1
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Yanagi KS, Jochim B, Kunjo SO, Breen P, Ruvkun G, Lehrbach N. Mutations in nucleotide metabolism genes bypass proteasome defects in png-1/NGLY1-deficient Caenorhabditis elegans. PLoS Biol 2024; 22:e3002720. [PMID: 38991033 PMCID: PMC11265709 DOI: 10.1371/journal.pbio.3002720] [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: 12/17/2023] [Revised: 07/23/2024] [Accepted: 06/21/2024] [Indexed: 07/13/2024] Open
Abstract
The conserved SKN-1A/Nrf1 transcription factor regulates the expression of proteasome subunit genes and is essential for maintenance of adequate proteasome function in animal development, aging, and stress responses. Unusual among transcription factors, SKN-1A/Nrf1 is a glycoprotein synthesized in the endoplasmic reticulum (ER). N-glycosylated SKN-1A/Nrf1 exits the ER and is deglycosylated in the cytosol by the PNG-1/NGLY1 peptide:N-glycanase. Deglycosylation edits the protein sequence of SKN-1A/Nrf1 by converting N-glycosylated asparagine residues to aspartate, which is necessary for SKN-1A/Nrf1 transcriptional activation of proteasome subunit genes. Homozygous loss-of-function mutations in the peptide:N-glycanase (NGLY1) gene cause NGLY1 deficiency, a congenital disorder of deglycosylation. There are no effective treatments for NGLY1 deficiency. Since SKN-1A/Nrf1 is a major client of NGLY1, the resulting proteasome deficit contributes to NGLY1 disease. We sought to identify targets for mitigation of proteasome dysfunction in NGLY1 deficiency that might indicate new avenues for treatment. We isolated mutations that suppress the sensitivity to proteasome inhibitors caused by inactivation of the NGLY1 ortholog PNG-1 in Caenorhabditis elegans. We identified multiple suppressor mutations affecting 3 conserved genes: rsks-1, tald-1, and ent-4. We show that the suppressors act through a SKN-1/Nrf-independent mechanism and confer proteostasis benefits consistent with amelioration of proteasome dysfunction. ent-4 encodes an intestinal nucleoside/nucleotide transporter, and we show that restriction of nucleotide availability is beneficial, whereas a nucleotide-rich diet exacerbates proteasome dysfunction in PNG-1/NGLY1-deficient C. elegans. Our findings suggest that dietary or pharmacological interventions altering nucleotide availability have the potential to mitigate proteasome insufficiency in NGLY1 deficiency and other diseases associated with proteasome dysfunction.
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Affiliation(s)
- Katherine S. Yanagi
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, Washington, United States of America
| | - Briar Jochim
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, Washington, United States of America
| | - Sheikh Omar Kunjo
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, Washington, United States of America
| | - Peter Breen
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, United States of America
| | - Gary Ruvkun
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Nicolas Lehrbach
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, Washington, United States of America
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2
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Yoshida K, Suehiro Y, Mitani S. Protocol for forward genetic screening to identify novel factors involved in a biological process in Caenorhabditis elegans. STAR Protoc 2024; 5:103114. [PMID: 38843399 PMCID: PMC11216056 DOI: 10.1016/j.xpro.2024.103114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 04/15/2024] [Accepted: 05/16/2024] [Indexed: 06/26/2024] Open
Abstract
Forward genetic screens have been a powerful tool for discovering genes involved in various biological processes in Caenorhabditis elegans. Here, we present a protocol for forward genetic screening to identify novel factors involved in a biological process in C. elegans. We describe steps for mutagenesis, screening, and backcrossing. To save time and effort, we also detail procedures for utilizing whole-genome sequencing to exclude mutants of previously characterized genes from crosses for mapping mutations. For complete details on the use and execution of this protocol, please refer to Yoshida et al.1.
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Affiliation(s)
- Keita Yoshida
- Department of Physiology, Tokyo Women's Medical University School of Medicine, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan.
| | - Yuji Suehiro
- Department of Physiology, Tokyo Women's Medical University School of Medicine, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan
| | - Shohei Mitani
- Department of Physiology, Tokyo Women's Medical University School of Medicine, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan; Department of Physiology, The Nippon Dental University School of Life Dentistry, 1-9-20 Fujimi, Chiyoda-ku, Tokyo 102-8159, Japan.
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3
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Breen PC, Kanakanui KG, Newman MA, Dowen RH. The F-box protein FBXL-5 governs vitellogenesis and lipid homeostasis in C. elegans. Front Cell Dev Biol 2024; 12:1389077. [PMID: 38946799 PMCID: PMC11211535 DOI: 10.3389/fcell.2024.1389077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Accepted: 05/22/2024] [Indexed: 07/02/2024] Open
Abstract
The molecular mechanisms that govern the metabolic commitment to reproduction, which often occurs at the expense of somatic reserves, remain poorly understood. We identified the Caenorhabditis elegans F-box protein FBXL-5 as a negative regulator of maternal provisioning of vitellogenin lipoproteins, which mediate the transfer of intestinal lipids to the germline. Mutations in fbxl-5 partially suppress the vitellogenesis defects observed in the heterochronic mutants lin-4 and lin-29, both of which ectopically express fbxl-5 at the adult developmental stage. FBXL-5 functions in the intestine to negatively regulate expression of the vitellogenin genes; and consistently, intestine-specific over-expression of FBXL-5 is sufficient to inhibit vitellogenesis, restrict lipid accumulation, and shorten lifespan. Our epistasis analyses suggest that fbxl-5 functions in concert with cul-6, a cullin gene, and the Skp1-related gene skr-3 to regulate vitellogenesis. Additionally, fbxl-5 acts genetically upstream of rict-1, which encodes the core mTORC2 protein Rictor, to govern vitellogenesis. Together, our results reveal an unexpected role for a SCF ubiquitin-ligase complex in controlling intestinal lipid homeostasis by engaging mTORC2 signaling.
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Affiliation(s)
- Peter C Breen
- Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, NC, Unites States
| | - Kendall G Kanakanui
- Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, NC, Unites States
| | - Martin A Newman
- Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, NC, Unites States
| | - Robert H Dowen
- Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, NC, Unites States
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, Unites States
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, Unites States
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4
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Torzone SK, Breen PC, Cohen NR, Simmons KN, Dowen RH. The TWK-26 potassium channel governs nutrient absorption in the C. elegans intestine. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.06.592787. [PMID: 38766028 PMCID: PMC11100751 DOI: 10.1101/2024.05.06.592787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Ion channels are necessary for proper water and nutrient absorption in the intestine, which supports cellular metabolism and organismal growth. While a role for Na + co-transporters and pumps in intestinal nutrient absorption is well defined, how individual K + uniporters function to maintain ion homeostasis is poorly understood. Using Caenorhabditis elegans , we show that a gain-of-function mutation in twk-26 , which encodes a two-pore domain K + ion channel orthologous to human KCNK3, facilitates nutrient absorption and suppresses the metabolic and developmental defects displayed by impaired intestinal MAP Kinase (MAPK) signaling. Mutations in drl-1 and flr-4, which encode two components of this MAPK pathway, cause severe growth defects, reduced lipid storage, and a dramatic increase in autophagic lysosomes, which mirror dietary restriction phenotypes. Additionally, these MAPK mutants display structural defects of the intestine and an impaired defecation motor program. We find that activation of TWK-26 reverses the dietary restriction-like state of the MAPK mutants by restoring intestinal nutrient absorption without correcting the intestinal bloating or defecation defects. This study provides unique insight into the mechanisms by which intestinal K + ion channels support intestinal metabolic homeostasis.
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5
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Breen PC, Kanakanui KG, Newman MA, Dowen RH. The F-box protein FBXL-5 governs vitellogenesis and lipid homeostasis in C. elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.18.590113. [PMID: 38712300 PMCID: PMC11071313 DOI: 10.1101/2024.04.18.590113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
The molecular mechanisms that govern the metabolic commitment to reproduction, which often occurs at the expense of somatic reserves, remain poorly understood. We identified the C. elegans F-box protein FBXL-5 as a negative regulator of maternal provisioning of vitellogenin lipoproteins, which mediate the transfer of intestinal lipids to the germline. Mutations in fbxl-5 partially suppress the vitellogenesis defects observed in the heterochronic mutants lin-4 and lin-29, both of which ectopically express fbxl-5 at the adult developmental stage. FBXL-5 functions in the intestine to negatively regulate expression of the vitellogenin genes; and consistently, intestine-specific over-expression of FBXL-5 is sufficient to inhibit vitellogenesis, restrict lipid accumulation, and shorten lifespan. Our epistasis analyses suggest that fbxl-5 functions in concert with cul-6 , a cullin gene, and the Skp1-related gene skr-3 to regulate vitellogenesis. Additionally, fbxl-5 acts genetically upstream of rict-1 , which encodes the core mTORC2 protein Rictor, to govern vitellogenesis. Together, our results reveal an unexpected role for a SCF ubiquitin-ligase complex in controlling intestinal lipid homeostasis by engaging mTORC2 signaling.
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6
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Grover M, Gang SS, Troemel ER, Barkoulas M. Proteasome inhibition triggers tissue-specific immune responses against different pathogens in C. elegans. PLoS Biol 2024; 22:e3002543. [PMID: 38466732 PMCID: PMC10957088 DOI: 10.1371/journal.pbio.3002543] [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: 08/23/2023] [Revised: 03/21/2024] [Accepted: 02/09/2024] [Indexed: 03/13/2024] Open
Abstract
Protein quality control pathways play important roles in resistance against pathogen infection. For example, the conserved transcription factor SKN-1/NRF up-regulates proteostasis capacity after blockade of the proteasome and also promotes resistance against bacterial infection in the nematode Caenorhabditis elegans. SKN-1/NRF has 3 isoforms, and the SKN-1A/NRF1 isoform, in particular, regulates proteasomal gene expression upon proteasome dysfunction as part of a conserved bounce-back response. We report here that, in contrast to the previously reported role of SKN-1 in promoting resistance against bacterial infection, loss-of-function mutants in skn-1a and its activating enzymes ddi-1 and png-1 show constitutive expression of immune response programs against natural eukaryotic pathogens of C. elegans. These programs are the oomycete recognition response (ORR), which promotes resistance against oomycetes that infect through the epidermis, and the intracellular pathogen response (IPR), which promotes resistance against intestine-infecting microsporidia. Consequently, skn-1a mutants show increased resistance to both oomycete and microsporidia infections. We also report that almost all ORR/IPR genes induced in common between these programs are regulated by the proteasome and interestingly, specific ORR/IPR genes can be induced in distinct tissues depending on the exact trigger. Furthermore, we show that increasing proteasome function significantly reduces oomycete-mediated induction of multiple ORR markers. Altogether, our findings demonstrate that proteasome regulation keeps innate immune responses in check in a tissue-specific manner against natural eukaryotic pathogens of the C. elegans epidermis and intestine.
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Affiliation(s)
- Manish Grover
- Department of Life Sciences, Imperial College, London, United Kingdom
| | - Spencer S. Gang
- School of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Emily R. Troemel
- School of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
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7
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Bin JM, Suminaite D, Benito-Kwiecinski SK, Kegel L, Rubio-Brotons M, Early JJ, Soong D, Livesey MR, Poole RJ, Lyons DA. Importin 13-dependent axon diameter growth regulates conduction speeds along myelinated CNS axons. Nat Commun 2024; 15:1790. [PMID: 38413580 PMCID: PMC10899189 DOI: 10.1038/s41467-024-45908-6] [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: 06/01/2023] [Accepted: 02/06/2024] [Indexed: 02/29/2024] Open
Abstract
Axon diameter influences the conduction properties of myelinated axons, both directly, and indirectly through effects on myelin. However, we have limited understanding of mechanisms controlling axon diameter growth in the central nervous system, preventing systematic dissection of how manipulating diameter affects myelination and conduction along individual axons. Here we establish zebrafish to study axon diameter. We find that importin 13b is required for axon diameter growth, but does not affect cell body size or axon length. Using neuron-specific ipo13b mutants, we assess how reduced axon diameter affects myelination and conduction, and find no changes to myelin thickness, precision of action potential propagation, or ability to sustain high frequency firing. However, increases in conduction speed that occur along single myelinated axons with development are tightly linked to their growth in diameter. This suggests that axon diameter growth is a major driver of increases in conduction speeds along myelinated axons over time.
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Affiliation(s)
- Jenea M Bin
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH16 4SB, UK.
| | - Daumante Suminaite
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH16 4SB, UK
| | | | - Linde Kegel
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH16 4SB, UK
| | - Maria Rubio-Brotons
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH16 4SB, UK
| | - Jason J Early
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH16 4SB, UK
| | - Daniel Soong
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH16 4SB, UK
| | - Matthew R Livesey
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH16 4SB, UK
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, S10 2HQ, UK
- Neuroscience Institute, University of Sheffield, Sheffield, S10 2TN, UK
| | - Richard J Poole
- Department of Cell and Developmental Biology, University College London, London, WC1E 6BT, UK
| | - David A Lyons
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, EH16 4SB, UK.
