelium discoideum gametes. Both homologs are responsible for the sexual cell fusion. One mating type (III) out of 3 is HAP2-GCS1-independent, corresponding to female.
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Affiliation(s)
- Marina Okamoto
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
| | - Lixy Yamada
- Sugashima Marine Biological Laboratory, Graduate School of Science, Nagoya University, 429-63 Sugashima, Toba, Mie 517-0004, Japan
| | - Yukie Fujisaki
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
| | - Gareth Bloomfield
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK
| | - Kentaro Yoshida
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
| | - Hidekazu Kuwayama
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
| | - Hitoshi Sawada
- Sugashima Marine Biological Laboratory, Graduate School of Science, Nagoya University, 429-63 Sugashima, Toba, Mie 517-0004, Japan
| | - Toshiyuki Mori
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hideko Urushihara
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
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Gotesman M, Williams SA. Using a Handheld Gene Gun for Genetic Transformation of Tetrahymena thermophila. Methods Mol Biol 2016; 1365:373-383. [PMID: 26498798 DOI: 10.1007/978-1-4939-3124-8_22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
This chapter describes protocols for using a handheld gene gun to deliver transformation vectors for overexpression of genes or gene replacement in the macronucleus of Tetrahymena thermophila. The protocols provide helpful information for preparing Tetrahymena for biolistic bombardment, preparation of vector-coated microcarriers, and basic gene gun operating procedures.
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Affiliation(s)
- Michael Gotesman
- Department of Biology, Technion - Israel Institute of Technology, Technion, Haifa, 3200003, Israel.
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Plattner H. Signalling in ciliates: long- and short-range signals and molecular determinants for cellular dynamics. Biol Rev Camb Philos Soc 2015; 92:60-107. [PMID: 26487631 DOI: 10.1111/brv.12218] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 07/28/2015] [Accepted: 08/21/2015] [Indexed: 12/30/2022]
Abstract
In ciliates, unicellular representatives of the bikont branch of evolution, inter- and intracellular signalling pathways have been analysed mainly in Paramecium tetraurelia, Paramecium multimicronucleatum and Tetrahymena thermophila and in part also in Euplotes raikovi. Electrophysiology of ciliary activity in Paramecium spp. is a most successful example. Established signalling mechanisms include plasmalemmal ion channels, recently established intracellular Ca2+ -release channels, as well as signalling by cyclic nucleotides and Ca2+ . Ca2+ -binding proteins (calmodulin, centrin) and Ca2+ -activated enzymes (kinases, phosphatases) are involved. Many organelles are endowed with specific molecules cooperating in signalling for intracellular transport and targeted delivery. Among them are recently specified soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs), monomeric GTPases, H+ -ATPase/pump, actin, etc. Little specification is available for some key signal transducers including mechanosensitive Ca2+ -channels, exocyst complexes and Ca2+ -sensor proteins for vesicle-vesicle/membrane interactions. The existence of heterotrimeric G-proteins and of G-protein-coupled receptors is still under considerable debate. Serine/threonine kinases dominate by far over tyrosine kinases (some predicted by phosphoproteomic analyses). Besides short-range signalling, long-range signalling also exists, e.g. as firmly installed microtubular transport rails within epigenetically determined patterns, thus facilitating targeted vesicle delivery. By envisaging widely different phenomena of signalling and subcellular dynamics, it will be shown (i) that important pathways of signalling and cellular dynamics are established already in ciliates, (ii) that some mechanisms diverge from higher eukaryotes and (iii) that considerable uncertainties still exist about some essential aspects of signalling.
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Affiliation(s)
- Helmut Plattner
- Department of Biology, University of Konstanz, PO Box M625, 78457, Konstanz, Germany
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Mori T, Kawai-Toyooka H, Igawa T, Nozaki H. Gamete Dialogs in Green Lineages. MOLECULAR PLANT 2015; 8:1442-54. [PMID: 26145252 DOI: 10.1016/j.molp.2015.06.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 06/15/2015] [Accepted: 06/28/2015] [Indexed: 05/20/2023]
Abstract
Gamete fusion is a core process of sexual reproduction and, in both plants and animals, different sex gametes fuse within species. Although most of the molecular factors involved in gamete interaction are still unknown in various sex-possessing eukaryotes, reports of such factors in algae and land plants have been increasing in the past decade. In particular, knowledge of gamete interaction in flowering plants and green algae has increased since the identification of the conserved gamete fusion factor generative cell specific 1/hapless 2 (GCS1/HAP2). GCS1 was first identified as a pollen generative cell-specific transmembrane protein in the lily (Lilium longiflorum), and was then shown to function not only in flowering plant gamete fusion but also in various eukaryotes, including unicellular protists and metazoans. In addition, although initially restricted to Chlamydomonas, knowledge of gamete attachment in flowering plants was also acquired. This review focuses on recent progress in the study of gamete interaction in volvocine green algae and flowering plants and discusses conserved mechanisms of gamete recognition, attachment, and fusion leading to zygote formation.
