1
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Tian L, Li Y, Shi Y. Dark and Dronc activation in Drosophila melanogaster. Proc Natl Acad Sci U S A 2024; 121:e2312784121. [PMID: 38381783 PMCID: PMC10907274 DOI: 10.1073/pnas.2312784121] [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: 07/26/2023] [Accepted: 01/19/2024] [Indexed: 02/23/2024] Open
Abstract
The onset of apoptosis is characterized by a cascade of caspase activation, where initiator caspases are activated by a multimeric adaptor complex known as the apoptosome. In Drosophila melanogaster, the initiator caspase Dronc undergoes autocatalytic activation in the presence of the Dark apoptosome. Despite rigorous investigations, the activation mechanism for Dronc remains elusive. Here, we report the cryo-EM structures of an auto-inhibited Dark monomer and a single-layered, multimeric Dark/Dronc complex. Our biochemical analysis suggests that the auto-inhibited Dark oligomerizes upon binding to Dronc, which is sufficient for the activation of both Dark and Dronc. In contrast, the previously observed double-ring Dark apoptosome may represent a non-functional or "off-pathway" conformation. These findings expand our understanding on the molecular mechanism of apoptosis in Drosophila.
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Affiliation(s)
- Lu Tian
- Beijing Frontier Research Center for Biological Structures, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing100084, China
| | - Yini Li
- Beijing Frontier Research Center for Biological Structures, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing100084, China
| | - Yigong Shi
- Beijing Frontier Research Center for Biological Structures, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing100084, China
- Westlake Laboratory of Life Sciences and Biomedicine, Westlake Institute for Advanced Study, Hangzhou310024, China
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou310024, China
- Institute of Biology, Westlake Institute for Advanced Study, Hangzhou310024, China
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2
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Matamoro-Vidal A, Cumming T, Davidović A, Levillayer F, Levayer R. Patterned apoptosis has an instructive role for local growth and tissue shape regulation in a fast-growing epithelium. Curr Biol 2024; 34:376-388.e7. [PMID: 38215743 PMCID: PMC10808510 DOI: 10.1016/j.cub.2023.12.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 07/13/2023] [Accepted: 12/11/2023] [Indexed: 01/14/2024]
Abstract
What regulates organ size and shape remains one fundamental mystery of modern biology. Research in this area has primarily focused on deciphering the regulation in time and space of growth and cell division, while the contribution of cell death has been overall neglected. This includes studies of the Drosophila wing, one of the best-characterized systems for the study of growth and patterning, undergoing massive growth during larval stage and important morphogenetic remodeling during pupal stage. So far, it has been assumed that cell death was relatively neglectable in this tissue both during larval stage and pupal stage, and as a result, the pattern of growth was usually attributed to the distribution of cell division. Here, using systematic mapping and registration combined with quantitative assessment of clone size and disappearance as well as live imaging, we outline a persistent pattern of cell death and clone elimination emerging in the larval wing disc and persisting during pupal wing morphogenesis. Local variation of cell death is associated with local variation of clone size, pointing to an impact of cell death on local growth that is not fully compensated by proliferation. Using morphometric analyses of adult wing shape and genetic perturbations, we provide evidence that patterned death locally and globally affects adult wing shape and size. This study describes a roadmap for precise assessment of the contribution of cell death to tissue shape and outlines an important instructive role of cell death in modulating quantitatively local growth and morphogenesis of a fast-growing tissue.
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Affiliation(s)
- Alexis Matamoro-Vidal
- Department of Developmental and Stem Cell Biology, Institut Pasteur, CNRS UMR 3738, Université Paris Cité, Cell Death and Epithelial Homeostasis Unit, 75015 Paris, France
| | - Tom Cumming
- Department of Developmental and Stem Cell Biology, Institut Pasteur, CNRS UMR 3738, Université Paris Cité, Cell Death and Epithelial Homeostasis Unit, 75015 Paris, France; PPU program Institut Pasteur, Sorbonne Université, Collège Doctoral, 75005 Paris, France
| | - Anđela Davidović
- Institut Pasteur, Université Paris Cité, Bioinformatics and Biostatistics Hub, 75015 Paris, France
| | - Florence Levillayer
- Department of Developmental and Stem Cell Biology, Institut Pasteur, CNRS UMR 3738, Université Paris Cité, Cell Death and Epithelial Homeostasis Unit, 75015 Paris, France
| | - Romain Levayer
- Department of Developmental and Stem Cell Biology, Institut Pasteur, CNRS UMR 3738, Université Paris Cité, Cell Death and Epithelial Homeostasis Unit, 75015 Paris, France.
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3
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Nowaskie RR, Kitch A, Adams A, Anandaraj A, Apawan E, Bañuelos L, Betz CJ, Bogunia JM, Buechlein N, Burns MR, Collier HA, Collins Z, Combs K, Dakarian VD, Daniel A, De Jesus III CM, Erickson JD, Estrada B, Estrada K, Fields S, Gabriel M, Garcia RM, Gitamo S, Granath E, Hardin SN, Hattling E, Henriquez AVL, Hernandez D, Johnson L, Kim AH, Kolley LK, Larue KM, Lockwood E, Longoria N, Lopez C, Lopez-Roca Fernandez RC, Lozano S, Manthie C, May T, Mehrzad Z, Mendoza I, Mohan S, Mounthachak C, Muyizere M, Myers MR, Newton J, Nwawueze A, Paredes AJ, Pezdek MN, Phat Nguyen H, Pobuda N, Sadat S, Sailor JJ, Santiago D, Sbarbaro M, Schultz III DE, Senobari AN, Shouse EM, Snarski SM, Solano E, Solis Campos N, Stewart E, Szczepaniak J, Tejeda M, Teoli DF, Tran M, Trivedi N, Uribe Aristizabal L, Vargas BZ, Walker III KW, Wasiqi J, Wong J, Zachrel A, Shah HP, Small E, Watts CT, Croonquist P, Devergne O, Jones AK, Taylor EE, Kagey JD, Merkle JA. clifford B.4.1 , an allele of CG1603 , causes tissue overgrowth in the Drosophila melanogaster eye. MICROPUBLICATION BIOLOGY 2023; 2023:10.17912/micropub.biology.000936. [PMID: 37680216 PMCID: PMC10481159 DOI: 10.17912/micropub.biology.000936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 08/15/2023] [Accepted: 08/17/2023] [Indexed: 09/09/2023]
Abstract
Mutant B.4.1 , generated via EMS mutagenesis in Drosophila melanogaster , was studied by undergraduate students participating in the Fly-CURE. After inducing genetically mosaic tissue in the adult eye, B.4.1 mutant tissue displays a robust increase in cell division and a rough appearance. Complementation mapping and sequence analysis identified a nonsense mutation in the gene CG1603 , which we named clifford ( cliff ) due to observed increases in red-pigmented mutant tissue compared to controls. cliff encodes a zinc finger-containing protein implicated in transcriptional control. RNAi knockdown of cliff similarly results in rough eyes, confirming a role for Cliff in eye development.
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Affiliation(s)
| | - Ashley Kitch
- University of Evansville, Evansville, Indiana, United States
| | - Abby Adams
- Northern Illinois University, DeKalb, Illinois, United States
| | - Abinaya Anandaraj
- Anoka-Ramsey Community College, Coon Rapids, Minnesota, United States
| | - Ethan Apawan
- The University of Texas at San Antonio, San Antonio, Texas, United States
| | | | - Cassandra J Betz
- Anoka-Ramsey Community College, Coon Rapids, Minnesota, United States
| | - Julia M Bogunia
- Northern Illinois University, DeKalb, Illinois, United States
| | | | - Morgan R Burns
- Northern Illinois University, DeKalb, Illinois, United States
| | | | - Zach Collins
- Northern Illinois University, DeKalb, Illinois, United States
| | - Kynzie Combs
- University of Evansville, Evansville, Indiana, United States
| | - Vana D Dakarian
- Northern Illinois University, DeKalb, Illinois, United States
| | - Abigail Daniel
- University of Evansville, Evansville, Indiana, United States
| | | | - John D Erickson
- University of Evansville, Evansville, Indiana, United States
| | - Bianca Estrada
- Northern Illinois University, DeKalb, Illinois, United States
| | - Kevin Estrada
- Northern Illinois University, DeKalb, Illinois, United States
| | - Sydney Fields
- Northern Illinois University, DeKalb, Illinois, United States
| | - Maya Gabriel
- The University of Texas at San Antonio, San Antonio, Texas, United States
| | | | - Sylvia Gitamo
- Anoka-Ramsey Community College, Coon Rapids, Minnesota, United States
| | - Emma Granath
- Northern Illinois University, DeKalb, Illinois, United States
| | - Sabrina N Hardin
- The University of Texas at San Antonio, San Antonio, Texas, United States
| | - Emily Hattling
- Anoka-Ramsey Community College, Coon Rapids, Minnesota, United States
| | | | - Destiny Hernandez
- The University of Texas at San Antonio, San Antonio, Texas, United States
| | - Luke Johnson
- Anoka-Ramsey Community College, Coon Rapids, Minnesota, United States
| | - Annie H Kim
- University of Evansville, Evansville, Indiana, United States
| | | | | | - Erin Lockwood
- Northern Illinois University, DeKalb, Illinois, United States
| | - Nelia Longoria
- The University of Texas at San Antonio, San Antonio, Texas, United States
| | - Cassandra Lopez
- Northern Illinois University, DeKalb, Illinois, United States
| | | | - Sofia Lozano
- The University of Texas at San Antonio, San Antonio, Texas, United States
| | - Carissa Manthie
- Anoka-Ramsey Community College, Coon Rapids, Minnesota, United States
| | - Trinity May
- Anoka-Ramsey Community College, Coon Rapids, Minnesota, United States
| | - Zorah Mehrzad
- University of Evansville, Evansville, Indiana, United States
| | - Itzel Mendoza
- Northern Illinois University, DeKalb, Illinois, United States
| | - Somya Mohan
- The University of Texas at San Antonio, San Antonio, Texas, United States
| | | | | | | | - Jayce Newton
- Northern Illinois University, DeKalb, Illinois, United States
| | | | | | | | - Hoang Phat Nguyen
- Anoka-Ramsey Community College, Coon Rapids, Minnesota, United States
| | - Nadia Pobuda
- Anoka-Ramsey Community College, Coon Rapids, Minnesota, United States
| | - Sahar Sadat
- Northern Illinois University, DeKalb, Illinois, United States
| | | | - David Santiago
- Northern Illinois University, DeKalb, Illinois, United States
| | | | | | | | - Emma M Shouse
- University of Evansville, Evansville, Indiana, United States
| | - Sarah M Snarski
- Northern Illinois University, DeKalb, Illinois, United States
| | | | | | - Elnora Stewart
- University of Evansville, Evansville, Indiana, United States
| | | | - Michael Tejeda
- Northern Illinois University, DeKalb, Illinois, United States
| | - Dominic F Teoli
- Northern Illinois University, DeKalb, Illinois, United States
| | - Michael Tran
- The University of Texas at San Antonio, San Antonio, Texas, United States
| | - Nishita Trivedi
- University of Evansville, Evansville, Indiana, United States
| | | | - Bryan Z Vargas
- Northern Illinois University, DeKalb, Illinois, United States
| | | | - Joseph Wasiqi
- Northern Illinois University, DeKalb, Illinois, United States
| | - Joyi Wong
- The University of Texas at San Antonio, San Antonio, Texas, United States
| | - Adira Zachrel
- Northern Illinois University, DeKalb, Illinois, United States
| | - Hemin P Shah
- Northern Illinois University, DeKalb, Illinois, United States
| | - Elizabeth Small
- Northern Illinois University, DeKalb, Illinois, United States
| | - Charlie T Watts
- University of Evansville, Evansville, Indiana, United States
| | - Paula Croonquist
- Anoka-Ramsey Community College, Coon Rapids, Minnesota, United States
| | | | - Amy K Jones
- The University of Texas at San Antonio, San Antonio, Texas, United States
| | | | - Jacob D Kagey
- University of Detroit Mercy, Detroit, Michigan, United States
| | - Julie A Merkle
- University of Evansville, Evansville, Indiana, United States
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4
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Wu Y, Sun Y, Richet E, Han Z, Chai J. Structural basis for negative regulation of the Escherichia coli maltose system. Nat Commun 2023; 14:4925. [PMID: 37582800 PMCID: PMC10427625 DOI: 10.1038/s41467-023-40447-y] [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: 12/18/2022] [Accepted: 07/26/2023] [Indexed: 08/17/2023] Open
Abstract
Proteins from the signal transduction ATPases with numerous domains (STAND) family are known to play an important role in innate immunity. However, it remains less well understood how they function in transcriptional regulation. MalT is a bacterial STAND that controls the Escherichia coli maltose system. Inactive MalT is sequestered by different inhibitory proteins such as MalY. Here, we show that MalY interacts with one oligomerization interface of MalT to form a 2:2 complex. MalY represses MalT activity by blocking its oligomerization and strengthening ADP-mediated MalT autoinhibition. A loop region N-terminal to the nucleotide-binding domain (NBD) of MalT has a dual role in mediating MalT autoinhibition and activation. Structural comparison shows that ligand-binding induced oligomerization is required for stabilizing the C-terminal domains and conferring DNA-binding activity. Together, our study reveals the mechanism whereby a prokaryotic STAND is inhibited by a repressor protein and offers insights into signaling by STAND transcription activators.