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8
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Mullan TW, Felton T, Tam J, Kasem O, Yeung TJ, Memar N, Schnabel R, Poole RJ. Control of successive unequal cell divisions by neural cell fate regulators determines embryonic neuroblast cell size. Development 2024; 151:dev200981. [PMID: 38205939 PMCID: PMC10911278 DOI: 10.1242/dev.200981] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 01/02/2024] [Indexed: 01/12/2024]
Abstract
Asymmetric cell divisions often generate daughter cells of unequal size in addition to different fates. In some contexts, daughter cell size asymmetry is thought to be a key input to specific binary cell fate decisions. An alternative possibility is that unequal division is a mechanism by which a variety of cells of different sizes are generated during embryonic development. We show here that two unequal cell divisions precede neuroblast formation in the C lineage of Caenorhabditis elegans. The equalisation of these divisions in a pig-1/MELK mutant background has little effect on neuroblast specification. Instead, we demonstrate that let-19/MDT13 is a regulator of the proneural basic helix-loop-helix transcription factor hlh-14/ASCL1 and find that both are required to concomitantly regulate the acquisition of neuroblast identity and neuroblast cell size. Thus, embryonic neuroblast cell size in this lineage is progressively regulated in parallel with identity by key neural cell fate regulators. We propose that key cell fate determinants have a previously unappreciated function in regulating unequal cleavage, and therefore cell size, of the progenitor cells whose daughter cell fates they then go on to specify.
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Affiliation(s)
- Thomas W. Mullan
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK
| | - Terry Felton
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK
| | - Janis Tam
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK
| | - Osama Kasem
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK
| | - Tim J. Yeung
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK
| | - Nadin Memar
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK
- Institut für Genetik, TU Braunschweig, D-38106 Braunschweig, Germany
| | - Ralf Schnabel
- Institut für Genetik, TU Braunschweig, D-38106 Braunschweig, Germany
| | - Richard J. Poole
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK
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9
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Lemieux GA, Yoo S, Lin L, Vohra M, Ashrafi K. The steroid hormone ADIOL promotes learning by reducing neural kynurenic acid levels. Genes Dev 2023; 37:998-1016. [PMID: 38092521 PMCID: PMC10760639 DOI: 10.1101/gad.350745.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 11/22/2023] [Indexed: 12/28/2023]
Abstract
Reductions in brain kynurenic acid levels, a neuroinhibitory metabolite, improve cognitive function in diverse organisms. Thus, modulation of kynurenic acid levels is thought to have therapeutic potential in a range of brain disorders. Here we report that the steroid 5-androstene 3β, 17β-diol (ADIOL) reduces kynurenic acid levels and promotes associative learning in Caenorhabditis elegans We identify the molecular mechanisms through which ADIOL links peripheral metabolic pathways to neural mechanisms of learning capacity. Moreover, we show that in aged animals, which normally experience rapid cognitive decline, ADIOL improves learning capacity. The molecular mechanisms that underlie the biosynthesis of ADIOL as well as those through which it promotes kynurenic acid reduction are conserved in mammals. Thus, rather than a minor intermediate in the production of sex steroids, ADIOL is an endogenous hormone that potently regulates learning capacity by causing reductions in neural kynurenic acid levels.
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Affiliation(s)
- George A Lemieux
- Department of Physiology, University of California, San Francisco, San Francisco, California 94143, USA
| | - Shinja Yoo
- Department of Physiology, University of California, San Francisco, San Francisco, California 94143, USA
| | - Lin Lin
- Department of Physiology, University of California, San Francisco, San Francisco, California 94143, USA
| | - Mihir Vohra
- Department of Physiology, University of California, San Francisco, San Francisco, California 94143, USA
| | - Kaveh Ashrafi
- Department of Physiology, University of California, San Francisco, San Francisco, California 94143, USA
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10
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Honey KL, Torzone SK, Dowen RH. The C. elegansflr-3(ut9) mutation is a loss-of-function insertion within the drl-1 locus. MICROPUBLICATION BIOLOGY 2023; 2023:10.17912/micropub.biology.001047. [PMID: 38116473 PMCID: PMC10728751 DOI: 10.17912/micropub.biology.001047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 11/10/2023] [Accepted: 12/01/2023] [Indexed: 12/21/2023]
Abstract
The genes encoding the mitogen-activated protein kinases DRL-1 and FLR-4 are required for growth and lipid homeostasis in C. elegans . Interestingly, the flr-3 ( ut9 ) mutant, which was previously isolated in a forward genetic screen for mutations that confer fluoride resistance, phenocopies the drl-1 and flr-4 loss-of-function mutants; however, the genetic identity of flr-3 is unknown. Through whole genome sequencing, we found that the flr-3 ( ut9 ) mutation is an insertion in the drl-1 locus and disrupts drl-1 gene function, resulting in dramatic growth defects and impaired vitellogenin production.
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Affiliation(s)
- Kendra L. Honey
- Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Sarah K. Torzone
- Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Robert H. Dowen
- Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
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11
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Alexander KD, Ramachandran S, Biswas K, Lambert CM, Russell J, Oliver DB, Armstrong W, Rettler M, Liu S, Doitsidou M, Bénard C, Walker AK, Francis MM. The homeodomain transcriptional regulator DVE-1 directs a program for synapse elimination during circuit remodeling. Nat Commun 2023; 14:7520. [PMID: 37980357 PMCID: PMC10657367 DOI: 10.1038/s41467-023-43281-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 11/02/2023] [Indexed: 11/20/2023] Open
Abstract
The elimination of synapses during circuit remodeling is critical for brain maturation; however, the molecular mechanisms directing synapse elimination and its timing remain elusive. We show that the transcriptional regulator DVE-1, which shares homology with special AT-rich sequence-binding (SATB) family members previously implicated in human neurodevelopmental disorders, directs the elimination of juvenile synaptic inputs onto remodeling C. elegans GABAergic neurons. Juvenile acetylcholine receptor clusters and apposing presynaptic sites are eliminated during the maturation of wild-type GABAergic neurons but persist into adulthood in dve-1 mutants, producing heightened motor connectivity. DVE-1 localization to GABAergic nuclei is required for synapse elimination, consistent with DVE-1 regulation of transcription. Pathway analysis of putative DVE-1 target genes, proteasome inhibitor, and genetic experiments implicate the ubiquitin-proteasome system in synapse elimination. Together, our findings define a previously unappreciated role for a SATB family member in directing synapse elimination during circuit remodeling, likely through transcriptional regulation of protein degradation processes.
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Affiliation(s)
- Kellianne D Alexander
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Program in Neuroscience, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Shankar Ramachandran
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Kasturi Biswas
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Program in Neuroscience, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Christopher M Lambert
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Julia Russell
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Devyn B Oliver
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Program in Neuroscience, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - William Armstrong
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Monika Rettler
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Samuel Liu
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Program in Neuroscience, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Maria Doitsidou
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, Scotland
| | - Claire Bénard
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA
- Department of Biological Sciences, Université du Québec à Montréal, Quebec, Canada
| | - Amy K Walker
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Michael M Francis
- Department of Neurobiology, University of Massachusetts Chan Medical School, Worcester, MA, USA.
- Program in Neuroscience, University of Massachusetts Chan Medical School, Worcester, MA, USA.
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12
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Maroilley T, Rahit KMTH, Chida AR, Cotra F, Rodrigues Alves Barbosa V, Tarailo-Graovac M. Model Organism Modifier (MOM): a user-friendly Galaxy workflow to detect modifiers from genome sequencing data using Caenorhabditis elegans. G3 (BETHESDA, MD.) 2023; 13:jkad184. [PMID: 37585487 PMCID: PMC10627290 DOI: 10.1093/g3journal/jkad184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 04/21/2023] [Accepted: 08/05/2023] [Indexed: 08/18/2023]
Abstract
Genetic modifiers are variants modulating phenotypic outcomes of a primary detrimental variant. They contribute to rare diseases phenotypic variability, but their identification is challenging. Genetic screening with model organisms is a widely used method for demystifying genetic modifiers. Forward genetics screening followed by whole genome sequencing allows the detection of variants throughout the genome but typically produces thousands of candidate variants making the interpretation and prioritization process very time-consuming and tedious. Despite whole genome sequencing is more time and cost-efficient, usage of computational pipelines specific to modifier identification remains a challenge for biological-experiment-focused laboratories doing research with model organisms. To facilitate a broader implementation of whole genome sequencing in genetic screens, we have developed Model Organism Modifier or MOM, a pipeline as a user-friendly Galaxy workflow. Model Organism Modifier analyses raw short-read whole genome sequencing data and implements tailored filtering to provide a Candidate Variant List short enough to be further manually curated. We provide a detailed tutorial to run the Galaxy workflow Model Organism Modifier and guidelines to manually curate the Candidate Variant Lists. We have tested Model Organism Modifier on published and validated Caenorhabditis elegans modifiers screening datasets. As whole genome sequencing facilitates high-throughput identification of genetic modifiers in model organisms, Model Organism Modifier provides a user-friendly solution to implement the bioinformatics analysis of the short-read datasets in laboratories without expertise or support in Bioinformatics.
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Affiliation(s)
- Tatiana Maroilley
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
- Department of Medical Genetics, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - K M Tahsin Hassan Rahit
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
- Department of Medical Genetics, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Afiya Razia Chida
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
- Department of Medical Genetics, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Filip Cotra
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
- Department of Medical Genetics, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Victoria Rodrigues Alves Barbosa
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
- Department of Medical Genetics, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Maja Tarailo-Graovac
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
- Department of Medical Genetics, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
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13
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Trivedi M, Camara LJ, Bülow HE, Tang LTH. CRISPR-mediated genome editing allows for efficient on demand creation of >200 kb deficiencies with precise boundaries. MICROPUBLICATION BIOLOGY 2023; 2023:10.17912/micropub.biology.000949. [PMID: 37954518 PMCID: PMC10638593 DOI: 10.17912/micropub.biology.000949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Revised: 10/02/2023] [Accepted: 10/24/2023] [Indexed: 11/14/2023]
Abstract
Deficiency mapping remains a useful tool in the process of identifying causative genetic lesions in C. elegans mutant strains isolated from forward genetic screens, in particular of non-coding mutants. However, there are significant areas across the genome with no deficiency coverage at all, and the boundaries of many deficiencies remain poorly defined. Here, we describe a simple methodology to generate balanced deficiency strains with up to 230 kb molecularly defined deletions (mini-deficiencies) using CRISPR/Cas9, thus providing a simple path for both precise and tailored deficiency mapping.
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Affiliation(s)
- Meera Trivedi
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, United States
| | - Lamine J. Camara
- Department of Genetics, Albert Einstein College of Medicine, Bronx, New York, United States
| | - Hannes E. Bülow
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, United States
- Department of Genetics, Albert Einstein College of Medicine, Bronx, New York, United States
| | - Leo T. H. Tang
- Department of Genetics, Albert Einstein College of Medicine, Bronx, New York, United States
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14
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Ho J, Guerrero LA, Libuda DE, Luxton GWG, Starr DA. Actin and CDC-42 contribute to nuclear migration through constricted spaces in C. elegans. Development 2023; 150:dev202115. [PMID: 37756590 PMCID: PMC10617605 DOI: 10.1242/dev.202115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 09/15/2023] [Indexed: 09/29/2023]
Abstract
Successful nuclear migration through constricted spaces between cells or in the extracellular matrix relies on the ability of the nucleus to deform. Little is known about how this takes place in vivo. We have studied confined nuclear migration in Caenorhabditis elegans larval P cells, which is mediated by the LINC complex to pull nuclei towards the minus ends of microtubules. Null mutations of the LINC component unc-84 lead to a temperature-dependent phenotype, suggesting a parallel pathway for P-cell nuclear migration. A forward genetic screen for enhancers of unc-84 identified cgef-1 (CDC-42 guanine nucleotide exchange factor). Knockdown of CDC-42 in the absence of the LINC complex led to a P-cell nuclear migration defect. Expression of constitutively active CDC-42 partially rescued nuclear migration in cgef-1; unc-84 double mutants, suggesting that CDC-42 functions downstream of CGEF-1. The Arp2/3 complex and non-muscle myosin II (NMY-2) were also found to function parallel to the LINC pathway. In our model, CGEF-1 activates CDC-42, which induces actin polymerization through the Arp2/3 complex to deform the nucleus during nuclear migration, and NMY-2 helps to push the nucleus through confined spaces.