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Affiliation(s)
- Toshiyuki Mori
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
| | - Hiroko Kawai-Toyooka
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Tomoko Igawa
- Graduate School of Horticulture, Chiba University, 648 Matsudo, Matsudo, Chiba 271-8510, Japan
| | - Hisayoshi Nozaki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
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Plattner H, Verkhratsky A. The ancient roots of calcium signalling evolutionary tree. Cell Calcium 2015; 57:123-32. [DOI: 10.1016/j.ceca.2014.12.004] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 12/05/2014] [Indexed: 12/26/2022]
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Liu Y, Pei J, Grishin N, Snell WJ. The cytoplasmic domain of the gamete membrane fusion protein HAP2 targets the protein to the fusion site in Chlamydomonas and regulates the fusion reaction. Development 2015; 142:962-71. [PMID: 25655701 DOI: 10.1242/dev.118844] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Cell-cell fusion between gametes is a defining step during development of eukaryotes, yet we know little about the cellular and molecular mechanisms of the gamete membrane fusion reaction. HAP2 is the sole gamete-specific protein in any system that is broadly conserved and shown by gene disruption to be essential for gamete fusion. The wide evolutionary distribution of HAP2 (also known as GCS1) indicates it was present in the last eukaryotic common ancestor and, therefore, dissecting its molecular properties should provide new insights into fundamental features of fertilization. HAP2 acts at a step after membrane adhesion, presumably directly in the merger of the lipid bilayers. Here, we use the unicellular alga Chlamydomonas to characterize contributions of key regions of HAP2 to protein location and function. We report that mutation of three strongly conserved residues in the ectodomain has no effect on targeting or fusion, although short deletions that include those residues block surface expression and fusion. Furthermore, HAP2 lacking a 237-residue segment of the cytoplasmic region is expressed at the cell surface, but fails to localize at the apical membrane patch specialized for fusion and fails to rescue fusion. Finally, we provide evidence that the ancient HAP2 contained a juxta-membrane, multi-cysteine motif in its cytoplasmic region, and that mutation of a cysteine dyad in this motif preserves protein localization, but substantially impairs HAP2 fusion activity. Thus, the ectodomain of HAP2 is essential for its surface expression, and the cytoplasmic region targets HAP2 to the site of fusion and regulates the fusion reaction.
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Affiliation(s)
- Yanjie Liu
- Department of Cell Biology, University of Texas Southwestern Medical Center, 6000 Harry Hines Boulevard, Dallas, TX 75390-9039, USA
| | - Jimin Pei
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, 6000 Harry Hines Boulevard, Dallas, TX 75390-9039, USA
| | - Nick Grishin
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, 6000 Harry Hines Boulevard, Dallas, TX 75390-9039, USA
| | - William J Snell
- Department of Cell Biology, University of Texas Southwestern Medical Center, 6000 Harry Hines Boulevard, Dallas, TX 75390-9039, USA
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Membrane dynamics at the nuclear exchange junction during early mating (one to four hours) in the ciliate Tetrahymena thermophila. EUKARYOTIC CELL 2014; 14:116-27. [PMID: 25107923 DOI: 10.1128/ec.00164-14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Using serial-section transmission electron microscopy and three-dimensional (3D) electron tomography, we characterized membrane dynamics that accompany the construction of a nuclear exchange junction between mating cells in the ciliate Tetrahymena thermophila. Our methods revealed a number of previously unknown features. (i) Membrane fusion is initiated by the extension of hundreds of 50-nm-diameter protrusions from the plasma membrane. These protrusions extend from both mating cells across the intercellular space to fuse with membrane of the mating partner. (ii) During this process, small membrane-bound vesicles or tubules are shed from the plasma membrane and into the extracellular space within the junction. The resultant vesicle-filled pockets within the extracellular space are referred to as junction lumens. (iii) As junction lumens fill with extracellular microvesicles and swell, the plasma membrane limiting these swellings undergoes another deformation, pinching off vesicle-filled vacuoles into the cytoplasm (reclamation). (iv) These structures (resembling multivesicular bodies) seem to associate with autophagosomes abundant near the exchange junction. We propose a model characterizing the membrane-remodeling events that establish cytoplasmic continuity between mating Tetrahymena cells. We also discuss the possible role of nonvesicular lipid transport in conditioning the exchange junction lipid environment. Finally, we raise the possibility of an intercellular signaling mechanism involving microvesicle shedding and uptake.
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