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CRISPR screens in Drosophila cells identify Vsg as a Tc toxin receptor. Nature 2022; 610:349-355. [PMID: 36171290 PMCID: PMC9631961 DOI: 10.1038/s41586-022-05250-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 08/18/2022] [Indexed: 11/08/2022]
Abstract
Entomopathogenic nematodes are widely used as biopesticides1,2. Their insecticidal activity depends on symbiotic bacteria such as Photorhabdus luminescens, which produces toxin complex (Tc) toxins as major virulence factors3-6. No protein receptors are known for any Tc toxins, which limits our understanding of their specificity and pathogenesis. Here we use genome-wide CRISPR-Cas9-mediated knockout screening in Drosophila melanogaster S2R+ cells and identify Visgun (Vsg) as a receptor for an archetypal P. luminescens Tc toxin (pTc). The toxin recognizes the extracellular O-glycosylated mucin-like domain of Vsg that contains high-density repeats of proline, threonine and serine (HD-PTS). Vsg orthologues in mosquitoes and beetles contain HD-PTS and can function as pTc receptors, whereas orthologues without HD-PTS, such as moth and human versions, are not pTc receptors. Vsg is expressed in immune cells, including haemocytes and fat body cells. Haemocytes from Vsg knockout Drosophila are resistant to pTc and maintain phagocytosis in the presence of pTc, and their sensitivity to pTc is restored through the transgenic expression of mosquito Vsg. Last, Vsg knockout Drosophila show reduced bacterial loads and lethality from P. luminescens infection. Our findings identify a proteinaceous Tc toxin receptor, reveal how Tc toxins contribute to P. luminescens pathogenesis, and establish a genome-wide CRISPR screening approach for investigating insecticidal toxins and pathogens.
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Zhang CU, Cadigan KM. The matrix protein Tiggrin regulates plasmatocyte maturation in Drosophila larva. Development 2017; 144:2415-2427. [PMID: 28526755 DOI: 10.1242/dev.149641] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Accepted: 05/11/2017] [Indexed: 01/24/2023]
Abstract
The lymph gland (LG) is a major source of hematopoiesis during Drosophila development. In this tissue, prohemocytes differentiate into multiple lineages, including macrophage-like plasmatocytes, which comprise the vast majority of mature hemocytes. Previous studies have uncovered genetic pathways that regulate prohemocyte maintenance and some cell fate choices between hemocyte lineages. However, less is known about how the plasmatocyte pool of the LG is established and matures. Here, we report that Tiggrin, a matrix protein expressed in the LG, is a specific regulator of plasmatocyte maturation. Tiggrin mutants exhibit precocious maturation of plasmatocytes, whereas Tiggrin overexpression blocks this process, resulting in a buildup of intermediate progenitors (IPs) expressing prohemocyte and hemocyte markers. These IPs likely represent a transitory state in prohemocyte to plasmatocyte differentiation. We also found that overexpression of Wee1 kinase, which slows G2/M progression, results in a phenotype similar to Tiggrin overexpression, whereas String/Cdc25 expression phenocopies Tiggrin mutants. Further analysis revealed that Wee1 inhibits plasmatocyte maturation through upregulation of Tiggrin transcription. Our results elucidate connections between the extracellular matrix and cell cycle regulators in the regulation of hematopoiesis.