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Affiliation(s)
- Jamie Ho
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
| | - Leslie A. Guerrero
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
| | - Diana E. Libuda
- Department of Biology, University of Oregon, Eugene, OR 97403, USA
| | - G. W. Gant Luxton
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
| | - Daniel A. Starr
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
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15
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Drury F, Grover M, Hintze M, Saunders J, Fasseas MK, Constantinou C, Barkoulas M. A PAX6-regulated receptor tyrosine kinase pairs with a pseudokinase to activate immune defense upon oomycete recognition in Caenorhabditis elegans. Proc Natl Acad Sci U S A 2023; 120:e2300587120. [PMID: 37725647 PMCID: PMC10523662 DOI: 10.1073/pnas.2300587120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 08/21/2023] [Indexed: 09/21/2023] Open
Abstract
Oomycetes were recently discovered as natural pathogens of Caenorhabditis elegans, and pathogen recognition alone was shown to be sufficient to activate a protective transcriptional program characterized by the expression of multiple chitinase-like (chil) genes. However, the molecular mechanisms underlying oomycete recognition in animals remain fully unknown. We performed here a forward genetic screen to uncover regulators of chil gene induction and found several independent loss-of-function alleles of old-1 and flor-1, which encode receptor tyrosine kinases belonging to the C. elegans-specific KIN-16 family. We report that OLD-1 and FLOR-1 are both necessary for mounting the immune response and act in the epidermis. FLOR-1 is a pseudokinase that acts downstream of the active kinase OLD-1 and regulates OLD-1 levels at the plasma membrane. Interestingly, the old-1 locus is adjacent to the chil genes in the C. elegans genome, thereby revealing a genetic cluster important for oomycete resistance. Furthermore, we demonstrate that old-1 expression at the anterior side of the epidermis is regulated by the VAB-3/PAX6 transcription factor, well known for its role in visual system development in other animals. Taken together, our study reveals both conserved and species-specific factors shaping the activation and spatial characteristics of the immune response to oomycete recognition.
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Affiliation(s)
- Florence Drury
- Department of Life Sciences, Imperial College, LondonSW7 2AZ, United Kingdom
| | - Manish Grover
- Department of Life Sciences, Imperial College, LondonSW7 2AZ, United Kingdom
| | - Mark Hintze
- Department of Life Sciences, Imperial College, LondonSW7 2AZ, United Kingdom
| | - Jonathan Saunders
- Department of Life Sciences, Imperial College, LondonSW7 2AZ, United Kingdom
| | - Michael K. Fasseas
- Department of Life Sciences, Imperial College, LondonSW7 2AZ, United Kingdom
| | - Charis Constantinou
- Department of Life Sciences, Imperial College, LondonSW7 2AZ, United Kingdom
| | - Michalis Barkoulas
- Department of Life Sciences, Imperial College, LondonSW7 2AZ, United Kingdom
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16
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Vozdek R, Wang B, Li KH, Pramstaller PP, Hicks AA, Ma DK. Fluorescent reporter of Caenorhabditis elegans Parkin: Regulators of its abundance and role in autophagy-lysosomal dynamics. OPEN RESEARCH EUROPE 2023; 2:23. [PMID: 37811477 PMCID: PMC10556562 DOI: 10.12688/openreseurope.14235.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 09/11/2023] [Indexed: 10/10/2023]
Abstract
Background: Parkin, which when mutated leads to early-onset Parkinson's disease, acts as an E3 ubiquitin ligase. How Parkin is regulated for selective protein and organelle targeting is not well understood. Here, we used protein interactor and genetic screens in Caenorhabditis elegans ( C. elegans) to identify new regulators of Parkin abundance and showed their impact on autophagy-lysosomal dynamics and alpha-Synuclein processing. Methods: We generated a transgene encoding mCherry-tagged C. elegans Parkin - Parkinson's Disease Related 1 (PDR-1). We performed protein interactor screen using Co-immunoprecipitation followed by mass spectrometry analysis to identify putative interacting partners of PDR-1. Ribonucleic acid interference (RNAi) screen and an unbiased mutagenesis screen were used to identify genes regulating PDR-1 abundance. Confocal microscopy was used for the identification of the subcellular localization of PDR-1 and alpha-Synuclein processing. Results: We show that the mCherry::pdr-1 transgene rescues the mitochondrial phenotype of pdr-1 mutants and that the expressed PDR-1 reporter is localized in the cytosol with enriched compartmentalization in the autophagy-lysosomal system. We determined that the transgenic overexpression of the PDR-1 reporter, due to inactivated small interfering RNA (siRNA) generation pathway, disrupts autophagy-lysosomal dynamics. From the RNAi screen of putative PDR-1 interactors we found that the inactivated Adenine Nucleotide Translocator ant-1.1/hANT, or hybrid ubiquitin genes ubq-2/h UBA52 and ubl-1/h RPS27A encoding a single copy of ubiquitin fused to the ribosomal proteins L40 and S27a, respectively, induced PDR-1 abundance and affected lysosomal dynamics. In addition, we demonstrate that the abundant PDR-1 plays a role in alpha-Synuclein processing. Conclusions: These data show that the abundant reporter of C. elegans Parkin affects the autophagy-lysosomal system together with alpha-Synuclein processing which can help in understanding the pathology in Parkin-related diseases.
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Affiliation(s)
- Roman Vozdek
- Institute for Biomedicine, Eurac Research, Affiliated institute of the University of Lübeck, Bolzano, 39100, Italy
| | - Bingying Wang
- Cardiovascular Research Institute and Department of Physiology, University of California San Francisco, San Francisco, CA, 94158, USA
| | - Kathy H. Li
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA, 94158, USA
| | - Peter P. Pramstaller
- Institute for Biomedicine, Eurac Research, Affiliated institute of the University of Lübeck, Bolzano, 39100, Italy
| | - Andrew A. Hicks
- Institute for Biomedicine, Eurac Research, Affiliated institute of the University of Lübeck, Bolzano, 39100, Italy
| | - Dengke K. Ma
- Cardiovascular Research Institute and Department of Physiology, University of California San Francisco, San Francisco, CA, 94158, USA
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17
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Torzone SK, Park AY, Breen PC, Cohen NR, Dowen RH. Opposing action of the FLR-2 glycoprotein hormone and DRL-1/FLR-4 MAP kinases balance p38-mediated growth and lipid homeostasis in C. elegans. PLoS Biol 2023; 21:e3002320. [PMID: 37773960 PMCID: PMC10566725 DOI: 10.1371/journal.pbio.3002320] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Revised: 10/11/2023] [Accepted: 09/02/2023] [Indexed: 10/01/2023] Open
Abstract
Animals integrate developmental and nutritional signals before committing crucial resources to growth and reproduction; however, the pathways that perceive and respond to these inputs remain poorly understood. Here, we demonstrate that DRL-1 and FLR-4, which share similarity with mammalian mitogen-activated protein kinases, maintain lipid homeostasis in the C. elegans intestine. DRL-1 and FLR-4 function in a protein complex at the plasma membrane to promote development, as mutations in drl-1 or flr-4 confer slow growth, small body size, and impaired lipid homeostasis. To identify factors that oppose DRL-1/FLR-4, we performed a forward genetic screen for suppressors of the drl-1 mutant phenotypes and identified mutations in flr-2 and fshr-1, which encode the orthologues of follicle stimulating hormone and its putative G protein-coupled receptor, respectively. In the absence of DRL-1/FLR-4, neuronal FLR-2 acts through intestinal FSHR-1 and protein kinase A signaling to restrict growth. Furthermore, we show that opposing signaling through DRL-1 and FLR-2 coordinates TIR-1 oligomerization, which modulates downstream p38/PMK-1 activity, lipid homeostasis, and development. Finally, we identify a surprising noncanonical role for the developmental transcription factor PHA-4/FOXA in the intestine where it restricts growth in response to impaired DRL-1 signaling. Our work uncovers a complex multi-tissue signaling network that converges on p38 signaling to maintain homeostasis during development.
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Affiliation(s)
- Sarah K. Torzone
- Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Aaron Y. Park
- Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Peter C. Breen
- Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Natalie R. Cohen
- Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Robert H. Dowen
- Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
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18
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Townley R, Deniaud A, Stacy KS, Torres CSR, Cheraghi F, Wicker NB, de la Cova CC. The E3/E4 ubiquitin ligase UFD-2 suppresses normal and oncogenic signaling mediated by a Raf ortholog in Caenorhabditis elegans. Sci Signal 2023; 16:eabq4355. [PMID: 37643243 PMCID: PMC10656100 DOI: 10.1126/scisignal.abq4355] [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: 04/11/2022] [Accepted: 08/10/2023] [Indexed: 08/31/2023]
Abstract
Signaling by the kinase cascade composed of Raf, MEK, and ERK is critical for animal development and is often inappropriately activated in human malignancies. We sought to identify factors that control signaling mediated by the Caenorhabditis elegans Raf ortholog LIN-45. A genetic screen showed that the degradation of LIN-45 required the E3/E4 ubiquitin ligase UFD-2. Both UFD-2 and its partner, the ATP-dependent segregase CDC-48, were required for the developmental regulation of LIN-45 protein abundance. We showed that UFD-2 acted in the same pathway as the E3 ubiquitin ligase SCFSEL-10 to decrease LIN-45 abundance in cells in which Raf-MEK-ERK signaling was most highly active. UFD-2 also reduced the protein abundance of activated LIN-45 carrying a mutation equivalent to the cancer-associated BRAF(V600E) variant. Our structure-function studies showed that the disruption of LIN-45 domains that mediate protein-protein interactions, including the conserved cysteine-rich domain and 14-3-3 binding motifs, were required for UFD-2-independent degradation of LIN-45. We propose a model in which UFD-2 and CDC-48 act downstream of SCFSEL-10 to remove LIN-45 from its protein interaction partners and facilitate proteasomal targeting and degradation. These findings imply that UFD-2 and CDC-48 may be important for Raf degradation during normal and oncogenic Ras and MAPK signaling in mammalian cells.
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Affiliation(s)
- Robert Townley
- Department of Biological Sciences, University of Wisconsin-Milwaukee; Milwaukee, Wisconsin, 53201 USA
| | - Augustin Deniaud
- Department of Biological Sciences, University of Wisconsin-Milwaukee; Milwaukee, Wisconsin, 53201 USA
| | - Kennedy S. Stacy
- Department of Biological Sciences, University of Wisconsin-Milwaukee; Milwaukee, Wisconsin, 53201 USA
| | | | - Fatemeh Cheraghi
- Department of Biological Sciences, University of Wisconsin-Milwaukee; Milwaukee, Wisconsin, 53201 USA
| | - Nicole B. Wicker
- Department of Biological Sciences, University of Wisconsin-Milwaukee; Milwaukee, Wisconsin, 53201 USA
| | - Claire C. de la Cova
- Department of Biological Sciences, University of Wisconsin-Milwaukee; Milwaukee, Wisconsin, 53201 USA
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19
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Almoril-Porras A, Calvo AC, Niu L, Beagan J, Hawk JD, Aljobeh A, Wisdom EM, Ren I, Díaz-García M, Wang ZW, Colón-Ramos DA. Specific configurations of electrical synapses filter sensory information to drive choices in behavior. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.01.551556. [PMID: 37577611 PMCID: PMC10418224 DOI: 10.1101/2023.08.01.551556] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Synaptic configurations in precisely wired circuits underpin how sensory information is processed by the nervous system, and the emerging animal behavior. This is best understood for chemical synapses, but far less is known about how electrical synaptic configurations modulate, in vivo and in specific neurons, sensory information processing and context-specific behaviors. We discovered that INX-1, a gap junction protein that forms electrical synapses, is required to deploy context-specific behavioral strategies during C. elegans thermotaxis behavior. INX-1 couples two bilaterally symmetric interneurons, and this configuration is required for the integration of sensory information during migration of animals across temperature gradients. In inx-1 mutants, uncoupled interneurons display increased excitability and responses to subthreshold temperature stimuli, resulting in abnormally longer run durations and context-irrelevant tracking of isotherms. Our study uncovers a conserved configuration of electrical synapses that, by increasing neuronal capacitance, enables differential processing of sensory information and the deployment of context-specific behavioral strategies.
