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Benton D, Jaeger EC, Kilner A, Kimble A, Lowry J, Schleicher EM, Power KM, Uibel D, Eisele C, Bowerman B, Lyczak R. Interactions between the WEE-1.3 kinase and the PAM-1 aminopeptidase in oocyte maturation and the early C. elegans embryo. G3-GENES GENOMES GENETICS 2021; 11:6157833. [PMID: 33681968 PMCID: PMC8049411 DOI: 10.1093/g3journal/jkab063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 02/23/2021] [Indexed: 11/25/2022]
Abstract
Puromycin-sensitive aminopeptidases are found across phyla and are known to regulate the cell-cycle and play a protective role in neurodegenerative disease. PAM-1 is a puromycin-sensitive aminopeptidase important for meiotic exit and polarity establishment in the one-cell Caenorhabditis elegans embryo. Despite conservation of this aminopeptidase, little is known about its targets during development. In order to identify novel interactors, we conducted a suppressor screen and isolated four suppressing mutations in three genes that partially rescued the maternal-effect lethality of pam-1 mutants. Suppressed strains show improved embryonic viability and polarization of the anterior–posterior axis. We identified a missense mutation in wee-1.3 in one of these suppressed strains. WEE-1.3 is an inhibitory kinase that regulates maturation promoting factor. Although the missense mutation suppressed polarity phenotypes in pam-1, it does so without restoring centrosome–cortical contact or altering the cortical actomyosin cytoskeleton. To see if PAM-1 and WEE-1.3 interact in other processes, we examined oocyte maturation. Although depletion of wee-1.3 causes sterility due to precocious oocyte maturation, this effect was lessened in pam-1 worms, suggesting that PAM-1 and WEE-1.3 interact in this process. Levels of WEE-1.3 were comparable between wild-type and pam-1 strains, suggesting that WEE-1.3 is not a direct target of the aminopeptidase. Thus, we have established an interaction between PAM-1 and WEE-1.3 in multiple developmental processes and have identified suppressors that are likely to further our understanding of the role of puromycin-sensitive aminopeptidases during development.
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Affiliation(s)
- Dorothy Benton
- Biology Department, Ursinus College, 601 E Main Street, Collegeville, PA 19426, USA
| | - Eva C Jaeger
- Biology Department, Ursinus College, 601 E Main Street, Collegeville, PA 19426, USA
| | - Arielle Kilner
- Biology Department, Ursinus College, 601 E Main Street, Collegeville, PA 19426, USA.,Biomedical Studies Department, Graduate School of Biomedical Sciences and Professional Studies, Drexel University College of Medicine, 2900 W. Queen Lane Philadelphia, PA 19129, US A
| | - Ashley Kimble
- Biology Department, Ursinus College, 601 E Main Street, Collegeville, PA 19426, USA
| | - Josh Lowry
- Institute of Molecular Biology, 1229 University of Oregon, 1318 Franklin Blvd., Eugene, OR 97403, USA
| | - Emily M Schleicher
- Biology Department, Ursinus College, 601 E Main Street, Collegeville, PA 19426, USA
| | - Kaiden M Power
- Biology Department, Ursinus College, 601 E Main Street, Collegeville, PA 19426, USA
| | - Danielle Uibel
- Biology Department, Ursinus College, 601 E Main Street, Collegeville, PA 19426, USA
| | - Caprice Eisele
- Biology Department, Ursinus College, 601 E Main Street, Collegeville, PA 19426, USA
| | - Bruce Bowerman
- Institute of Molecular Biology, 1229 University of Oregon, 1318 Franklin Blvd., Eugene, OR 97403, USA
| | - Rebecca Lyczak
- Biology Department, Ursinus College, 601 E Main Street, Collegeville, PA 19426, USA
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Jud MC, Lowry J, Padilla T, Clifford E, Yang Y, Fennell F, Miller AK, Hamill D, Harvey AM, Avila-Zavala M, Shao H, Nguyen Tran N, Bao Z, Bowerman B. A genetic screen for temperature-sensitive morphogenesis-defective Caenorhabditis elegans mutants. G3-GENES GENOMES GENETICS 2021; 11:6169531. [PMID: 33713117 PMCID: PMC8133775 DOI: 10.1093/g3journal/jkab026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 01/18/2021] [Indexed: 11/21/2022]
Abstract
Morphogenesis involves coordinated cell migrations and cell shape changes that generate tissues and organs, and organize the body plan. Cell adhesion and the cytoskeleton are important for executing morphogenesis, but their regulation remains poorly understood. As genes required for embryonic morphogenesis may have earlier roles in development, temperature-sensitive embryonic-lethal mutations are useful tools for investigating this process. From a collection of ∼200 such Caenorhabditis elegans mutants, we have identified 17 that have highly penetrant embryonic morphogenesis defects after upshifts from the permissive to the restrictive temperature, just prior to the cell shape changes that mediate elongation of the ovoid embryo into a vermiform larva. Using whole genome sequencing, we identified the causal mutations in seven affected genes. These include three genes that have roles in producing the extracellular matrix, which is known to affect the morphogenesis of epithelial tissues in multicellular organisms: the rib-1 and rib-2 genes encode glycosyltransferases, and the emb-9 gene encodes a collagen subunit. We also used live imaging to characterize epidermal cell shape dynamics in one mutant, or1219ts, and observed cell elongation defects during dorsal intercalation and ventral enclosure that may be responsible for the body elongation defects. These results indicate that our screen has identified factors that influence morphogenesis and provides a platform for advancing our understanding of this fundamental biological process.
