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Liu J, Jin T, Ran L, Zhao Z, Zhu R, Xie G, Bi X. Profiling ATM regulated genes in Drosophila at physiological condition and after ionizing radiation. Hereditas 2022; 159:41. [PMID: 36271387 PMCID: PMC9587650 DOI: 10.1186/s41065-022-00254-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 10/06/2022] [Indexed: 11/17/2022] Open
Abstract
Background ATM (ataxia-telangiectasia mutated) protein kinase is highly conserved in metazoan, and plays a critical role at DNA damage response, oxidative stress, metabolic stress, immunity, RNA biogenesis etc. Systemic profiling of ATM regulated genes, including protein-coding genes, miRNAs, and long non-coding RNAs, will greatly improve our understanding of ATM functions and its regulation. Results 1) differentially expressed protein-coding genes, miRNAs, and long non-coding RNAs in atm mutated flies were identified at physiological condition and after X-ray irradiation. 2) functions of differentially expressed genes in atm mutated flies, regardless of protein-coding genes or non-coding RNAs, are closely related with metabolic process, immune response, DNA damage response or oxidative stress. 3) these phenomena are persistent after irradiation. 4) there is a cross-talk regulation towards miRNAs by ATM, E2f1, and p53 during development and after irradiation. 5) knock-out flies or knock-down flies of most irradiation-induced miRNAs were sensitive to ionizing radiation. Conclusions We provide a valuable resource of protein-coding genes, miRNAs, and long non-coding RNAs, for understanding ATM functions and regulations. Our work provides the new evidence of inter-dependence among ATM-E2F1-p53 for the regulation of miRNAs. Supplementary Information The online version contains supplementary material available at 10.1186/s41065-022-00254-9.
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Affiliation(s)
- Jun Liu
- School of Medicine, Nantong University, Nantong, 226001, China
| | - Tianyu Jin
- College of Basic Medical Medicine, Dalian Medical University, Dalian, 116044, China
| | - Lanxi Ran
- College of Basic Medical Medicine, Dalian Medical University, Dalian, 116044, China
| | - Ze Zhao
- College of Basic Medical Medicine, Dalian Medical University, Dalian, 116044, China
| | - Rui Zhu
- College of Basic Medical Medicine, Dalian Medical University, Dalian, 116044, China
| | - Gangcai Xie
- School of Medicine, Nantong University, Nantong, 226001, China.
| | - Xiaolin Bi
- School of Medicine, Nantong University, Nantong, 226001, China. .,College of Basic Medical Medicine, Dalian Medical University, Dalian, 116044, China.
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2
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Expression and Function of Toll Pathway Components in the Early Development of the Wasp Nasonia vitripennis. J Dev Biol 2022; 10:jdb10010007. [PMID: 35225961 PMCID: PMC8883978 DOI: 10.3390/jdb10010007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 01/20/2022] [Accepted: 01/22/2022] [Indexed: 11/22/2022] Open
Abstract
The Toll signaling pathway is the main source of embryonic DV polarity in the fly Drosophila melanogaster. This pathway appears to have been co-opted from an ancestral innate immunity system within the insects and has been deployed in different ways among insect taxa. Here we report the expression and function of homologs of the important components of the D. melanogaster Toll pathway in the wasp Nasonia vitripennis. We found homologs for all the components; many components had one or more additional paralogs in the wasp relative the fly. We also found significant deviations in expression patterns of N. vitripennis homologs. Finally, we provide some preliminary functional analyses of the N. vitripennis homologs, where we find a mixture of conservation and divergence of function.
