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Leger MM, Ros-Rocher N, Najle SR, Ruiz-Trillo I. Rel/NF-κB Transcription Factors Emerged at the Onset of Opisthokonts. Genome Biol Evol 2022; 14:6499270. [PMID: 34999783 PMCID: PMC8763368 DOI: 10.1093/gbe/evab289] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/27/2021] [Indexed: 12/23/2022] Open
Abstract
The Rel/NF-κB transcription factor family has myriad roles in immunity, development, and differentiation in animals, and was considered a key innovation for animal multicellularity. Rel homology domain-containing proteins were previously hypothesized to have originated in a last common ancestor of animals and some of their closest unicellular relatives. However, key taxa were missing from previous analyses, necessitating a systematic investigation into the distribution and evolution of these proteins. Here, we address this knowledge gap by surveying taxonomically broad data from eukaryotes, with a special emphasis on lineages closely related to animals. We report an earlier origin for Rel/NF-κB proteins than previously described, in the last common ancestor of animals and fungi, and show that even in the sister group to fungi, these proteins contain elements that in animals are necessary for the subcellular regulation of Rel/NF-κB.
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Affiliation(s)
- Michelle M Leger
- Institute of Evolutionary Biology (Consejo Superior de Investigaciones Científicas-Universitat Pompeu Fabra), Barcelona, Catalonia, Spain
| | - Núria Ros-Rocher
- Institute of Evolutionary Biology (Consejo Superior de Investigaciones Científicas-Universitat Pompeu Fabra), Barcelona, Catalonia, Spain
| | - Sebastián R Najle
- Institute of Evolutionary Biology (Consejo Superior de Investigaciones Científicas-Universitat Pompeu Fabra), Barcelona, Catalonia, Spain
| | - Iñaki Ruiz-Trillo
- Institute of Evolutionary Biology (Consejo Superior de Investigaciones Científicas-Universitat Pompeu Fabra), Barcelona, Catalonia, Spain.,Department of Genetics, Microbiology and Statistics, Institute for Research on Biodiversity, University of Barcelona, Catalonia, Spain.,Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Catalonia, Spain
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Ingham VA, Elg S, Nagi SC, Dondelinger F. Capturing the transcription factor interactome in response to sub-lethal insecticide exposure. CURRENT RESEARCH IN INSECT SCIENCE 2021; 1:None. [PMID: 34977825 PMCID: PMC8702396 DOI: 10.1016/j.cris.2021.100018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 06/15/2021] [Accepted: 07/21/2021] [Indexed: 12/02/2022]
Abstract
The increasing levels of pesticide resistance in agricultural pests and disease vectors represents a threat to both food security and global health. As insecticide resistance intensity strengthens and spreads, the likelihood of a pest encountering a sub-lethal dose of pesticide dramatically increases. Here, we apply dynamic Bayesian networks to a transcriptome time-course generated using sub-lethal pyrethroid exposure on a highly resistant Anopheles coluzzii population. The model accounts for circadian rhythm and ageing effects allowing high confidence identification of transcription factors with key roles in pesticide response. The associations generated by this model show high concordance with lab-based validation and identifies 44 transcription factors putatively regulating insecticide-responsive transcripts. We identify six key regulators, with each displaying differing enrichment terms, demonstrating the complexity of pesticide response. The considerable overlap of resistance mechanisms in agricultural pests and disease vectors strongly suggests that these findings are relevant in a wide variety of pest species.
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3
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Zhou B, Lindsay SA, Wasserman SA. Alternative NF-κB Isoforms in the Drosophila Neuromuscular Junction and Brain. PLoS One 2015; 10:e0132793. [PMID: 26167685 PMCID: PMC4500392 DOI: 10.1371/journal.pone.0132793] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 06/19/2015] [Indexed: 11/19/2022] Open
Abstract
The Drosophila NF-κB protein Dorsal is expressed at the larval neuromuscular junction, where its expression appears unrelated to known Dorsal functions in embryonic patterning and innate immunity. Using confocal microscopy with domain-specific antisera, we demonstrate that larval muscle expresses only the B isoform of Dorsal, which arises by intron retention. We find that Dorsal B interacts with and stabilizes Cactus at the neuromuscular junction, but exhibits Cactus independent localization and an absence of detectable nuclear translocation. We further find that the Dorsal-related immune factor Dif encodes a B isoform, reflecting a conservation of B domains across a range of insect NF-κB proteins. Carrying out mutagenesis of the Dif locus via a site-specific recombineering approach, we demonstrate that Dif B is the major, if not sole, Dif isoform in the mushroom bodies of the larval brain. The Dorsal and Dif B isoforms thus share a specific association with nervous system tissues as well as an alternative protein structure.