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Affiliation(s)
- Molly C Jud
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Josh Lowry
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Thalia Padilla
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Erin Clifford
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Yuqi Yang
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Francesca Fennell
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Alexander K Miller
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Danielle Hamill
- Department of Zoology, Ohio Wesleyan University, Delaware, OH, 43015, USA
| | - Austin M Harvey
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Martha Avila-Zavala
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Hong Shao
- Developmental Biology Program, Sloan Kettering Institute, New York, NY, 10065, USA
| | - Nhan Nguyen Tran
- Developmental Biology Program, Sloan Kettering Institute, New York, NY, 10065, USA
| | - Zhirong Bao
- Developmental Biology Program, Sloan Kettering Institute, New York, NY, 10065, USA
| | - Bruce Bowerman
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
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53
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Ruegenberg S, Mayr FAMC, Atanassov I, Baumann U, Denzel MS. Protein kinase A controls the hexosamine pathway by tuning the feedback inhibition of GFAT-1. Nat Commun 2021; 12:2176. [PMID: 33846315 PMCID: PMC8041777 DOI: 10.1038/s41467-021-22320-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 03/10/2021] [Indexed: 02/01/2023] Open
Abstract
The hexosamine pathway (HP) is a key anabolic pathway whose product uridine 5'-diphospho-N-acetyl-D-glucosamine (UDP-GlcNAc) is an essential precursor for glycosylation processes in mammals. It modulates the ER stress response and HP activation extends lifespan in Caenorhabditis elegans. The highly conserved glutamine fructose-6-phosphate amidotransferase 1 (GFAT-1) is the rate-limiting HP enzyme. GFAT-1 activity is modulated by UDP-GlcNAc feedback inhibition and via phosphorylation by protein kinase A (PKA). Molecular consequences of GFAT-1 phosphorylation, however, remain poorly understood. Here, we identify the GFAT-1 R203H substitution that elevates UDP-GlcNAc levels in C. elegans. In human GFAT-1, the R203H substitution interferes with UDP-GlcNAc inhibition and with PKA-mediated Ser205 phosphorylation. Our data indicate that phosphorylation affects the interactions of the two GFAT-1 domains to control catalytic activity. Notably, Ser205 phosphorylation has two discernible effects: it lowers baseline GFAT-1 activity and abolishes UDP-GlcNAc feedback inhibition. PKA controls the HP by uncoupling the metabolic feedback loop of GFAT-1.
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Affiliation(s)
- Sabine Ruegenberg
- grid.419502.b0000 0004 0373 6590Max Planck Institute for Biology of Ageing, Cologne, Germany ,grid.6190.e0000 0000 8580 3777Institute of Biochemistry, University of Cologne, Cologne, Germany
| | - Felix A. M. C. Mayr
- grid.419502.b0000 0004 0373 6590Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Ilian Atanassov
- grid.419502.b0000 0004 0373 6590Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Ulrich Baumann
- grid.6190.e0000 0000 8580 3777Institute of Biochemistry, University of Cologne, Cologne, Germany
| | - Martin S. Denzel
- grid.419502.b0000 0004 0373 6590Max Planck Institute for Biology of Ageing, Cologne, Germany ,grid.6190.e0000 0000 8580 3777CECAD - Cluster of Excellence, University of Cologne, Cologne, Germany ,grid.6190.e0000 0000 8580 3777Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
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54
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Marshall-Phelps KLH, Kegel L, Baraban M, Ruhwedel T, Almeida RG, Rubio-Brotons M, Klingseisen A, Benito-Kwiecinski SK, Early JJ, Bin JM, Suminaite D, Livesey MR, Möbius W, Poole RJ, Lyons DA. Neuronal activity disrupts myelinated axon integrity in the absence of NKCC1b. J Cell Biol 2021; 219:151733. [PMID: 32364583 PMCID: PMC7337504 DOI: 10.1083/jcb.201909022] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 03/09/2020] [Accepted: 04/07/2020] [Indexed: 02/07/2023] Open
Abstract
Through a genetic screen in zebrafish, we identified a mutant with disruption to myelin in both the CNS and PNS caused by a mutation in a previously uncharacterized gene, slc12a2b, predicted to encode a Na+, K+, and Cl- (NKCC) cotransporter, NKCC1b. slc12a2b/NKCC1b mutants exhibited a severe and progressive pathology in the PNS, characterized by dysmyelination and swelling of the periaxonal space at the axon-myelin interface. Cell-type-specific loss of slc12a2b/NKCC1b in either neurons or myelinating Schwann cells recapitulated these pathologies. Given that NKCC1 is critical for ion homeostasis, we asked whether the disruption to myelinated axons in slc12a2b/NKCC1b mutants is affected by neuronal activity. Strikingly, we found that blocking neuronal activity completely prevented and could even rescue the pathology in slc12a2b/NKCC1b mutants. Together, our data indicate that NKCC1b is required to maintain neuronal activity-related solute homeostasis at the axon-myelin interface, and the integrity of myelinated axons.