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3
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Alpar L, Bergantiños C, Johnston LA. Spatially Restricted Regulation of Spätzle/Toll Signaling during Cell Competition. Dev Cell 2018; 46:706-719.e5. [PMID: 30146479 PMCID: PMC6156939 DOI: 10.1016/j.devcel.2018.08.001] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 06/11/2018] [Accepted: 07/25/2018] [Indexed: 01/15/2023]
Abstract
Cell competition employs comparisons of fitness to selectively eliminate cells sensed as less healthy. In Drosophila, apoptotic elimination of the weaker "loser" cells from growing wing discs is induced by a signaling module consisting of the Toll ligand Spätzle (Spz), several Toll-related receptors, and NF-κB factors. How this module is activated and restricted to competing disc cells is unknown. Here, we use Myc-induced cell competition to demonstrate that loser cell elimination requires local wing disc synthesis of Spz. We identify Spz processing enzyme (SPE) and modular serine protease (ModSP) as activators of Spz-regulated competitive signaling and show that "winner" cells trigger elimination of nearby WT cells by boosting SPE production. Moreover, Spz requires both Toll and Toll-8 to induce apoptosis of wing disc cells. Thus, during cell competition, Spz-mediated signaling is strictly confined to the imaginal disc, allowing errors in tissue fitness to be corrected without compromising organismal physiology.
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Affiliation(s)
- Lale Alpar
- Department of Biological Sciences, Columbia University Medical Center, New York, NY, 10032, USA.,Department of Genetics and Development, Columbia University Medical Center, New York, NY, 10032, USA
| | - Cora Bergantiños
- Department of Genetics and Development, Columbia University Medical Center, New York, NY, 10032, USA
| | - Laura A. Johnston
- Department of Genetics and Development, Columbia University Medical Center, New York, NY, 10032, USA.,Correspondence:
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4
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Stein D, Cho YS, Stevens LM. Localized serine protease activity and the establishment of Drosophila embryonic dorsoventral polarity. Fly (Austin) 2013; 7:161-7. [PMID: 24047959 DOI: 10.4161/fly.25141] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Drosophila embryo dorsoventral polarity is established by a maternally encoded signal transduction pathway in which three sequentially acting serine proteases, Gastrulation Defective, Snake and Easter, generate the ligand that activates the Toll receptor on the ventral side of the embryo. The spatial regulation of this pathway depends upon ventrally restricted expression of the Pipe sulfotransferase in the ovarian follicle during egg formation. Several recent observations have advanced our understanding of the mechanism regulating the spatially restricted activation of Toll. First, several protein components of the vitelline membrane layer of the eggshell have been determined to be targets of Pipe-mediated sulfation. Second, the processing of Easter by Snake has been identified as the first Pipe-dependent, ventrally-restricted processing event in the pathway. Finally, Gastrulation Defective has been shown to undergo Pipe-dependent, ventral localization within the perivitelline space and to facilitate Snake-mediated processing of Easter. Together, these observations suggest that Gastrulation Defective, localized on the interior ventral surface of the eggshell in association with Pipe-sulfated eggshell proteins, recruits and mediates an interaction between Snake and Easter. This event leads to ventrally-restricted processing and activation of Easter and consequently, localized formation of the Toll ligand, and Toll activation.
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Affiliation(s)
- David Stein
- Section of Molecular Cell and Developmental Biology; Institute for Cellular and Molecular Biology; University of Texas at Austin; Austin, TX USA
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5
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Patterson RA, Juarez MT, Hermann A, Sasik R, Hardiman G, McGinnis W. Serine proteolytic pathway activation reveals an expanded ensemble of wound response genes in Drosophila. PLoS One 2013; 8:e61773. [PMID: 23637905 PMCID: PMC3634835 DOI: 10.1371/journal.pone.0061773] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 03/13/2013] [Indexed: 01/01/2023] Open
Abstract
After injury to the animal epidermis, a variety of genes are transcriptionally activated in nearby cells to regenerate the missing cells and facilitate barrier repair. The range and types of diffusible wound signals that are produced by damaged epidermis and function to activate repair genes during epidermal regeneration remains a subject of very active study in many animals. In Drosophila embryos, we have discovered that serine protease function is locally activated around wound sites, and is also required for localized activation of epidermal repair genes. The serine protease trypsin is sufficient to induce a striking global epidermal wound response without inflicting cell death or compromising the integrity of the epithelial barrier. We developed a trypsin wounding treatment as an amplification tool to more fully understand the changes in the Drosophila transcriptome that occur after epidermal injury. By comparing our array results with similar results on mammalian skin wounding we can see which evolutionarily conserved pathways are activated after epidermal wounding in very diverse animals. Our innovative serine protease-mediated wounding protocol allowed us to identify 8 additional genes that are activated in epidermal cells in the immediate vicinity of puncture wounds, and the functions of many of these genes suggest novel genetic pathways that may control epidermal wound repair. Additionally, our data augments the evidence that clean puncture wounding can mount a powerful innate immune transcriptional response, with different innate immune genes being activated in an interesting variety of ways. These include puncture-induced activation only in epidermal cells in the immediate vicinity of wounds, or in all epidermal cells, or specifically in the fat body, or in multiple tissues.
