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Critchlow JT, Prakash A, Zhong KY, Tate AT. Mapping the functional form of the trade-off between infection resistance and reproductive fitness under dysregulated immune signaling. PLoS Pathog 2024; 20:e1012049. [PMID: 38408106 PMCID: PMC10919860 DOI: 10.1371/journal.ppat.1012049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 03/07/2024] [Accepted: 02/15/2024] [Indexed: 02/28/2024] Open
Abstract
Immune responses benefit organismal fitness by clearing parasites but also exact costs associated with immunopathology and energetic investment. Hosts manage these costs by tightly regulating the induction of immune signaling to curtail excessive responses and restore homeostasis. Despite the theoretical importance of turning off the immune response to mitigate these costs, experimentally connecting variation in the negative regulation of immune responses to organismal fitness remains a frontier in evolutionary immunology. In this study, we used a dose-response approach to manipulate the RNAi-mediated knockdown efficiency of cactus (IκBα), a central regulator of Toll pathway signal transduction in flour beetles (Tribolium castaneum). By titrating cactus activity across four distinct levels, we derived the shape of the relationship between immune response investment and traits associated with host fitness, including infection susceptibility, lifespan, fecundity, body mass, and gut homeostasis. Cactus knock-down increased the overall magnitude of inducible immune responses and delayed their resolution in a dsRNA dose-dependent manner, promoting survival and resistance following bacterial infection. However, these benefits were counterbalanced by dsRNA dose-dependent costs to lifespan, fecundity, body mass, and gut integrity. Our results allowed us to move beyond the qualitative identification of a trade-off between immune investment and fitness to actually derive its functional form. This approach paves the way to quantitatively compare the evolution and impact of distinct regulatory elements on life-history trade-offs and fitness, filling a crucial gap in our conceptual and theoretical models of immune signaling network evolution and the maintenance of natural variation in immune systems.
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Affiliation(s)
- Justin T Critchlow
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Arun Prakash
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Katherine Y Zhong
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Ann T Tate
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
- Evolutionary Studies Institute, Vanderbilt University, Nashville, Tennessee, United States of America
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2
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Critchlow JT, Prakash A, Zhong KY, Tate AT. Mapping the functional form of the trade-off between infection resistance and reproductive fitness under dysregulated immune signaling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.10.552815. [PMID: 37645726 PMCID: PMC10461925 DOI: 10.1101/2023.08.10.552815] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Immune responses benefit organismal fitness by clearing parasites but also exact costs associated with immunopathology and energetic investment. Hosts manage these costs by tightly regulating the induction of immune signaling to curtail excessive responses and restore homeostasis. Despite the theoretical importance of turning off the immune response to mitigate these costs, experimentally connecting variation in the negative regulation of immune responses to organismal fitness remains a frontier in evolutionary immunology. In this study, we used a dose-response approach to manipulate the RNAi-mediated knockdown efficiency of cactus (IκBα), a central regulator of Toll pathway signal transduction in flour beetles (Tribolium castaneum). By titrating cactus activity along a continuous gradient, we derived the shape of the relationship between immune response investment and traits associated with host fitness, including infection susceptibility, lifespan, fecundity, body mass, and gut homeostasis. Cactus knock-down increased the overall magintude of inducible immune responses and delayed their resolution in a dsRNA dose-dependent manner, promoting survival and resistance following bacterial infection. However, these benefits were counterbalanced by dsRNA dose-dependent costs to lifespan, fecundity, body mass, and gut integrity. Our results allowed us to move beyond the qualitative identification of a trade-off between immune investment and fitness to actually derive its functional form. This approach paves the way to quantitatively compare the evolution and impact of distinct regulatory elements on life-history trade-offs and fitness, filling a crucial gap in our conceptual and theoretical models of immune signaling network evolution and the maintenance of natural variation in immune systems.
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Affiliation(s)
- Justin T. Critchlow
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Arun Prakash
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Katherine Y. Zhong
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Ann T. Tate
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
- Evolutionary Studies Institute, Vanderbilt University, Nashville, Tennessee, United States of America
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3
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Taghert PH. The incidence of candidate binding sites for β-arrestin in Drosophila neuropeptide GPCRs. PLoS One 2022; 17:e0275410. [PMID: 36318573 PMCID: PMC9624432 DOI: 10.1371/journal.pone.0275410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 10/14/2022] [Indexed: 01/24/2023] Open
Abstract
To support studies of neuropeptide neuromodulation, I have studied beta-arrestin binding sites (BBS's) by evaluating the incidence of BBS sequences among the C terminal tails (CTs) of each of the 49 Drosophila melanogaster neuropeptide GPCRs. BBS were identified by matches with a prediction derived from structural analysis of rhodopsin:arrestin and vasopressin receptor: arrestin complexes [1]. To increase the rigor of the identification, I determined the conservation of BBS sequences between two long-diverged species D. melanogaster and D. virilis. There is great diversity in the profile of BBS's in this group of GPCRs. I present evidence for conserved BBS's in a majority of the Drosophila neuropeptide GPCRs; notably some have no conserved BBS sequences. In addition, certain GPCRs display numerous conserved compound BBS's, and many GPCRs display BBS-like sequences in their intracellular loop (ICL) domains as well. Finally, 20 of the neuropeptide GPCRs are expressed as protein isoforms that vary in their CT domains. BBS profiles are typically different across related isoforms suggesting a need to diversify and regulate the extent and nature of GPCR:arrestin interactions. This work provides the initial basis to initiate future in vivo, genetic analyses in Drosophila to evaluate the roles of arrestins in neuropeptide GPCR desensitization, trafficking and signaling.