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Affiliation(s)
| | - Linde Kegel
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Marion Baraban
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Torben Ruhwedel
- Electron Microscopy Core Unit, Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Rafael G Almeida
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | | | - Anna Klingseisen
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | | | - Jason J Early
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Jenea M Bin
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Daumante Suminaite
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Matthew R Livesey
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Wiebke Möbius
- Electron Microscopy Core Unit, Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Richard J Poole
- Department of Cell and Developmental Biology, University College London, London, UK
| | - David A Lyons
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
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55
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Derisbourg MJ, Wester LE, Baddi R, Denzel MS. Mutagenesis screen uncovers lifespan extension through integrated stress response inhibition without reduced mRNA translation. Nat Commun 2021; 12:1678. [PMID: 33723245 PMCID: PMC7960713 DOI: 10.1038/s41467-021-21743-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 01/29/2021] [Indexed: 12/12/2022] Open
Abstract
Protein homeostasis is modulated by stress response pathways and its deficiency is a hallmark of aging. The integrated stress response (ISR) is a conserved stress-signaling pathway that tunes mRNA translation via phosphorylation of the translation initiation factor eIF2. ISR activation and translation initiation are finely balanced by eIF2 kinases and by the eIF2 guanine nucleotide exchange factor eIF2B. However, the role of the ISR during aging remains poorly understood. Using a genomic mutagenesis screen for longevity in Caenorhabditis elegans, we define a role of eIF2 modulation in aging. By inhibiting the ISR, dominant mutations in eIF2B enhance protein homeostasis and increase lifespan. Consistently, full ISR inhibition using phosphorylation-defective eIF2α or pharmacological ISR inhibition prolong lifespan. Lifespan extension through impeding the ISR occurs without a reduction in overall protein synthesis. Instead, we observe changes in the translational efficiency of a subset of mRNAs, of which the putative kinase kin-35 is required for lifespan extension. Evidently, lifespan is limited by the ISR and its inhibition may provide an intervention in aging.
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Affiliation(s)
| | - Laura E Wester
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Ruth Baddi
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Martin S Denzel
- Max Planck Institute for Biology of Ageing, Cologne, Germany.
- CECAD - Cluster of Excellence, University of Cologne, Cologne, Germany.
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.
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56
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Lup SD, Wilson-Sánchez D, Andreu-Sánchez S, Micol JL. Easymap: A User-Friendly Software Package for Rapid Mapping-by-Sequencing of Point Mutations and Large Insertions. FRONTIERS IN PLANT SCIENCE 2021; 12:655286. [PMID: 34040621 PMCID: PMC8143052 DOI: 10.3389/fpls.2021.655286] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 03/18/2021] [Indexed: 05/15/2023]
Abstract
Mapping-by-sequencing strategies combine next-generation sequencing (NGS) with classical linkage analysis, allowing rapid identification of the causal mutations of the phenotypes exhibited by mutants isolated in a genetic screen. Computer programs that analyze NGS data obtained from a mapping population of individuals derived from a mutant of interest to identify a causal mutation are available; however, the installation and usage of such programs requires bioinformatic skills, modifying or combining pieces of existing software, or purchasing licenses. To ease this process, we developed Easymap, an open-source program that simplifies the data analysis workflows from raw NGS reads to candidate mutations. Easymap can perform bulked segregant mapping of point mutations induced by ethyl methanesulfonate (EMS) with DNA-seq or RNA-seq datasets, as well as tagged-sequence mapping for large insertions, such as transposons or T-DNAs. The mapping analyses implemented in Easymap have been validated with experimental and simulated datasets from different plant and animal model species. Easymap was designed to be accessible to all users regardless of their bioinformatics skills by implementing a user-friendly graphical interface, a simple universal installation script, and detailed mapping reports, including informative images and complementary data for assessment of the mapping results. Easymap is available at http://genetics.edu.umh.es/resources/easymap; its Quickstart Installation Guide details the recommended procedure for installation.