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Affiliation(s)
- Yuang Wu
- Institute of Biochemistry, University of Cologne, Cologne, Germany
- Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Yue Sun
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Evelyne Richet
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, INSERM U1306, Unité Biologie et génétique de la paroi bactérienne, Paris, France
| | - Zhifu Han
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Jijie Chai
- Institute of Biochemistry, University of Cologne, Cologne, Germany.
- Max Planck Institute for Plant Breeding Research, Cologne, Germany.
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, China.
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, China.
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5
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Aamidor SE, Cardoso-Júnior CAM, Harianto J, Nowell CJ, Cole L, Oldroyd BP, Ronai I. Reproductive plasticity and oogenesis in the queen honey bee (Apis mellifera). JOURNAL OF INSECT PHYSIOLOGY 2022; 136:104347. [PMID: 34902433 DOI: 10.1016/j.jinsphys.2021.104347] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 11/28/2021] [Accepted: 12/07/2021] [Indexed: 06/14/2023]
Abstract
In the honey bee (Apis mellifera), queen and worker castes originate from identical genetic templates but develop into different phenotypes. Queens lay up to 2000 eggs daily whereas workers are sterile in the queen's presence. Periodically queens stop laying: during swarming, when resources are scarce in winter, and when they are confined to a cage by beekeepers. We used confocal microscopy and gene expression assays to investigate the control of oogenesis in the ovaries of honey bee queens that were caged inside and outside the colony. We find evidence that queens use a different combination of 'checkpoints' to regulate oogenesis compared to honey bee workers and other insect species. However, both queen and worker castes likely use the same programmed cell death pathways to terminate oocyte development at their caste-specific checkpoints. Our results also suggest that a key factor driving the termination of oogenesis in queens is nutritional stress. Thus, queens may regulate oogenesis via the same regulatory pathways that were utilised by ancestral solitary species but likely have adjusted physiological checkpoints to suit their highly-derived life history.
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Affiliation(s)
- Sarah E Aamidor
- Behaviour and Genetics of Social Insects Laboratory, Ecology and Evolution, School of Life and Environmental Science, Macleay Building A12, University of Sydney, NSW 2006, Australia.
| | - Carlos A M Cardoso-Júnior
- Departamento de Biologia Celulare Bioagentes Patogênicos, Faculdade de Medicina de Ribeirao Preto, Universidade de Sao Paulo, Ribeirao Preto, Brazil
| | - Januar Harianto
- School of Life and Environmental Science, Macleay Building A12, University of Sydney, NSW 2006, Australia
| | - Cameron J Nowell
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Victoria, Australia
| | - Louise Cole
- Microbial Imaging Facility, I3 Institute, Faculty of Science, The University of Technology Sydney, Australia
| | - Benjamin P Oldroyd
- Behaviour and Genetics of Social Insects Laboratory, Ecology and Evolution, School of Life and Environmental Science, Macleay Building A12, University of Sydney, NSW 2006, Australia
| | - Isobel Ronai
- Behaviour and Genetics of Social Insects Laboratory, Ecology and Evolution, School of Life and Environmental Science, Macleay Building A12, University of Sydney, NSW 2006, Australia
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6
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Kiyozumi D, Ikawa M. Proteolysis in Reproduction: Lessons From Gene-Modified Organism Studies. Front Endocrinol (Lausanne) 2022; 13:876370. [PMID: 35600599 PMCID: PMC9114714 DOI: 10.3389/fendo.2022.876370] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 03/28/2022] [Indexed: 12/17/2022] Open
Abstract
The physiological roles of proteolysis are not limited to degrading unnecessary proteins. Proteolysis plays pivotal roles in various biological processes through cleaving peptide bonds to activate and inactivate proteins including enzymes, transcription factors, and receptors. As a wide range of cellular processes is regulated by proteolysis, abnormalities or dysregulation of such proteolytic processes therefore often cause diseases. Recent genetic studies have clarified the inclusion of proteases and protease inhibitors in various reproductive processes such as development of gonads, generation and activation of gametes, and physical interaction between gametes in various species including yeast, animals, and plants. Such studies not only clarify proteolysis-related factors but the biological processes regulated by proteolysis for successful reproduction. Here the physiological roles of proteases and proteolysis in reproduction will be reviewed based on findings using gene-modified organisms.
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Affiliation(s)
- Daiji Kiyozumi
- Research Institute for Microbial Diseases, Osaka University, Suita, Japan
- PRESTO, Japan Science and Technology Agency, Kawaguchi, Japan
| | - Masahito Ikawa
- Research Institute for Microbial Diseases, Osaka University, Suita, Japan
- The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
- CREST, Japan Science and Technology Agency, Kawaguchi, Japan
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7
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Dziedziech A, Theopold U. Proto-pyroptosis: An Ancestral Origin for Mammalian Inflammatory Cell Death Mechanism in Drosophila melanogaster. J Mol Biol 2021; 434:167333. [PMID: 34756921 DOI: 10.1016/j.jmb.2021.167333] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 10/18/2021] [Accepted: 10/21/2021] [Indexed: 02/07/2023]
Abstract
Pyroptosis has been described in mammalian systems to be a form of programmed cell death that is important in immune function through the subsequent release of cytokines and immune effectors upon cell bursting. This form of cell death has been increasingly well-characterized in mammals and can occur using alternative routes however, across phyla, there has been little evidence for the existence of pyroptosis. Here we provide evidence for an ancient origin of pyroptosis in an in vivo immune scenario in Drosophila melanogaster. Crystal cells, a type of insect blood cell, were recruited to wounds and ruptured subsequently releasing their cytosolic content in a caspase-dependent manner. This inflammatory-based programmed cell death mechanism fits the features of pyroptosis, never before described in an in vivo immune scenario in insects and relies on ancient apoptotic machinery to induce proto-pyroptosis. Further, we unveil key players upstream in the activation of cell death in these cells including the apoptosome which may play an alternative role akin to the inflammasome in proto-pyroptosis. Thus, Drosophila may be a suitable model for studying the functional significance of pyroptosis in the innate immune system.
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Affiliation(s)
- A Dziedziech
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE 10691 Stockholm, Sweden.
| | - U Theopold
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE 10691 Stockholm, Sweden.
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8
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Buhlman LM, Krishna G, Jones TB, Thomas TC. Drosophila as a model to explore secondary injury cascades after traumatic brain injury. Biomed Pharmacother 2021; 142:112079. [PMID: 34463269 PMCID: PMC8458259 DOI: 10.1016/j.biopha.2021.112079] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/11/2021] [Accepted: 08/17/2021] [Indexed: 12/14/2022] Open
Abstract
Drosophilae are emerging as a valuable model to study traumatic brain injury (TBI)-induced secondary injury cascades that drive persisting neuroinflammation and neurodegenerative pathology that imposes significant risk for long-term neurological deficits. As in mammals, TBI in Drosophila triggers axonal injury, metabolic crisis, oxidative stress, and a robust innate immune response. Subsequent neurodegeneration stresses quality control systems and perpetuates an environment for neuroprotection, regeneration, and delayed cell death via highly conserved cell signaling pathways. Fly injury models continue to be developed and validated for both whole-body and head-specific injury to isolate, evaluate, and modulate these parallel pathways. In conjunction with powerful genetic tools, the ability for longitudinal evaluation, and associated neurological deficits that can be tested with established behavioral tasks, Drosophilae are an attractive model to explore secondary injury cascades and therapeutic intervention after TBI. Here, we review similarities and differences between mammalian and fly pathophysiology and highlight strategies for their use in translational neurotrauma research.