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Affiliation(s)
- Paul H. Taghert
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States of America
- * E-mail:
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Jian S, Leng J, Wen Z, Luo H, Hu C, Wen C, Hu B. β-arrestin interacts with TRAF6 to negatively regulate the NF-κB pathway in triangle sail mussel Hyriopsis cumingii. FISH & SHELLFISH IMMUNOLOGY 2022; 127:65-73. [PMID: 35705131 DOI: 10.1016/j.fsi.2022.06.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 06/06/2022] [Accepted: 06/08/2022] [Indexed: 06/15/2023]
Abstract
As members of arrestins family, β-arrestins are widely expressed in monocytes, macrophages, neutrophils and other immune cells. They can regulate the immune response of bodies through various ways. In the present study, a β-arrestin homolog named Hcβ-arrestin was cloned and identified from Hyriopsis cumingii. Predicted Hcβ-arrestin protein contained a conserved arrestin domain, which could be further divided into arrestin-N (39-192aa) and arrestin-C (211-365aa). Amino acid sequence alignment showed that it had the highest identity with Mytilus galloprovincialis and Mytilus edulis counterpart, which was 89.02% and 87.68%, respectively. Furthermore, real-time quantitative PCR analysis showed that the Hcβ-arrestin gene was widely expressed in the detected tissues and with the highest expression in hepatopancreas. The transcription of Hcβ-arrestin in hepatopancreas and gill of mussels was significantly up-regulated after stimulation with peptidoglycan, lipopolysaccharide (LPS) and polyinosinic polycytidylic acid. Knockdown of Hcβ-arrestin gene significantly increased the expression of some antibacterial effector genes, such as lysozyme, LPS-binding protein/bactericidal permeability increasing protein and theromacin in hepatopancreas and gills of LPS stimulated mussels, but only had little effect on TLR pathway genes. In addition, GST pull-down assay confirmed that Hcβ-arrestin can bind to HcTRAF6 protein in vitro. Dual luciferase reporter assay showed that the co-expression of HcTRAF6 and Hcβ-arrestin inhibited the activation of NF-κB reporter by HcTRAF6. These findings indicated that Hcβ-arrestins could interact with HcTRAF6 to negatively regulate the NF-κB pathway in H. cumingii.
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Affiliation(s)
- ShaoQing Jian
- Department of Aquatic Sciences, College of Life Sciences, Nanchang University, Nanchang, 330031, China
| | - JiangHe Leng
- Department of Aquatic Sciences, College of Life Sciences, Nanchang University, Nanchang, 330031, China
| | - ZiYi Wen
- Department of Biological Sciences, College of Life Sciences, Nanchang University, Nanchang, 330031, China
| | - HaiYang Luo
- Department of Ecology, College of Life Sciences, Nanchang University, Nanchang, 330031, China
| | - ChengXi Hu
- Department of Aquatic Sciences, College of Life Sciences, Nanchang University, Nanchang, 330031, China
| | - ChunGen Wen
- Department of Aquatic Sciences, College of Life Sciences, Nanchang University, Nanchang, 330031, China
| | - BaoQing Hu
- Department of Aquatic Sciences, College of Life Sciences, Nanchang University, Nanchang, 330031, China.
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5
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Hegde S, Sreejan A, Gadgil CJ, Ratnaparkhi GS. SUMOylation of Dorsal attenuates Toll/NF-κB signaling. Genetics 2022; 221:iyac081. [PMID: 35567478 PMCID: PMC9252280 DOI: 10.1093/genetics/iyac081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Accepted: 05/03/2022] [Indexed: 11/29/2022] Open
Abstract
In Drosophila, Toll/NF-κB signaling plays key roles in both animal development and in host defense. The activation, intensity, and kinetics of Toll signaling are regulated by posttranslational modifications such as phosphorylation, SUMOylation, or ubiquitination that target multiple proteins in the Toll/NF-κB cascade. Here, we have generated a CRISPR-Cas9 edited Dorsal (DL) variant that is SUMO conjugation resistant. Intriguingly, embryos laid by dlSCR mothers overcome dl haploinsufficiency and complete the developmental program. This ability appears to be a result of higher transcriptional activation by DLSCR. In contrast, SUMOylation dampens DL transcriptional activation, ultimately conferring robustness to the dorso-ventral program. In the larval immune response, dlSCR animals show an increase in crystal cell numbers, stronger activation of humoral defense genes, and high cactus levels. A mathematical model that evaluates the contribution of the small fraction of SUMOylated DL (1-5%) suggests that it acts to block transcriptional activation, which is driven primarily by DL that is not SUMO conjugated. Our findings define SUMO conjugation as an important regulator of the Toll signaling cascade, in both development and host defense. Our results broadly suggest that SUMO attenuates DL at the level of transcriptional activation. Furthermore, we hypothesize that SUMO conjugation of DL may be part of a Ubc9-dependent mechanism that restrains Toll/NF-κB signaling.
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Affiliation(s)
- Sushmitha Hegde
- Biology, Indian Institute of Science Education & Research, Pune 411008, India
| | - Ashley Sreejan
- Chemical Engineering and Process Development Division, CSIR—National Chemical Laboratory, Pune 411008, India
| | - Chetan J Gadgil
- Chemical Engineering and Process Development Division, CSIR—National Chemical Laboratory, Pune 411008, India
- CSIR—Institute of Genomics and Integrative Biology, New Delhi 110020, India
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6
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Mutations of γCOP Gene Disturb Drosophila melanogaster Innate Immune Response to Pseudomonas aeruginosa. Int J Mol Sci 2022; 23:ijms23126499. [PMID: 35742941 PMCID: PMC9223523 DOI: 10.3390/ijms23126499] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 05/31/2022] [Accepted: 06/08/2022] [Indexed: 01/27/2023] Open
Abstract
Drosophila melanogaster (the fruit fly) is a valuable experimental platform for modeling host–pathogen interactions. It is also commonly used to define innate immunity pathways and to understand the mechanisms of both host tolerance to commensal microbiota and response to pathogenic agents. Herein, we investigate how the host response to bacterial infection is mirrored in the expression of genes of Imd and Toll pathways when D. melanogaster strains with different γCOP genetic backgrounds are infected with Pseudomonas aeruginosa ATCC 27853. Using microarray technology, we have interrogated the whole-body transcriptome of infected versus uninfected fruit fly males with three specific genotypes, namely wild-type Oregon, γCOPS057302/TM6B and γCOP14a/γCOP14a. While the expression of genes pertaining to Imd and Toll is not significantly modulated by P. aeruginosa infection in Oregon males, many of the components of these cascades are up- or downregulated in both infected and uninfected γCOPS057302/TM6B and γCOP14a/γCOP14a males. Thus, our results suggest that a γCOP genetic background modulates the gene expression profiles of Imd and Toll cascades involved in the innate immune response of D. melanogaster, inducing the occurrence of immunological dysfunctions in γCOP mutants.