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Affiliation(s)
- Rachel A. Patterson
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, California, United States of America
| | - Michelle T. Juarez
- Sophie Davis School of Biomedical Education, City College New York, New York, New York, United States of America
| | - Anita Hermann
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, California, United States of America
| | - Roman Sasik
- Department of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Gary Hardiman
- Department of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - William McGinnis
- Section of Cell and Developmental Biology, University of California San Diego, La Jolla, California, United States of America
- * E-mail:
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6
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Cho YS, Stevens LM, Sieverman KJ, Nguyen J, Stein D. A ventrally localized protease in the Drosophila egg controls embryo dorsoventral polarity. Curr Biol 2012; 22:1013-8. [PMID: 22578419 DOI: 10.1016/j.cub.2012.03.065] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Revised: 03/30/2012] [Accepted: 03/30/2012] [Indexed: 11/16/2022]
Abstract
Drosophila embryo dorsoventral (DV) polarity is defined by serine protease activity in the perivitelline space (PVS) between the embryonic membrane and the inner layer of the eggshell. Gastrulation Defective (GD) cleaves and activates Snake (Snk). Activated Snk cleaves and activates Easter (Ea), exclusively on the ventral side of the embryo. Activated Ea then processes Spätzle (Spz) into the activating ligand for Toll, a transmembrane receptor that is distributed throughout the embryonic plasma membrane. Ventral activation of Toll depends upon the activity of the Pipe sulfotransferase in the ventral region of the follicular epithelium that surrounds the developing oocyte. Pipe transfers sulfate residues to several protein components of the inner vitelline membrane layer of the eggshell. Here we show that GD protein becomes localized in the ventral PVS in a Pipe-dependent process. Moreover, ventrally concentrated GD acts to promote the cleavage of Ea by Snk through an extracatalytic mechanism that is distinct from GD's proteolytic activation of Snk. Together, these observations illuminate the mechanism through which spatially restricted sulfotransferase activity in the developing egg chamber leads to localization of serine protease activity and ultimately to spatially specific activation of the Toll receptor in the Drosophila embryo.
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Affiliation(s)
- Yong Suk Cho
- Section of Molecular Cell and Developmental Biology and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX, 78712, USA
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7
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A new factor in the Aedes aegypti immune response: CLSP2 modulates melanization. EMBO Rep 2011; 12:938-43. [PMID: 21760616 DOI: 10.1038/embor.2011.130] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2010] [Revised: 05/12/2011] [Accepted: 06/07/2011] [Indexed: 11/08/2022] Open
Abstract
Microbial infections in the mosquito Aedes aegypti activate the newly identified CLSP1 and CLSP2 genes, which encode modular proteins composed of elastase-like serine protease and C-type lectin domains. These genes are predominantly regulated by the immune deficiency pathway, but also by the Toll pathway. Silencing of CLSP2, but not CLSP1, results in the activation of prophenoloxidase (PPO), the terminal enzyme in the melanization cascade, suggesting that CLSP2 is a negative modulator of this reaction. Haemolymph PPO activation is normally inhibited in the presence of Plasmodium parasites, but in CLSP2-depleted mosquitoes, the Plasmodium-induced block of melanization is reverted, and these mosquitoes are refractory to the parasite. Thus, CLSP2 is a new component of the mosquito immune response.