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57
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Zhang W, He F, Ronan EA, Liu H, Gong J, Liu J, Xu XS. Regulation of photosensation by hydrogen peroxide and antioxidants in C. elegans. PLoS Genet 2020; 16:e1009257. [PMID: 33301443 PMCID: PMC7755287 DOI: 10.1371/journal.pgen.1009257] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Revised: 12/22/2020] [Accepted: 11/05/2020] [Indexed: 11/22/2022] Open
Abstract
The eyeless C. elegans exhibits robust phototaxis behavior in response to short-wavelength light, particularly UV light. C. elegans senses light through LITE-1, a unique photoreceptor protein that belongs to the invertebrate taste receptor family. However, it remains unclear how LITE-1 is regulated. Here, we performed a forward genetic screen for genes that when mutated suppress LITE-1 function. One group of lite-1 suppressors are the genes required for producing the two primary antioxidants thioredoxin and glutathione, suggesting that oxidization of LITE-1 inhibits its function. Indeed, the oxidant hydrogen peroxide (H2O2) suppresses phototaxis behavior and inhibits the photoresponse in photoreceptor neurons, whereas other sensory behaviors are relatively less vulnerable to H2O2. Conversely, antioxidants can rescue the phenotype of lite-1 suppressor mutants and promote the photoresponse. As UV light illumination generates H2O2, we propose that upon light activation of LITE-1, light-produced H2O2 then deactivates LITE-1 to terminate the photoresponse, while antioxidants may promote LITE-1’s recovery from its inactive state. Our studies provide a potential mechanism by which H2O2 and antioxidants act synergistically to regulate photosensation in C. elegans. The nematode C. elegans possesses a unique photoreceptor protein, LITE-1, which mediates a light-avoidance behavior upon light exposure. C. elegans avoids short-wavelength light, particularly UV light, providing a potential mechanism by which worms escape from the dangerous UV rays in the sunlight. However, it is not clear how LITE-1 is regulated. Here, we performed a genetic screen to identify genes regulating LITE-1. We uncovered six genes that when mutated suppress LITE-1 function. All these genes are involved in regenerating cellular antioxidants that function to clear reactive oxygen species, particularly hydrogen peroxide (H2O2), suggesting that the function of LITE-1 is vulnerable to H2O2. Indeed, we show that H2O2 exposure inhibits LITE-1 function, while antioxidants promote it. Notably, other sensory functions are relatively less sensitive to H2O2. As UV light illumination is known to generate H2O2 within the cell, this provides a potential mechanism to turn off LITE-1. Our results uncover a potential mechanism of LITE-1 regulation, where antioxidants and oxidants act to promote and suppress LITE-1 function, respectively.
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Affiliation(s)
- Wenyuan Zhang
- College of Life Science and Technology, Key Laboratory of Molecular Biophysics of MOE, Huazhong University of Science and Technology, Wuhan, Hubei, China
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Feiteng He
- College of Life Science and Technology, Key Laboratory of Molecular Biophysics of MOE, Huazhong University of Science and Technology, Wuhan, Hubei, China
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Elizabeth A. Ronan
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Hongkang Liu
- College of Life Science and Technology, Key Laboratory of Molecular Biophysics of MOE, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Jianke Gong
- College of Life Science and Technology, Key Laboratory of Molecular Biophysics of MOE, Huazhong University of Science and Technology, Wuhan, Hubei, China
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Jianfeng Liu
- College of Life Science and Technology, Key Laboratory of Molecular Biophysics of MOE, Huazhong University of Science and Technology, Wuhan, Hubei, China
- * E-mail: (JL); (XZSX)
| | - X.Z. Shawn Xu
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- * E-mail: (JL); (XZSX)
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Kawamura K, Maruyama IN. Mutation in histone deacetylase HDA-3 leads to shortened locomotor healthspan in Caenorhabditis elegans. Aging (Albany NY) 2020; 12:23525-23547. [PMID: 33276344 PMCID: PMC7762513 DOI: 10.18632/aging.202296] [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: 06/09/2020] [Accepted: 11/10/2020] [Indexed: 12/16/2022]
Abstract
Some genes are essential for survival, while other genes play modulatory roles on health and survival. Genes that play modulatory roles may promote an organism’s survival and health by fine-tuning physiological processes. An unbiased search for genes that alter an organism’s ability to maintain aspects of health may uncover modulators of lifespan and healthspan. From an unbiased screen for Caenorhabditis elegans mutants that show a progressive decline in motility, we aimed to identify genes that play a modulatory role in maintenance of locomotor healthspan. Here we report the involvement of hda-3, encoding a class I histone deacetylase, as a genetic factor that contributes in the maintenance of general health and locomotion in C. elegans. We identified a missense mutation in HDA-3 as the causative mutation in one of the isolated strains that show a progressive decline in maximum velocity and travel distance. From transcriptome analysis, we found a cluster of genes on Chromosome II carrying BATH domains that were downregulated by hda-3. Furthermore, downregulation of individual bath genes leads to significant decline in motility. Our study identifies genetic factors that modulate the maintenance of locomotor healthspan and may reveal potential targets for delaying age-related locomotor decline.