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Zhou H, Li S, Pan W, Wu S, Ma F, Jin P. Interaction of lncRNA-CR33942 with Dif/Dorsal Facilitates Antimicrobial Peptide Transcriptions and Enhances Drosophila Toll Immune Responses. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2022; 208:1978-1988. [PMID: 35379744 DOI: 10.4049/jimmunol.2100658] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 02/02/2022] [Indexed: 01/08/2023]
Abstract
The Drosophila Toll signaling pathway mainly responds to Gram-positive (G+) bacteria or fungal infection, which is highly conserved with mammalian TLR signaling pathway. Although many positive and negative regulators involved in the immune response of the Toll pathway have been identified in Drosophila, the roles of long noncoding RNAs (lncRNAs) in Drosophila Toll immune responses are poorly understood to date. In this study, our results demonstrate that lncRNA-CR33942 is mainly expressed in the nucleus and upregulated after Micrococcus luteus infection. Especially, lncRNA-CR33942 not only modulates differential expressions of multiple antimicrobial peptide genes but also affects the Drosophila survival rate during response to G+ bacterial infection based on the transiently overexpressing and the knockdown lncRNA-CR33942 assays in vivo. Mechanically, lncRNA-CR33942 interacts with the NF-κB transcription factors Dorsal-related immunity factor/Dorsal to promote the transcriptions of antimicrobial peptides drosomycin and metchnikowin, thus enhancing Drosophila Toll immune responses. Taken together, this study identifies lncRNA-CR33942 as a positive regulator of Drosophila innate immune response to G+ bacterial infection to facilitate Toll signaling via interacting with Dorsal-related immunity factor/Dorsal. It would be helpful to reveal the roles of lncRNAs in Toll immune response in Drosophila and provide insights into animal innate immunity.
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Affiliation(s)
- Hongjian Zhou
- Laboratory for Comparative Genomics and Bioinformatics and Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, People's Republic of China; and
| | - Shengjie Li
- Laboratory for Comparative Genomics and Bioinformatics and Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, People's Republic of China; and.,Jiangsu Provincial Key Construction Laboratory of Special Biomass Byproduct Resource Utilization, School of Food Science, Nanjing Xiaozhuang University, Nanjing, People's Republic of China
| | - Wanwan Pan
- Laboratory for Comparative Genomics and Bioinformatics and Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, People's Republic of China; and
| | - Shanshan Wu
- Laboratory for Comparative Genomics and Bioinformatics and Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, People's Republic of China; and
| | - Fei Ma
- Laboratory for Comparative Genomics and Bioinformatics and Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, People's Republic of China; and
| | - Ping Jin
- Laboratory for Comparative Genomics and Bioinformatics and Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, People's Republic of China; and
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8
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Zhou H, Li S, Wu S, Jin P, Ma F. LncRNA-CR11538 Decoys Dif/Dorsal to Reduce Antimicrobial Peptide Products for Restoring Drosophila Toll Immunity Homeostasis. Int J Mol Sci 2021; 22:ijms221810117. [PMID: 34576280 PMCID: PMC8468853 DOI: 10.3390/ijms221810117] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 09/12/2021] [Accepted: 09/17/2021] [Indexed: 11/29/2022] Open
Abstract
Avoiding excessive or insufficient immune responses and maintaining homeostasis are critical for animal survival. Although many positive or negative modulators involved in immune responses have been identified, little has been reported to date concerning whether the long non-coding RNA (lncRNA) can regulate Drosophila immunity response. In this study, we firstly discover that the overexpression of lncRNA-CR11538 can inhibit the expressions of antimicrobial peptides Drosomycin (Drs) and Metchnikowin (Mtk) in vivo, thereby suppressing the Toll signaling pathway. Secondly, our results demonstrate that lncRNA-CR11538 can interact with transcription factors Dif/Dorsal in the nucleus based on both subcellular localization and RIP analyses. Thirdly, our findings reveal that lncRNA-CR11538 can decoy Dif/Dorsal away from the promoters of Drs and Mtk to repress their transcriptions by ChIP-qPCR and dual luciferase report experiments. Fourthly, the dynamic expression changes of Drs, Dif, Dorsal and lncRNA-CR11538 in wild-type flies (w1118) at different time points after M. luteus stimulation disclose that lncRNA-CR11538 can help Drosophila restore immune homeostasis in the later period of immune response. Overall, our study reveals a novel mechanism by which lncRNA-CR11538 serves as a Dif/Dorsal decoy to downregulate antimicrobial peptide expressions for restoring Drosophila Toll immunity homeostasis, and provides a new insight into further studying the complex regulatory mechanism of animal innate immunity.
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Affiliation(s)
- Hongjian Zhou
- Laboratory for Comparative Genomics and Bioinformatics & Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Science, Nanjing Normal University, Nanjing 210046, China; (H.Z.); (S.L.); (S.W.); (F.M.)
| | - Shengjie Li
- Laboratory for Comparative Genomics and Bioinformatics & Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Science, Nanjing Normal University, Nanjing 210046, China; (H.Z.); (S.L.); (S.W.); (F.M.)
- Jiangsu Provincial Key Construction Laboratory of Special Biomass Byproduct Resource Utilization, School of Food Science, Nanjing Xiaozhuang University, Nanjing 211171, China
| | - Shanshan Wu
- Laboratory for Comparative Genomics and Bioinformatics & Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Science, Nanjing Normal University, Nanjing 210046, China; (H.Z.); (S.L.); (S.W.); (F.M.)
| | - Ping Jin
- Laboratory for Comparative Genomics and Bioinformatics & Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Science, Nanjing Normal University, Nanjing 210046, China; (H.Z.); (S.L.); (S.W.); (F.M.)
- Correspondence: ; Tel.: +86-25-85891050
| | - Fei Ma
- Laboratory for Comparative Genomics and Bioinformatics & Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Science, Nanjing Normal University, Nanjing 210046, China; (H.Z.); (S.L.); (S.W.); (F.M.)