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8
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Kellenberger C, Leone P, Coquet L, Jouenne T, Reichhart JM, Roussel A. Structure-function analysis of grass clip serine protease involved in Drosophila Toll pathway activation. J Biol Chem 2011; 286:12300-7. [PMID: 21310954 DOI: 10.1074/jbc.m110.182741] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Grass is a clip domain serine protease (SP) involved in a proteolytic cascade triggering the Toll pathway activation of Drosophila during an immune response. Epistasic studies position it downstream of the apical protease ModSP and upstream of the terminal protease Spaetzle-processing enzyme. Here, we report the crystal structure of Grass zymogen. We found that Grass displays a rather deep active site cleft comparable with that of proteases of coagulation and complement cascades. A key distinctive feature is the presence of an additional loop (75-loop) in the proximity of the activation site localized on a protruding loop. All biochemical attempts to hydrolyze the activation site of Grass failed, strongly suggesting restricted access to this region. The 75-loop is thus proposed to constitute an original mechanism to prevent spontaneous activation. A comparison of Grass with clip serine proteases of known function involved in analogous proteolytic cascades allowed us to define two groups, according to the presence of the 75-loop and the conformation of the clip domain. One group (devoid of the 75-loop) contains penultimate proteases whereas the other contains terminal proteases. Using this classification, Grass appears to be a terminal protease. This result is evaluated according to the genetic data documenting Grass function.
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Affiliation(s)
- Christine Kellenberger
- Architecture et Fonction des Macromolécules Biologiques UMR6098, Parc Scientifique et Technologique de Luminy, 13288 Marseille Cedex 09, France.
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9
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Activation of Snake in a serine protease cascade that defines the dorsoventral axis is atypical and pipe-independent in Drosophila embryos. FEBS Lett 2010; 584:3557-60. [PMID: 20638387 DOI: 10.1016/j.febslet.2010.07.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Revised: 07/07/2010] [Accepted: 07/12/2010] [Indexed: 11/20/2022]
Abstract
During Drosophila embryogenesis, establishment of ventral and lateral cell fates requires spatial regulation of an extracellular serine protease cascade composed of Nudel, Gastrulation Defective (GD), Snake, and Easter. Pipe, a sulfotransferase expressed ventrally during oogenesis, sulfates secreted targets that somehow confer positive spatial input to this cascade. Nudel and GD activation are pipe-independent, while Easter activation requires pipe. The effect of pipe on Snake activation has been unknown. Here we show that Snake activation is cascade-dependent but pipe-independent. These findings support a conclusion that Snake's activation of Easter is the first spatially regulated step in the dorsoventral protease cascade.
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10
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A single modular serine protease integrates signals from pattern-recognition receptors upstream of the Drosophila Toll pathway. Proc Natl Acad Sci U S A 2009; 106:12442-7. [PMID: 19590012 DOI: 10.1073/pnas.0901924106] [Citation(s) in RCA: 143] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The Drosophila Toll receptor does not interact directly with microbial determinants, but is instead activated by a cleaved form of the cytokine-like molecule Spätzle. During the immune response, Spätzle is processed by complex cascades of serine proteases, which are activated by secreted pattern-recognition receptors. Here, we demonstrate the essential role of ModSP, a modular serine protease, in the activation of the Toll pathway by gram-positive bacteria and fungi. Our analysis shows that ModSP integrates signals originating from the circulating recognition molecules GNBP3 and PGRP-SA and connects them to the Grass-SPE-Spätzle extracellular pathway upstream of the Toll receptor. It also reveals the conserved role of modular serine proteases in the activation of insect immune reactions.