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Affiliation(s)
- Kazuto Kawamura
- Information Processing Biology Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Kunigami-gun, Okinawa, Japan
| | - Ichiro N Maruyama
- Information Processing Biology Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Kunigami-gun, Okinawa, Japan
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59
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Hodgens C, Chang N, Schaller GE, Kieber JJ. Mutagenomics: A Rapid, High-Throughput Method to Identify Causative Mutations from a Genetic Screen. PLANT PHYSIOLOGY 2020; 184:1658-1673. [PMID: 32887734 PMCID: PMC7723078 DOI: 10.1104/pp.20.00609] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 09/02/2020] [Indexed: 05/30/2023]
Abstract
Genetic screens are powerful tools to dissect complex biological processes, but a rate-limiting step is often the cloning of targeted genes. Here, we present a strategy, "mutagenomics," to identify causal mutations from a screen in a high throughput fashion in the absence of backcrossing. Mutagenomics is initiated by sequencing the genomes of the mutants identified, which are then subjected to a three-stage pipeline. The first stage identifies sequence changes in genes previously linked to the targeted pathway. The second stage uses heuristics derived from a simulation strategy to identify genes that are represented by multiple independent alleles more often than expected by chance. The third stage identifies candidate genes for the remaining lines by sequencing multiple lines of common descent. Our simulations indicate that sequencing as few as three to four sibling lines generally results in fewer than five candidate genes. We applied mutagenomics to a screen for Arabidopsis (Arabidopsis thaliana) mutants involved in the response to the phytohormone cytokinin. Mutagenomics identified likely causative genes for many of the mutant lines analyzed from this screen, including 13 alleles of the gene encoding the ARABIDOPSIS HIS KINASE4 cytokinin receptor. The screen also identified 1-AMINOCYCLOPROPANE-1-CARBOXYLATE (ACC) SYNTHASE7, an ACC synthase homolog involved in ethylene biosynthesis, and ELONGATED HYPOCOTYL5 (HY5), a master transcriptional regulator of photomorphogenesis. HY5 was found to mediate a subset of the transcriptional response to cytokinin. Mutagenomics has the potential to accelerate the pace and utility of genetic screens in Arabidopsis.
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Affiliation(s)
- Charles Hodgens
- Department of Biology, University of North Carolina at Chapel Hill, North Carolina 27599
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| | - Nicole Chang
- Department of Biology, University of North Carolina at Chapel Hill, North Carolina 27599
| | - G Eric Schaller
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755
| | - Joseph J Kieber
- Department of Biology, University of North Carolina at Chapel Hill, North Carolina 27599
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
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60
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PhenoMIP: High-Throughput Phenotyping of Diverse Caenorhabditis elegans Populations via Molecular Inversion Probes. G3-GENES GENOMES GENETICS 2020; 10:3977-3990. [PMID: 32868407 PMCID: PMC7642933 DOI: 10.1534/g3.120.401656] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Whether generated within a lab setting or isolated from the wild, variant alleles continue to be an important resource for decoding gene function in model organisms such as Caenorhabditis elegans. With advances in massively parallel sequencing, multiple whole-genome sequenced (WGS) strain collections are now available to the research community. The Million Mutation Project (MMP) for instance, analyzed 2007 N2-derived, mutagenized strains. Individually, each strain averages ∼400 single nucleotide variants amounting to ∼80 protein-coding variants. The effects of these variants, however, remain largely uncharacterized and querying the breadth of these strains for phenotypic changes requires a method amenable to rapid and sensitive high-throughput analysis. Here we present a pooled competitive fitness approach to quantitatively phenotype subpopulations of sequenced collections via molecular inversion probes (PhenoMIP). We phenotyped the relative fitness of 217 mutant strains on multiple food sources and classified these into five categories. We also demonstrate on a subset of these strains, that their fitness defects can be genetically mapped. Overall, our results suggest that approximately 80% of MMP mutant strains may have a decreased fitness relative to the lab reference, N2. The costs of generating this form of analysis through WGS methods would be prohibitive while PhenoMIP analysis in this manner is accomplished at less than one-tenth of projected WGS costs. We propose methods for applying PhenoMIP to a broad range of population selection experiments in a cost-efficient manner that would be useful to the community at large.
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61
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Sahu PK, Sao R, Mondal S, Vishwakarma G, Gupta SK, Kumar V, Singh S, Sharma D, Das BK. Next Generation Sequencing Based Forward Genetic Approaches for Identification and Mapping of Causal Mutations in Crop Plants: A Comprehensive Review. PLANTS 2020; 9:plants9101355. [PMID: 33066352 PMCID: PMC7602136 DOI: 10.3390/plants9101355] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 09/14/2020] [Accepted: 09/21/2020] [Indexed: 11/16/2022]
Abstract
The recent advancements in forward genetics have expanded the applications of mutation techniques in advanced genetics and genomics, ahead of direct use in breeding programs. The advent of next-generation sequencing (NGS) has enabled easy identification and mapping of causal mutations within a short period and at relatively low cost. Identifying the genetic mutations and genes that underlie phenotypic changes is essential for understanding a wide variety of biological functions. To accelerate the mutation mapping for crop improvement, several high-throughput and novel NGS based forward genetic approaches have been developed and applied in various crops. These techniques are highly efficient in crop plants, as it is relatively easy to grow and screen thousands of individuals. These approaches have improved the resolution in quantitative trait loci (QTL) position/point mutations and assisted in determining the functional causative variations in genes. To be successful in the interpretation of NGS data, bioinformatics computational methods are critical elements in delivering accurate assembly, alignment, and variant detection. Numerous bioinformatics tools/pipelines have been developed for such analysis. This article intends to review the recent advances in NGS based forward genetic approaches to identify and map the causal mutations in the crop genomes. The article also highlights the available bioinformatics tools/pipelines for reducing the complexity of NGS data and delivering the concluding outcomes.