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Affiliation(s)
- Agustin Almoril-Porras
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine; New Haven, CT 06536, USA
| | - Ana C. Calvo
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine; New Haven, CT 06536, USA
| | - Longgang Niu
- Department of Neuroscience, University of Connecticut Health Center; Farmington, CT 06030, USA
| | - Jonathan Beagan
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine; New Haven, CT 06536, USA
| | - Josh D. Hawk
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine; New Haven, CT 06536, USA
| | - Ahmad Aljobeh
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine; New Haven, CT 06536, USA
| | - Elias M. Wisdom
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine; New Haven, CT 06536, USA
| | - Ivy Ren
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine; New Haven, CT 06536, USA
| | - Malcom Díaz-García
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine; New Haven, CT 06536, USA
| | - Zhao-Wen Wang
- Department of Neuroscience, University of Connecticut Health Center; Farmington, CT 06030, USA
| | - Daniel A. Colón-Ramos
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine; New Haven, CT 06536, USA
- Wu Tsai Institute, Yale University; New Haven, CT 06510, USA
- Marine Biological Laboratory; Woods Hole, MA, USA
- Instituto de Neurobiología, Recinto de Ciencias Médicas, Universidad de Puerto Rico; San Juan 00901, Puerto Rico
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20
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Puri D, Sharma S, Samaddar S, Ravivarma S, Banerjee S, Ghosh-Roy A. Muscleblind-1 interacts with tubulin mRNAs to regulate the microtubule cytoskeleton in C. elegans mechanosensory neurons. PLoS Genet 2023; 19:e1010885. [PMID: 37603562 PMCID: PMC10470942 DOI: 10.1371/journal.pgen.1010885] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 08/31/2023] [Accepted: 07/26/2023] [Indexed: 08/23/2023] Open
Abstract
Regulation of the microtubule cytoskeleton is crucial for the development and maintenance of neuronal architecture, and recent studies have highlighted the significance of regulated RNA processing in the establishment and maintenance of neural circuits. In a genetic screen conducted using mechanosensory neurons of C. elegans, we identified a mutation in muscleblind-1/mbl-1 as a suppressor of loss of kinesin-13 family microtubule destabilizing factor klp-7. Muscleblind-1(MBL-1) is an RNA-binding protein that regulates the splicing, localization, and stability of RNA. Our findings demonstrate that mbl-1 is required cell-autonomously for axon growth and proper synapse positioning in the posterior lateral microtubule (PLM) neuron. Loss of mbl-1 leads to increased microtubule dynamics and mixed orientation of microtubules in the anterior neurite of PLM. These defects are also accompanied by abnormal axonal transport of the synaptic protein RAB-3 and reduction of gentle touch sensation in mbl-1 mutant. Our data also revealed that mbl-1 is genetically epistatic to mec-7 (β tubulin) and mec-12 (α tubulin) in regulating axon growth. Furthermore, mbl-1 is epistatic to sad-1, an ortholog of BRSK/Brain specific-serine/threonine kinase and a known regulator of synaptic machinery, for synapse formation at the correct location of the PLM neurite. Notably, the immunoprecipitation of MBL-1 resulted in the co-purification of mec-7, mec-12, and sad-1 mRNAs, suggesting a direct interaction between MBL-1 and these transcripts. Additionally, mbl-1 mutants exhibited reduced levels and stability of mec-7 and mec-12 transcripts. Our study establishes a previously unknown link between RNA-binding proteins and cytoskeletal machinery, highlighting their crucial roles in the development and maintenance of the nervous system.
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Affiliation(s)
- Dharmendra Puri
- National Brain Research Centre, Manesar, Gurgaon, Haryana, India
| | - Sunanda Sharma
- National Brain Research Centre, Manesar, Gurgaon, Haryana, India
| | - Sarbani Samaddar
- National Brain Research Centre, Manesar, Gurgaon, Haryana, India
| | - Sruthy Ravivarma
- National Brain Research Centre, Manesar, Gurgaon, Haryana, India
| | - Sourav Banerjee
- National Brain Research Centre, Manesar, Gurgaon, Haryana, India
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21
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Cubillas C, Sandoval Del Prado LE, Goldacker S, Fujii C, Pinski AN, Zielke J, Wang D. The alg-1 Gene Is Necessary for Orsay Virus Replication in Caenorhabditis elegans. J Virol 2023; 97:e0006523. [PMID: 37017532 PMCID: PMC10134801 DOI: 10.1128/jvi.00065-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 03/10/2023] [Indexed: 04/06/2023] Open
Abstract
The establishment of the Orsay virus-Caenorhabditis elegans infection model has enabled the identification of host factors essential for virus infection. Argonautes are RNA interacting proteins evolutionary conserved in the three domains of life that are key components of small RNA pathways. C. elegans encodes 27 argonautes or argonaute-like proteins. Here, we determined that mutation of the argonaute-like gene 1, alg-1, results in a greater than 10,000-fold reduction in Orsay viral RNA levels, which could be rescued by ectopic expression of alg-1. Mutation in ain-1, a known interactor of ALG-1 and component of the RNA-induced silencing complex, also resulted in a significant reduction in Orsay virus levels. Viral RNA replication from an endogenous transgene replicon system was impaired by the lack of ALG-1, suggesting that ALG-1 plays a role during the replication stage of the virus life cycle. Orsay virus RNA levels were unaffected by mutations in the ALG-1 RNase H-like motif that ablate the slicer activity of ALG-1. These findings demonstrate a novel function of ALG-1 in promoting Orsay virus replication in C. elegans. IMPORTANCE All viruses are obligate intracellular parasites that recruit the cellular machinery of the host they infect to support their own proliferation. We used Caenorhabditis elegans and its only known infecting virus, Orsay virus, to identify host proteins relevant for virus infection. We determined that ALG-1, a protein previously known to be important in influencing worm life span and the expression levels of thousands of genes, is required for Orsay virus infection of C. elegans. This is a new function attributed to ALG-1 that was not recognized before. In humans, it has been shown that AGO2, a close relative protein to ALG-1, is essential for hepatitis C virus replication. This demonstrates that through evolution from worms to humans, some proteins have maintained similar functions, and consequently, this suggests that studying virus infection in a simple worm model has the potential to provide novel insights into strategies used by viruses to proliferate.
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Affiliation(s)
- Ciro Cubillas
- Department of Molecular Microbiology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
- Department of Pathology & Immunology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Luis Enrique Sandoval Del Prado
- Department of Molecular Microbiology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
- Department of Pathology & Immunology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Sydney Goldacker
- Department of Molecular Microbiology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
- Department of Pathology & Immunology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Chika Fujii
- Department of Molecular Microbiology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
- Department of Pathology & Immunology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Amanda N. Pinski
- Department of Molecular Microbiology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
- Department of Pathology & Immunology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Jon Zielke
- Department of Molecular Microbiology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
- Department of Pathology & Immunology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
| | - David Wang
- Department of Molecular Microbiology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
- Department of Pathology & Immunology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri, USA
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22
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Xuan Z, Yang S, Clark B, Hill SE, Manning L, Colón-Ramos DA. The active zone protein Clarinet regulates synaptic sorting of ATG-9 and presynaptic autophagy. PLoS Biol 2023; 21:e3002030. [PMID: 37053235 PMCID: PMC10101500 DOI: 10.1371/journal.pbio.3002030] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 02/08/2023] [Indexed: 04/14/2023] Open
Abstract
Autophagy is essential for cellular homeostasis and function. In neurons, autophagosome biogenesis is temporally and spatially regulated to occur near presynaptic sites, in part via the trafficking of autophagy transmembrane protein ATG-9. The molecules that regulate autophagy by sorting ATG-9 at synapses remain largely unknown. Here, we conduct forward genetic screens at single synapses of C. elegans neurons and identify a role for the long isoform of the active zone protein Clarinet (CLA-1L) in regulating sorting of autophagy protein ATG-9 at synapses, and presynaptic autophagy. We determine that disrupting CLA-1L results in abnormal accumulation of ATG-9 containing vesicles enriched with clathrin. The ATG-9 phenotype in cla-1(L) mutants is not observed for other synaptic vesicle proteins, suggesting distinct mechanisms that regulate sorting of ATG-9-containing vesicles and synaptic vesicles. Through genetic analyses, we uncover the adaptor protein complexes that genetically interact with CLA-1 in ATG-9 sorting. We also determine that CLA-1L extends from the active zone to the periactive zone and genetically interacts with periactive zone proteins in ATG-9 sorting. Our findings reveal novel roles for active zone proteins in the sorting of ATG-9 and in presynaptic autophagy.
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Affiliation(s)
- Zhao Xuan
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Neuroscience and Cell Biology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Sisi Yang
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Neuroscience and Cell Biology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Benjamin Clark
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Neuroscience and Cell Biology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Sarah E. Hill
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Neuroscience and Cell Biology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Laura Manning
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Neuroscience and Cell Biology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Daniel A. Colón-Ramos
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Neuroscience and Cell Biology, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Instituto de Neurobiología, Recinto de Ciencias Médicas, Universidad de Puerto Rico, San Juan,Puerto Rico
- Wu Tsai Institute, Yale University, New Haven, Connecticut, United States of America
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23
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Kawano T, Kashiwagi M, Kanuka M, Chen CK, Yasugaki S, Hatori S, Miyazaki S, Tanaka K, Fujita H, Nakajima T, Yanagisawa M, Nakagawa Y, Hayashi Y. ER proteostasis regulators cell-non-autonomously control sleep. Cell Rep 2023; 42:112267. [PMID: 36924492 DOI: 10.1016/j.celrep.2023.112267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 01/17/2023] [Accepted: 02/28/2023] [Indexed: 03/17/2023] Open
Abstract
Sleep is regulated by peripheral tissues under fatigue. The molecular pathways in peripheral cells that trigger systemic sleep-related signals, however, are unclear. Here, a forward genetic screen in C. elegans identifies 3 genes that strongly affect sleep amount: sel-1, sel-11, and mars-1. sel-1 and sel-11 encode endoplasmic reticulum (ER)-associated degradation components, whereas mars-1 encodes methionyl-tRNA synthetase. We find that these machineries function in non-neuronal tissues and that the ER unfolded protein response components inositol-requiring enzyme 1 (IRE1)/XBP1 and protein kinase R-like ER kinase (PERK)/eukaryotic initiation factor-2α (eIF2α)/activating transcription factor-4 (ATF4) participate in non-neuronal sleep regulation, partly by reducing global translation. Neuronal epidermal growth factor receptor (EGFR) signaling is also required. Mouse studies suggest that this mechanism is conserved in mammals. Considering that prolonged wakefulness increases ER proteostasis stress in peripheral tissues, our results suggest that peripheral ER proteostasis factors control sleep homeostasis. Moreover, based on our results, peripheral tissues likely cope with ER stress not only by the well-established cell-autonomous mechanisms but also by promoting the individual's sleep.
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Affiliation(s)
- Taizo Kawano
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba 305-8575, Japan
| | - Mitsuaki Kashiwagi
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba 305-8575, Japan; Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Mika Kanuka
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba 305-8575, Japan
| | - Chung-Kuan Chen
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba 305-8575, Japan; Doctoral Program in Biomedical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Shinnosuke Yasugaki
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba 305-8575, Japan; Doctoral Program in Biomedical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Sena Hatori
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba 305-8575, Japan; PhD Program in Humanics, School of Integrative and Global Majors, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Shinichi Miyazaki
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba 305-8575, Japan; PhD Program in Humanics, School of Integrative and Global Majors, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Kaeko Tanaka
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba 305-8575, Japan
| | - Hidetoshi Fujita
- Department of Biomedical Engineering, Osaka Institute of Technology, Osaka 535-8585, Japan
| | - Toshiro Nakajima
- Institute of Medical Science, Tokyo Medical University, Shinjuku-ku, Tokyo 160-8402, Japan
| | - Masashi Yanagisawa
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba 305-8575, Japan; Life Science Center, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba 305-8575, Japan; Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Yoshimi Nakagawa
- Department of Complex Biosystem Research, Institute of Natural Medicine, University of Toyama, Toyama, Toyama 930-0194, Japan
| | - Yu Hayashi
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba 305-8575, Japan; Department of Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan; Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
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Miles J, Townend S, Milonaitytė D, Smith W, Hodge F, Westhead DR, van Oosten-Hawle P. Transcellular chaperone signaling is an intercellular stress-response distinct from the HSF-1-mediated heat shock response. PLoS Biol 2023; 21:e3001605. [PMID: 36780563 PMCID: PMC9956597 DOI: 10.1371/journal.pbio.3001605] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 02/24/2023] [Accepted: 01/20/2023] [Indexed: 02/15/2023] Open
Abstract
Organismal proteostasis is maintained by intercellular signaling processes including cell nonautonomous stress responses such as transcellular chaperone signaling (TCS). When TCS is activated upon tissue-specific knockdown of hsp-90 in the Caenorhabditis elegans intestine, heat-inducible hsp-70 is induced in muscle cells at the permissive temperature resulting in increased heat stress resistance and lifespan extension. However, our understanding of the molecular mechanism and signaling factors mediating transcellular activation of hsp-70 expression from one tissue to another is still in its infancy. Here, we conducted a combinatorial approach using transcriptome RNA-Seq profiling and a forward genetic mutagenesis screen to elucidate how stress signaling from the intestine to the muscle is regulated. We find that the TCS-mediated "gut-to-muscle" induction of hsp-70 expression is suppressed by HSF-1 and instead relies on transcellular-X-cross-tissue (txt) genes. We identify a key role for the PDZ-domain guanylate cyclase txt-1 and the homeobox transcription factor ceh-58 as signaling hubs in the stress receiving muscle cells to initiate hsp-70 expression and facilitate TCS-mediated heat stress resistance and lifespan extension. Our results provide a new view on cell-nonautonomous regulation of "inter-tissue" stress responses in an organism that highlight a key role for the gut. Our data suggest that the HSF-1-mediated heat shock response is switched off upon TCS activation, in favor of an intercellular stress-signaling route to safeguard survival.