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11
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Shah PK, Tripathi LP, Jensen LJ, Gahnim M, Mason C, Furlong EE, Rodrigues V, White KP, Bork P, Sowdhamini R. Enhanced function annotations for Drosophila serine proteases: a case study for systematic annotation of multi-member gene families. Gene 2007; 407:199-215. [PMID: 17996400 DOI: 10.1016/j.gene.2007.10.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2007] [Revised: 09/09/2007] [Accepted: 10/07/2007] [Indexed: 12/30/2022]
Abstract
Systematically annotating function of enzymes that belong to large protein families encoded in a single eukaryotic genome is a very challenging task. We carried out such an exercise to annotate function for serine-protease family of the trypsin fold in Drosophila melanogaster, with an emphasis on annotating serine-protease homologues (SPHs) that may have lost their catalytic function. Our approach involves data mining and data integration to provide function annotations for 190 Drosophila gene products containing serine-protease-like domains, of which 35 are SPHs. This was accomplished by analysis of structure-function relationships, gene-expression profiles, large-scale protein-protein interaction data, literature mining and bioinformatic tools. We introduce functional residue clustering (FRC), a method that performs hierarchical clustering of sequences using properties of functionally important residues and utilizes correlation co-efficient as a quantitative similarity measure to transfer in vivo substrate specificities to proteases. We show that the efficiency of transfer of substrate-specificity information using this method is generally high. FRC was also applied on Drosophila proteases to assign putative competitive inhibitor relationships (CIRs). Microarray gene-expression data were utilized to uncover a large-scale and dual involvement of proteases in development and in immune response. We found specific recruitment of SPHs and proteases with CLIP domains in immune response, suggesting evolution of a new function for SPHs. We also suggest existence of separate downstream protease cascades for immune response against bacterial/fungal infections and parasite/parasitoid infections. We verify quality of our annotations using information from RNAi screens and other evidence types. Utilization of such multi-fold approaches results in 10-fold increase of function annotation for Drosophila serine proteases and demonstrates value in increasing annotations in multiple genomes.
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Affiliation(s)
- Parantu K Shah
- European Molecular Biology Laboratory, Meyerhofstrasse 1, Heidelberg, Germany
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12
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Keränen SVE, Fowlkes CC, Luengo Hendriks CL, Sudar D, Knowles DW, Malik J, Biggin MD. Three-dimensional morphology and gene expression in the Drosophila blastoderm at cellular resolution II: dynamics. Genome Biol 2007; 7:R124. [PMID: 17184547 PMCID: PMC1794437 DOI: 10.1186/gb-2006-7-12-r124] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2006] [Revised: 11/17/2006] [Accepted: 12/21/2006] [Indexed: 11/10/2022] Open
Abstract
A new spatio-temporal coordinate framework for studying three-dimensional patterns of gene expression in the Drosophila blastoderm is presented that takes account of previously undetected morphological movements. Background To accurately describe gene expression and computationally model animal transcriptional networks, it is essential to determine the changing locations of cells in developing embryos. Results Using automated image analysis methods, we provide the first quantitative description of temporal changes in morphology and gene expression at cellular resolution in whole embryos, using the Drosophila blastoderm as a model. Analyses based on both fixed and live embryos reveal complex, previously undetected three-dimensional changes in nuclear density patterns caused by nuclear movements prior to gastrulation. Gene expression patterns move, in part, with these changes in morphology, but additional spatial shifts in expression patterns are also seen, supporting a previously proposed model of pattern dynamics based on the induction and inhibition of gene expression. We show that mutations that disrupt either the anterior/posterior (a/p) or the dorsal/ventral (d/v) transcriptional cascades alter morphology and gene expression along both the a/p and d/v axes in a way suggesting that these two patterning systems interact via both transcriptional and morphological mechanisms. Conclusion Our work establishes a new strategy for measuring temporal changes in the locations of cells and gene expression patterns that uses fixed cell material and computational modeling. It also provides a coordinate framework for the blastoderm embryo that will allow increasingly accurate spatio-temporal modeling of both the transcriptional control network and morphogenesis.