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Affiliation(s)
- Bo Zhou
- Section of Cell & Developmental Biology, Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Scott A. Lindsay
- Section of Cell & Developmental Biology, Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Steven A. Wasserman
- Section of Cell & Developmental Biology, Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
- * E-mail:
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Ferreira ÁG, Naylor H, Esteves SS, Pais IS, Martins NE, Teixeira L. The Toll-dorsal pathway is required for resistance to viral oral infection in Drosophila. PLoS Pathog 2014; 10:e1004507. [PMID: 25473839 PMCID: PMC4256459 DOI: 10.1371/journal.ppat.1004507] [Citation(s) in RCA: 146] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 10/08/2014] [Indexed: 01/22/2023] Open
Abstract
Pathogen entry route can have a strong impact on the result of microbial infections in different hosts, including insects. Drosophila melanogaster has been a successful model system to study the immune response to systemic viral infection. Here we investigate the role of the Toll pathway in resistance to oral viral infection in D. melanogaster. We show that several Toll pathway components, including Spätzle, Toll, Pelle and the NF-kB-like transcription factor Dorsal, are required to resist oral infection with Drosophila C virus. Furthermore, in the fat body Dorsal is translocated from the cytoplasm to the nucleus and a Toll pathway target gene reporter is upregulated in response to Drosophila C Virus infection. This pathway also mediates resistance to several other RNA viruses (Cricket paralysis virus, Flock House virus, and Nora virus). Compared with control, viral titres are highly increased in Toll pathway mutants. The role of the Toll pathway in resistance to viruses in D. melanogaster is restricted to oral infection since we do not observe a phenotype associated with systemic infection. We also show that Wolbachia and other Drosophila-associated microbiota do not interact with the Toll pathway-mediated resistance to oral infection. We therefore identify the Toll pathway as a new general inducible pathway that mediates strong resistance to viruses with a route-specific role. These results contribute to a better understanding of viral oral infection resistance in insects, which is particularly relevant in the context of transmission of arboviruses by insect vectors. Pathogenic microbes can enter their hosts through different routes. This can have a strong impact on which host defensive mechanisms are elicited and in disease outcome. We used the model organism Drosophila melanogaster to understand how resistance to viruses differs between infection by direct virus entry into the body cavity and infection through feeding on food with the virus. We show that the Toll pathway is required to resist oral infection with different RNA viruses. On the other hand this pathway does not influence the outcome of viral infection performed by injection. Together our results show that the Toll pathway has a route-specific general antiviral effect. Our work expands the role of this classical innate immunity pathway and contributes to a better understanding of viral oral infection resistance in insects. This is particularly relevant because insect vectors of emerging human viral diseases, like dengue, are infected through feeding on contaminated hosts.
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Affiliation(s)
| | - Huw Naylor
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | | | | | | | - Luis Teixeira
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
- * E-mail: ,
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5
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Stein RSL, Li N, He W, Komives E, Wang W. Recognition of methylated peptides by Drosophila melanogaster polycomb chromodomain. J Proteome Res 2013; 12:1467-77. [PMID: 23320494 DOI: 10.1021/pr3011205] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Lysine methylation is one of the important post-translational modifications (PTMs) that regulate protein functions. Up to now, proteomic identification of this PTM remains a challenge due to the lack of effective enrichment methods in mass spectrometry experiments. To address this challenge, we present here a systematic approach to predicting peptides in which lysine residues may be methylated to mediate protein-protein interactions. We used the chromodomain of the polycomb protein in Drosophila melanogaster as a model system to illustrate the success of this approach. We started with molecular dynamics simulations and free energy analyses on the histone peptides complexed with the polycomb chromodomain to understand how the binding specificity is achieved. We next conducted virtual mutagenesis to quantify each domain and peptide residue's contribution to the domain-peptide recognition, based on which scoring scheme was developed to evaluate the possibility of any lysine-containing peptides to be methylated and recognized by the chromodomain. A peptide microarray experiment on a panel of conserved histone peptides showed a satisfactory prediction accuracy of the scoring scheme. Next, we implemented a bioinformatics pipeline that integrates multiple lines of evidence including conservation, subcellular localization, and mass spectrometry data to scan the fly proteome for a systematic identification of possible methyllysine-containing peptides. These putative chromodomain-binding peptides suggest unknown functions of the important regulator protein polycomb and provide a list of candidate methylation events for follow-up investigations.