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Affiliation(s)
- Jay Miles
- School of Molecular and Cell Biology & Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Sarah Townend
- School of Molecular and Cell Biology & Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Dovilė Milonaitytė
- School of Molecular and Cell Biology & Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - William Smith
- School of Molecular and Cell Biology & Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Francesca Hodge
- School of Molecular and Cell Biology & Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - David R. Westhead
- School of Molecular and Cell Biology & Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Patricija van Oosten-Hawle
- School of Molecular and Cell Biology & Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
- * E-mail:
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25
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Lup SD, Navarro-Quiles C, Micol JL. Versatile mapping-by-sequencing with Easymap v.2. FRONTIERS IN PLANT SCIENCE 2023; 14:1042913. [PMID: 36778692 PMCID: PMC9909543 DOI: 10.3389/fpls.2023.1042913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 01/04/2023] [Indexed: 06/18/2023]
Abstract
Mapping-by-sequencing combines Next Generation Sequencing (NGS) with classical genetic mapping by linkage analysis to establish gene-to-phenotype relationships. Although numerous tools have been developed to analyze NGS datasets, only a few are available for mapping-by-sequencing. One such tool is Easymap, a versatile, easy-to-use package that performs automated mapping of point mutations and large DNA insertions. Here, we describe Easymap v.2, which also maps small insertion/deletions (InDels), and includes workflows to perform QTL-seq and variant density mapping analyses. Each mapping workflow can accommodate different experimental designs, including outcrossing and backcrossing, F2, M2, and M3 mapping populations, chemically induced mutation and natural variant mapping, input files containing single-end or paired-end reads of genomic or complementary DNA sequences, and alternative control sample files in FASTQ and VCF formats. Easymap v.2 can also be used as a variant analyzer in the absence of a mapping algorithm and includes a multi-threading option.
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26
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Fujii C, Wang D. Novel insights into virus–host interactions using the model organism C. elegans. Adv Virus Res 2023; 115:135-158. [PMID: 37173064 DOI: 10.1016/bs.aivir.2023.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
Abstract
Viruses continue to pose a public health threat raising the need for effective management strategies. Currently existing antiviral therapeutics are often specific to only a single viral species, and resistance to the therapeutic can often arise, and therefore new therapeutics are needed. The C. elegans-Orsay virus system offers a powerful platform for studying RNA virus-host interactions that could ultimately lead to novel targets for antiviral therapy. The relative simplicity of C. elegans, the well-established experimental tools, and its extensive evolutionary conservation of genes and pathways with mammals are key features of this model. Orsay virus, a bisegmented positive sense RNA virus, is a natural pathogen of C. elegans. Orsay virus infection can be studied in a multicellular organismal context, overcoming some of the limitations inherent to tissue culture-based systems. Moreover, compared to mice, the rapid generation time of C. elegans enables robust and facile forward genetics. This review aims to summarize studies that have laid the foundation for the C. elegans-Orsay virus experimental system, experimental tools, and key examples of C. elegans host factors that impact Orsay virus infection that have evolutionarily conserved function in mammalian virus infection.
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27
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Ren J, Sang Y, Aballay A. Cholinergic receptor-Wnt pathway controls immune activation by sensing intestinal dysfunction. Cell Rep 2022; 41:111575. [DOI: 10.1016/j.celrep.2022.111575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 09/09/2022] [Accepted: 10/06/2022] [Indexed: 11/06/2022] Open
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28
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Winter AD, Tjahjono E, Beltrán LJ, Johnstone IL, Bulleid NJ, Page AP. Dietary-derived vitamin B12 protects Caenorhabditis elegans from thiol-reducing agents. BMC Biol 2022; 20:228. [PMID: 36209095 PMCID: PMC9548181 DOI: 10.1186/s12915-022-01415-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 09/20/2022] [Indexed: 11/24/2022] Open
Abstract
Background One-carbon metabolism, which includes the folate and methionine cycles, involves the transfer of methyl groups which are then utilised as a part of multiple physiological processes including redox defence. During the methionine cycle, the vitamin B12-dependent enzyme methionine synthetase converts homocysteine to methionine. The enzyme S-adenosylmethionine (SAM) synthetase then uses methionine in the production of the reactive methyl carrier SAM. SAM-binding methyltransferases then utilise SAM as a cofactor to methylate proteins, small molecules, lipids, and nucleic acids. Results We describe a novel SAM methyltransferase, RIPS-1, which was the single gene identified from forward genetic screens in Caenorhabditis elegans looking for resistance to lethal concentrations of the thiol-reducing agent dithiothreitol (DTT). As well as RIPS-1 mutation, we show that in wild-type worms, DTT toxicity can be overcome by modulating vitamin B12 levels, either by using growth media and/or bacterial food that provide higher levels of vitamin B12 or by vitamin B12 supplementation. We show that active methionine synthetase is required for vitamin B12-mediated DTT resistance in wild types but is not required for resistance resulting from RIPS-1 mutation and that susceptibility to DTT is partially suppressed by methionine supplementation. A targeted RNAi modifier screen identified the mitochondrial enzyme methylmalonyl-CoA epimerase as a strong genetic enhancer of DTT resistance in a RIPS-1 mutant. We show that RIPS-1 is expressed in the intestinal and hypodermal tissues of the nematode and that treating with DTT, β-mercaptoethanol, or hydrogen sulfide induces RIPS-1 expression. We demonstrate that RIPS-1 expression is controlled by the hypoxia-inducible factor pathway and that homologues of RIPS-1 are found in a small subset of eukaryotes and bacteria, many of which can adapt to fluctuations in environmental oxygen levels. Conclusions This work highlights the central importance of dietary vitamin B12 in normal metabolic processes in C. elegans, defines a new role for this vitamin in countering reductive stress, and identifies RIPS-1 as a novel methyltransferase in the methionine cycle. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-022-01415-y.
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Affiliation(s)
- Alan D Winter
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, G61 1QH, UK
| | - Elissa Tjahjono
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, G61 1QH, UK
| | - Leonardo J Beltrán
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, G61 1QH, UK
| | - Iain L Johnstone
- School of Molecular Biosciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Neil J Bulleid
- School of Molecular Biosciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Antony P Page
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, G61 1QH, UK.
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29
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Gang SS, Grover M, Reddy KC, Raman D, Chang YT, Ekiert DC, Barkoulas M, Troemel ER. A pals-25 gain-of-function allele triggers systemic resistance against natural pathogens of C. elegans. PLoS Genet 2022; 18:e1010314. [PMID: 36191002 PMCID: PMC9560605 DOI: 10.1371/journal.pgen.1010314] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 10/13/2022] [Accepted: 09/15/2022] [Indexed: 11/15/2022] Open
Abstract
Regulation of immunity throughout an organism is critical for host defense. Previous studies in the nematode Caenorhabditis elegans have described an "ON/OFF" immune switch comprised of the antagonistic paralogs PALS-25 and PALS-22, which regulate resistance against intestinal and epidermal pathogens. Here, we identify and characterize a PALS-25 gain-of-function mutant protein with a premature stop (Q293*), which we find is freed from physical repression by its negative regulator, the PALS-22 protein. PALS-25(Q293*) activates two related gene expression programs, the Oomycete Recognition Response (ORR) against natural pathogens of the epidermis, and the Intracellular Pathogen Response (IPR) against natural intracellular pathogens of the intestine. A subset of ORR/IPR genes is upregulated in pals-25(Q293*) mutants, and they are resistant to oomycete infection in the epidermis, and microsporidia and virus infection in the intestine, but without compromising growth. Surprisingly, we find that activation of PALS-25 seems to primarily stimulate the downstream bZIP transcription factor ZIP-1 in the epidermis, with upregulation of gene expression in both the epidermis and in the intestine. Interestingly, we find that PALS-22/25-regulated epidermal-to-intestinal signaling promotes resistance to the N. parisii intestinal pathogen, demonstrating cross-tissue protective immune induction from one epithelial tissue to another in C. elegans.
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Affiliation(s)
- Spencer S. Gang
- School of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Manish Grover
- Department of Life Sciences, Imperial College, London, United Kingdom
| | - Kirthi C. Reddy
- School of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Deevya Raman
- School of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Ya-Ting Chang
- Departments of Cell Biology and Microbiology, New York University School of Medicine, New York, New York, United States of America
| | - Damian C. Ekiert
- Departments of Cell Biology and Microbiology, New York University School of Medicine, New York, New York, United States of America
| | | | - Emily R. Troemel
- School of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
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30
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Ptchd1 mediates opioid tolerance via cholesterol-dependent effects on μ-opioid receptor trafficking. Nat Neurosci 2022; 25:1179-1190. [PMID: 35982154 DOI: 10.1038/s41593-022-01135-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 07/11/2022] [Indexed: 11/09/2022]
Abstract
Repeated exposure to opioids causes tolerance, which limits their analgesic utility and contributes to overdose and abuse liability. However, the molecular mechanisms underpinning tolerance are not well understood. Here, we used a forward genetic screen in Caenorhabditis elegans for unbiased identification of genes regulating opioid tolerance which revealed a role for PTR-25/Ptchd1. We found that PTR-25/Ptchd1 controls μ-opioid receptor trafficking and that these effects were mediated by the ability of PTR-25/Ptchd1 to control membrane cholesterol content. Electrophysiological studies showed that loss of Ptchd1 in mice reduced opioid-induced desensitization of neurons in several brain regions and the peripheral nervous system. Mice and C. elegans lacking Ptchd1/PTR-25 display similarly augmented responses to opioids. Ptchd1 knockout mice fail to develop analgesic tolerance and have greatly diminished somatic withdrawal. Thus, we propose that Ptchd1 plays an evolutionarily conserved role in protecting the μ-opioid receptor against overstimulation.
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31
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Rahman M, Ramirez‐Suarez NJ, Diaz‐Balzac CA, Bülow HE. Specific N-glycans regulate an extracellular adhesion complex during somatosensory dendrite patterning. EMBO Rep 2022; 23:e54163. [PMID: 35586945 PMCID: PMC9253746 DOI: 10.15252/embr.202154163] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 04/13/2022] [Accepted: 04/22/2022] [Indexed: 09/19/2023] Open
Abstract
N-glycans are molecularly diverse sugars borne by over 70% of proteins transiting the secretory pathway and have been implicated in protein folding, stability, and localization. Mutations in genes important for N-glycosylation result in congenital disorders of glycosylation that are often associated with intellectual disability. Here, we show that structurally distinct N-glycans regulate an extracellular protein complex involved in the patterning of somatosensory dendrites in Caenorhabditis elegans. Specifically, aman-2/Golgi alpha-mannosidase II, a conserved key enzyme in the biosynthesis of specific N-glycans, regulates the activity of the Menorin adhesion complex without obviously affecting the protein stability and localization of its components. AMAN-2 functions cell-autonomously to allow for decoration of the neuronal transmembrane receptor DMA-1/LRR-TM with the correct set of high-mannose/hybrid/paucimannose N-glycans. Moreover, distinct types of N-glycans on specific N-glycosylation sites regulate DMA-1/LRR-TM receptor function, which, together with three other extracellular proteins, forms the Menorin adhesion complex. In summary, specific N-glycan structures regulate dendrite patterning by coordinating the activity of an extracellular adhesion complex, suggesting that the molecular diversity of N-glycans can contribute to developmental specificity in the nervous system.
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Affiliation(s)
- Maisha Rahman
- Department of GeneticsAlbert Einstein College of MedicineBronxNYUSA
- Dominick P. Purpura Department of NeuroscienceAlbert Einstein College of MedicineBronxNYUSA
| | - Nelson J Ramirez‐Suarez
- Department of GeneticsAlbert Einstein College of MedicineBronxNYUSA
- Present address:
Institute of Science and Technology AustriaKlosterneuburgAustria
| | - Carlos A Diaz‐Balzac
- Department of GeneticsAlbert Einstein College of MedicineBronxNYUSA
- Present address:
University of RochesterRochesterNYUSA
| | - Hannes E Bülow
- Department of GeneticsAlbert Einstein College of MedicineBronxNYUSA
- Dominick P. Purpura Department of NeuroscienceAlbert Einstein College of MedicineBronxNYUSA
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32
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Li P, Li G, Zhang YW, Zuo JF, Liu JY, Zhang YM. A combinatorial strategy to identify various types of QTLs for quantitative traits using extreme phenotype individuals in an F 2 population. PLANT COMMUNICATIONS 2022; 3:100319. [PMID: 35576159 PMCID: PMC9251438 DOI: 10.1016/j.xplc.2022.100319] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 03/07/2022] [Accepted: 03/22/2022] [Indexed: 06/09/2023]
Abstract
Theoretical and applied studies demonstrate the difficulty of detecting extremely over-dominant and small-effect genes for quantitative traits via bulked segregant analysis (BSA) in an F2 population. To address this issue, we proposed an integrated strategy for mapping various types of quantitative trait loci (QTLs) for quantitative traits via a combination of BSA and whole-genome sequencing. In this strategy, the numbers of read counts of marker alleles in two extreme pools were used to predict the numbers of read counts of marker genotypes. These observed and predicted numbers were used to construct a new statistic, Gw, for detecting quantitative trait genes (QTGs), and the method was named dQTG-seq1. This method was significantly better than existing BSA methods. If the goal was to identify extremely over-dominant and small-effect genes, another reserved DNA/RNA sample from each extreme phenotype F2 plant was sequenced, and the observed numbers of marker alleles and genotypes were used to calculate Gw to detect QTGs; this method was named dQTG-seq2. In simulated and real rice dataset analyses, dQTG-seq2 could identify many more extremely over-dominant and small-effect genes than BSA and QTL mapping methods. dQTG-seq2 may be extended to other heterogeneous mapping populations. The significance threshold of Gw in this study was determined by permutation experiments. In addition, a handbook for the R software dQTG.seq, which is available at https://cran.r-project.org/web/packages/dQTG.seq/index.html, has been provided in the supplemental materials for the users' convenience. This study provides a new strategy for identifying all types of QTLs for quantitative traits in an F2 population.