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Affiliation(s)
- Soile VE Keränen
- Berkeley Drosophila Transcription Network Project, Genomics Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720, USA
| | - Charless C Fowlkes
- Berkeley Drosophila Transcription Network Project, Department of Electrical Engineering and Computer Science, University of California, Berkeley, California 94720, USA
| | - Cris L Luengo Hendriks
- Berkeley Drosophila Transcription Network Project, Life Sciences Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720, USA
| | - Damir Sudar
- Berkeley Drosophila Transcription Network Project, Life Sciences Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720, USA
| | - David W Knowles
- Berkeley Drosophila Transcription Network Project, Life Sciences Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720, USA
| | - Jitendra Malik
- Berkeley Drosophila Transcription Network Project, Department of Electrical Engineering and Computer Science, University of California, Berkeley, California 94720, USA
| | - Mark D Biggin
- Berkeley Drosophila Transcription Network Project, Genomics Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720, USA
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LeMosy EK. Proteolytic regulatory mechanisms in the formation of extracellular morphogen gradients. ACTA ACUST UNITED AC 2006; 78:243-55. [PMID: 17061259 DOI: 10.1002/bdrc.20074] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Growth factors are secreted into the extracellular space, where they encounter soluble inhibitors, extracellular matrix glycoproteins and proteoglycans, and proteolytic enzymes that can each modulate the spatial distribution, activity state, and receptor interactions of these signaling molecules. During development, morphogenetic gradients of these growth factors pattern fields of cells responsive to different levels of signaling, creating such structures as the branched pattern of airways and vasculature, and the arrangement of digits in the hand. This review focuses specifically on the roles of proteolytic enzymes and their regulators in the generation of such activity gradients. Evidence from Drosophila developmental pathways provides a detailed understanding of general mechanisms underlying proteolytic control of morphogen gradients, while recent studies of several mammalian growth factors illustrate the relevance of this proteolytic control to human development and disease.
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Affiliation(s)
- Ellen K LeMosy
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta, Georgia 30912, USA.
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14
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Moussian B, Roth S. Dorsoventral axis formation in the Drosophila embryo--shaping and transducing a morphogen gradient. Curr Biol 2006; 15:R887-99. [PMID: 16271864 DOI: 10.1016/j.cub.2005.10.026] [Citation(s) in RCA: 175] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The graded nuclear location of the transcription factor Dorsal along the dorsoventral axis of the early Drosophila embryo provides positional information for the determination of different cell fates. Nuclear uptake of Dorsal depends on a complex signalling pathway comprising two parts: an extracellular proteolytic cascade transmits the dorsoventral polarity of the egg chamber to the early embryo and generates a gradient of active Spätzle protein, the ligand of the receptor Toll; an intracellular cascade downstream of Toll relays this graded signal to embryonic nuclei. The slope of the Dorsal gradient is not determined by diffusion of extracellular or intracellular components from a local source, but results from self-organised patterning, in which positive and negative feedback is essential to create and maintain the ratio of key factors at different levels, thereby establishing and stabilising the graded spatial information for Dorsal nuclear uptake.