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Affiliation(s)
- Lori M Buhlman
- Biomedical Sciences Program, Midwestern University, Glendale, AZ, USA.
| | - Gokul Krishna
- Department of Child Health, University of Arizona College of Medicine - Phoenix, Phoenix, AZ, USA; Barrow Neurological Institute at Phoenix Children's Hospital, Phoenix, AZ, USA
| | - T Bucky Jones
- Department of Anatomy, Midwestern University, Glendale, AZ, USA
| | - Theresa Currier Thomas
- Department of Child Health, University of Arizona College of Medicine - Phoenix, Phoenix, AZ, USA; Barrow Neurological Institute at Phoenix Children's Hospital, Phoenix, AZ, USA; Phoenix VA Health Care System, Phoenix, AZ, USA.
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9
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Hounsell C, Fan Y. The Duality of Caspases in Cancer, as Told through the Fly. Int J Mol Sci 2021; 22:8927. [PMID: 34445633 PMCID: PMC8396359 DOI: 10.3390/ijms22168927] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 08/15/2021] [Accepted: 08/17/2021] [Indexed: 12/12/2022] Open
Abstract
Caspases, a family of cysteine-aspartic proteases, have an established role as critical components in the activation and initiation of apoptosis. Alongside this a variety of non-apoptotic caspase functions in proliferation, differentiation, cellular plasticity and cell migration have been reported. The activity level and context are important factors in determining caspase function. As a consequence of their critical role in apoptosis and beyond, caspases are uniquely situated to have pathological roles, including in cancer. Altered caspase function is a common trait in a variety of cancers, with apoptotic evasion defined as a "hallmark of cancer". However, the role that caspases play in cancer is much more complex, acting both to prevent and to promote tumourigenesis. This review focuses on the major findings in Drosophila on the dual role of caspases in tumourigenesis. This has major implications for cancer treatments, including chemotherapy and radiotherapy, with the activation of apoptosis being the end goal. However, such treatments may inadvertently have adverse effects on promoting tumour progression and acerbating the cancer. A comprehensive understanding of the dual role of caspases will aid in the development of successful cancer therapeutic approaches.
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Affiliation(s)
| | - Yun Fan
- School of Biosciences, University of Birmingham, Birmingham B15 2TT, UK;
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10
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Jia H, Xue S, Lei L, Fan M, Peng S, Li T, Nagarajan R, Carver B, Ma Z, Deng J, Yan L. A semi-dominant NLR allele causes whole-seedling necrosis in wheat. PLANT PHYSIOLOGY 2021; 186:483-496. [PMID: 33576803 PMCID: PMC8154059 DOI: 10.1093/plphys/kiab058] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 01/26/2021] [Indexed: 05/26/2023]
Abstract
Programmed cell death (PCD) and apoptosis have key functions in development and disease resistance in diverse organisms; however, the induction of necrosis remains poorly understood. Here, we identified a semi-dominant mutant allele that causes the necrotic death of the entire seedling (DES) of wheat (Triticum aestivum L.) in the absence of any pathogen or external stimulus. Positional cloning of the lethal allele mDES1 revealed that this premature death via necrosis was caused by a point mutation from Asp to Asn at amino acid 441 in a nucleotide-binding leucine-rich repeat protein containing nucleotide-binding domain and leucine-rich repeats. The overexpression of mDES1 triggered necrosis and PCD in transgenic plants. However, transgenic wheat harboring truncated wild-type DES1 proteins produced through gene editing that exhibited no significant developmental defects. The point mutation in mDES1 did not cause changes in this protein in the oligomeric state, but mDES1 failed to interact with replication protein A leading to abnormal mitotic cell division. DES1 is an ortholog of Sr35, which recognizes a Puccinia graminis f. sp. tritici stem rust disease effector in wheat, but mDES1 gained function as a direct inducer of plant death. These findings shed light on the intersection of necrosis, apoptosis, and autoimmunity in plants.
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Affiliation(s)
- Haiyan Jia
- Department of Plant and Soil Sciences, Oklahoma State University, Stillwater, OK 74078, USA
- Crop Genomics and Bioinformatics Center and National Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Jiangsu, Nanjing 210095, China
| | - Shulin Xue
- Department of Plant and Soil Sciences, Oklahoma State University, Stillwater, OK 74078, USA
- Crop Genomics and Bioinformatics Center and National Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Jiangsu, Nanjing 210095, China
| | - Lei Lei
- Department of Plant and Soil Sciences, Oklahoma State University, Stillwater, OK 74078, USA
| | - Min Fan
- Department of Plant and Soil Sciences, Oklahoma State University, Stillwater, OK 74078, USA
- Crop Genomics and Bioinformatics Center and National Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Jiangsu, Nanjing 210095, China
| | - Shuxia Peng
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Tian Li
- Department of Plant and Soil Sciences, Oklahoma State University, Stillwater, OK 74078, USA
| | - Ragupathi Nagarajan
- Department of Plant and Soil Sciences, Oklahoma State University, Stillwater, OK 74078, USA
| | - Brett Carver
- Department of Plant and Soil Sciences, Oklahoma State University, Stillwater, OK 74078, USA
| | - Zhengqiang Ma
- Crop Genomics and Bioinformatics Center and National Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Jiangsu, Nanjing 210095, China
| | - Junpeng Deng
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Liuling Yan
- Department of Plant and Soil Sciences, Oklahoma State University, Stillwater, OK 74078, USA
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11
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Zaveri A, Bose A, Sharma S, Rajendran A, Biswas P, Shenoy AR, Visweswariah SS. Mycobacterial STAND adenylyl cyclases: The HTH domain binds DNA to form biocrystallized nucleoids. Biophys J 2021; 120:1231-1246. [PMID: 33217386 PMCID: PMC8059089 DOI: 10.1016/j.bpj.2020.11.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 11/03/2020] [Accepted: 11/10/2020] [Indexed: 01/13/2023] Open
Abstract
Mycobacteria harbor a unique class of adenylyl cyclases with a complex domain organization consisting of an N-terminal putative adenylyl cyclase domain fused to a nucleotide-binding adaptor shared by apoptotic protease-activating factor-1, plant resistance proteins, and CED-4 (NB-ARC) domain, a tetratricopeptide repeat (TPR) domain, and a C-terminal helix-turn-helix (HTH) domain. The products of the rv0891c-rv0890c genes represent a split gene pair, where Rv0891c has sequence similarity to adenylyl cyclases, and Rv0890c harbors the NB-ARC-TPR-HTH domains. Rv0891c had very low adenylyl cyclase activity so it could represent a pseudoenzyme. By analyzing the genomic locus, we could express and purify Rv0890c and find that the NB-ARC domain binds ATP and ADP, but does not hydrolyze these nucleotides. Using systematic evolution of ligands by exponential enrichment (SELEX), we identified DNA sequences that bound to the HTH domain of Rv0890c. Uniquely, the HTH domain could also bind RNA. Atomic force microscopy revealed that binding of Rv0890c to DNA was sequence independent, and binding of adenine nucleotides to the protein induced the formation of higher order structures that may represent biocrystalline nucleoids. This represents the first characterization of this group of proteins and their unusual biochemical properties warrant further studies into their physiological roles in future.
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Affiliation(s)
- Anisha Zaveri
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India
| | - Avipsa Bose
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India
| | - Suruchi Sharma
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India
| | - Abinaya Rajendran
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India
| | - Priyanka Biswas
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India
| | - Avinash R Shenoy
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India
| | - Sandhya S Visweswariah
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India.
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12
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Lindblad JL, Tare M, Amcheslavsky A, Shields A, Bergmann A. Non-apoptotic enteroblast-specific role of the initiator caspase Dronc for development and homeostasis of the Drosophila intestine. Sci Rep 2021; 11:2645. [PMID: 33514791 PMCID: PMC7846589 DOI: 10.1038/s41598-021-81261-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 01/05/2021] [Indexed: 02/07/2023] Open
Abstract
The initiator caspase Dronc is the only CARD-domain containing caspase in Drosophila and is essential for apoptosis. Here, we report that homozygous dronc mutant adult animals are short-lived due to the presence of a poorly developed, defective and leaky intestine. Interestingly, this mutant phenotype can be significantly rescued by enteroblast-specific expression of dronc+ in dronc mutant animals, suggesting that proper Dronc function specifically in enteroblasts, one of four cell types in the intestine, is critical for normal development of the intestine. Furthermore, enteroblast-specific knockdown of dronc in adult intestines triggers hyperplasia and differentiation defects. These enteroblast-specific functions of Dronc do not require the apoptotic pathway and thus occur in a non-apoptotic manner. In summary, we demonstrate that an apoptotic initiator caspase has a very critical non-apoptotic function for normal development and for the control of the cell lineage in the adult midgut and therefore for proper physiology and homeostasis.
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Affiliation(s)
- Jillian L Lindblad
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA, 01605, USA
| | - Meghana Tare
- Department of Biological Sciences, Birla Institute of Technology and Science, Pilani, Pilani, Rajasthan, 333031, India
| | - Alla Amcheslavsky
- University of Massachusetts Medical School, MassBiologics, 460 Walk Hill Road, Boston, MA, USA
| | - Alicia Shields
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA, 01605, USA
| | - Andreas Bergmann
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA, 01605, USA.
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13
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Arthurton L, Nahotko DA, Alonso J, Wendler F, Baena‐Lopez LA. Non-apoptotic caspase activation preserves Drosophila intestinal progenitor cells in quiescence. EMBO Rep 2020; 21:e48892. [PMID: 33135280 PMCID: PMC7726796 DOI: 10.15252/embr.201948892] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 09/21/2020] [Accepted: 10/01/2020] [Indexed: 12/11/2022] Open
Abstract
Caspase malfunction in stem cells often precedes the appearance and progression of multiple types of cancer, including human colorectal cancer. However, the caspase-dependent regulation of intestinal stem cell properties remains poorly understood. Here, we demonstrate that Dronc, the Drosophila ortholog of caspase-9/2 in mammals, limits the number of intestinal progenitor cells and their entry into the enterocyte differentiation programme. Strikingly, these unexpected roles for Dronc are non-apoptotic and have been uncovered under experimental conditions without epithelial replenishment. Supporting the non-apoptotic nature of these functions, we show that they require the enzymatic activity of Dronc, but are largely independent of the apoptotic pathway. Alternatively, our genetic and functional data suggest that they are linked to the caspase-mediated regulation of Notch signalling. Our findings provide novel insights into the non-apoptotic, caspase-dependent modulation of stem cell properties that could improve our understanding of the origin of intestinal malignancies.