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Affiliation(s)
- Pei Li
- Crop Information Center, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Guo Li
- Crop Information Center, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Ya-Wen Zhang
- Crop Information Center, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Jian-Fang Zuo
- Crop Information Center, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Jin-Yang Liu
- Crop Information Center, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement, Institute of Industrial Crops, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Yuan-Ming Zhang
- Crop Information Center, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
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33
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Raissig MT, Woods DP. The wild grass Brachypodium distachyon as a developmental model system. Curr Top Dev Biol 2022; 147:33-71. [PMID: 35337454 DOI: 10.1016/bs.ctdb.2021.12.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The arrival of cheap and high-throughput sequencing paired with efficient gene editing technologies allows us to use non-traditional model systems and mechanistically approach biological phenomena beyond what was conceivable just a decade ago. Venturing into different model systems enables us to explore for example clade-specific environmental responses to changing climates or the genetics and development of clade-specific organs, tissues and cell types. We-both early career researchers working with the wild grass model Brachypodium distachyon-want to use this review to (1) highlight why we think B. distachyon is a fantastic grass developmental model system, (2) summarize the tools and resources that have enabled discoveries made in B. distachyon, and (3) discuss a handful of developmental biology vignettes made possible by using B. distachyon as a model system. Finally, we want to conclude by (4) relating our personal stories with this emerging model system and (5) share what we think is important to consider before starting work with an emerging model system.
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Affiliation(s)
- Michael T Raissig
- Centre for Organismal Studies Heidelberg, Heidelberg University, Heidelberg, Germany; Institute of Plant Sciences, University of Bern, Bern, Switzerland.
| | - Daniel P Woods
- Department of Plant Sciences, University of California, Davis, CA, United States; Howard Hughes Medical Institute, Chevy Chase, MD, United States.
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34
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Bonacossa-Pereira I, Coakley S, Hilliard MA. Neuron-epidermal attachment protects hyper-fragile axons from mechanical strain. Cell Rep 2022; 38:110501. [PMID: 35263583 DOI: 10.1016/j.celrep.2022.110501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 12/06/2021] [Accepted: 02/15/2022] [Indexed: 11/03/2022] Open
Abstract
Axons experience significant strain caused by organismal development and movement. A combination of intrinsic mechanical resistance and external shielding by surrounding tissues prevents axonal damage, although the precise mechanisms are unknown. Here, we reveal a neuroprotective function of neuron-epidermal attachment in Caenorhabditis elegans. We show that a gain-of-function mutation in the epidermal hemidesmosome component LET-805/myotactin, in combination with a loss-of-function mutation in UNC-70/β-spectrin, disrupts the uniform attachment and subsequent embedment of sensory axons within the epidermis during development. This generates regions of high tension within axons, leading to spontaneous axonal breaks and degeneration. Completely preventing attachment, by disrupting HIM-4/hemicentin or MEC-5/collagen, eliminates tension and alleviates damage. Finally, we demonstrate that progressive neuron-epidermal attachment via LET-805/myotactin is induced by the axon during development, as well as during regeneration after injury. Together, these results reveal that establishment of uniform neuron-epidermal attachment is critical to protect axons from mechanical strain during development.
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Affiliation(s)
- Igor Bonacossa-Pereira
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Sean Coakley
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia.
| | - Massimo A Hilliard
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia.
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35
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Robinson-Thiewes S, Kershner AM, Shin H, Haupt KA, Kroll-Connor P, Kimble J. A sensitized genetic screen to identify regulators of Caenorhabditis elegans germline stem cells. G3 (BETHESDA, MD.) 2022; 12:jkab439. [PMID: 35100350 PMCID: PMC9210287 DOI: 10.1093/g3journal/jkab439] [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] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 12/08/2021] [Indexed: 11/26/2022]
Abstract
GLP-1/Notch signaling and a downstream RNA regulatory network maintain germline stem cells in Caenorhabditis elegans. In mutants lacking the GLP-1 receptor, all germline stem cells enter the meiotic cell cycle precociously and differentiate into sperm. This dramatic germline stem cell defect is called the "Glp" phenotype. The lst-1 and sygl-1 genes are direct targets of Notch transcriptional activation and functionally redundant. Whereas single lst-1 and sygl-1 mutants are fertile, lst-1 sygl-1 double mutants are sterile with a Glp phenotype. We set out to identify genes that function redundantly with either lst-1 or sygl-1 to maintain germline stem cells. To this end, we conducted forward genetic screens for mutants with a Glp phenotype in genetic backgrounds lacking functional copies of either lst-1 or sygl-1. The screens generated 9 glp-1 alleles, 2 lst-1 alleles, and 1 allele of pole-1, which encodes the catalytic subunit of DNA polymerase ε. Three glp-1 alleles reside in Ankyrin repeats not previously mutated. pole-1 single mutants have a low penetrance Glp phenotype that is enhanced by loss of sygl-1. Thus, the screen uncovered 1 locus that interacts genetically with sygl-1 and generated useful mutations for further studies of germline stem cell regulation.
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Affiliation(s)
| | | | - Heaji Shin
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Kimberly A Haupt
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Peggy Kroll-Connor
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Judith Kimble
- Department of Genetics, University of Wisconsin-Madison, Madison, WI 53706, USA
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
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36
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Korhonen PK, Shaban B, Faux NG, Kinkar L, Chang BCH, Wang D, Yang B, Young ND, Gasser RB. 'Escalibur' - a practical pipeline for the de novo-analysis of nucleotide variation in non-model eukaryotes. Mol Ecol Resour 2022; 22:2120-2126. [PMID: 35182034 PMCID: PMC9314989 DOI: 10.1111/1755-0998.13600] [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: 10/25/2021] [Revised: 02/03/2022] [Accepted: 02/14/2022] [Indexed: 11/10/2022]
Abstract
The revolution in genomics has enabled large‐scale population genetic investigations of a wide range of organisms, but there has been a relatively limited focus on improving analytical pipelines. To efficiently analyse large data sets, highly integrated and automated software pipelines, which are easy to use, efficient, reliable, reproducible and run in multiple computational environments, are required. A number of software workflows have been developed to handle and process such data sets for population genetic analyses, but effective, specialized pipelines for genetic and statistical analyses of nonmodel organisms are lacking. For most species, resources for variomes (sets of genetic variations found in populations of species) are not available, and/or genome assemblies are often incomplete and fragmented, complicating the selection of the most suitable reference genome when multiple assemblies are available. Additionally, the biological samples used often contain extraneous DNA from sources other than the species under investigation (e.g., microbial contamination), which needs to be removed prior to genetic analyses. For these reasons, we established a new pipeline, called Escalibur, which includes: functionalities, such as data trimming and mapping; selection of a suitable reference genome; removal of contaminating read data; recalibration of base calls; and variant‐calling. Escalibur uses a proven gatk variant caller and workflow description language (WDL), and is, therefore, a highly efficient and scalable pipeline for the genome‐wide identification of nucleotide variation in eukaryotes. This pipeline is available at https://gitlab.unimelb.edu.au/bioscience/escalibur (version 0.3‐beta) and is essentially applicable to any prokaryote or eukaryote.
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Affiliation(s)
- Pasi K Korhonen
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, 3010, Victoria, Australia
| | - Babak Shaban
- Melbourne Data Analytics Platform (MDAP), The University of Melbourne, Parkville, 3010, Victoria, Australia
| | - Noel G Faux
- Melbourne Data Analytics Platform (MDAP), The University of Melbourne, Parkville, 3010, Victoria, Australia
| | - Liina Kinkar
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, 3010, Victoria, Australia
| | - Bill C H Chang
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, 3010, Victoria, Australia
| | - Daxi Wang
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, 3010, Victoria, Australia.,BGI-Shenzhen, Shenzhen, China
| | - Bicheng Yang
- BGI Australia, Oceania, BGI Group, CBCRB Building, Herston Road, Herston, Queensland, 4006, Australia
| | - Neil D Young
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, 3010, Victoria, Australia
| | - Robin B Gasser
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, 3010, Victoria, Australia
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37
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White RJ, Mackay E, Wilson SW, Busch-Nentwich EM. Allele-specific gene expression can underlie altered transcript abundance in zebrafish mutants. eLife 2022; 11:72825. [PMID: 35175196 PMCID: PMC8884726 DOI: 10.7554/elife.72825] [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: 08/05/2021] [Accepted: 02/16/2022] [Indexed: 11/13/2022] Open
Abstract
In model organisms, RNA-sequencing (RNA-seq) is frequently used to assess the effect of genetic mutations on cellular and developmental processes. Typically, animals heterozygous for a mutation are crossed to produce offspring with different genotypes. Resultant embryos are grouped by genotype to compare homozygous mutant embryos to heterozygous and wild-type siblings. Genes that are differentially expressed between the groups are assumed to reveal insights into the pathways affected by the mutation. Here we show that in zebrafish, differentially expressed genes are often over-represented on the same chromosome as the mutation due to different levels of expression of alleles from different genetic backgrounds. Using an incross of haplotype-resolved wild-type fish, we found evidence of widespread allele-specific expression, which appears as differential expression when comparing embryos homozygous for a region of the genome to their siblings. When analysing mutant transcriptomes, this means that the differential expression of genes on the same chromosome as a mutation of interest may not be caused by that mutation. Typically, the genomic location of a differentially expressed gene is not considered when interpreting its importance with respect to the phenotype. This could lead to pathways being erroneously implicated or overlooked due to the noise of spurious differentially expressed genes on the same chromosome as the mutation. These observations have implications for the interpretation of RNA-seq experiments involving outbred animals and non-inbred model organisms.
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Affiliation(s)
- Richard J White
- Cambridge Institute of Therapeutic Immunology & Infectious Disease (CITIID), Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Eirinn Mackay
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Stephen W Wilson
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Elisabeth M Busch-Nentwich
- Cambridge Institute of Therapeutic Immunology & Infectious Disease (CITIID), Department of Medicine, University of Cambridge, Cambridge, United Kingdom.,School of Biological and Behavioural Sciences, Faculty of Science and Engineering, Queen Mary University of London, London, United Kingdom
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38
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Tucker DK, Adams CS, Prasad G, Ackley BD. The Immunoglobulin Superfamily Members syg-2 and syg-1 Regulate Neurite Development in C. elegans. J Dev Biol 2022; 10:jdb10010003. [PMID: 35076532 PMCID: PMC8788504 DOI: 10.3390/jdb10010003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 12/27/2021] [Accepted: 01/04/2022] [Indexed: 11/20/2022] Open
Abstract
Neurons form elaborate networks by guiding axons and dendrites to appropriate destinations. Neurites require information about the relative body axes during the initial projection from the cell body, and failure to receive or interpret those cues correctly can result in outgrowth errors. We identified a mutation in the Ig superfamily member syg-2 in a screen for animals with anterior/posterior (A/P) axon guidance defects. We found that syg-2 and its cognate Ig family member syg-1 appear to function in a linear genetic pathway to control the outgrowth of GABAergic axons. We determined that this pathway works in parallel to Wnt signaling. Specifically, mutations in syg-2 or syg-1 selectively affected the embryonically derived Dorsal D-type (DD) GABAergic neurons. We found no evidence that these mutations affected the Ventral D-type neurons (VD) that form later, during the first larval stage. In addition, mutations in syg-1 or syg-2 could result in the DD neurons forming multiple processes, becoming bipolar, rather than the expected pseudounipolar morphology. Given SYG-2′s essential function in synaptogenesis of the hermaphrodite-specific neurons (HSNs), we also examined DD neuron synapses in syg-2 mutants. We found syg-2 mutants had a decreased number of synapses formed, but synaptic morphology was largely normal. These results provide further evidence that the GABAergic motorneurons use multiple guidance pathways during development.