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9
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Tang R, Huang W, Guan J, Liu Q, Beerntsen BT, Ling E. Drosophila H2Av negatively regulates the activity of the IMD pathway via facilitating Relish SUMOylation. PLoS Genet 2021; 17:e1009718. [PMID: 34370736 PMCID: PMC8376203 DOI: 10.1371/journal.pgen.1009718] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 08/19/2021] [Accepted: 07/14/2021] [Indexed: 12/15/2022] Open
Abstract
Insects depend on the innate immune response for defense against a wide array of pathogens. Central to Drosophila immunity are antimicrobial peptides (AMPs), released into circulation when pathogens trigger either of the two widely studied signal pathways, Toll or IMD. The Toll pathway responds to infection by Gram-positive bacteria and fungi while the IMD pathway is activated by Gram-negative bacteria. During activation of the IMD pathway, the NF-κB-like transcription factor Relish is phosphorylated and then cleaved, which is crucial for IMD-dependent AMP gene induction. Here we show that loss-of-function mutants of the unconventional histone variant H2Av upregulate IMD-dependent AMP gene induction in germ-free Drosophila larvae and adults. After careful dissection of the IMD pathway, we found that Relish has an epistatic relationship with H2Av. In the H2Av mutant larvae, SUMOylation is down-regulated, suggesting a possible role of SUMOylation in the immune phenotype. Eventually we demonstrated that Relish is mostly SUMOylated on amino acid K823. Loss of the potential SUMOylation site leads to significant auto-activation of Relish in vivo. Further work indicated that H2Av regulates Relish SUMOylation after physically interacting with Su(var)2-10, the E3 component of the SUMOylation pathway. Biochemical analysis suggested that SUMOylation of Relish prevents its cleavage and activation. Our findings suggest a new mechanism by which H2Av can negatively regulate, and thus prevent spontaneous activation of IMD-dependent AMP production, through facilitating SUMOylation of the NF-κB like transcription factor Relish. Toll and IMD signaling pathways should be involved in the production of antimicrobial peptides in animals upon infection. Immunity responses are energy consuming. Thus, these two pathways are fine-tuned. Animal H2A variant histones are involved in many physiological functions. In Drosophila, the production of antibacterial peptides is out of control in the mutant of H2A variant (H2Av810). After careful examination, we found that Relish, the transcription factor of the IMD pathway, was activated in this mutant. Eventually we demonstrate that Relish can be SUMOylated with the involvement of H2Av. Loss of the main SUMOylation site in Relish induces it to auto-activate following over-expression. Therefore, H2Av is a negative regulator of the IMD signaling pathway by maintaining the normal level of Relish SUMOylation in Drosophila.
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Affiliation(s)
- Ruijuan Tang
- University of Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Wuren Huang
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Jingmin Guan
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Qiuning Liu
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- Jiangsu Key Laboratory for Bioresources of Saline Soils, Jiangsu Synthetic Innovation Center for Coastal Bio-agriculture, Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection, School of Wetland, Yancheng Teachers University, Yancheng, China
| | - Brenda T. Beerntsen
- Veterinary Pathobiology, University of Missouri, Columbia, Missouri, United States of America
| | - Erjun Ling
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
- * E-mail:
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10
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The role of SUMOylation during development. Biochem Soc Trans 2021; 48:463-478. [PMID: 32311032 PMCID: PMC7200636 DOI: 10.1042/bst20190390] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 03/24/2020] [Accepted: 03/25/2020] [Indexed: 12/17/2022]
Abstract
During the development of multicellular organisms, transcriptional regulation plays an important role in the control of cell growth, differentiation and morphogenesis. SUMOylation is a reversible post-translational process involved in transcriptional regulation through the modification of transcription factors and through chromatin remodelling (either modifying chromatin remodelers or acting as a ‘molecular glue’ by promoting recruitment of chromatin regulators). SUMO modification results in changes in the activity, stability, interactions or localization of its substrates, which affects cellular processes such as cell cycle progression, DNA maintenance and repair or nucleocytoplasmic transport. This review focuses on the role of SUMO machinery and the modification of target proteins during embryonic development and organogenesis of animals, from invertebrates to mammals.
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11
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Signaling cross-talk during development: Context-specific networking of Notch, NF-κB and JNK signaling pathways in Drosophila. Cell Signal 2021; 82:109937. [PMID: 33529757 DOI: 10.1016/j.cellsig.2021.109937] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 01/25/2021] [Accepted: 01/26/2021] [Indexed: 01/08/2023]
Abstract
Multicellular organisms depend on a handful of core signaling pathways that regulate a variety of cell fate choices. Often these relatively simple signals integrate to form a large and complex signaling network to achieve a distinct developmental fate in a context-specific manner. Various pathway-dependent and independent events control the assembly of signaling complexes. Notch pathway is one such conserved signaling mechanism that integrates with other signaling pathways to exhibit a context-dependent pleiotropic output. To understand how Notch signaling provides a spectrum of distinct outputs, it is important to understand various regulatory switches involved in mediating signaling cross-talk of Notch with other pathways. Here, we review our current understanding as to how Notch signal integrates with JNK and NF-κB signaling pathways in Drosophila to regulate various developmental events such as sensory organ precursor formation, innate immunity, dorsal closure, establishment of planar cell polarity as well as during proliferation and tumor progression. We highlight the importance of conserved signaling molecules during these cross-talks and debate further possibilities of novel switches that may be involved in mediating these cross-talk events.
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12
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Younes S, Al-Sulaiti A, Nasser EAA, Najjar H, Kamareddine L. Drosophila as a Model Organism in Host-Pathogen Interaction Studies. Front Cell Infect Microbiol 2020; 10:214. [PMID: 32656090 PMCID: PMC7324642 DOI: 10.3389/fcimb.2020.00214] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 04/20/2020] [Indexed: 12/29/2022] Open
Abstract
Owing to the genetic similarities and conserved pathways between a fruit fly and mammals, the use of the Drosophila model as a platform to unveil novel mechanisms of infection and disease progression has been justified and widely instigated. Gaining proper insight into host-pathogen interactions and identifying chief factors involved in host defense and pathogen virulence in Drosophila serves as a foundation to establish novel strategies for infectious disease prevention and control in higher organisms, including humans.