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Affiliation(s)
- Lewis Arthurton
- Sir William Dunn School of PathologyUniversity of OxfordOxfordshireUK
| | | | - Jana Alonso
- Laboratorio de Agrobiología Juan José Bravo Rodríguez (Cabildo Insular de La Palma)Unidad Técnica del IPNA‐CSICSanta Cruz de La PalmaSpain
| | - Franz Wendler
- Sir William Dunn School of PathologyUniversity of OxfordOxfordshireUK
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14
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Bolobolova EU, Dorogova NV, Fedorova SA. Major Scenarios of Genetically Regulated Cell Death during Oogenesis in Drosophilamelanogaster. RUSS J GENET+ 2020. [DOI: 10.1134/s1022795420060034] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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15
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Wang LH, Baker NE. Salvador-Warts-Hippo pathway regulates sensory organ development via caspase-dependent nonapoptotic signaling. Cell Death Dis 2019; 10:669. [PMID: 31511495 PMCID: PMC6739336 DOI: 10.1038/s41419-019-1924-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Revised: 08/03/2019] [Accepted: 08/27/2019] [Indexed: 12/19/2022]
Abstract
The fundamental roles for the Salvador–Warts–Hippo (SWH) pathway are widely characterized in growth regulation and organ size control. However, the function of SWH pathway is less known in cell fate determination. Here we uncover a novel role of the SWH signaling pathway in determination of cell fate during neural precursor (sensory organ precursor, SOP) development. Inactivation of the SWH pathway in SOP of the wing imaginal discs affects caspase-dependent bristle patterning in an apoptosis-independent process. Such nonapoptotic functions of caspases have been implicated in inflammation, proliferation, cellular remodeling, and cell fate determination. Our data indicate an effect on the Wingless (Wg)/Wnt pathway. Previously, caspases were proposed to cleave and activate a negative regulator of Wg/Wnt signaling, Shaggy (Sgg)/GSK3β. Surprisingly, we found that a noncleavable form of Sgg encoded from the endogenous locus after CRISPR-Cas9 modification supported almost normal bristle patterning, indicating that Sgg might not be the main target of the caspase-dependent nonapoptotic process. Collectively, our results outline a new function of SWH signaling that crosstalks to caspase-dependent nonapoptotic signaling and Wg/Wnt signaling in neural precursor development, which might be implicated in neuronal pathogenesis.
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Affiliation(s)
- Lan-Hsin Wang
- Graduate Institute of Life Sciences, National Defense Medical Center, 161 Sec 6, Minquan E. Rd, Taipei, 11490, Taiwan.
| | - Nicholas E Baker
- Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY, 10461, USA. .,Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY, 10461, USA. .,Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY, 10461, USA.
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16
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Cullin-4B E3 ubiquitin ligase mediates Apaf-1 ubiquitination to regulate caspase-9 activity. PLoS One 2019; 14:e0219782. [PMID: 31329620 PMCID: PMC6645535 DOI: 10.1371/journal.pone.0219782] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 07/01/2019] [Indexed: 11/25/2022] Open
Abstract
Apoptotic protease-activating factor 1 (Apaf-1) is a component of apoptosome, which regulates caspase-9 activity. In addition to apoptosis, Apaf-1 plays critical roles in the intra-S-phase checkpoint; therefore, impaired expression of Apaf-1 has been demonstrated in chemotherapy-resistant malignant melanoma and nuclear translocation of Apaf-1 has represented a favorable prognosis of patients with non-small cell lung cancer. In contrast, increased levels of Apaf-1 protein are observed in the brain in Huntington’s disease. The regulation of Apaf-1 protein is not yet fully understood. In this study, we show that etoposide triggers the interaction of Apaf-1 with Cullin-4B, resulting in enhanced Apaf-1 ubiquitination. Ubiquitinated Apaf-1, which was degraded in healthy cells, binds p62 and forms aggregates in the cytosol. This complex of ubiquitinated Apaf-1 and p62 induces caspase-9 activation following MG132 treatment of HEK293T cells that stably express bcl-xl. These results show that ubiquitinated Apaf-1 may activate caspase-9 under conditions of proteasome impairment.
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17
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Animal NLRs continue to inform plant NLR structure and function. Arch Biochem Biophys 2019; 670:58-68. [PMID: 31071301 DOI: 10.1016/j.abb.2019.05.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 04/10/2019] [Accepted: 05/01/2019] [Indexed: 12/22/2022]
Abstract
Plant NLRs share many of the structural hallmarks of their animal counterparts. At a functional level, the central nucleotide-binding pocket appears to have binding and hydrolysis activities, similar to that of animal NLRs. The TIR domains of plant NLRs have been shown to self-associate, and there is emerging evidence that full-length plant NLRs may do so as well. It is therefore tempting to speculate that plant NLRs may form higher-order complexes similar to those of the mammalian inflammasome. Here we review the available knowledge on structure-function relationships in plant NLRs, focusing on how the information available on animal NLRs informs the mechanism of plant NLR function, and highlight the evidence that innate immunity signalling pathways in multicellular organisms often require the formation of higher-order protein complexes.
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18
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Tixeira R, Poon IKH. Disassembly of dying cells in diverse organisms. Cell Mol Life Sci 2019; 76:245-257. [PMID: 30317529 PMCID: PMC11105331 DOI: 10.1007/s00018-018-2932-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 09/25/2018] [Accepted: 10/01/2018] [Indexed: 01/09/2023]
Abstract
Programmed cell death (PCD) is a conserved phenomenon in multicellular organisms required to maintain homeostasis. Among the regulated cell death pathways, apoptosis is a well-described form of PCD in mammalian cells. One of the characteristic features of apoptosis is the change in cellular morphology, often leading to the fragmentation of the cell into smaller membrane-bound vesicles through a process called apoptotic cell disassembly. Interestingly, some of these morphological changes and cell disassembly are also noted in cells of other organisms including plants, fungi and protists while undergoing 'apoptosis-like PCD'. This review will describe morphologic features leading to apoptotic cell disassembly, as well as its regulation and function in mammalian cells. The occurrence of cell disassembly during cell death in other organisms namely zebrafish, fly and worm, as well as in other eukaryotic cells will also be discussed.
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Affiliation(s)
- Rochelle Tixeira
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia.
| | - Ivan K H Poon
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia.
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19
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Yalonetskaya A, Mondragon AA, Elguero J, McCall K. I Spy in the Developing Fly a Multitude of Ways to Die. J Dev Biol 2018; 6:E26. [PMID: 30360387 PMCID: PMC6316796 DOI: 10.3390/jdb6040026] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 10/18/2018] [Accepted: 10/19/2018] [Indexed: 12/11/2022] Open
Abstract
Cell proliferation and cell death are two opposing, yet complementary fundamental processes in development. Cell proliferation provides new cells, while developmental programmed cell death adjusts cell numbers and refines structures as an organism grows. Apoptosis is the best-characterized form of programmed cell death; however, there are many other non-apoptotic forms of cell death that occur throughout development. Drosophila is an excellent model for studying these varied forms of cell death given the array of cellular, molecular, and genetic techniques available. In this review, we discuss select examples of apoptotic and non-apoptotic cell death that occur in different tissues and at different stages of Drosophila development. For example, apoptosis occurs throughout the nervous system to achieve an appropriate number of neurons. Elsewhere in the fly, non-apoptotic modes of developmental cell death are employed, such as in the elimination of larval salivary glands and midgut during metamorphosis. These and other examples discussed here demonstrate the versatility of Drosophila as a model organism for elucidating the diverse modes of programmed cell death.
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Affiliation(s)
- Alla Yalonetskaya
- Cell and Molecular Biology Program, Department of Biology, 5 Cummington Mall, Boston University, Boston, MA 02215, USA.
| | - Albert A Mondragon
- Molecular Biology, Cell Biology, and Biochemistry Program, 5 Cummington Mall, Boston University, Boston, MA 02215, USA.
| | - Johnny Elguero
- Cell and Molecular Biology Program, Department of Biology, 5 Cummington Mall, Boston University, Boston, MA 02215, USA.
| | - Kimberly McCall
- Cell and Molecular Biology Program, Department of Biology, 5 Cummington Mall, Boston University, Boston, MA 02215, USA.
- Molecular Biology, Cell Biology, and Biochemistry Program, 5 Cummington Mall, Boston University, Boston, MA 02215, USA.
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20
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Gillespie JJ, Driscoll TP, Verhoeve VI, Rahman MS, Macaluso KR, Azad AF. A Tangled Web: Origins of Reproductive Parasitism. Genome Biol Evol 2018; 10:2292-2309. [PMID: 30060072 PMCID: PMC6133264 DOI: 10.1093/gbe/evy159] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/26/2018] [Indexed: 12/13/2022] Open
Abstract
While typically a flea parasite and opportunistic human pathogen, the presence of Rickettsia felis (strain LSU-Lb) in the non-blood-feeding, parthenogenetically reproducing booklouse, Liposcelis bostrychophila, provides a system to ascertain factors governing not only host transitions but also obligate reproductive parasitism (RP). Analysis of plasmid pLbAR, unique to R. felis str. LSU-Lb, revealed a toxin–antitoxin module with similar features to prophage-encoded toxin–antitoxin modules utilized by parasitic Wolbachia strains to induce another form of RP, cytoplasmic incompatibility, in their arthropod hosts. Curiously, multiple deubiquitinase and nuclease domains of the large (3,841 aa) pLbAR toxin, as well the entire antitoxin, facilitated the detection of an assortment of related proteins from diverse intracellular bacteria, including other reproductive parasites. Our description of these remarkable components of the intracellular mobilome, including their presence in certain arthropod genomes, lends insight on the evolution of RP, while invigorating research on parasite-mediated biocontrol of arthropod-borne viral and bacterial pathogens.
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Affiliation(s)
- Joseph J Gillespie
- Department of Microbiology and Immunology, University of Maryland School of Medicine
| | | | | | | | - Kevin R Macaluso
- Vector-borne Disease Laboratories, Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University
| | - Abdu F Azad
- Department of Microbiology and Immunology, University of Maryland School of Medicine
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21
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Dorstyn L, Akey CW, Kumar S. New insights into apoptosome structure and function. Cell Death Differ 2018; 25:1194-1208. [PMID: 29765111 DOI: 10.1038/s41418-017-0025-z] [Citation(s) in RCA: 126] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 10/23/2017] [Accepted: 10/25/2017] [Indexed: 02/08/2023] Open
Abstract
The apoptosome is a platform that activates apical procaspases in response to intrinsic cell death signals. Biochemical and structural studies in the past two decades have extended our understanding of apoptosome composition and structure, while illuminating the requirements for initiator procaspase activation. A number of studies have now provided high-resolution structures for apoptosomes from C. elegans (CED-4), D. melanogaster (Dark), and H. sapiens (Apaf-1), which define critical protein interfaces, including intra and interdomain interactions. This work also reveals interactions of apoptosomes with their respective initiator caspases, CED-3, Dronc and procaspase-9. Structures of the human apoptosome have defined the requirements for cytochrome c binding, which triggers the conversion of inactive Apaf-1 molecules to an extended, assembly competent state. While recent data have provided a detailed understanding of apoptosome formation and procaspase activation, they also highlight important evolutionary differences with functional implications for caspase activation. Comparison of the CARD/CARD disks and apoptosomes formed by CED-4, Dark and Apaf-1. Cartoons of the active states of the CARD-CARD disks, illustrating the two CED-4 CARD tetrameric ring layers (CED4a and CED4b; top row) and the binding of 8 Dronc CARDs and between 3-4 pc-9 CARDs, to the Dark and Apaf-1 CARD disk respectively (middle and lower rows). Ribbon diagrams of the active CED-4, Dark and Apaf-1 apoptosomes are shown (right column).