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Affiliation(s)
- Chen U Zhang
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Ken M Cadigan
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
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Nyegaard M, Rendtorff ND, Nielsen MS, Corydon TJ, Demontis D, Starnawska A, Hedemand A, Buniello A, Niola F, Overgaard MT, Leal SM, Ahmad W, Wikman FP, Petersen KB, Crüger DG, Oostrik J, Kremer H, Tommerup N, Frödin M, Steel KP, Tranebjærg L, Børglum AD. A Novel Locus Harbouring a Functional CD164 Nonsense Mutation Identified in a Large Danish Family with Nonsyndromic Hearing Impairment. PLoS Genet 2015. [PMID: 26197441 PMCID: PMC4510537 DOI: 10.1371/journal.pgen.1005386] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Nonsyndromic hearing impairment (NSHI) is a highly heterogeneous condition with more than eighty known causative genes. However, in the clinical setting, a large number of NSHI families have unexplained etiology, suggesting that there are many more genes to be identified. In this study we used SNP-based linkage analysis and follow up microsatellite markers to identify a novel locus (DFNA66) on chromosome 6q15-21 (LOD 5.1) in a large Danish family with dominantly inherited NSHI. By locus specific capture and next-generation sequencing, we identified a c.574C>T heterozygous nonsense mutation (p.R192*) in CD164. This gene encodes a 197 amino acid transmembrane sialomucin (known as endolyn, MUC-24 or CD164), which is widely expressed and involved in cell adhesion and migration. The mutation segregated with the phenotype and was absent in 1200 Danish control individuals and in databases with whole-genome and exome sequence data. The predicted effect of the mutation was a truncation of the last six C-terminal residues of the cytoplasmic tail of CD164, including a highly conserved canonical sorting motif (YXXФ). In whole blood from an affected individual, we found by RT-PCR both the wild-type and the mutated transcript suggesting that the mutant transcript escapes nonsense mediated decay. Functional studies in HEK cells demonstrated that the truncated protein was almost completely retained on the plasma cell membrane in contrast to the wild-type protein, which targeted primarily to the endo-lysosomal compartments, implicating failed endocytosis as a possible disease mechanism. In the mouse ear, we found CD164 expressed in the inner and outer hair cells of the organ of Corti, as well as in other locations in the cochlear duct. In conclusion, we have identified a new DFNA locus located on chromosome 6q15-21 and implicated CD164 as a novel gene for hearing impairment.
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Affiliation(s)
- Mette Nyegaard
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- Centre for Integrative Sequencing (iSEQ), Aarhus University, Aarhus, Denmark
- * E-mail:
| | - Nanna D. Rendtorff
- Wilhelm Johannsen Centre for Functional Genome Research, Department of Cellular and Molecular Medicine (ICMM), The Panum Institute, University of Copenhagen, Copenhagen, Denmark
- Department of Otorhinolaryngology, Head & Neck Surgery and Audiology, Bispebjerg Hospital/Rigshospitalet, Copenhagen, Denmark
- Clinical Genetic Clinic, Kennedy Center, Copenhagen University Hospital, Rigshospitalet, Glostrup, Denmark
| | | | | | - Ditte Demontis
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- Centre for Integrative Sequencing (iSEQ), Aarhus University, Aarhus, Denmark
| | - Anna Starnawska
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- Centre for Integrative Sequencing (iSEQ), Aarhus University, Aarhus, Denmark
| | - Anne Hedemand
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- Centre for Integrative Sequencing (iSEQ), Aarhus University, Aarhus, Denmark
| | - Annalisa Buniello
- Wolfson Centre for Age-Related Diseases, King's College London, London, United Kingdom
| | - Francesco Niola
- Biotech Research & Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | | | - Suzanne M. Leal
- Center for Statistical Genetics, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Wasim Ahmad
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Friedrik P. Wikman
- Department of Molecular Medicine, Aarhus University Hospital, Skejby, Aarhus, Denmark
| | | | | | - Jaap Oostrik
- Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, Nijmegen, Netherlands
| | - Hannie Kremer
- Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, Nijmegen, Netherlands
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Nijmegen, Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Nijmegen, Netherlands
| | - Niels Tommerup
- Wilhelm Johannsen Centre for Functional Genome Research, Department of Cellular and Molecular Medicine (ICMM), The Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Morten Frödin
- Biotech Research & Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Karen P. Steel
- Wolfson Centre for Age-Related Diseases, King's College London, London, United Kingdom
| | - Lisbeth Tranebjærg
- Wilhelm Johannsen Centre for Functional Genome Research, Department of Cellular and Molecular Medicine (ICMM), The Panum Institute, University of Copenhagen, Copenhagen, Denmark
- Department of Otorhinolaryngology, Head & Neck Surgery and Audiology, Bispebjerg Hospital/Rigshospitalet, Copenhagen, Denmark
- Clinical Genetic Clinic, Kennedy Center, Copenhagen University Hospital, Rigshospitalet, Glostrup, Denmark
| | - Anders D. Børglum
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- Centre for Integrative Sequencing (iSEQ), Aarhus University, Aarhus, Denmark