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Affiliation(s)
- Salma Younes
- Biomedical Sciences Department, College of Health Sciences, QU Health, Qatar University, Doha, Qatar
| | - Asma Al-Sulaiti
- Biomedical Sciences Department, College of Health Sciences, QU Health, Qatar University, Doha, Qatar
| | | | - Hoda Najjar
- Biomedical Sciences Department, College of Health Sciences, QU Health, Qatar University, Doha, Qatar
| | - Layla Kamareddine
- Biomedical Sciences Department, College of Health Sciences, QU Health, Qatar University, Doha, Qatar
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13
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Martin AC. The Physical Mechanisms of Drosophila Gastrulation: Mesoderm and Endoderm Invagination. Genetics 2020; 214:543-560. [PMID: 32132154 PMCID: PMC7054018 DOI: 10.1534/genetics.119.301292] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 11/21/2019] [Indexed: 12/14/2022] Open
Abstract
A critical juncture in early development is the partitioning of cells that will adopt different fates into three germ layers: the ectoderm, the mesoderm, and the endoderm. This step is achieved through the internalization of specified cells from the outermost surface layer, through a process called gastrulation. In Drosophila, gastrulation is achieved through cell shape changes (i.e., apical constriction) that change tissue curvature and lead to the folding of a surface epithelium. Folding of embryonic tissue results in mesoderm and endoderm invagination, not as individual cells, but as collective tissue units. The tractability of Drosophila as a model system is best exemplified by how much we know about Drosophila gastrulation, from the signals that pattern the embryo to the molecular components that generate force, and how these components are organized to promote cell and tissue shape changes. For mesoderm invagination, graded signaling by the morphogen, Spätzle, sets up a gradient in transcriptional activity that leads to the expression of a secreted ligand (Folded gastrulation) and a transmembrane protein (T48). Together with the GPCR Mist, which is expressed in the mesoderm, and the GPCR Smog, which is expressed uniformly, these signals activate heterotrimeric G-protein and small Rho-family G-protein signaling to promote apical contractility and changes in cell and tissue shape. A notable feature of this signaling pathway is its intricate organization in both space and time. At the cellular level, signaling components and the cytoskeleton exhibit striking polarity, not only along the apical-basal cell axis, but also within the apical domain. Furthermore, gene expression controls a highly choreographed chain of events, the dynamics of which are critical for primordium invagination; it does not simply throw the cytoskeletal "on" switch. Finally, studies of Drosophila gastrulation have provided insight into how global tissue mechanics and movements are intertwined as multiple tissues simultaneously change shape. Overall, these studies have contributed to the view that cells respond to forces that propagate over great distances, demonstrating that cellular decisions, and, ultimately, tissue shape changes, proceed by integrating cues across an entire embryo.
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Affiliation(s)
- Adam C Martin
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142
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Scalf CS, Chariker JH, Rouchka EC, Ashley NT. Transcriptomic analysis of immune response to bacterial lipopolysaccharide in zebra finch (Taeniopygia guttata). BMC Genomics 2019; 20:647. [PMID: 31412766 PMCID: PMC6693190 DOI: 10.1186/s12864-019-6016-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 08/05/2019] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Despite the convergence of rapid technological advances in genomics and the maturing field of ecoimmunology, our understanding of the genes that regulate immunity in wild populations is still nascent. Previous work to assess immune function has relied upon relatively crude measures of immunocompetence. However, with next-generation RNA-sequencing, it is now possible to create a profile of gene expression in response to an immune challenge. In this study, captive zebra finch (Taeniopygia guttata; adult males) were challenged with bacterial lipopolysaccharide (LPS) or vehicle to stimulate the innate immune system. 2 hours after injection, birds were euthanized and hypothalami, spleen, and red blood cells (RBCs) were collected. Taking advantage of the fully sequenced genome of zebra finch, total RNA was isolated, sequenced, and partially annotated in these tissue/cells. RESULTS In hypothalamus, there were 707 significantly upregulated transcripts, as well as 564 and 144 in the spleen and RBCs, respectively, relative to controls. Also, 155 transcripts in the hypothalamus, 606 in the spleen, and 61 in the RBCs were significantly downregulated. More specifically, a number of immunity-related transcripts (e.g., IL-1β, RSAD2, SOCS3) were upregulated among tissues/cells. Additionally, transcripts involved in metabolic processes (APOD, LRAT, RBP4) were downregulated. CONCLUSIONS These results suggest a potential trade-off in expression of genes that regulate immunity and metabolism in birds challenged with LPS. This finding is consistent with a hypothermic response to LPS treatment in small birds. Unlike mammals, birds have nucleated RBCs, and these results support a novel transcriptomic response of avian RBCs to immune challenge.
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Affiliation(s)
- Cassandra S Scalf
- Department of Biology, Western Kentucky University, Bowling Green, KY, 42101-1800, USA
| | - Julia H Chariker
- Department of Neuroscience Training, University of Louisville, Louisville, KY, 40292, USA
| | - Eric C Rouchka
- Department of Computer Engineering and Computer Science, University of Louisville, Louisville, KY, 40292, USA
| | - Noah T Ashley
- Department of Biology, Western Kentucky University, Bowling Green, KY, 42101-1800, USA.
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15
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Structure-function analysis of β-arrestin Kurtz reveals a critical role of receptor interactions in downregulation of GPCR signaling in vivo. Dev Biol 2019; 455:409-419. [PMID: 31325455 DOI: 10.1016/j.ydbio.2019.07.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Revised: 06/15/2019] [Accepted: 07/16/2019] [Indexed: 01/14/2023]
Abstract
Arrestins control signaling via the G protein coupled receptors (GPCRs), serving as both signal terminators and transducers. Previous studies identified several structural elements in arrestins that contribute to their functions as GPCR regulators. However, the importance of these elements in vivo is unclear, and the developmental roles of arrestins are not well understood. We carried out an in vivo structure-function analysis of Kurtz (Krz), the single ortholog of mammalian β-arrestins in the Drosophila genome. A combination of Krz mutations affecting the GPCR-phosphosensing and receptor core-binding ("finger loop") functions (Krz-KKVL/A) resulted in a complete loss of Krz activity during development. Endosome recruitment and bioluminescence resonance energy transfer (BRET) assays revealed that the KKVL/A mutations abolished the GPCR-binding ability of Krz. We found that the isolated "finger loop" mutation (Krz-VL/A), while having a negligible effect on GPCR internalization, severely affected Krz function, suggesting that tight receptor interactions are necessary for proper termination of signaling in vivo. Genetic analysis as well as live imaging demonstrated that mutations in Krz led to hyperactivity of the GPCR Mist (also known as Mthl1), which is activated by its ligand Folded gastrulation (Fog) and is responsible for cellular contractility and epithelial morphogenesis. Krz mutations affected two developmental events that are under the control of Fog-Mist signaling: gastrulation and morphogenesis of the wing. Overall, our data reveal the functional importance in vivo of direct β-arrestin/GPCR binding, which is mediated by the recognition of the phosphorylated receptor tail and receptor core interaction. These Krz-GPCR interactions are critical for setting the correct level of Fog-Mist signaling during epithelial morphogenesis.