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Affiliation(s)
- Parmeshwar K. Sahu
- Department of Genetics and Plant Breeding, Indira Gandhi Krishi Vishwavidyalaya, Raipur 492012, Chhattisgarh, India; (P.K.S.); (R.S.)
| | - Richa Sao
- Department of Genetics and Plant Breeding, Indira Gandhi Krishi Vishwavidyalaya, Raipur 492012, Chhattisgarh, India; (P.K.S.); (R.S.)
| | - Suvendu Mondal
- Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai 400085, India; (S.M.); (G.V.); (S.K.G.); (S.S.)
- Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, India
| | - Gautam Vishwakarma
- Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai 400085, India; (S.M.); (G.V.); (S.K.G.); (S.S.)
- Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, India
| | - Sudhir Kumar Gupta
- Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai 400085, India; (S.M.); (G.V.); (S.K.G.); (S.S.)
- Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, India
| | - Vinay Kumar
- ICAR-National Institute of Biotic Stress Management, Baronda, Raipur 493225, Chhattisgarh, India;
| | - Sudhir Singh
- Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai 400085, India; (S.M.); (G.V.); (S.K.G.); (S.S.)
| | - Deepak Sharma
- Department of Genetics and Plant Breeding, Indira Gandhi Krishi Vishwavidyalaya, Raipur 492012, Chhattisgarh, India; (P.K.S.); (R.S.)
- Correspondence: (D.S.); (B.K.D.)
| | - Bikram K. Das
- Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai 400085, India; (S.M.); (G.V.); (S.K.G.); (S.S.)
- Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, India
- Correspondence: (D.S.); (B.K.D.)
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62
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Giese GE, Walker MD, Ponomarova O, Zhang H, Li X, Minevich G, Walhout AJ. Caenorhabditis elegans methionine/S-adenosylmethionine cycle activity is sensed and adjusted by a nuclear hormone receptor. eLife 2020; 9:60259. [PMID: 33016879 PMCID: PMC7561351 DOI: 10.7554/elife.60259] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 10/02/2020] [Indexed: 01/17/2023] Open
Abstract
Vitamin B12 is an essential micronutrient that functions in two metabolic pathways: the canonical propionate breakdown pathway and the methionine/S-adenosylmethionine (Met/SAM) cycle. In Caenorhabditis elegans, low vitamin B12, or genetic perturbation of the canonical propionate breakdown pathway results in propionate accumulation and the transcriptional activation of a propionate shunt pathway. This propionate-dependent mechanism requires nhr-10 and is referred to as ‘B12-mechanism-I’. Here, we report that vitamin B12 represses the expression of Met/SAM cycle genes by a propionate-independent mechanism we refer to as ‘B12-mechanism-II’. This mechanism is activated by perturbations in the Met/SAM cycle, genetically or due to low dietary vitamin B12. B12-mechanism-II requires nhr-114 to activate Met/SAM cycle gene expression, the vitamin B12 transporter, pmp-5, and adjust influx and efflux of the cycle by activating msra-1 and repressing cbs-1, respectively. Taken together, Met/SAM cycle activity is sensed and transcriptionally adjusted to be in a tight metabolic regime.
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Affiliation(s)
- Gabrielle E Giese
- Program in Systems Biology and Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, United States
| | - Melissa D Walker
- Program in Systems Biology and Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, United States
| | - Olga Ponomarova
- Program in Systems Biology and Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, United States
| | - Hefei Zhang
- Program in Systems Biology and Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, United States
| | - Xuhang Li
- Program in Systems Biology and Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, United States
| | - Gregory Minevich
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, United States
| | - Albertha Jm Walhout
- Program in Systems Biology and Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, United States
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63
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Harnessing the power of genetics: fast forward genetics in Caenorhabditis elegans. Mol Genet Genomics 2020; 296:1-20. [PMID: 32888055 DOI: 10.1007/s00438-020-01721-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Accepted: 08/27/2020] [Indexed: 12/23/2022]
Abstract
Forward genetics is a powerful tool to unravel molecular mechanisms of diverse biological processes. The success of genetic screens primarily relies on the ease of genetic manipulation of an organism and the availability of a plethora of genetic tools. The roundworm Caenorhabditis elegans has been one of the favorite models for genetic studies due to its hermaphroditic lifestyle, ease of maintenance, and availability of various genetic manipulation tools. The strength of C. elegans genetics is highlighted by the leading role of this organism in the discovery of several conserved biological processes. In this review, the principles and strategies for forward genetics in C. elegans are discussed. Further, the recent advancements that have drastically accelerated the otherwise time-consuming process of mutation identification, making forward genetic screens a method of choice for understanding biological functions, are discussed. The emphasis of the review has been on providing practical and conceptual pointers for designing genetic screens that will identify mutations, specifically disrupting the biological processes of interest.