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Affiliation(s)
- Loretta Dorstyn
- Center for Cancer Biology, University of South Australia and SA Pathology, Frome Road, Adelaide, SA, 5001, Australia.
| | - Christopher W Akey
- Department of Physiology and Biophysics, Boston University School of Medicine, 700 Albany Street, Boston, MA, 02118, USA
| | - Sharad Kumar
- Center for Cancer Biology, University of South Australia and SA Pathology, Frome Road, Adelaide, SA, 5001, Australia.
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22
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Starfish Apaf-1 activates effector caspase-3/9 upon apoptosis of aged eggs. Sci Rep 2018; 8:1611. [PMID: 29371610 PMCID: PMC5785508 DOI: 10.1038/s41598-018-19845-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 01/09/2018] [Indexed: 11/29/2022] Open
Abstract
Caspase-3-related DEVDase activity is initiated upon apoptosis in unfertilized starfish eggs. In this study, we cloned a starfish procaspase-3 corresponding to mammalian effector caspase containing a CARD that is similar to the amino terminal CARD of mammalian capsase-9, and we named it procaspase-3/9. Recombinant procaspase-3/9 expressed at 15 °C was cleaved to form active caspase-3/9 which has DEVDase activity. Microinjection of the active caspase-3/9 into starfish oocytes/eggs induced apoptosis. An antibody against the recombinant protein recognized endogenous procaspase-3/9 in starfish oocytes, which was cleaved upon apoptosis in aged unfertilized eggs. These results indicate that caspase-3/9 is an effector caspase in starfish. To verify the mechanism of caspase-3/9 activation, we cloned starfish Apaf-1 containing a CARD, a NOD, and 11 WD40 repeat regions, and we named it sfApaf-1. Recombinant sfApaf-1 CARD interacts with recombinant caspase-3/9 CARD and with endogenous procaspase-3/9 in cell-free preparations made from starfish oocytes, causing the formation of active caspase-3/9. When the cell-free preparation without mitochondria was incubated with inactive recombinant procaspase-3/9 expressed at 37 °C, DEVDase activity increased and apoptosome-like complexes were formed in the high molecular weight fractions containing both sfApaf-1 and cleaved caspase-3/9. These results suggest that sfApaf-1 activation is not dependent on cytochrome c.
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23
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Tango7 regulates cortical activity of caspases during reaper-triggered changes in tissue elasticity. Nat Commun 2017; 8:603. [PMID: 28928435 PMCID: PMC5605750 DOI: 10.1038/s41467-017-00693-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 07/20/2017] [Indexed: 11/08/2022] Open
Abstract
Caspases perform critical functions in both living and dying cells; however, how caspases perform physiological functions without killing the cell remains unclear. Here we identify a novel physiological function of caspases at the cortex of Drosophila salivary glands. In living glands, activation of the initiator caspase dronc triggers cortical F-actin dismantling, enabling the glands to stretch as they accumulate secreted products in the lumen. We demonstrate that tango7, not the canonical Apaf-1-adaptor dark, regulates dronc activity at the cortex; in contrast, dark is required for cytoplasmic activity of dronc during salivary gland death. Therefore, tango7 and dark define distinct subcellular domains of caspase activity. Furthermore, tango7-dependent cortical dronc activity is initiated by a sublethal pulse of the inhibitor of apoptosis protein (IAP) antagonist reaper. Our results support a model in which biological outcomes of caspase activation are regulated by differential amplification of IAP antagonists, unique caspase adaptor proteins, and mutually exclusive subcellular domains of caspase activity. Caspases are known for their role in cell death, but they can also participate in other physiological functions without killing the cells. Here the authors show that unique caspase adaptor proteins can regulate caspase activity within mutually-exclusive and independently regulated subcellular domains.
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24
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Proapoptotic function of deubiquitinase DUSP31 in Drosophila. Oncotarget 2017; 8:70452-70462. [PMID: 29050293 PMCID: PMC5642568 DOI: 10.18632/oncotarget.19715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2017] [Accepted: 06/26/2017] [Indexed: 11/25/2022] Open
Abstract
Drosophila have been used to identify new components in apoptosis regulation. The Drosophila protein Dark forms an octameric apoptosome complex that induces the initiator caspase Dronc to trigger the caspase cell death pathway and, therefore, plays an important role in controlling apoptosis. Caspases and Dark are constantly expressed in cells, but their activity is blocked by DIAP1 E3 ligase-mediated ubiquitination and subsequent inactivation or proteasomal degradation. One of the regulatory mechanisms that stabilize proapoptotic factors is the removal of ubiquitin chains by deubiquitinases. In this study performed a modified genetic screen for deubiquitinases (dsRNA lines) to identify those involved in stabilizing proapoptotic components. Loss-of-function alleles of deubiquitinase DUSP31 were identified as suppressors of the Dronc overexpression phenotype. DUSP31 deficiency also suppresses apoptosis induced by the RHG protein, Grim. Genetic analysis revealed for the first time that DUSP31 deficiency sufficiently suppresses the Dark phenotype, indicating its involvement in the control of Dark/Dronc apoptosome function in invertebrate apoptosis.
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25
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Li Y, Zhang L, Qu T, Tang X, Li L, Zhang G. Conservation and divergence of mitochondrial apoptosis pathway in the Pacific oyster, Crassostrea gigas. Cell Death Dis 2017; 8:e2915. [PMID: 28682310 PMCID: PMC5550854 DOI: 10.1038/cddis.2017.307] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 05/27/2017] [Accepted: 05/31/2017] [Indexed: 02/07/2023]
Abstract
Apoptosis is considered a crucial part of the host defense system in oysters according to previous reports; however, the exact process by which this occurs remains unclear. Besides, mitochondrial apoptosis is the primary method of apoptosis in vertebrate cells, but has been poorly studied in invertebrates and is quite controversial. In this study, we investigated the molecular mechanism of mitochondrial apoptosis in the Pacific oyster Crassostrea gigas. Notably, we show that most key elements involved in the vertebrate mitochondrial apoptosis pathway – including mitochondrial outer membrane permeabilization, cytochrome c release, and caspase activation – are also present in C. gigas. In contrast, the lack of Bcl-2 homology 3-only subfamily members and apoptotic protease activating factor-1 (APAF-1) protein revealed evolutionary diversity from other phyla. Our results support that mitochondrial apoptosis in animals predates the emergence of vertebrates, but suggest that an unexpectedly diverse mitochondrial apoptosis pathway may exist in invertebrates. In addition, our work provided new clues for an improved understanding of how bivalve acclimate themselves to an inconstant environment.
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Affiliation(s)
- Yingxiang Li
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,National &Local Joint Engineering Laboratory of Ecological Mariculture, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
| | - Linlin Zhang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,National &Local Joint Engineering Laboratory of Ecological Mariculture, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
| | - Tao Qu
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,National &Local Joint Engineering Laboratory of Ecological Mariculture, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
| | - Xueying Tang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,National &Local Joint Engineering Laboratory of Ecological Mariculture, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Li Li
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,National &Local Joint Engineering Laboratory of Ecological Mariculture, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
| | - Guofan Zhang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,National &Local Joint Engineering Laboratory of Ecological Mariculture, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
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26
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Caspase-dependent non-apoptotic processes in development. Cell Death Differ 2017; 24:1422-1430. [PMID: 28524858 PMCID: PMC5520453 DOI: 10.1038/cdd.2017.36] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 02/17/2017] [Accepted: 02/20/2017] [Indexed: 12/16/2022] Open
Abstract
Caspases are at the core of executing apoptosis by orchestrating cellular destruction with proteolytic cascades. Caspase-mediated proteolysis also controls diverse nonlethal cellular activities such as proliferation, differentiation, cell fate decision, and cytoskeletal reorganization. During the last decade or so, genetic studies of Drosophila have contributed to our understanding of the in vivo mechanism of the non-apoptotic cellular responses in developmental contexts. Furthermore, recent studies using C. elegans suggest that apoptotic signaling may play unexpected roles, which influence ageing and normal development at the organism level. In this review, we describe how the caspase activity is elaborately controlled during vital cellular processes at the level of subcellular localization, the duration and timing to avoid full apoptotic consequences, and also discuss the novel roles of non-apoptotic caspase signaling in adult homeostasis and physiology.
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Bentham A, Burdett H, Anderson PA, Williams SJ, Kobe B. Animal NLRs provide structural insights into plant NLR function. ANNALS OF BOTANY 2017; 119:827-702. [PMID: 27562749 PMCID: PMC5378188 DOI: 10.1093/aob/mcw171] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 05/26/2016] [Accepted: 06/07/2016] [Indexed: 05/18/2023]
Abstract
BACKGROUND The plant immune system employs intracellular NLRs (nucleotide binding [NB], leucine-rich repeat [LRR]/nucleotide-binding oligomerization domain [NOD]-like receptors) to detect effector proteins secreted into the plant cell by potential pathogens. Activated plant NLRs trigger a range of immune responses, collectively known as the hypersensitive response (HR), which culminates in death of the infected cell. Plant NLRs show structural and functional resemblance to animal NLRs involved in inflammatory and innate immune responses. Therefore, knowledge of the activation and regulation of animal NLRs can help us understand the mechanism of action of plant NLRs, and vice versa. SCOPE This review provides an overview of the innate immune pathways in plants and animals, focusing on the available structural and biochemical information available for both plant and animal NLRs. We highlight the gap in knowledge between the animal and plant systems, in particular the lack of structural information for plant NLRs, with crystal structures only available for the N-terminal domains of plant NLRs and an integrated decoy domain, in contrast to the more complete structures available for animal NLRs. We assess the similarities and differences between plant and animal NLRs, and use the structural information on the animal NLR pair NAIP/NLRC4 to derive a plausible model for plant NLR activation. CONCLUSIONS Signalling by cooperative assembly formation (SCAF) appears to operate in most innate immunity pathways, including plant and animal NLRs. Our proposed model of plant NLR activation includes three key steps: (1) initially, the NLR exists in an inactive auto-inhibited state; (2) a combination of binding by activating elicitor and ATP leads to a structural rearrangement of the NLR; and (3) signalling occurs through cooperative assembly of the resistosome. Further studies, structural and biochemical in particular, will be required to provide additional evidence for the different features of this model and shed light on the many existing variations, e.g. helper NLRs and NLRs containing integrated decoys.