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Affiliation(s)
- Dana K. Tucker
- The School of Natural Sciences, University of Central Missouri, Warrensburg, MO 64093, USA; (D.K.T.); (G.P.)
- Department of Molecular Biosciences, University of Kansas, 5004 Haworth Hall, 1200 Sunnyside Ave, Lawrence, KS 66045, USA;
| | - Chloe S. Adams
- Department of Molecular Biosciences, University of Kansas, 5004 Haworth Hall, 1200 Sunnyside Ave, Lawrence, KS 66045, USA;
| | - Gauri Prasad
- The School of Natural Sciences, University of Central Missouri, Warrensburg, MO 64093, USA; (D.K.T.); (G.P.)
| | - Brian D. Ackley
- Department of Molecular Biosciences, University of Kansas, 5004 Haworth Hall, 1200 Sunnyside Ave, Lawrence, KS 66045, USA;
- Correspondence:
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Sengupta T, Koonce NL, Vázquez-Martínez N, Moyle MW, Duncan LH, Emerson SE, Han X, Shao L, Wu Y, Santella A, Fan L, Bao Z, Mohler W, Shroff H, Colón-Ramos DA. Differential adhesion regulates neurite placement via a retrograde zippering mechanism. eLife 2021; 10:71171. [PMID: 34783657 PMCID: PMC8843091 DOI: 10.7554/elife.71171] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 11/15/2021] [Indexed: 11/13/2022] Open
Abstract
During development, neurites and synapses segregate into specific neighborhoods or layers within nerve bundles. The developmental programs guiding placement of neurites in specific layers, and hence their incorporation into specific circuits, are not well understood. We implement novel imaging methods and quantitative models to document the embryonic development of the C. elegans brain neuropil, and discover that differential adhesion mechanisms control precise placement of single neurites onto specific layers. Differential adhesion is orchestrated via developmentally-regulated expression of the IgCAM SYG-1, and its partner ligand SYG-2. Changes in SYG-1 expression across neuropil layers result in changes in adhesive forces, which sort SYG-2-expressing neurons. Sorting to layers occurs, not via outgrowth from the neurite tip, but via an alternate mechanism of retrograde zippering, involving interactions between neurite shafts. Our study indicates that biophysical principles from differential adhesion govern neurite placement and synaptic specificity in vivo in developing neuropil bundles.
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Affiliation(s)
- Titas Sengupta
- Yale University School of Medicine, New Haven, United States
| | - Noelle L Koonce
- Yale University School of Medicine, New Haven, United States
| | | | - Mark W Moyle
- Yale University School of Medicine, New Haven, United States
| | | | - Sarah E Emerson
- Yale University School of Medicine, New Haven, United States
| | - Xiaofei Han
- National Institutes of Health, Bethesda, United States
| | - Lin Shao
- Yale University School of Medicine, New Haven, United States
| | - Yicong Wu
- National Institutes of Health, Bethesda, United States
| | - Anthony Santella
- Developmental Biology Program, Molecular Cytology Core, Sloan-Kettering Institute, New York, United States
| | - Li Fan
- Helen and Robert Appel Alzheimer's Disease Institute, Weill Cornell Medicine, New York, United States
| | - Zhirong Bao
- Developmental Biology Program, Sloan-Kettering Institute, New York, United States
| | - William Mohler
- Department of Genetics and Developmental Biology, University of Connecticut Health Center, Farmington, United States
| | - Hari Shroff
- National Institutes of Health, Bethesda, United States
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40
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Hu Y, Hu X, Li D, Du Z, Shi K, He C, Zhang Y, Zhang D. The APC/C FZY-1/Cdc20 Complex Coordinates With OMA-1 to Regulate the Oocyte-to-Embryo Transition in Caenorhabditis elegans. Front Cell Dev Biol 2021; 9:749654. [PMID: 34722532 PMCID: PMC8554129 DOI: 10.3389/fcell.2021.749654] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 09/27/2021] [Indexed: 11/13/2022] Open
Abstract
During oocyte maturation and the oocyte-to-embryo transition, key developmental regulators such as RNA-binding proteins coordinate translation of particular messenger RNA (mRNAs) and related developmental processes by binding to their cognate maternal mRNAs. In the nematode Caenorhabditis elegans, these processes are regulated by a set of CCCH zinc finger proteins. Oocyte maturation defective-1 (OMA-1) and OMA-2 are two functionally redundant CCCH zinc finger proteins that turnover rapidly during the first embryonic cell division. These turnovers are required for proper transition from oogenesis to embryogenesis. A gain-of-function mutant of OMA-1, oma-1(zu405), stabilizes and delays degradation of OMA-1, resulting in delayed turnover and mis-segregation of other cell fate determinants, which eventually causes embryonic lethality. We performed a large-scale forward genetic screen to identify suppressors of the oma-1(zu405) mutant. We show here that multiple alleles affecting functions of various anaphase promoting complex/cyclosome (APC/C) subunits, including MAT-1, MAT-2, MAT-3, EMB-30, and FZY-1, suppress the gain-of-function mutant of OMA-1. Transcriptome analysis suggested that overall transcription in early embryos occurred after introducing mutations in APC/C genes into the oma-1(zu405) mutant. Mutations in APC/C genes prevent OMA-1 enrichment in P granules and correct delayed degradation of downstream cell fate determinants including pharynx and intestine in excess-1 (PIE-1), posterior segregation-1 (POS-1), muscle excess-3 (MEX-3), and maternal effect germ-cell defective-1 (MEG-1). We demonstrated that only the activator FZY-1, but not FZR-1, is incorporated in the APC/C complex to regulate the oocyte-to-embryo transition. Our findings suggested a genetic relationship linking the APC/C complex and OMA-1, and support a model in which the APC/C complex promotes P granule accumulation and modifies RNA binding of OMA-1 to regulate the oocyte-to-embryo transition process.
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Affiliation(s)
- Yabing Hu
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xuewen Hu
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Dongchen Li
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhenzhen Du
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Kun Shi
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Chenxia He
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ying Zhang
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Donglei Zhang
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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41
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Maurya AK, Sengupta P. xbx-4, a homolog of the Joubert syndrome gene FAM149B1, acts via the CCRK and RCK kinase cascade to regulate cilia morphology. Curr Biol 2021; 31:5642-5649.e5. [PMID: 34731674 DOI: 10.1016/j.cub.2021.10.027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 09/23/2021] [Accepted: 10/12/2021] [Indexed: 12/14/2022]
Abstract
Primary cilia are microtubule (MT)-based organelles that mediate sensory functions in multiple cell types. Disruption of cilia structure or function leads to a diverse collection of diseases termed ciliopathies.1-3 The highly conserved CCRK and RCK kinases (ICK/MOK/MAK) negatively regulate cilia length and structure in Chlamydomonas, C. elegans, and mammalian cells.4-10 How the activity of this kinase cascade is tuned to precisely regulate cilia architecture is unclear. Mutations in the Domain of Unknown Function 3719 (DUF3719)-containing protein FAM149B1 have recently been shown to elongate cilia via unknown mechanisms and result in the ciliopathy Joubert syndrome.11 Here we identify XBX-4, a DUF3719-containing protein related to human FAM149B1, as a regulator of the DYF-18 CCRK and DYF-5 MAK kinase pathway in C. elegans. As in dyf-18 and dyf-5 mutants,10 sensory neuron cilia are elongated in xbx-4 mutants and exhibit stabilized axonemal MTs. XBX-4 promotes DYF-18 CCRK function to regulate localization and function of DYF-5 MAK. We find that Joubert syndrome-associated mutations in the XBX-4 DUF3719 domain also elongate cilia in C. elegans. Our results identify a new metazoan-specific regulator of this highly conserved kinase pathway and suggest that FAM149B1 may similarly act via the CCRK/RCK kinase pathway to regulate ciliary homeostasis in humans.
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Affiliation(s)
- Ashish K Maurya
- Department of Biology, MS008, Brandeis University, 415 South Street, Waltham, MA 02454, USA.
| | - Piali Sengupta
- Department of Biology, MS008, Brandeis University, 415 South Street, Waltham, MA 02454, USA.
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42
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Loss of the Extracellular Matrix Protein DIG-1 Causes Glial Fragmentation, Dendrite Breakage, and Dendrite Extension Defects. J Dev Biol 2021; 9:jdb9040042. [PMID: 34698211 PMCID: PMC8544517 DOI: 10.3390/jdb9040042] [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: 08/12/2021] [Revised: 09/23/2021] [Accepted: 09/24/2021] [Indexed: 12/03/2022] Open
Abstract
The extracellular matrix (ECM) guides and constrains the shape of the nervous system. In C. elegans, DIG-1 is a giant ECM component that is required for fasciculation of sensory dendrites during development and for maintenance of axon positions throughout life. We identified four novel alleles of dig-1 in three independent screens for mutants affecting disparate aspects of neuronal and glial morphogenesis. First, we find that disruption of DIG-1 causes fragmentation of the amphid sheath glial cell in larvae and young adults. Second, it causes severing of the BAG sensory dendrite from its terminus at the nose tip, apparently due to breakage of the dendrite as animals reach adulthood. Third, it causes embryonic defects in dendrite fasciculation in inner labial (IL2) sensory neurons, as previously reported, as well as rare defects in IL2 dendrite extension that are enhanced by loss of the apical ECM component DYF-7, suggesting that apical and basolateral ECM contribute separately to dendrite extension. Our results highlight novel roles for DIG-1 in maintaining the cellular integrity of neurons and glia, possibly by creating a barrier between structures in the nervous system.
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43
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Mizeracka K, Rogers JM, Rumley JD, Shaham S, Bulyk ML, Murray JI, Heiman MG. Lineage-specific control of convergent differentiation by a Forkhead repressor. Development 2021; 148:272306. [PMID: 34423346 DOI: 10.1242/dev.199493] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 08/17/2021] [Indexed: 12/14/2022]
Abstract
During convergent differentiation, multiple developmental lineages produce a highly similar or identical cell type. However, few molecular players that drive convergent differentiation are known. Here, we show that the C. elegans Forkhead transcription factor UNC-130 is required in only one of three convergent lineages that produce the same glial cell type. UNC-130 acts transiently as a repressor in progenitors and newly-born terminal cells to allow the proper specification of cells related by lineage rather than by cell type or function. Specification defects correlate with UNC-130:DNA binding, and UNC-130 can be functionally replaced by its human homolog, the neural crest lineage determinant FoxD3. We propose that, in contrast to terminal selectors that activate cell type-specific transcriptional programs in terminally differentiating cells, UNC-130 acts early and specifically in one convergent lineage to produce a cell type that also arises from molecularly distinct progenitors in other lineages.
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Affiliation(s)
- Karolina Mizeracka
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA.,Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA
| | - Julia M Rogers
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.,Committee on Higher Degrees in Biophysics, Harvard University, Cambridge, MA 02138, USA
| | - Jonathan D Rumley
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Shai Shaham
- The Rockefeller University, New York, NY 10065, USA
| | - Martha L Bulyk
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.,Committee on Higher Degrees in Biophysics, Harvard University, Cambridge, MA 02138, USA.,Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - John I Murray
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Maxwell G Heiman
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA.,Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA
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44
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Han W, Li H, Yu X, Ke J, Guo F, Wang L. In vivo Toxicity Evaluation of a Nano-drug Delivery System Using a Caenorhabditis elegans Model System. Chem Res Chin Univ 2021. [DOI: 10.1007/s40242-021-1257-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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45
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Tsai CE, Yang FJ, Lee CH, Hsueh YP, Kuo CJ, Chen CS. The conserved regulator of autophagy and innate immunity hlh-30/TFEB mediates tolerance of enterohemorrhagic Escherichia coli in Caenorhabditis elegans. Genetics 2021; 217:1-17. [PMID: 33683370 DOI: 10.1093/genetics/iyaa052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 12/07/2020] [Indexed: 11/14/2022] Open
Abstract
Infection with antibiotic-resistant bacteria is an emerging life-threatening issue worldwide. Enterohemorrhagic Escherichia coli O157: H7 (EHEC) causes hemorrhagic colitis and hemolytic uremic syndrome via contaminated food. Treatment of EHEC infection with antibiotics is contraindicated because of the risk of worsening the syndrome through the secreted toxins. Identifying the host factors involved in bacterial infection provides information about how to combat this pathogen. In our previous study, we showed that EHEC colonizes in the intestine of Caenorhabditis elegans. However, the host factors involved in EHEC colonization remain elusive. Thus, in this study, we aimed to identify the host factors involved in EHEC colonization. We conducted forward genetic screens to isolate mutants that enhanced EHEC colonization and named this phenotype enhanced intestinal colonization (Inc). Intriguingly, four mutants with the Inc phenotype showed significantly increased EHEC-resistant survival, which contrasts with our current knowledge. Genetic mapping and whole-genome sequencing (WGS) revealed that these mutants have loss-of-function mutations in unc-89. Furthermore, we showed that the tolerance of unc-89(wf132) to EHEC relied on HLH-30/TFEB activation. These findings suggest that hlh-30 plays a key role in pathogen tolerance in C. elegans.