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64
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MutantHuntWGS: A Pipeline for Identifying Saccharomyces cerevisiae Mutations. G3-GENES GENOMES GENETICS 2020; 10:3009-3014. [PMID: 32605926 PMCID: PMC7466961 DOI: 10.1534/g3.120.401396] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
MutantHuntWGS is a user-friendly pipeline for analyzing Saccharomyces cerevisiae whole-genome sequencing data. It uses available open-source programs to: (1) perform sequence alignments for paired and single-end reads, (2) call variants, and (3) predict variant effect and severity. MutantHuntWGS outputs a shortlist of variants while also enabling access to all intermediate files. To demonstrate its utility, we use MutantHuntWGS to assess multiple published datasets; in all cases, it detects the same causal variants reported in the literature. To encourage broad adoption and promote reproducibility, we distribute a containerized version of the MutantHuntWGS pipeline that allows users to install and analyze data with only two commands. The MutantHuntWGS software and documentation can be downloaded free of charge from https://github.com/mae92/MutantHuntWGS.
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65
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Woods DP, Dong Y, Bouché F, Mayer K, Varner L, Ream TS, Thrower N, Wilkerson C, Cartwright A, Sibout R, Laudencia-Chingcuanco D, Vogel J, Amasino RM. Mutations in the predicted DNA polymerase subunit POLD3 result in more rapid flowering of Brachypodium distachyon. THE NEW PHYTOLOGIST 2020; 227:1725-1735. [PMID: 32173866 DOI: 10.1111/nph.16546] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Accepted: 02/18/2020] [Indexed: 06/10/2023]
Abstract
The timing of reproduction is a critical developmental decision in the life cycle of many plant species. Fine mapping of a rapid-flowering mutant was done using whole-genome sequence data from bulked DNA from a segregating F2 mapping populations. The causative mutation maps to a gene orthologous with the third subunit of DNA polymerase δ (POLD3), a previously uncharacterized gene in plants. Expression analyses of POLD3 were conducted via real time qPCR to determine when and in what tissues the gene is expressed. To better understand the molecular basis of the rapid-flowering phenotype, transcriptomic analyses were conducted in the mutant vs wild-type. Consistent with the rapid-flowering mutant phenotype, a range of genes involved in floral induction and flower development are upregulated in the mutant. Our results provide the first characterization of the developmental and gene expression phenotypes that result from a lesion in POLD3 in plants.
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Affiliation(s)
- Daniel P Woods
- Laboratory of Genetics, University of Wisconsin, 425-G Henry Mall, Madison, WI, 53706, USA
- United States Department of Energy Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, WI, 53706, USA
- Department of Biochemistry, University of Wisconsin, 433 Babcock Dr., Madison, WI, 53706, USA
| | - Yinxin Dong
- Department of Biochemistry, University of Wisconsin, 433 Babcock Dr., Madison, WI, 53706, USA
- College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Frédéric Bouché
- Department of Biochemistry, University of Wisconsin, 433 Babcock Dr., Madison, WI, 53706, USA
| | - Kevin Mayer
- Laboratory of Genetics, University of Wisconsin, 425-G Henry Mall, Madison, WI, 53706, USA
| | - Leah Varner
- Department of Biochemistry, University of Wisconsin, 433 Babcock Dr., Madison, WI, 53706, USA
| | - Thomas S Ream
- United States Department of Energy Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, WI, 53706, USA
- Department of Biochemistry, University of Wisconsin, 433 Babcock Dr., Madison, WI, 53706, USA
| | - Nicholas Thrower
- United States Department of Energy Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, WI, 53706, USA
- Department of Plant Biology and Department of Molecular Biology and Biochemistry, Michigan State University, East Lansing, MI, 48824, USA
| | - Curtis Wilkerson
- United States Department of Energy Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, WI, 53706, USA
- Department of Plant Biology and Department of Molecular Biology and Biochemistry, Michigan State University, East Lansing, MI, 48824, USA
| | - Amy Cartwright
- United States Department of Energy Joint Genome Institute, Berkeley, CA, 94720, USA
| | - Richard Sibout
- INRAE, UR BIA, F-44316, Nantes, France
- Institut Jean-Pierre Bourgin, UMR 1318, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78000, Versailles, France
| | | | - John Vogel
- United States Department of Energy Joint Genome Institute, Berkeley, CA, 94720, USA
- Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- University of California Berkeley, Berkeley, CA, 94704, USA
| | - Richard M Amasino
- Laboratory of Genetics, University of Wisconsin, 425-G Henry Mall, Madison, WI, 53706, USA
- United States Department of Energy Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, WI, 53706, USA
- Department of Biochemistry, University of Wisconsin, 433 Babcock Dr., Madison, WI, 53706, USA
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66
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Huntingtin-interacting protein family members have a conserved pro-viral function from Caenorhabditis elegans to humans. Proc Natl Acad Sci U S A 2020; 117:22462-22472. [PMID: 32839311 PMCID: PMC7486723 DOI: 10.1073/pnas.2006914117] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Understanding host–virus interaction mechanisms is critical to identify novel drug targets for development of antiviral therapeutics. The C. elegans–Orsay virus infection system offers an innovative approach for discovering host factors required for virus infection. The hipr-1 gene was determined to be essential in C. elegans for Orsay virus infection at an early stage of the virus life cycle. Studies of its orthologs in human cell culture determined that both HIP1 and HIP1R are important for Coxsackie B3 virus infection, highlighting the evolutionarily conserved role of HIP-family proteins in virus infection from nematodes to humans. Huntingtin-interacting protein family members are evolutionarily conserved from yeast to humans, and they are known to be key factors in clathrin-mediated endocytosis. Here we identified the Caenorhabditis elegans protein huntingtin-interacting protein-related 1 (HIPR-1) as a host factor essential for Orsay virus infection of C. elegans. Ablation of HIPR-1 resulted in a greater than 10,000-fold reduction in viral RNA, which could be rescued by ectopic expression of HIPR-1. Viral RNA replication from an endogenous transgene replicon system was not affected by lack of HIPR-1, suggesting that HIPR-1 plays a role during an early, prereplication virus life-cycle stage. Ectopic expression of HIPR-1 mutants demonstrated that neither the clathrin light chain-binding domain nor the clathrin heavy chain-binding motif were needed for virus infection, whereas the inositol phospholipid-binding and F-actin–binding domains were essential. In human cell culture, deletion of the human HIP orthologs HIP1 and HIP1R led to decreased infection by Coxsackie B3 virus. Finally, ectopic expression of a chimeric HIPR-1 harboring the human HIP1 ANTH (AP180 N-terminal homology) domain rescued Orsay infection in C. elegans, demonstrating conservation of its function through evolution. Collectively, these findings further our knowledge of cellular factors impacting viral infection in C. elegans and humans.