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Affiliation(s)
- Bernard Moussian
- Department of Genetics, Max-Planck Institute for Developmental Biology, Spemannstr. 35, 72076 Tübingen, Germany
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15
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Ramos GC, Vaz NM, Saalfeld K. Wings for Flying, Lymphocytes for Defense: Spandrels, Exaptation and Specific Immunity. ACTA ACUST UNITED AC 2006. [DOI: 10.1159/000095881] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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16
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Coffeen WC, Wolpert TJ. Purification and characterization of serine proteases that exhibit caspase-like activity and are associated with programmed cell death in Avena sativa. THE PLANT CELL 2004; 16:857-73. [PMID: 15020745 PMCID: PMC412861 DOI: 10.1105/tpc.017947] [Citation(s) in RCA: 124] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2003] [Accepted: 01/27/2004] [Indexed: 05/18/2023]
Abstract
Victoria blight of Avena sativa (oat) is caused by the fungus Cochliobolus victoriae, which is pathogenic because of the production of the toxin victorin. The victorin-induced response in sensitive A. sativa has been characterized as a form of programmed cell death (PCD) and displays morphological and biochemical features similar to apoptosis, including chromatin condensation, DNA laddering, cell shrinkage, altered mitochondrial function, and ordered, substrate-specific proteolytic events. Victorin-induced proteolysis of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) is shown to be prevented by caspase-specific and general protease inhibitors. Evidence is presented for a signaling cascade leading to Rubisco proteolysis that involves multiple proteases. Furthermore, two proteases that are apparently involved in the Rubisco proteolytic cascade were purified and characterized. These proteases exhibit caspase specificity and display amino acid sequences homologous to plant subtilisin-like Ser proteases. The proteases are constitutively present in an active form and are relocalized to the extracellular fluid after induction of PCD by either victorin or heat shock. The role of the enzymes as processive proteases involved in a signal cascade during the PCD response is discussed.
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Affiliation(s)
- Warren C Coffeen
- Department of Botany and Plant Pathology and Center for Gene Research and Biotechnology, Oregon State University, Corvallis 97331-2902, USA
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17
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Rose T, LeMosy EK, Cantwell AM, Banerjee-Roy D, Skeath JB, Di Cera E. Three-dimensional models of proteases involved in patterning of the Drosophila Embryo. Crucial role of predicted cation binding sites. J Biol Chem 2003; 278:11320-30. [PMID: 12493753 DOI: 10.1074/jbc.m211820200] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Three-dimensional models of the catalytic domains of Nudel (Ndl), Gastrulation Defective (Gd), Snake (Snk), and Easter (Ea), and their complexes with substrate suggest a possible organization of the enzyme cascade controlling the dorsoventral fate of the fruit fly embryo. The models predict that Gd activates Snk, which in turn activates Ea. Gd can be activated either autoproteolytically or by Ndl. The three-dimensional models of each enzyme-substrate complex in the cascade rationalize existing mutagenesis data and the associated phenotypes. The models also predict unanticipated features like a Ca(2+) binding site in Ea and a Na(+) binding site in Ndl and Gd. These binding sites are likely to play a crucial role in vivo as suggested by mutant enzymes introduced into embryos as mRNAs. The mutations in Gd that eliminate Na(+) binding cause an apparent increase in activity, whereas mutations in Ea that abrogate Ca(2+) binding result in complete loss of activity. A mutation in Ea predicted to introduce Na(+) binding results in apparently increased activity with ventralization of the embryo, an effect not observed with wild-type Ea mRNA.
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Affiliation(s)
- Thierry Rose
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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Imler JL, Hoffmann JA. Toll receptors in Drosophila: a family of molecules regulating development and immunity. Curr Top Microbiol Immunol 2003; 270:63-79. [PMID: 12467244 DOI: 10.1007/978-3-642-59430-4_4] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
In recent years, Toll-like receptors (TLRs) have emerged as key receptors which detect microbes and initiate an inflammatory response. The Toll receptor was originally identified and characterized 14 years ago for its role in the embryonic development of the fruit-fly Drosophila melanogaster. Subsequently, it was also shown to be an essential component of the signaling pathway mediating the anti-fungal host defense in this model organism. New factors involved in the activation of the Toll receptor or in intracytoplasmic signaling during the immune response in Drosophila have recently been identified. The existence of significant functional differences between mammalian TLRs and Drosophila Toll receptors is also becoming apparent.