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Affiliation(s)
- Richard S L Stein
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0359, United States
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Ursic-Bedoya R, Buchhop J, Lowenberger C. Cloning and characterization of Dorsal homologues in the hemipteran Rhodnius prolixus. INSECT MOLECULAR BIOLOGY 2009; 18:681-9. [PMID: 19754745 DOI: 10.1111/j.1365-2583.2009.00909.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Rhodnius prolixus is an ancient haematophagous hemipteran insect capable of mounting a powerful immune response. This response is transcriptionally regulated in part by transcription factors of the Rel/Nuclear Factor kappa B (Rel/NF-kappaB) family. We have cloned and characterized three members of this transcription factor family in this insect. Dorsal 1A is primarily expressed in early developmental stages. In contrast, dorsal 1B and 1C, both differentially spliced products of dorsal 1A, are expressed primarily in the adult fat body in response to septic injury, suggesting their exclusive role in immunity. Additionally, we identified putative kappaB binding sites in the 5' upstream regions of target genes known to be involved in the innate immune response of insects.
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Affiliation(s)
- R Ursic-Bedoya
- Department of Biological Sciences, Simon Fraser University, Burnaby BC, Canada.
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Leeman JR, Gilmore TD. Alternative splicing in the NF-kappaB signaling pathway. Gene 2008; 423:97-107. [PMID: 18718859 DOI: 10.1016/j.gene.2008.07.015] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2008] [Revised: 07/08/2008] [Accepted: 07/09/2008] [Indexed: 10/21/2022]
Abstract
Activation of transcription factor NF-kappaB can affect the expression of several hundred genes, many of which are involved in inflammation and immunity. The proper NF-kappaB transcriptional response is primarily regulated by post-translational modification of NF-kappaB signaling constituents. Herein, we review the accumulating evidence suggesting that alternative splicing of NF-kappaB signaling components is another means of controlling NF-kappaB signaling. Several alternative splicing events in both the tumor necrosis factor and Toll/interleukin-1 NF-kappaB signaling pathways can inhibit the NF-kappaB response, whereas others enhance NF-kappaB signaling. Alternative splicing of mRNAs encoding some NF-kappaB signaling components can be induced by prolonged exposure to an NF-kappaB-activating signal, such as lipopolysaccharide, suggesting a mechanism for negative feedback to dampen excessive NF-kappaB signaling. Moreover, some NF-kappaB alternative splicing events appear to be specific for certain diseases, and could serve as therapeutic targets or biomarkers.
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Affiliation(s)
- Joshua R Leeman
- Department of Biology, Boston University, 5 Cummington Street, Boston, MA 02215, USA
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Mindorff EN, O'Keefe DD, Labbé A, Yang JP, Ou Y, Yoshikawa S, van Meyel DJ. A gain-of-function screen for genes that influence axon guidance identifies the NF-kappaB protein dorsal and reveals a requirement for the kinase Pelle in Drosophila photoreceptor axon targeting. Genetics 2007; 176:2247-63. [PMID: 17603113 PMCID: PMC1950629 DOI: 10.1534/genetics.107.072819] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
To identify novel regulators of nervous system development, we used the GAL4-UAS misexpression system in Drosophila to screen for genes that influence axon guidance in developing embryos. We mobilized the Gene Search (GS) P element and identified 42 lines with insertions in unique loci, including leak/roundabout2, which encodes an axon guidance receptor and confirms the utility of our screen. The genes we identified encode proteins of diverse classes, some acting near the cell surface and others in the cytoplasm or nucleus. We found that one GS line drove misexpression of the NF-kappaB transcription factor Dorsal, causing motor axons to bypass their correct termination sites. In the developing visual system, Dorsal misexpression also caused photoreceptor axons to reach incorrect positions within the optic lobe. This mistargeting occurred without observable changes of cell fate and correlated with localization of ectopic Dorsal in distal axons. We found that Dorsal and its inhibitor Cactus are expressed in photoreceptors, though neither was required for axon targeting. However, mutation analyses of genes known to act upstream of Dorsal revealed a requirement for the interleukin receptor-associated kinase family kinase Pelle for layer-specific targeting of photoreceptor axons, validating our screen as a means to identify new molecular determinants of nervous system development in vivo.