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Lye CM, Naylor HW, Sanson B. Subcellular localisations of the CPTI collection of YFP-tagged proteins in Drosophila embryos. Development 2014; 141:4006-17. [PMID: 25294944 PMCID: PMC4197698 DOI: 10.1242/dev.111310] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A key challenge in the post-genomic area is to identify the function of the genes discovered, with many still uncharacterised in all metazoans. A first step is transcription pattern characterisation, for which we now have near whole-genome coverage in Drosophila. However, we have much more limited information about the expression and subcellular localisation of the corresponding proteins. The Cambridge Protein Trap Consortium generated, via piggyBac transposition, over 600 novel YFP-trap proteins tagging just under 400 Drosophila loci. Here, we characterise the subcellular localisations and expression patterns of these insertions, called the CPTI lines, in Drosophila embryos. We have systematically analysed subcellular localisations at cellularisation (stage 5) and recorded expression patterns at stage 5, at mid-embryogenesis (stage 11) and at late embryogenesis (stages 15-17). At stage 5, 31% of the nuclear lines (41) and 26% of the cytoplasmic lines (67) show discrete localisations that provide clues on the function of the protein and markers for organelles or regions, including nucleoli, the nuclear envelope, nuclear speckles, centrosomes, mitochondria, the endoplasmic reticulum, Golgi, lysosomes and peroxisomes. We characterised the membranous/cortical lines (102) throughout stage 5 to 10 during epithelial morphogenesis, documenting their apico-basal position and identifying those secreted in the extracellular space. We identified the tricellular vertices as a specialized membrane domain marked by the integral membrane protein Sidekick. Finally, we categorised the localisation of the membranous/cortical proteins during cytokinesis.
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Affiliation(s)
- Claire M Lye
- The Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
| | - Huw W Naylor
- The Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
| | - Bénédicte Sanson
- The Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
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Tang J, Zhang L, She X, Zhou G, Yu F, Xiang J, Li G. Inhibiting CD164 expression in colon cancer cell line HCT116 leads to reduced cancer cell proliferation, mobility, and metastasis in vitro and in vivo. Cancer Invest 2012; 30:380-9. [PMID: 22409183 DOI: 10.3109/07357907.2012.666692] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
BACKGROUND CD164 (Endolyn) is a sialomucin, which has been found to play roles in regulating proliferation, adhesion, and differentiation of hematopoietic stem cells. Possible association of CD164 with solid cancer development remains unknown. METHODS AND RESULTS We first studied CD164 expression in biopsies from colorectal cancer, breast, and ovary cancer patients by semi-quantitative immunohistochemistry, and found that CD164 was strongly expressed in all the colorectal cancer samples compared to the matching normal colon tissues. The possible roles of CD164 in colon cancer development were further investigated using a well-established human colon cancer cell line HCT116. We found that knockdown of CD164 expression in HCT116 cells significantly inhibited cell proliferation, mobility, and metastasis in vitro and in vivo. The knockdown of CD164 expression was associated with decreased chemokine receptor CXCR4 expression HCT116 cell surface and immunoprecipitation studies showed that CD164 formed complexes with CXCR4. CONCLUSIONS CD164 is highly expressed in the colon cancer sites, and it promotes HCT116 colon cancer cell proliferation and metastasis both in vitro and in vivo, and the effects may act through regulating CXCR4 signaling pathway. Therefore, CD164 may be a new target for diagnosis and treatment for colon cancer.
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Affiliation(s)
- Jingqun Tang
- Department of Cardiothoracic Surgery, Xiangya Second Hospital, Central South University, Changsha, Hunan, P.R. China
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Genetic screen for regulators of lymph gland homeostasis and hemocyte maturation in Drosophila. G3-GENES GENOMES GENETICS 2012; 2:393-405. [PMID: 22413093 PMCID: PMC3291509 DOI: 10.1534/g3.111.001693] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Accepted: 01/20/2012] [Indexed: 12/25/2022]
Abstract
Blood cell development in the Drosophila lymph gland is controlled by multiple factors, most of them conserved from flies to mammals. The Drosophila homolog of vertebrate PDCD2, Zfrp8, is required in Drosophila hematopoietic stem cell development. Zfrp8 mutant larvae show a disruption of homeostasis in the lymph gland and vast lymph gland overgrowth. The loss of one copy of Zfrp8 also causes a lymph gland enlargement. This dominant phenotype can be modified by heterozygous mutations in cell-cycle genes and several genes functioning in blood development. To identify additional genes that function in hematopoiesis, we screened a collection of second and third chromosome deficiencies for modifiers of Zfrp8 heterozygous phenotype. Using deficiency mapping, available single gene mutations, and RNAi lines, we identified several novel factors required for lymph gland development and hemocyte differentiation. Distinct lymph gland phenotypes of nine of these genes are reported here for the first time. Importantly, the orthologs of four of them have a role in mammalian blood development and leukemogenesis. Our work has shown that the number of genes regulating normal blood cell development in Drosophila is much larger than expected, and that the complex molecular mechanisms regulating hemocyte differentiation are comparable to those in vertebrates.