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Raich N, Mahmoudi S, Emre D, Karess RE. Mad1 influences interphase nucleoplasm organization and chromatin regulation in Drosophila. Open Biol 2018; 8:rsob.180166. [PMID: 30333236 PMCID: PMC6223205 DOI: 10.1098/rsob.180166] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 09/21/2018] [Indexed: 12/15/2022] Open
Abstract
The Drosophila Mad1 spindle checkpoint protein helps organize several nucleoplasmic components, and flies lacking Mad1 present changes in gene expression reflecting altered chromatin conformation. In interphase, checkpoint protein Mad1 is usually described as localizing to the inner nuclear envelope by binding the nucleoporin Tpr, an interaction believed to contribute to proper mitotic regulation. Whether Mad1 has other nuclear interphase functions is unknown. We found in Drosophila that Mad1 is present in nuclei of both mitotic and postmitotic tissues. Three proteins implicated in various aspects of chromatin organization co-immunoprecipitated with Mad1 from fly embryos: Mtor/Tpr, the SUMO peptidase Ulp1 and Raf2, a subunit of a Polycomb-like complex. In primary spermatocytes, all four proteins colocalized in a previously undescribed chromatin-associated structure called here a MINT (Mad1-containing IntraNuclear Territory). MINT integrity required all four proteins. In mad1 mutant spermatocytes, the other proteins were no longer confined to chromatin domains but instead dispersed throughout the nucleoplasm. mad1 flies also presented phenotypes indicative of excessive chromatin of heterochromatic character during development of somatic tissues. Together these results suggest that Drosophila Mad1, by helping organize its interphase protein partners in the nucleoplasm, contributes to proper chromatin regulation.
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Affiliation(s)
- Natacha Raich
- CNRS, Institut Jacques Monod, UMR7592, Université Paris Diderot, Sorbonne Paris Cité, Paris Cedex 13 75205, France
| | - Souhir Mahmoudi
- CNRS, Institut Jacques Monod, UMR7592, Université Paris Diderot, Sorbonne Paris Cité, Paris Cedex 13 75205, France
| | - Doruk Emre
- CNRS, Institut Jacques Monod, UMR7592, Université Paris Diderot, Sorbonne Paris Cité, Paris Cedex 13 75205, France
| | - Roger E Karess
- CNRS, Institut Jacques Monod, UMR7592, Université Paris Diderot, Sorbonne Paris Cité, Paris Cedex 13 75205, France
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17
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Portela M, Yang L, Paul S, Li X, Veraksa A, Parsons LM, Richardson HE. Lgl reduces endosomal vesicle acidification and Notch signaling by promoting the interaction between Vap33 and the V-ATPase complex. Sci Signal 2018; 11:11/533/eaar1976. [PMID: 29871910 DOI: 10.1126/scisignal.aar1976] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Epithelial cell polarity is linked to the control of tissue growth and tumorigenesis. The tumor suppressor and cell polarity protein lethal-2-giant larvae (Lgl) promotes Hippo signaling and inhibits Notch signaling to restrict tissue growth in Drosophila melanogaster Notch signaling is greater in lgl mutant tissue than in wild-type tissue because of increased acidification of endosomal vesicles, which promotes the proteolytic processing and activation of Notch by γ-secretase. We showed that the increased Notch signaling and tissue growth defects of lgl mutant tissue depended on endosomal vesicle acidification mediated by the vacuolar adenosine triphosphatase (V-ATPase). Lgl promoted the activity of the V-ATPase by interacting with Vap33 (VAMP-associated protein of 33 kDa). Vap33 physically and genetically interacted with Lgl and V-ATPase subunits and repressed V-ATPase-mediated endosomal vesicle acidification and Notch signaling. Vap33 overexpression reduced the abundance of the V-ATPase component Vha44, whereas Lgl knockdown reduced the binding of Vap33 to the V-ATPase component Vha68-3. Our data indicate that Lgl promotes the binding of Vap33 to the V-ATPase, thus inhibiting V-ATPase-mediated endosomal vesicle acidification and thereby reducing γ-secretase activity, Notch signaling, and tissue growth. Our findings implicate the deregulation of Vap33 and V-ATPase activity in polarity-impaired epithelial cancers.
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Affiliation(s)
- Marta Portela
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia.,Cell Cycle and Development Laboratory, Peter MacCallum Cancer Centre, Melbourne, Victoria 3002, Australia.,Department of Molecular, Cellular and Developmental Neurobiology, Cajal Institute, Avenida Doctor Arce, 37, Madrid 28002, Spain
| | - Liu Yang
- Department of Biology, University of Massachusetts, Boston, MA 02125, USA
| | - Sayantanee Paul
- Department of Biology, University of Massachusetts, Boston, MA 02125, USA
| | - Xia Li
- Department of Mathematics and Statistics, La Trobe University, Melbourne, Victoria 3086, Australia
| | - Alexey Veraksa
- Department of Biology, University of Massachusetts, Boston, MA 02125, USA
| | - Linda M Parsons
- Cell Cycle and Development Laboratory, Peter MacCallum Cancer Centre, Melbourne, Victoria 3002, Australia.,Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Helena E Richardson
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia. .,Cell Cycle and Development Laboratory, Peter MacCallum Cancer Centre, Melbourne, Victoria 3002, Australia.,Sir Peter MacCallum Department of Oncology, Department of Anatomy and Neuroscience, Department of Biochemistry and Molecular Biology, University of Melbourne, Melbourne, Victoria 3010, Australia
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18
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The Biology of SUMO-Targeted Ubiquitin Ligases in Drosophila Development, Immunity, and Cancer. J Dev Biol 2018; 6:jdb6010002. [PMID: 29615551 PMCID: PMC5875560 DOI: 10.3390/jdb6010002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 12/27/2017] [Accepted: 12/27/2017] [Indexed: 12/12/2022] Open
Abstract
The ubiquitin and SUMO (small ubiquitin-like modifier) pathways modify proteins that in turn regulate diverse cellular processes, embryonic development, and adult tissue physiology. These pathways were originally discovered biochemically in vitro, leading to a long-standing challenge of elucidating both the molecular cross-talk between these pathways and their biological importance. Recent discoveries in Drosophila established that ubiquitin and SUMO pathways are interconnected via evolutionally conserved SUMO-targeted ubiquitin ligase (STUbL) proteins. STUbL are RING ubiquitin ligases that recognize SUMOylated substrates and catalyze their ubiquitination, and include Degringolade (Dgrn) in Drosophila and RNF4 and RNF111 in humans. STUbL are essential for early development of both the fly and mouse embryos. In the fly embryo, Dgrn regulates early cell cycle progression, sex determination, zygotic gene transcription, segmentation, and neurogenesis, among other processes. In the fly adult, Dgrn is required for systemic immune response to pathogens and intestinal stem cell regeneration upon infection. These functions of Dgrn are highly conserved in humans, where RNF4-dependent ubiquitination potentiates key oncoproteins, thereby accelerating tumorigenesis. Here, we review the lessons learned to date in Drosophila and highlight their relevance to cancer biology.