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Affiliation(s)
- J L Imler
- UPR9022 du CNRS, Institut de Biologie Moléculaire et Cellulaire, 15 rue Descartes, 67000 Strasbourg, France.
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Ponomareff G, Giordano H, DeLotto Y, DeLotto R. Interallelic complementation at the Drosophila melanogaster gastrulation defective locus defines discrete functional domains of the protein. Genetics 2001; 159:635-45. [PMID: 11606540 PMCID: PMC1461824 DOI: 10.1093/genetics/159.2.635] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The gastrulation defective (gd) locus encodes a novel serine protease that is involved in specifying the dorsal-ventral axis during embryonic development. Mutant alleles of gd have been classified into three complementation groups, two of which exhibit strong interallelic (intragenic) complementation. To understand the molecular basis of this interallelic complementation, we examined the complementation behavior of additional mutant alleles and sequenced alleles in all complementation groups. The data suggest that there are two discrete functional domains of Gd. A two-domain model of Gd suggesting that it is structurally similar to mammalian complement factors C2 and B has been previously proposed. To test this model we performed SP6 RNA microinjection to assay for activities associated with various domains of Gd. The microinjection data are consistent with the complement factor C2/B-like model. Site-directed mutagenesis suggests that Gd functions as a serine protease. An allele-specific interaction between an autoactivating form of Snake (Snk) and a gd allele altered in the protease domain suggests that Gd directly activates Snk in a protease activation cascade. We propose a model in which Gd is expressed during late oogenesis and bound within the perivitelline space but only becomes catalytically active during embryogenesis.
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Affiliation(s)
- G Ponomareff
- Cornell Graduate School of Medicine, New York, New York 10021, USA
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DeLotto R. Gastrulation defective, a complement factor C2/B-like protease, interprets a ventral prepattern in Drosophila. EMBO Rep 2001; 2:721-6. [PMID: 11493599 PMCID: PMC1083990 DOI: 10.1093/embo-reports/kve153] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
gastrulation defective (gd) encodes a serine protease required for specification of dorsal-ventral cell fates during Drosophila embryogenesis. Using RNA microinjection, I show that wild-type gd RNA can restore ventrolateral pattern elements with correct polarity with respect to egg shape in embryos lacking gd function. While low RNA concentrations restore ventrolateral pattern elements, higher concentrations ventralize the embryo. Gastrulation defective concentration has a rate-limiting effect on the domain of high Dorsal concentration but little effect upon the slope of the gradient. In embryos from pipe-null females, much higher RNA concentrations generate an ectopic axis oriented with respect to the site of injection. The data suggest that the Dorsal gradient is not directly determined by asymmetric cues in the eggshell but arises de novo within the perivitelline space as a consequence of self-regulatory properties of the protease cascade. A homology to the mammalian complement factors C2 and B is also described.
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Affiliation(s)
- R DeLotto
- Genetics Department, University of Copenhagen, Øster Farimagsgade 2A, DK-1353 Copenhagen K, Denmark.
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LeMosy EK, Tan YQ, Hashimoto C. Activation of a protease cascade involved in patterning the Drosophila embryo. Proc Natl Acad Sci U S A 2001; 98:5055-60. [PMID: 11296245 PMCID: PMC33162 DOI: 10.1073/pnas.081026598] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Dorsoventral patterning of the Drosophila embryo is initiated by a ventralizing signal. Production of this signal requires the serine proteases Gastrulation Defective (GD), Snake, and Easter, which genetic studies suggest act sequentially in a cascade that is activated locally in response to a ventral cue provided by the pipe gene. Here, we demonstrate biochemically that GD activates Snake, which in turn activates Easter. We also provide evidence that GD zymogen cleavage is important for triggering this cascade but is not spatially localized by pipe. Our results suggest that a broadly, rather than locally, activated protease cascade produces the ventralizing signal, so a distinct downstream step in this cascade must be spatially regulated to restrict signaling to the ventral side of the embryo.
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Affiliation(s)
- E K LeMosy
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
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