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Affiliation(s)
- Elizabeth N Mindorff
- Graduate Program in Neurological Sciences, McGill University, Montreal, Quebec, Canada
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Shin SW, Kokoza V, Bian G, Cheon HM, Kim YJ, Raikhel AS. REL1, a homologue of Drosophila dorsal, regulates toll antifungal immune pathway in the female mosquito Aedes aegypti. J Biol Chem 2005; 280:16499-507. [PMID: 15722339 DOI: 10.1074/jbc.m500711200] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Signaling by Drosophila Toll pathway activates two Rel/NF-kappaB transcription factors, Dorsal (Dl) and Dorsal-related immune factor (Dif). Dl plays a central role in the establishment of dorsoventral polarity during early embryogenesis, whereas Dif mediates the Toll receptor-dependent antifungal immune response in adult Drosophila. The absence of a Dif ortholog in mosquito genomes suggests that Dl may play its functional role in the mosquito Toll-mediated innate immune responses. We have cloned and molecularly characterized the gene homologous to Drosophila Dl and to Anopheles gambiae REL1 (Gambif1) from the yellow fever mosquito Aedes aegypti, named AaREL1. AaREL1 alternative transcripts encode two isoforms, AaREL1-A and AaREL1-B. Both transcripts are enriched during embryogenesis and are inducible by septic injury in larval and female mosquitoes. AaREL1 and AaREL2 (Aedes Relish) selectively bind to different kappaB motifs from insect immune gene promoters. Ectopic expression of AaREL1-A in both Drosophila mbn-2 cells and transgenic flies specifically activates Drosomycin and results in increased resistance against the fungus Beauveria bassiana. AaREL1-B acted cooperatively with AaREL1-A to enhance the immune gene activation in Aag-2 cells. The RNA interference knock-outs revealed that AaREL1 affected the expression of Aedes homologue of Drosophila Serpin-27A and mediated specific antifungal immune response against B. bassiana. These results indicate that the homologue of Dl, but not that of Dif, is a key regulator of the Toll antifungal immune pathway in A. aegypti female mosquitoes.
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Affiliation(s)
- Sang Woon Shin
- Department of Entomology and the Institute for Integrative Genome Biology, University of California, Riverside, California 92521, USA
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Hansen JM, Harris C. A novel hypothesis for thalidomide-induced limb teratogenesis: redox misregulation of the NF-kappaB pathway. Antioxid Redox Signal 2004; 6:1-14. [PMID: 14713331 DOI: 10.1089/152308604771978291] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Several hypotheses have been proposed to explain the mechanisms of thalidomide teratogenesis, although none adequately accounts for the observed malformations and explains the basis for species specificity. Recent observations that thalidomide increases the production of free radicals and elicits oxidative stress, coupled with new insights into the redox regulation of nuclear transcription factors, lead to the suggestion that thalidomide may act through redox misregulation of the limb outgrowth pathways. Oxidative stress, as marked by glutathione depletion/oxidation and a shift in intracellular redox potential toward the positive, occurs preferentially in limbs of thalidomide-sensitive rabbits, but not in resistant rats. DNA binding of nuclear factor kappa-B (NF-kappaB), a redox-sensitive transcription factor and key regulator of limb outgrowth, was shown to be significantly attenuated in rabbit limb cells and could be restored following the addition of a free radical spin-trapping agent, phenyl N-tert-butyl nitrone. The inability of NF-kappaB to bind to its DNA promoter results in the failure of limb cells to express fibroblast growth factor (FGF)-10 and twist in the limb progress zone (PZ) mesenchyme, which in turn attenuates expression of FGF-8 in the apical ectodermal ridge (AER). Failure to establish an FGF-10/FGF-8 feedback loop between the PZ and AER results in the truncation of limb outgrowth. We hypothesize that species-selective alterations in redox microenvironment caused by free radical production from thalidomide results in attenuation of the NF-kappaB-mediated gene expression that is responsible for limb outgrowth.