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Yang L, Paul S, DuBois-Coyne S, Kyriakakis P, Veraksa A. Medium-scale Preparation of Drosophila Embryo Extracts for Proteomic Experiments. J Vis Exp 2017. [PMID: 28605365 DOI: 10.3791/55804] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Analysis of protein-protein interactions (PPIs) has become an indispensable approach to study biological processes and mechanisms, such as cell signaling, organism development, and disease. It is often desirable to obtain PPI information using in vivo material, to gain the most natural and unbiased view of the interaction networks. The fruit fly Drosophila melanogaster is an excellent platform to study PPIs in vivo, and lends itself to straightforward approaches to isolating material for biochemical experiments. In particular, fruit fly embryos represent a convenient type of tissue to study PPIs, due to the ease of collecting animals at this developmental stage and the fact that the majority of proteins are expressed in embryogenesis, thus providing a relevant environment to reveal most PPIs. Here we present a protocol for collection of Drosophila embryos at medium scale (0.5-1 g), which is an ideal amount for a wide range of proteomic applications, including analysis of PPIs by affinity purification-mass spectrometry (AP-MS). We describe our designs for 1 L and 5 L cages for embryo collections that can be easily and inexpensively set up in any laboratory. We also provide a general protocol for embryo collection and protein extraction to generate lysates that can be directly used in downstream applications such as AP-MS. Our goal is to provide an accessible means for all researchers to carry out the analyses of PPIs in vivo.
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Affiliation(s)
- Liu Yang
- Biology Department, University of Massachusetts Boston
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20
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SUMO regulates the activity of Smoothened and Costal-2 in Drosophila Hedgehog signaling. Sci Rep 2017; 7:42749. [PMID: 28195188 PMCID: PMC5307382 DOI: 10.1038/srep42749] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 01/17/2017] [Indexed: 12/21/2022] Open
Abstract
In Hedgehog (Hh) signaling, the GPCR-family protein Smoothened (Smo) acts as a signal transducer that is regulated by phosphorylation and ubiquitination, which ultimately change the cell surface accumulation of Smo. However, it is not clear whether Smo is regulated by other post-translational modifications, such as sumoylation. Here, we demonstrate that knockdown of the small ubiquitin-related modifier (SUMO) pathway components Ubc9 (a SUMO-conjugating enzyme E2), PIAS (a SUMO-protein ligase E3), and Smt3 (the SUMO isoform in Drosophila) by RNAi prevents Smo accumulation and alters Smo activity in the wing. We further show that Hh-induced-sumoylation stabilizes Smo, whereas desumoylation by Ulp1 destabilizes Smo in a phosphorylation independent manner. Mechanistically, we discover that excessive Krz, the Drosophila β-arrestin 2, inhibits Smo sumoylation and prevents Smo accumulation through Krz regulatory domain. Krz likely facilitates the interaction between Smo and Ulp1 because knockdown of Krz by RNAi attenuates Smo-Ulp1 interaction. Finally, we provide evidence that Cos2 is also sumoylated, which counteracts its inhibitory role on Smo accumulation in the wing. Taken together, we have uncovered a novel mechanism for Smo activation by sumoylation that is regulated by Hh and Smo interacting proteins.
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Sun JJ, Lan JF, Shi XZ, Yang MC, Niu GJ, Ding D, Zhao XF, Yu XQ, Wang JX. β-Arrestins Negatively Regulate the Toll Pathway in Shrimp by Preventing Dorsal Translocation and Inhibiting Dorsal Transcriptional Activity. J Biol Chem 2016; 291:7488-504. [PMID: 26846853 DOI: 10.1074/jbc.m115.698134] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Indexed: 12/30/2022] Open
Abstract
The Toll signaling pathway plays an important role in the innate immunity ofDrosophila melanogasterand mammals. The activation and termination of Toll signaling are finely regulated in these animals. Although the primary components of the Toll pathway were identified in shrimp, the functions and regulation of the pathway are seldom studied. We first demonstrated that the Toll signaling pathway plays a central role in host defense againstStaphylococcus aureusby regulating expression of antimicrobial peptides in shrimp. We then found that β-arrestins negatively regulate Toll signaling in two different ways. β-Arrestins interact with the C-terminal PEST domain of Cactus through the arrestin-N domain, and Cactus interacts with the RHD domain of Dorsal via the ankyrin repeats domain, forming a heterotrimeric complex of β-arrestin·Cactus·Dorsal, with Cactus as the bridge. This complex prevents Cactus phosphorylation and degradation, as well as Dorsal translocation into the nucleus, thus inhibiting activation of the Toll signaling pathway. β-Arrestins also interact with non-phosphorylated ERK (extracellular signal-regulated protein kinase) through the arrestin-C domain to inhibit ERK phosphorylation, which affects Dorsal translocation into the nucleus and phosphorylation of Dorsal at Ser(276)that impairs Dorsal transcriptional activity. Our study suggests that β-arrestins negatively regulate the Toll signaling pathway by preventing Dorsal translocation and inhibiting Dorsal phosphorylation and transcriptional activity.