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Affiliation(s)
- Adam Bentham
- School of Biological Sciences, Flinders University, Adelaide, SA 5001, Australia
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Hayden Burdett
- School of Biological Sciences, Flinders University, Adelaide, SA 5001, Australia
| | - Peter A. Anderson
- School of Biological Sciences, Flinders University, Adelaide, SA 5001, Australia
| | - Simon J. Williams
- School of Biological Sciences, Flinders University, Adelaide, SA 5001, Australia
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland 4072, Australia
- Plant Sciences Division, Research School of Biology, The Australian National University, Canberra 2601, Australia
| | - Bostjan Kobe
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland 4072, Australia
- For correspondence. E-mail
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Kamber Kaya HE, Ditzel M, Meier P, Bergmann A. An inhibitory mono-ubiquitylation of the Drosophila initiator caspase Dronc functions in both apoptotic and non-apoptotic pathways. PLoS Genet 2017; 13:e1006438. [PMID: 28207763 PMCID: PMC5313150 DOI: 10.1371/journal.pgen.1006438] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 10/21/2016] [Indexed: 11/19/2022] Open
Abstract
Apoptosis is an evolutionary conserved cell death mechanism, which requires activation of initiator and effector caspases. The Drosophila initiator caspase Dronc, the ortholog of mammalian Caspase-2 and Caspase-9, has an N-terminal CARD domain that recruits Dronc into the apoptosome for activation. In addition to its role in apoptosis, Dronc also has non-apoptotic functions such as compensatory proliferation. One mechanism to control the activation of Dronc is ubiquitylation. However, the mechanistic details of ubiquitylation of Dronc are less clear. For example, monomeric inactive Dronc is subject to non-degradative ubiquitylation in living cells, while ubiquitylation of active apoptosome-bound Dronc triggers its proteolytic degradation in apoptotic cells. Here, we examined the role of non-degradative ubiquitylation of Dronc in living cells in vivo, i.e. in the context of a multi-cellular organism. Our in vivo data suggest that in living cells Dronc is mono-ubiquitylated on Lys78 (K78) in its CARD domain. This ubiquitylation prevents activation of Dronc in the apoptosome and protects cells from apoptosis. Furthermore, K78 ubiquitylation plays an inhibitory role for non-apoptotic functions of Dronc. We provide evidence that not all of the non-apoptotic functions of Dronc require its catalytic activity. In conclusion, we demonstrate a mechanism whereby Dronc’s apoptotic and non-apoptotic activities can be kept silenced in a non-degradative manner through a single ubiquitylation event in living cells. Apoptosis is a programmed cell death mechanism which is conserved from flies to humans. Apoptosis is mediated by proteases, termed caspases that cleave cellular proteins and trigger the death of the cell. Activation of caspases is regulated at various levels such as protein-protein interaction for initiator caspases and ubiquitylation. Caspase 9 in mammals and its Drosophila ortholog Dronc carry a protein-protein interaction domain (CARD) in their prodomain which interacts with scaffolding proteins to form the apoptosome, a cell-death platform. Here, we show that Dronc is mono-ubiquitylated at Lysine 78 in its CARD domain. This ubiquitylation interferes with the formation of the apoptosome, causing inhibition of apoptosis. In addition to its apoptotic function, Dronc also participates in events where caspase activity is not required for cell killing, but for regulating other functions, so-called non-apoptotic functions of caspases such as apoptosis-induced proliferation. We found that mono-ubiquitylation of Lysine 78 plays an inhibitory role for these non-apoptotic functions of Dronc. Interestingly, we demonstrate that the catalytic activity of Dronc is not strictly required in these processes. Our in vivo study sheds light on how a single mono-ubiquitylation event could inhibit both apoptotic and non-apoptotic functions of a caspase.
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Affiliation(s)
- Hatem Elif Kamber Kaya
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Mark Ditzel
- Institute for Genetics and Molecular Medicine, Edinburgh Cancer Research Centre, The University of Edinburgh, Edinburgh, United Kingdom
| | - Pascal Meier
- The Breast Cancer Now Toby Robins Research Centre, Institute of Cancer Research, Mary-Jean Mitchell Green Building, Chester Beatty Laboratories, London, United Kingdom
| | - Andreas Bergmann
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- * E-mail:
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Cheng TC, Akey IV, Yuan S, Yu Z, Ludtke SJ, Akey CW. A Near-Atomic Structure of the Dark Apoptosome Provides Insight into Assembly and Activation. Structure 2016; 25:40-52. [PMID: 27916517 DOI: 10.1016/j.str.2016.11.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Revised: 09/11/2016] [Accepted: 10/27/2016] [Indexed: 11/19/2022]
Abstract
In Drosophila, the Apaf-1-related killer (Dark) forms an apoptosome that activates procaspases. To investigate function, we have determined a near-atomic structure of Dark double rings using cryo-electron microscopy. We then built a nearly complete model of the apoptosome that includes 7- and 8-blade β-propellers. We find that the preference for dATP during Dark assembly may be governed by Ser325, which is in close proximity to the 2' carbon of the deoxyribose ring. Interestingly, β-propellers in V-shaped domains of the Dark apoptosome are more widely separated, relative to these features in the Apaf-1 apoptosome. This wider spacing may be responsible for the lack of cytochrome c binding to β-propellers in the Dark apoptosome. Our structure also highlights the roles of two loss-of-function mutations that may block Dark assembly. Finally, the improved model provides a framework to understand apical procaspase activation in the intrinsic cell death pathway.
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Affiliation(s)
- Tat Cheung Cheng
- Department of Physiology and Biophysics, Boston University School of Medicine, 700 Albany Street, Boston, MA 02118, USA
| | - Ildikó V Akey
- Department of Physiology and Biophysics, Boston University School of Medicine, 700 Albany Street, Boston, MA 02118, USA
| | - Shujun Yuan
- Department of Biologics Research - Protein Sciences, U.S. Innovation Center, Bayer Healthcare, 455 Mission Bay Boulevard South, San Francisco, CA 94158, USA
| | - Zhiheng Yu
- Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Steven J Ludtke
- National Center for Macromolecular Imaging, Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA
| | - Christopher W Akey
- Department of Physiology and Biophysics, Boston University School of Medicine, 700 Albany Street, Boston, MA 02118, USA.
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Melzer J, Broemer M. Nerve-racking - apoptotic and non-apoptotic roles of caspases in the nervous system of Drosophila. Eur J Neurosci 2016; 44:1683-90. [PMID: 26900934 DOI: 10.1111/ejn.13213] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 02/02/2016] [Accepted: 02/15/2016] [Indexed: 12/28/2022]
Abstract
Studies using Drosophila as a model system have contributed enormously to our knowledge of caspase function and regulation. Caspases are best known as central executioners of apoptosis but also control essential physiological processes in a non-apoptotic manner. The Drosophila genome codes for seven caspases and in this review we provide an overview of current knowledge about caspase function in the nervous system. Caspases regulate neuronal death at all developmental stages and in various neuronal populations. In contrast, non-apoptotic roles are less well understood. The development of new genetically encoded sensors for caspase activity provides unprecedented opportunities to study caspase function in the nervous system in more detail. In light of these new tools we discuss the potential of Drosophila as a model to discover new apoptotic and non-apoptotic neuronal roles of caspases.
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Affiliation(s)
- Juliane Melzer
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Meike Broemer
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
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Unsain N, Barker PA. New Views on the Misconstrued: Executioner Caspases and Their Diverse Non-apoptotic Roles. Neuron 2016; 88:461-74. [PMID: 26539888 DOI: 10.1016/j.neuron.2015.08.029] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Initially characterized for their roles in apoptosis, executioner caspases have emerged as important regulators of an array of cellular activities. This is especially true in the nervous system, where sublethal caspase activity has been implicated in axonal pathfinding and branching, axonal degeneration, dendrite pruning, regeneration, long-term depression, and metaplasticity. Here we examine the roles of sublethal executioner caspase activity in nervous system development and maintenance, consider the mechanisms that locally activate and restrain these potential killers, and discuss how their activity be subverted in neurodegenerative disease.
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Affiliation(s)
- Nicolas Unsain
- Laboratorio de Neurobiología, Instituto de Investigación Médica Mercedes y Martín Ferreyra, Instituto Nacional de Investigación Médica Córdoba-Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Córdoba, Friuli 2434, Córdoba (5016), Argentina
| | - Philip A Barker
- Irving K. Barber School of Arts and Sciences, University of British Columbia, Kelowna, BC V1V 1V7, Canada.
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Clavier A, Rincheval-Arnold A, Colin J, Mignotte B, Guénal I. Apoptosis in Drosophila: which role for mitochondria? Apoptosis 2015; 21:239-51. [DOI: 10.1007/s10495-015-1209-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Abstract
In multicellular organisms, cell death is a critical and active process that maintains tissue homeostasis and eliminates potentially harmful cells. There are three major types of morphologically distinct cell death: apoptosis (type I cell death), autophagic cell death (type II), and necrosis (type III). All three can be executed through distinct, and sometimes overlapping, signaling pathways that are engaged in response to specific stimuli. Apoptosis is triggered when cell-surface death receptors such as Fas are bound by their ligands (the extrinsic pathway) or when Bcl2-family proapoptotic proteins cause the permeabilization of the mitochondrial outer membrane (the intrinsic pathway). Both pathways converge on the activation of the caspase protease family, which is ultimately responsible for the dismantling of the cell. Autophagy defines a catabolic process in which parts of the cytosol and specific organelles are engulfed by a double-membrane structure, known as the autophagosome, and eventually degraded. Autophagy is mostly a survival mechanism; nevertheless, there are a few examples of autophagic cell death in which components of the autophagic signaling pathway actively promote cell death. Necrotic cell death is characterized by the rapid loss of plasma membrane integrity. This form of cell death can result from active signaling pathways, the best characterized of which is dependent on the activity of the protein kinase RIP3.