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Airoldi SJ, McLean PF, Shimada Y, Cooley L. Intercellular protein movement in syncytial Drosophila follicle cells. J Cell Sci 2011; 124:4077-86. [PMID: 22135360 DOI: 10.1242/jcs.090456] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Ring canals connecting Drosophila germline, follicle and imaginal disc cells provide direct contact of cytoplasm between cells. To date, little is known about the formation, structure, or function of the somatic ring canals present in follicle and imaginal disc cells. Here, we show by confocal and electron microscopy that Pavarotti kinesin-like protein and Visgun are stable components of somatic ring canals. Using live-cell confocal microscopy, we show that somatic ring canals form from the stabilization of mitotic cleavage furrows. In contrast to germline cells, syncytial follicle cells do not divide synchronously, are not maximally branched and their ring canals do not increase in size during egg chamber development. We show for the first time that somatic ring canals permit exchange of cytoplasmic proteins between follicle cells. These results provide insight into the composition and function of ring canals in somatic cells, implying a broader functional significance for syncytial organization of cells outside the germline.
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Affiliation(s)
- Stephanie J Airoldi
- Department of Genetics, Yale School of Medicine, 333 Cedar St., New Haven, CT 06520, USA
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Tang J, Luo Z, Zhou G, Song C, Yu F, Xiang J, Li G. Cis-regulatory functions of overlapping HIF-1alpha/E-box/AP-1-like sequences of CD164. BMC Mol Biol 2011; 12:44. [PMID: 21999799 PMCID: PMC3215284 DOI: 10.1186/1471-2199-12-44] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Accepted: 10/14/2011] [Indexed: 11/10/2022] Open
Abstract
Background CD164 (also known as MGC-24v or endolyn) is a sialomucin which has been suggested to participate in regulating the proliferation, cell adhesion and differentiation of hematopoietic stem and progenitor cells. CD164 is also involved in the development of cancer. The functions of cis-regulatory elements of CD164 remain relatively unknown. Methods In this study, we investigated the function of cis-regulatory elements within the promoter of CD164. We fused the 5'-flanking region of CD164 to a luciferase reporter vector. The minimal promoter region was confirmed by luciferase reporter assay. Using in silico analysis, we found the presence of one HIF-1alpha (HIF-1A) motif (5_-RCGTG-3_) overlapping E-box (CACGTG) and two AP-1-like binding sites (CGCTGTCCC, GTCTGTTG), one of which is also overlapped with HIF-1alpha sequence. Dual-luciferase assay was performed to examine the transcriptional activity of AP-1 and HIF-1alpha of CD164 promoter. Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) was performed to measure CD164 expression. Chromatin Immunoprecipitation was used to confirm the binding of HIF-1alpha and CD164. Results Co-transfection of c-jun, HIF-1alpha and minimal promoter region construct demonstrated that c-jun and HIF-1alpha bound the CD164 promoter and promoted CD164 expression. Hypoxia treatment also led to the up-regulation of CD164 expression. The mutation of overlapping sequences resulted in the reduced expression of CD164 induced by HIF-1alpha. Chromatin Immunoprecipitation demonstrated that the HIF-1alpha bound the minimal promoter region. Conclusions Determination of the optimal promoter region and transcription factors governing CD164 expression is useful in understanding CD164 functions. These results suggest that cis-regulatory elements of CD164 overlapping HIF-1alpha/E-box/AP-1-like sequences may play important regulatory roles.
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Affiliation(s)
- Jingqun Tang
- Department of Cardiothoracic Surgery, Xiangya Second Hospital, Central South University, Changsha, Hunan, 410011, PR China
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