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Kawai N, Shimada M, Kawahara H, Satoh N, Yokosawa H. Regulation of ascidian Rel by its alternative splice variant. ACTA ACUST UNITED AC 2003; 270:4459-68. [PMID: 14622274 DOI: 10.1046/j.1432-1033.2003.03838.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The Rel/NF-kappaB family of transcription factors play key roles in morphogenesis and immune responses. We reported previously that As-rel1 and As-rel2 of the ascidian Halocynthia roretzi are involved in notochord formation. The As-rel1 protein is a typical Rel/NF-kappaB family member, whereas the As-rel2 protein is a novel truncated product of As-rel1 that lacks a nuclear localization signal and the unique C-terminal region. Here, we present conclusive evidence that As-rel1 and As-rel2 are generated from a single gene by alternative splicing. We analyzed the roles of As-rel2 using cells transfected with As-rel1 or As-rel2 or both. As-rel1 was localized in the nucleus and As-rel2 in the cytoplasm when they were transfected individually. In contrast, when they were transfected simultaneously, both were localized in the nucleus because of the association of As-rel2 with As-rel1. In this case, the transcriptional activity of As-rel1 was suppressed by As-rel2. Ascidian IkappaB was found to sequester As-rel1 in the cytoplasm and suppress its transcriptional activity when As-rel1 and IkappaB were transfected simultaneously. In contrast, when As-rel1 and IkappaB were transfected together with As-rel2, As-rel1 was transported into the nucleus and its transcriptional activity was rescued from inhibition by IkappaB, whereas As-rel2 remained localized in the cytoplasm, suggesting IkappaB sequestration in the cytoplasm by As-rel2. From these findings, we conclude that the alternative splice variant, As-rel2, regulates the nuclear localization and transcriptional activity of As-rel1.
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Affiliation(s)
- Narudo Kawai
- Department of Biochemistry, Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
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Affiliation(s)
- M Meister
- Institut de Biologie Moléculaire et Cellulaire, Strasbourg, France
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Abstract
The Drosophila Rel/NF-kappaB transcription factors - Dorsal, Dif, and Relish - control several biological processes, including embryonic pattern formation, muscle development, immunity, and hematopoiesis. Molecular-genetic analysis of 12 mutations that cause embryonic dorsal/ventral patterning defects has defined the steps that control the formation of this axis. Regulated activation of the Toll receptor leads to the establishment of a gradient of nuclear Dorsal protein, which in turn governs the subdivision of the axis and specification of ventral, lateral and dorsal fates. Phenotypic analysis of dorsal-ventral embryonic mutants and the characterization of the two other fly Rel proteins, Dif and Relish, have shown that the intracellular portion of the Toll to Cactus pathway also controls the innate immune response in Drosophila. Innate immunity and hematopoiesis are regulated by analogous Rel/NF-kappaB-family pathways in mammals. The elucidation of the complex regulation and diverse functions of Drosophila Rel proteins underscores the relevance of basic studies in Drosophila.
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Affiliation(s)
- S Govind
- Department of Biology, City College and The Graduate Center of The City University of New York, 138th Street and Convent Avenue, New York, NY 10031, USA
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14
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Manfruelli P, Reichhart JM, Steward R, Hoffmann JA, Lemaitre B. A mosaic analysis in Drosophila fat body cells of the control of antimicrobial peptide genes by the Rel proteins Dorsal and DIF. EMBO J 1999; 18:3380-91. [PMID: 10369678 PMCID: PMC1171418 DOI: 10.1093/emboj/18.12.3380] [Citation(s) in RCA: 168] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Expression of the gene encoding the antifungal peptide Drosomycin in Drosophila adults is controlled by the Toll signaling pathway. The Rel proteins Dorsal and DIF (Dorsal-related immunity factor) are possible candidates for the transactivating protein in the Toll pathway that directly regulates the drosomycin gene. We have examined the requirement of Dorsal and DIF for drosomycin expression in larval fat body cells, the predominant immune-responsive tissue, using the yeast site-specific flp/FRT recombination system to generate cell clones homozygous for a deficiency uncovering both the dorsal and the dif genes. Here we show that in the absence of both genes, the immune-inducibility of drosomycin is lost but can be rescued by overexpression of either dorsal or dif under the control of a heat-shock promoter. This result suggests a functional redundancy between both Rel proteins in the control of drosomycin gene expression in the larvae of Drosophila. Interestingly, the gene encoding the antibacterial peptide Diptericin remains fully inducible in the absence of the dorsal and dif genes. Finally, we have used fat body cell clones homozygous for various mutations to show that a linear activation cascade Spaetzle--> Toll-->Cactus-->Dorsal/DIF leads to the induction of the drosomycin gene in larval fat body cells.
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Affiliation(s)
- P Manfruelli
- Institut de Biologie Moléculaire et Cellulaire, UPR 9022 du Centre National de la Recherche Scientifique, 15, Rue René Descartes, F-67084 Strasbourg Cedex, France
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