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Affiliation(s)
- Douglas R Green
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105
| | - Fabien Llambi
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105
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Abstract
The apoptotic machinery is highly conserved throughout evolution, and central to the regulation of apoptosis is the caspase family of cysteine proteases. Insights into the regulation and function of apoptosis in mammals have come from studies using model organisms. Drosophila provides an exceptional model system for identifying the function of conserved mechanisms regulating apoptosis, especially during development. The characteristic patterns of apoptosis during Drosophila development have been well described, as has the apoptotic response following DNA damage. The focus of this discussion is to introduce methodologies for monitoring apoptosis during Drosophila development and also in Drosophila cell lines.
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Affiliation(s)
- Donna Denton
- Centre for Cancer Biology, University of South Australia, Adelaide, South Australia 5001, Australia
| | - Sharad Kumar
- Centre for Cancer Biology, University of South Australia, Adelaide, South Australia 5001, Australia
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Guntermann S, Fraser B, Hazes B, Foley E. Independent Proteolytic Activities Control the Stability and Size of Drosophila Inhibitor of Apoptosis 2 Protein. J Innate Immun 2015; 7:518-29. [PMID: 25968339 DOI: 10.1159/000381475] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Accepted: 03/09/2015] [Indexed: 12/11/2022] Open
Abstract
The Drosophila immune deficiency pathway defends many bacterial pathogens and bears striking molecular similarities to the mammalian tumor necrosis factor signal transduction pathway. Orthologous inhibitors of apoptosis ubiquitin ligases act at a proximal stage of both responses to coordinate the assembly of signal transduction platforms that shape host immune responses. Despite the importance of inhibitor of apoptosis proteins within evolutionarily conserved innate immune responses, we know relatively little about the cellular machinery that controls inhibitor of apoptosis activity. In this study, we examined the molecular basis for inhibitor of apoptosis 2 protein regulation in the immune deficiency pathway. Our studies identified two distinct proteolytic events that determine the stability and composition of cellular inhibitor of apoptosis 2 protein pools. We found that apoptotic caspase activity cleaves inhibitor of apoptosis 2 at an N-terminal aspartate to generate a truncated protein that retains the ability to interact with immune deficiency pathway members. We also showed that a C-terminal ubiquitin ligase activity within inhibitor of apoptosis 2 directs the proteasomal destruction of full-length and truncated inhibitor of apoptosis 2 isoforms. These studies add to our appreciation of the regulation of innate immunity and suggest potential links between apoptotic caspases and innate defenses.
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Affiliation(s)
- Silvia Guntermann
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alta., Canada
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36
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Accorsi A, Zibaee A, Malagoli D. The multifaceted activity of insect caspases. JOURNAL OF INSECT PHYSIOLOGY 2015; 76:17-23. [PMID: 25783954 DOI: 10.1016/j.jinsphys.2015.03.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 02/09/2015] [Accepted: 03/09/2015] [Indexed: 06/04/2023]
Abstract
Caspases are frequently considered synonymous with apoptotic cell death. Increasing evidence demonstrates that these proteases may exert their activities in non-apoptotic functions. The non-apoptotic roles of caspases may include developmentally regulated autophagy during insect metamorphosis, as well as neuroblast self-renewal and the immune response. Here, we summarize the established knowledge and the recent advances in the multiple roles of insect caspases to highlight their relevance for physiological processes and survival.
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Affiliation(s)
- A Accorsi
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - A Zibaee
- Department of Plant Protection, Faculty of Agricultural Sciences, University of Guilan, Rasht, Iran
| | - D Malagoli
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy.
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37
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Pang Y, Bai XC, Yan C, Hao Q, Chen Z, Wang JW, Scheres SHW, Shi Y. Structure of the apoptosome: mechanistic insights into activation of an initiator caspase from Drosophila. Genes Dev 2015; 29:277-87. [PMID: 25644603 PMCID: PMC4318144 DOI: 10.1101/gad.255877.114] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The autocatalytic activation of an initiator caspase, exemplified by caspase-9 in mammals or its ortholog, Dronc, in fruit flies, is facilitated by a multimeric adaptor complex known as the apoptosome. Pang et al. report two cryo-EM structures: the complete Dark apoptosome at an overall resolution of 4.0 Å and a complex between the Dark apoptosome and the CARD of Dronc at 4.1 Å resolution. The structural findings, together with structure-guided biochemical analyses, allow delineation of the molecular mechanisms for Dronc activation. Apoptosis is executed by a cascade of caspase activation. The autocatalytic activation of an initiator caspase, exemplified by caspase-9 in mammals or its ortholog, Dronc, in fruit flies, is facilitated by a multimeric adaptor complex known as the apoptosome. The underlying mechanism by which caspase-9 or Dronc is activated by the apoptosome remains unknown. Here we report the electron cryomicroscopic (cryo-EM) structure of the intact apoptosome from Drosophila melanogaster at 4.0 Å resolution. Analysis of the Drosophila apoptosome, which comprises 16 molecules of the Dark protein (Apaf-1 ortholog), reveals molecular determinants that support the assembly of the 2.5-MDa complex. In the absence of dATP or ATP, Dronc zymogen potently induces formation of the Dark apoptosome, within which Dronc is efficiently activated. At 4.1 Å resolution, the cryo-EM structure of the Dark apoptosome bound to the caspase recruitment domain (CARD) of Dronc (Dronc-CARD) reveals two stacked rings of Dronc-CARD that are sandwiched between two octameric rings of the Dark protein. The specific interactions between Dronc-CARD and both the CARD and the WD40 repeats of a nearby Dark protomer are indispensable for Dronc activation. These findings reveal important mechanistic insights into the activation of initiator caspase by the apoptosome.
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Affiliation(s)
- Yuxuan Pang
- Ministry of Education Protein Science Laboratory, Center for Structural Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Xiao-chen Bai
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Chuangye Yan
- Ministry of Education Protein Science Laboratory, Center for Structural Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Qi Hao
- Ministry of Education Protein Science Laboratory, Center for Structural Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Zheqin Chen
- Ministry of Education Protein Science Laboratory, Center for Structural Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Jia-Wei Wang
- Center for Structural Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Sjors H W Scheres
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Yigong Shi
- Ministry of Education Protein Science Laboratory, Center for Structural Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, School of Medicine, Tsinghua University, Beijing 100084, China;
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38
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Creagh EM. Caspase crosstalk: integration of apoptotic and innate immune signalling pathways. Trends Immunol 2014; 35:631-640. [PMID: 25457353 DOI: 10.1016/j.it.2014.10.004] [Citation(s) in RCA: 114] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 10/14/2014] [Accepted: 10/15/2014] [Indexed: 01/30/2023]
Abstract
The caspase family of cysteine proteases has been functionally divided into two groups: those involved in apoptosis and those involved in innate immune signalling. Recent findings have identified 'apoptotic' caspases within inflammasome complexes and revealed that 'inflammatory' caspases are capable of inducing cell death, suggesting that the earlier view of caspase function may have been overly simplistic. Here, I review evidence attributing nonclassical functions to many caspases and propose that caspases serve as critical mediators in the integration of apoptotic and inflammatory pathways, thereby forming an integrated signalling system that regulates cell death and innate immune responses during development, infection, and homeostasis.
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Affiliation(s)
- Emma M Creagh
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College, Dublin, Ireland.
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40
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Transcriptional profiling of apoptosis-deficient Drosophila mutants. GENOMICS DATA 2014; 2:254-7. [PMID: 26484104 PMCID: PMC4535892 DOI: 10.1016/j.gdata.2014.08.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 07/29/2014] [Accepted: 08/01/2014] [Indexed: 12/04/2022]
Abstract
Apoptosis is a fundamental way to remove damaged or unwanted cells during both developmental and post-developmental stages. Apoptosis deficiency leads to various diseases including cancer. To know the physiological changes in apoptosis-deficient mutants, we conducted non-biased transcriptomic analysis of Drosophila darkcd4 mutants. As recently reported, combined with metabolome and genetic analysis, we identified systemic immune response, energy wasting, as well as alteration in S-adenosyl-methionine metabolism in response to necrotic cells [1]. Here, we describe in detail how we obtained validated microarray dataset deposited in Gene Expression Omnibus (GSE47853). Our data provide a resource for searching transcriptional alterations in Drosophila apoptosis-deficient mutants.
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Kim CH, Paik D, Rus F, Silverman N. The caspase-8 homolog Dredd cleaves Imd and Relish but is not inhibited by p35. J Biol Chem 2014; 289:20092-101. [PMID: 24891502 DOI: 10.1074/jbc.m113.544841] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In Drosophila, the Imd pathway is activated by diaminopimelic acid-type peptidoglycan and triggers the humoral innate immune response, including the robust induction of antimicrobial peptide gene expression. Imd and Relish, two essential components of this pathway, are both endoproteolytically cleaved upon immune stimulation. Genetic analyses have shown that these cleavage events are dependent on the caspase-8 like Dredd, suggesting that Imd and Relish are direct substrates of Dredd. Among the seven Drosophila caspases, we find that Dredd uniquely promotes Imd and Relish processing, and purified recombinant Dredd cleaves Imd and Relish in vitro. In addition, interdomain cleavage of Dredd is not required for Imd or Relish processing and is not observed during immune stimulation. Baculovirus p35, a suicide substrate of executioner caspases, is not cleaved by purified Dredd in vitro. Consistent with this biochemistry but contrary to earlier reports, p35 does not interfere with Imd signaling in S2* cells or in vivo.
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Affiliation(s)
- Chan-Hee Kim
- From the Division of Infectious Diseases, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605
| | - Donggi Paik
- From the Division of Infectious Diseases, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605
| | - Florentina Rus
- From the Division of Infectious Diseases, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605
| | - Neal Silverman
- From the Division of Infectious Diseases, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605
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Dimorphic ovary differentiation in honeybee (Apis mellifera) larvae involves caste-specific expression of homologs of ark and buffy cell death genes. PLoS One 2014; 9:e98088. [PMID: 24844304 PMCID: PMC4028266 DOI: 10.1371/journal.pone.0098088] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Accepted: 04/28/2014] [Indexed: 01/25/2023] Open
Abstract
The establishment of the number of repeated structural units, the ovarioles, in the ovaries is one of the critical events that shape caste polyphenism in social insects. In early postembryonic development, honeybee (Apis mellifera) larvae have a pair of ovaries, each one consisting of almost two hundred ovariole primordia. While practically all these ovarioles continue developing in queen-destined larvae, they undergo massive programmed cell death (PCD) in worker-destined larvae. So as to gain insight into the molecular basis of this fundamental process in caste differentiation we used quantitative PCR (qPCR) and fluorescent in situ hybridization (FISH) to investigate the expression of the Amark and Ambuffy genes in the ovaries of the two honeybee castes throughout the fifth larval instar. These are the homologs of ark and buffy Drosophila melanogaster genes, respectively, involved in activating and inhibiting PCD. Caste-specific expression patterns were found during this time-window defining ovariole number. Amark transcript levels were increased when ovariole resorption was intensified in workers, but remained at low levels in queen ovaries. The transcripts were mainly localized at the apical end of all the worker ovarioles, but appeared in only a few queen ovarioles, thus strongly suggesting a function in mediating massive ovariolar cell death in worker larvae. Ambuffy was mainly expressed in the peritoneal sheath cells covering each ovariole. The levels of Ambuffy transcripts increased earlier in the developing ovaries of queens than in workers. Consistent with a protective role against cell death, Ambuffy transcripts were localized in practically all queen ovarioles, but only in few worker ovarioles. The results are indicative of a functional relationship between the expression of evolutionary conserved cell death genes and the morphological events leading to caste-specific ovary differentiation in a social insect.