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Affiliation(s)
- Chia-En Tsai
- Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan
| | - Fang-Jung Yang
- Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan
| | - Ching-Han Lee
- Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan.,Molecular and Cell Biology, Taiwan International Graduate Program, Academia Sinica, Taipei 11490, Taiwan.,Taiwan International Graduate Program, National Defense Medical Center, Taipei 11490, Taiwan
| | - Yen-Ping Hsueh
- Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan.,Molecular and Cell Biology, Taiwan International Graduate Program, Academia Sinica, Taipei 11490, Taiwan.,Taiwan International Graduate Program, National Defense Medical Center, Taipei 11490, Taiwan.,Department of Biochemical Science and Technology, National Taiwan University, Taipei 10617, Taiwan
| | - Cheng-Ju Kuo
- Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan
| | - Chang-Shi Chen
- Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan
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46
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Charlesworth AG, Seroussi U, Lehrbach NJ, Renaud MS, Sundby AE, Molnar RI, Lao RX, Willis AR, Woock JR, Aber MJ, Diao AJ, Reinke AW, Ruvkun G, Claycomb JM. Two isoforms of the essential C. elegans Argonaute CSR-1 differentially regulate sperm and oocyte fertility. Nucleic Acids Res 2021; 49:8836-8865. [PMID: 34329465 PMCID: PMC8421154 DOI: 10.1093/nar/gkab619] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 07/01/2021] [Accepted: 07/19/2021] [Indexed: 01/09/2023] Open
Abstract
The Caenorhabditis elegans genome encodes nineteen functional Argonaute proteins that use 22G-RNAs, 26G-RNAs, miRNAs or piRNAs to regulate target transcripts. Only one Argonaute is essential under normal laboratory conditions: CSR-1. While CSR-1 has been studied widely, nearly all studies have overlooked the fact that the csr-1 locus encodes two isoforms. These isoforms differ by an additional 163 amino acids present in the N-terminus of CSR-1a. Using CRISPR-Cas9 genome editing to introduce GFP::3xFLAG into the long (CSR-1a) and short (CSR-1b) isoforms, we found that CSR-1a is expressed during spermatogenesis and in several somatic tissues, including the intestine. CSR-1b is expressed constitutively in the germline. small RNA sequencing of CSR-1 complexes shows that they interact with partly overlapping sets of 22G-RNAs. Phenotypic analyses reveal that the essential functions of csr-1 described in the literature coincide with CSR-1b, while CSR-1a plays tissue specific functions. During spermatogenesis, CSR-1a integrates into an sRNA regulatory network including ALG-3, ALG-4 and WAGO-10 that is necessary for fertility at 25°C. In the intestine, CSR-1a silences immunity and pathogen-responsive genes, and its loss results in improved survival from the pathogen Pseudomonas aeruginosa. Our findings functionally distinguish the CSR-1 isoforms and highlight the importance of studying each AGO isoform independently.
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Affiliation(s)
| | - Uri Seroussi
- Department of Molecular Genetics, University of Toronto Toronto, ON M5S 1A8 Canada
| | - Nicolas J Lehrbach
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Mathias S Renaud
- Department of Molecular Genetics, University of Toronto Toronto, ON M5S 1A8 Canada
| | - Adam E Sundby
- Department of Molecular Genetics, University of Toronto Toronto, ON M5S 1A8 Canada
| | - Ruxandra I Molnar
- Department of Molecular Genetics, University of Toronto Toronto, ON M5S 1A8 Canada
| | - Robert X Lao
- Department of Molecular Genetics, University of Toronto Toronto, ON M5S 1A8 Canada
| | - Alexandra R Willis
- Department of Molecular Genetics, University of Toronto Toronto, ON M5S 1A8 Canada
| | - Jenna R Woock
- Department of Molecular Genetics, University of Toronto Toronto, ON M5S 1A8 Canada
| | - Matthew J Aber
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Annette J Diao
- Department of Molecular Genetics, University of Toronto Toronto, ON M5S 1A8 Canada
| | - Aaron W Reinke
- Department of Molecular Genetics, University of Toronto Toronto, ON M5S 1A8 Canada
| | - Gary Ruvkun
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Julie M Claycomb
- Department of Molecular Genetics, University of Toronto Toronto, ON M5S 1A8 Canada
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47
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Tang LTH, Trivedi M, Freund J, Salazar CJ, Rahman M, Ramirez-Suarez NJ, Lee G, Wang Y, Grant BD, Bülow HE. The CATP-8/P5A-type ATPase functions in multiple pathways during neuronal patterning. PLoS Genet 2021; 17:e1009475. [PMID: 34197450 PMCID: PMC8279360 DOI: 10.1371/journal.pgen.1009475] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 07/14/2021] [Accepted: 06/10/2021] [Indexed: 11/18/2022] Open
Abstract
The assembly of neuronal circuits involves the migrations of neurons from their place of birth to their final location in the nervous system, as well as the coordinated growth and patterning of axons and dendrites. In screens for genes required for patterning of the nervous system, we identified the catp-8/P5A-ATPase as an important regulator of neural patterning. P5A-ATPases are part of the P-type ATPases, a family of proteins known to serve a conserved function as transporters of ions, lipids and polyamines in unicellular eukaryotes, plants, and humans. While the function of many P-type ATPases is relatively well understood, the function of P5A-ATPases in metazoans remained elusive. We show here, that the Caenorhabditis elegans ortholog catp-8/P5A-ATPase is required for defined aspects of nervous system development. Specifically, the catp-8/P5A-ATPase serves functions in shaping the elaborately sculpted dendritic trees of somatosensory PVD neurons. Moreover, catp-8/P5A-ATPase is required for axonal guidance and repulsion at the midline, as well as embryonic and postembryonic neuronal migrations. Interestingly, not all axons at the midline require catp-8/P5A-ATPase, although the axons run in the same fascicles and navigate the same space. Similarly, not all neuronal migrations require catp-8/P5A-ATPase. A CATP-8/P5A-ATPase reporter is localized to the ER in most, if not all, tissues and catp-8/P5A-ATPase can function both cell-autonomously and non-autonomously to regulate neuronal development. Genetic analyses establish that catp-8/P5A-ATPase can function in multiple pathways, including the Menorin pathway, previously shown to control dendritic patterning in PVD, and Wnt signaling, which functions to control neuronal migrations. Lastly, we show that catp-8/P5A-ATPase is required for localizing select transmembrane proteins necessary for dendrite morphogenesis. Collectively, our studies suggest that catp-8/P5A-ATPase serves diverse, yet specific, roles in different genetic pathways and may be involved in the regulation or localization of transmembrane and secreted proteins to specific subcellular compartments.
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Affiliation(s)
- Leo T. H. Tang
- Department of Genetics Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Meera Trivedi
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Jenna Freund
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Christopher J. Salazar
- Department of Genetics Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Maisha Rahman
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Nelson J. Ramirez-Suarez
- Department of Genetics Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Garrett Lee
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Yu Wang
- Department of Molecular Biology & Biochemistry, Rutgers Center for Lipid Research, Rutgers University, Piscataway, New Jersey, United States of America
| | - Barth D. Grant
- Department of Molecular Biology & Biochemistry, Rutgers Center for Lipid Research, Rutgers University, Piscataway, New Jersey, United States of America
| | - Hannes E. Bülow
- Department of Genetics Albert Einstein College of Medicine, Bronx, New York, United States of America
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, United States of America
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48
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Koneru SL, Hintze M, Katsanos D, Barkoulas M. Cryptic genetic variation in a heat shock protein modifies the outcome of a mutation affecting epidermal stem cell development in C. elegans. Nat Commun 2021; 12:3263. [PMID: 34059684 PMCID: PMC8166903 DOI: 10.1038/s41467-021-23567-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 04/29/2021] [Indexed: 12/13/2022] Open
Abstract
A fundamental question in medical genetics is how the genetic background modifies the phenotypic outcome of mutations. We address this question by focusing on the seam cells, which display stem cell properties in the epidermis of Caenorhabditis elegans. We demonstrate that a putative null mutation in the GATA transcription factor egl-18, which is involved in seam cell fate maintenance, is more tolerated in the CB4856 isolate from Hawaii than the lab reference strain N2 from Bristol. We identify multiple quantitative trait loci (QTLs) underlying the difference in phenotype expressivity between the two isolates. These QTLs reveal cryptic genetic variation that reinforces seam cell fate through potentiating Wnt signalling. Within one QTL region, a single amino acid deletion in the heat shock protein HSP-110 in CB4856 is sufficient to modify Wnt signalling and seam cell development, highlighting that natural variation in conserved heat shock proteins can shape phenotype expressivity. How the genetic background modifies the expression of mutations is a key question that is addressed in this study in the context of seam cell development in Caenorhabditis elegans isolates. One amino acid deletion in a conserved heat shock protein is sufficient to shape phenotype expressivity upon mutation of a GATA transcription factor.
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Affiliation(s)
- Sneha L Koneru
- Department of Life Sciences, Imperial College, London, United Kingdom
| | - Mark Hintze
- Department of Life Sciences, Imperial College, London, United Kingdom
| | - Dimitris Katsanos
- Department of Life Sciences, Imperial College, London, United Kingdom
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49
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Kaur S, Aballay A. G-Protein-Coupled Receptor SRBC-48 Protects against Dendrite Degeneration and Reduced Longevity Due to Infection. Cell Rep 2021; 31:107662. [PMID: 32433971 DOI: 10.1016/j.celrep.2020.107662] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 03/06/2020] [Accepted: 04/28/2020] [Indexed: 02/07/2023] Open
Abstract
Increasing evidence suggests that deficient immune modulation and microbial infections underline neurodegeneration, but the mechanisms remain obscure. Here, we show that the G-protein-coupled receptor (GPCR) SRBC-48, which belongs to the class BC serpentine receptors, has a protective role in Caenorhabditis elegans dendrite degeneration caused by Pseudomonas aeruginosa infection. Our results indicate that SRBC-48 functions in a cell-autonomous manner in AWC neurons to protect against infection-associated dendrite degeneration. The absence of SRBC-48 results in a reduced lifespan caused by a pathogen infection early in life that induces dendrite degeneration. The decreased longevity in animals deficient in SRBC-48 is due to uncontrolled activation of immune genes, particularly those regulated by the FOXO family transcription factor DAF-16 that is part of the insulin/insulin-like growth factor (IGF)-1 receptor homolog DAF-2. These results reveal how an infection early in life can not only induce dendrite degeneration but also reduce lifespan.
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Affiliation(s)
- Supender Kaur
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, OR 97239, USA
| | - Alejandro Aballay
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, OR 97239, USA.
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50
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Hintze M, Katsanos D, Shahrezaei V, Barkoulas M. Phenotypic Robustness of Epidermal Stem Cell Number in C. elegans Is Modulated by the Activity of the Conserved N-acetyltransferase nath-10/NAT10. Front Cell Dev Biol 2021; 9:640856. [PMID: 34084768 PMCID: PMC8168469 DOI: 10.3389/fcell.2021.640856] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Accepted: 04/19/2021] [Indexed: 12/14/2022] Open
Abstract
Individual cells and organisms experience perturbations from internal and external sources, yet manage to buffer these to produce consistent phenotypes, a property known as robustness. While phenotypic robustness has often been examined in unicellular organisms, it has not been sufficiently studied in multicellular animals. Here, we investigate phenotypic robustness in Caenorhabditis elegans seam cells. Seam cells are stem cell-like epithelial cells along the lateral edges of the animal, which go through asymmetric and symmetric divisions contributing cells to the hypodermis and neurons, while replenishing the stem cell reservoir. The terminal number of seam cells is almost invariant in the wild-type population, allowing the investigation of how developmental precision is achieved. We report here that a loss-of-function mutation in the highly conserved N-acetyltransferase nath-10/NAT10 increases seam cell number variance in the isogenic population. RNA-seq analysis revealed increased levels of mRNA transcript variability in nath-10 mutant populations, which may have an impact on the phenotypic variability observed. Furthermore, we found disruption of Wnt signaling upon perturbing nath-10 function, as evidenced by changes in POP-1/TCF nuclear distribution and ectopic activation of its GATA transcription factor target egl-18. These results highlight that NATH-10/NAT-10 can influence phenotypic variability partly through modulation of the Wnt signaling pathway.
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Affiliation(s)
- Mark Hintze
- Department of Life Sciences, Imperial College, London, United Kingdom
| | - Dimitris Katsanos
- Department of Life Sciences, Imperial College, London, United Kingdom
| | - Vahid Shahrezaei
- Department of Mathematics, Imperial College, London, United Kingdom
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