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Affiliation(s)
- Jie-Jie Sun
- From the Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China and
| | - Jiang-Feng Lan
- From the Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China and
| | - Xiu-Zhen Shi
- From the Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China and
| | - Ming-Chong Yang
- From the Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China and
| | - Guo-Juan Niu
- From the Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China and
| | - Ding Ding
- From the Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China and
| | - Xiao-Fan Zhao
- From the Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China and
| | - Xiao-Qiang Yu
- the Division of Molecular Biology and Biochemistry, School of Biological Sciences, University of Missouri, Kansas City, Missouri 64110
| | - Jin-Xing Wang
- From the Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China and
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Abstract
Small ubiquitin-like modifier (SUMO) modification modulates the expression of defense genes in Drosophila, activated by the Toll/nuclear factor-κB and immune-deficient/nuclear factor-κB signaling networks. We have, however, limited understanding of the SUMO-modulated regulation of the immune response and lack information on SUMO targets in the immune system. In this study, we measured the changes to the SUMO proteome in S2 cells in response to a lipopolysaccharide challenge and identified 1619 unique proteins in SUMO-enriched lysates. A confident set of 710 proteins represents the immune-induced SUMO proteome and analysis suggests that specific protein domains, cellular pathways, and protein complexes respond to immune stress. A small subset of the confident set was validated by in-bacto SUMOylation and shown to be bona-fide SUMO targets. These include components of immune signaling pathways such as Caspar, Jra, Kay, cdc42, p38b, 14-3-3ε, as well as cellular proteins with diverse functions, many being components of protein complexes, such as prosß4, Rps10b, SmD3, Tango7, and Aats-arg. Caspar, a human FAF1 ortholog that negatively regulates immune-deficient signaling, is SUMOylated at K551 and responds to treatment with lipopolysaccharide in cultured cells. Our study is one of the first to describe SUMO proteome for the Drosophila immune response. Our data and analysis provide a global framework for the understanding of SUMO modification in the host response to pathogens.
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Cao X, He Y, Hu Y, Wang Y, Chen YR, Bryant B, Clem RJ, Schwartz LM, Blissard G, Jiang H. The immune signaling pathways of Manduca sexta. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2015; 62:64-74. [PMID: 25858029 PMCID: PMC4476939 DOI: 10.1016/j.ibmb.2015.03.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2015] [Revised: 03/16/2015] [Accepted: 03/17/2015] [Indexed: 05/10/2023]
Abstract
Signal transduction pathways and their coordination are critically important for proper functioning of animal immune systems. Our knowledge of the constituents of the intracellular signaling network in insects mainly comes from genetic analyses in Drosophila melanogaster. To facilitate future studies of similar systems in the tobacco hornworm and other lepidopteran insects, we have identified and examined the homologous genes in the genome of Manduca sexta. Based on 1:1 orthologous relationships in most cases, we hypothesize that the Toll, Imd, MAPK-JNK-p38 and JAK-STAT pathways are intact and operative in this species, as are most of the regulatory mechanisms. Similarly, cellular processes such as autophagy, apoptosis and RNA interference probably function in similar ways, because their mediators and modulators are mostly conserved in this lepidopteran species. We have annotated a total of 186 genes encoding 199 proteins, studied their domain structures and evolution, and examined their mRNA levels in tissues at different life stages. Such information provides a genomic perspective of the intricate signaling system in a non-drosophiline insect.
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Affiliation(s)
- Xiaolong Cao
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Yan He
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Yingxia Hu
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Yang Wang
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Yun-Ru Chen
- Boyce Thompson Institute, Cornell University, Ithaca, NY 14853, USA
| | - Bart Bryant
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Rollie J Clem
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | | | - Gary Blissard
- Boyce Thompson Institute, Cornell University, Ithaca, NY 14853, USA
| | - Haobo Jiang
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA.
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Dynamic regulation of innate immune responses in Drosophila by Senju-mediated glycosylation. Proc Natl Acad Sci U S A 2015; 112:5809-14. [PMID: 25901322 DOI: 10.1073/pnas.1424514112] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The innate immune system is the first line of defense encountered by invading pathogens. Delayed and/or inadequate innate immune responses can result in failure to combat pathogens, whereas excessive and/or inappropriate responses cause runaway inflammation. Therefore, immune responses are tightly regulated from initiation to resolution and are repressed during the steady state. It is well known that glycans presented on pathogens play important roles in pathogen recognition and the interactions between host molecules and microbes; however, the function of glycans of host organisms in innate immune responses is less well known. Here, we show that innate immune quiescence and strength of the immune response are controlled by host glycosylation involving a novel UDP-galactose transporter called Senju. In senju mutants, reduced expression of galactose-containing glycans resulted in hyperactivation of the Toll signaling pathway in the absence of immune challenges. Genetic epistasis and biochemical analyses revealed that Senju regulates the Toll signaling pathway at a step that converts Toll ligand Spatzle to its active form. Interestingly, Toll activation in immune-challenged wild type (WT) flies reduced the expression of galactose-containing glycans. Suppression of the degalactosylation by senju overexpression resulted in reduced induction of Toll-dependent expression of an antimicrobial peptide, Drosomycin, and increased susceptibility to infection with Gram-positive bacteria. These data suggest that Senju-mediated galactosylation suppresses undesirable Toll signaling activation during the steady state; however, Toll activation in response to infection leads to degalactosylation, which raises the immune response to an adequate level and contributes to the prompt elimination of pathogens.
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A roadmap to understanding toll pathway changes: an educational primer for use with "regulation of toll signaling and inflammation by β-arrestin and the SUMO protease Ulp1". Genetics 2015; 196:923-9. [PMID: 24723732 DOI: 10.1534/genetics.114.162289] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
An article by Anjum et al. in the December 2013 issue of GENETICS can be used to illustrate reverse genetic manipulation in a model organism, targeted RNA interference, synergistic gene interaction, and biochemical regulation of gene expression using post-translational modification. This Primer provides background information, technical explanations of methods and genetic approaches from the study, an example approach for classroom use, and discussion questions to promote understanding of the research article.
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Abstract
In this commentary, Brian P. Lazzaro and David S. Schneider examine the topic of the Genetics of Immunity as explored in this month's issues of GENETICS and G3: Genes|Genomes|Genetics. These inaugural articles are part of a joint Genetics of Immunity collection (ongoing) in the GSA journals.
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