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Obata F, Kuranaga E, Tomioka K, Ming M, Takeishi A, Chen CH, Soga T, Miura M. Necrosis-driven systemic immune response alters SAM metabolism through the FOXO-GNMT axis. Cell Rep 2014; 7:821-33. [PMID: 24746817 DOI: 10.1016/j.celrep.2014.03.046] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 02/25/2014] [Accepted: 03/18/2014] [Indexed: 01/27/2023] Open
Abstract
Sterile inflammation triggered by endogenous factors is thought to contribute to the pathogenesis of acute and chronic inflammatory diseases. Here, we demonstrate that apoptosis-deficient mutants spontaneously develop a necrosis-driven systemic immune response in Drosophila and provide an in vivo model for studying the organismal response to sterile inflammation. Metabolomic analysis of hemolymph from apoptosis-deficient mutants revealed increased sarcosine and reduced S-adenosyl-methionine (SAM) levels due to glycine N-methyltransferase (Gnmt) upregulation. We showed that Gnmt was elevated in response to Toll activation induced by the local necrosis of wing epidermal cells. Necrosis-driven inflammatory conditions induced dFoxO hyperactivation, leading to an energy-wasting phenotype. Gnmt was cell-autonomously upregulated by dFoxO in the fat body as a possible rheostat for controlling energy loss, which functioned during fasting as well as inflammatory conditions. We propose that the dFoxO-Gnmt axis is essential for the maintenance of organismal SAM metabolism and energy homeostasis.
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Affiliation(s)
- Fumiaki Obata
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan; CREST, Japan Science and Technology Agency, Chiyoda-ku, Tokyo 102-0075, Japan
| | - Erina Kuranaga
- Laboratory for Histogenetic Dynamics, RIKEN CDB, Kobe 650-0047, Japan
| | - Katsura Tomioka
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Ming Ming
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Asuka Takeishi
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Chun-Hong Chen
- National Health Research Institutes, Zhunan, Miaoli County 35053, Taiwan
| | - Tomoyoshi Soga
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata 997-0052, Japan
| | - Masayuki Miura
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan; CREST, Japan Science and Technology Agency, Chiyoda-ku, Tokyo 102-0075, Japan.
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Ming M, Obata F, Kuranaga E, Miura M. Persephone/Spätzle pathogen sensors mediate the activation of Toll receptor signaling in response to endogenous danger signals in apoptosis-deficient Drosophila. J Biol Chem 2014; 289:7558-68. [PMID: 24492611 DOI: 10.1074/jbc.m113.543884] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Apoptosis is an evolutionarily conserved mechanism that removes damaged or unwanted cells, effectively maintaining cellular homeostasis. It has long been suggested that a deficiency in this type of naturally occurring cell death could potentially lead to necrosis, resulting in the release of endogenous immunogenic molecules such as damage-associated molecular patterns (DAMPs) and a noninfectious inflammatory response. However, the details about how danger signals from apoptosis-deficient cells are detected and translated to an immune response are largely unknown. In this study, we found that Drosophila mutants deficient for Dronc, the key initiator caspase required for apoptosis, produced the active form of the endogenous Toll ligand Spätzle (Spz). We speculated that, as a system for sensing potential DAMPs in the hemolymph, the dronc mutants constitutively activate a proteolytic cascade that leads to Spz proteolytic processing. We demonstrated that Toll signaling activation required the action of Persephone, a CLIP domain serine protease that usually reacts to microbial proteolytic activities. Our findings show that the Persephone proteolytic cascade plays a crucial role in mediating DAMP-induced systemic responses in apoptosis-deficient Drosophila mutants.
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Affiliation(s)
- Ming Ming
- From the Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
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45
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Chai J, Shi Y. Apoptosome and inflammasome: conserved machineries for caspase activation. Natl Sci Rev 2014. [DOI: 10.1093/nsr/nwt025] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Apoptosome and inflammasome are multimeric protein complexes that mediate the activation of specific caspases at the onset of apoptosis and inflammation. The central component of apoptosome or inflammasome is a tripartite scaffold protein, exemplified by Apaf-1 and NLRC4, which contains an amino-terminal homotypic interaction motif, a central nucleotide-binding oligomerization domain and a carboxyl-terminal ligand-sensing domain. In the absence of death cue or an inflammatory signal, Apaf-1 or NLRC4 exists in an auto-inhibited, monomeric state, which is stabilized by adenosine diphosphate (ADP). Binding to an apoptosis- or inflammation-inducing ligand, together with replacement of ADP by adenosine triphosphate (ATP), results in the formation of a multimeric apoptosome or inflammasome. The assembled apoptosome and inflammasome serve as dedicated machineries to facilitate the activation of specific caspases. In this review, we describe the structure and functional mechanisms of mammalian inflammasome and apoptosomes from three representative organisms. Emphasis is placed on the molecular mechanism of caspase activation and the shared features of apoptosomes and inflammasomes.
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Affiliation(s)
- Jijie Chai
- Center for Life Sciences, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Yigong Shi
- Center for Life Sciences, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China
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46
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47
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Denton D, Aung-Htut MT, Kumar S. Developmentally programmed cell death in Drosophila. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:3499-3506. [DOI: 10.1016/j.bbamcr.2013.06.014] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 06/16/2013] [Indexed: 12/24/2022]
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48
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Modi V, Sankararamakrishnan R. Antiapoptotic Bcl-2 homolog CED-9 in Caenorhabditis elegans
: Dynamics of BH3 and CED-4 binding regions and comparison with mammalian antiapoptotic Bcl-2 proteins. Proteins 2013; 82:1035-47. [DOI: 10.1002/prot.24476] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2013] [Revised: 10/16/2013] [Accepted: 11/04/2013] [Indexed: 12/29/2022]
Affiliation(s)
- Vivek Modi
- Department of Biological Sciences & Bioengineering; Indian Institute of Technology Kanpur; Kanpur 208016 India
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49
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D'Brot A, Chen P, Vaishnav M, Yuan S, Akey CW, Abrams JM. Tango7 directs cellular remodeling by the Drosophila apoptosome. Genes Dev 2013; 27:1650-5. [PMID: 23913920 DOI: 10.1101/gad.219287.113] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
It is now well appreciated that the apoptosome, which governs caspase-dependent cell death, also drives nonapoptotic caspase activation to remodel cells. However, the determinants that specify whether the apoptosome acts to kill or remodel have yet to be identified. Here we report that Tango7 collaborates with the Drosophila apoptosome to drive a caspase-dependent remodeling process needed to resolve individual sperm from a syncytium. In these cells, Tango7 is required for caspase activity and localizes to the active apoptosome compartment via its C terminus. Furthermore, Tango7 directly stimulates the activity of this complex in vitro. We propose that Tango7 specifies the Drosophila apoptosome as an effector of cellular remodeling.
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Affiliation(s)
- Alejandro D'Brot
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
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50
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Li SS, Zhang ZY, Yang CJ, Lian HY, Cai P. Gene expression and reproductive abilities of male Drosophila melanogaster subjected to ELF-EMF exposure. Mutat Res 2013; 758:95-103. [PMID: 24157427 DOI: 10.1016/j.mrgentox.2013.10.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2012] [Revised: 10/03/2013] [Accepted: 10/10/2013] [Indexed: 11/24/2022]
Abstract
Extremely low frequency electromagnetic field (ELF-EMF) exposure is attracting increased attention as a possible disease-inducing factor. The in vivo effects of short-term and long-term ELF-EMF exposure on male Drosophila melanogaster were studied using transcriptomic analysis for preliminary screening and QRT-PCR for further verification. Transcriptomic analysis indicated that 439 genes were up-regulated and 874 genes were down-regulated following short-term exposures and that 514 genes were up-regulated and 1206 genes were down-regulated following long-term exposures (expression >2- or <0.5-fold, respectively). In addition, there are 238 up-regulated genes and 598 down-regulated genes in the intersection of short-term and long-term exposure (expression >2- or <0.5-fold). The DEGs (differentially expressed genes) in D. melanogaster following short-term exposures were involved in metabolic processes, cytoskeletal organization, mitotic spindle organization, cell death, protein modification and proteolysis. Long-term exposure let to changes in expression of genes involved in metabolic processes, response to stress, mitotic spindle organization, aging, cell death and cellular respiration. In the intersection of short-term and long-term exposure, a series of DEGs were related to apoptosis, aging, immunological stress and reproduction. To check the ELF-EMF effects on reproduction, some experiments on male reproduction ability were performed. Their results indicated that short-term ELF-EMF exposure may decrease the reproductive ability of males, but long-term exposures had no effect on reproductive ability. Down-regulation of ark gene in the exposed males suggests that the decrease in reproductive capacity may be induced by the effects of ELF-EMF exposure on spermatogenesis through the caspase pathway. QRT-PCR analysis confirmed that jra, ark and decay genes were down regulated in males exposed for 1 Generation (1G) and 72 h, which suggests that apoptosis may be inhibited in vivo. ELF-EMF exposure may have accelerated cell senescence, as suggested by the down-regulation of both cat and jra genes and the up-regulation of hsp22 gene. Up-regulation of totA and hsp22 genes during exposure suggests that exposed flies might induce an in vivo immune response to counter the adverse effects encountered during ELF-EMF exposure. Down-regulation of cat genes suggests that the partial oxidative protection system might be restrained, especially during short-term exposures. This study demonstrates the bioeffects of ELF-EMF exposure and provides evidence for understanding the in vivo mechanisms of ELF-EMF exposure on male D. melanogaster.
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Affiliation(s)
- Si-Si Li
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, PR China
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