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67
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LaBella ML, Hujber EJ, Moore KA, Rawson RL, Merrill SA, Allaire PD, Ailion M, Hollien J, Bastiani MJ, Jorgensen EM. Casein Kinase 1δ Stabilizes Mature Axons by Inhibiting Transcription Termination of Ankyrin. Dev Cell 2020; 52:88-103.e18. [PMID: 31910362 DOI: 10.1016/j.devcel.2019.12.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 10/09/2019] [Accepted: 12/10/2019] [Indexed: 01/19/2023]
Abstract
After axon outgrowth and synapse formation, the nervous system transitions to a stable architecture. In C. elegans, this transition is marked by the appearance of casein kinase 1δ (CK1δ) in the nucleus. In CK1δ mutants, neurons continue to sprout growth cones into adulthood, leading to a highly ramified nervous system. Nervous system architecture in these mutants is completely restored by suppressor mutations in ten genes involved in transcription termination. CK1δ prevents termination by phosphorylating and inhibiting SSUP-72. SSUP-72 would normally remodel the C-terminal domain of RNA polymerase in anticipation of termination. The antitermination activity of CK1δ establishes the mature state of a neuron by promoting the expression of the long isoform of a single gene, the cytoskeleton protein Ankyrin.
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Affiliation(s)
- Matthew L LaBella
- Department of Biology, Howard Hughes Medical Institute, University of Utah, Salt Lake City, UT, USA
| | - Edward J Hujber
- Department of Biology, Howard Hughes Medical Institute, University of Utah, Salt Lake City, UT, USA
| | - Kristin A Moore
- Department of Biology, University of Utah, Salt Lake City, UT, USA
| | - Randi L Rawson
- Department of Biology, Howard Hughes Medical Institute, University of Utah, Salt Lake City, UT, USA
| | - Sean A Merrill
- Department of Biology, Howard Hughes Medical Institute, University of Utah, Salt Lake City, UT, USA
| | - Patrick D Allaire
- Department of Biology, Howard Hughes Medical Institute, University of Utah, Salt Lake City, UT, USA
| | - Michael Ailion
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Julie Hollien
- Department of Biology, University of Utah, Salt Lake City, UT, USA
| | | | - Erik M Jorgensen
- Department of Biology, Howard Hughes Medical Institute, University of Utah, Salt Lake City, UT, USA.
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68
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The Predicted RNA-Binding Protein ETR-1/CELF1 Acts in Muscles To Regulate Neuroblast Migration in Caenorhabditis elegans. G3-GENES GENOMES GENETICS 2020; 10:2365-2376. [PMID: 32398235 PMCID: PMC7341121 DOI: 10.1534/g3.120.401182] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Neuroblast migration is a critical aspect of nervous system development (e.g., neural crest migration). In an unbiased forward genetic screen, we identified a novel player in neuroblast migration, the ETR-1/CELF1 RNA binding protein. CELF1 RNA binding proteins are involved in multiple aspects of RNA processing including alternative splicing, stability, and translation. We find that a specific mutation in alternatively-spliced exon 8 results in migration defects of the AQR and PQR neurons, and not the embryonic lethality and body wall muscle defects of complete knockdown of the locus. Surprisingly, ETR-1 was required in body wall muscle cells for AQR/PQR migration (i.e., it acts cell non-autonomously). Genetic interactions indicate that ETR-1 acts with Wnt signaling, either in the Wnt pathway or in a parallel pathway. Possibly, ETR-1 is involved in the production of a Wnt signal or a parallel signal by the body wall muscles that controls AQR and PQR neuronal migration. In humans, CELF1 is involved in a number of neuromuscular disorders. If the role of ETR-1/CELF1 is conserved, these disorders might also involve cell or neuronal migration. Finally, we describe a technique of amplicon sequencing to detect rare, cell-specific genome edits by CRISPR/Cas9 in vivo (CRISPR-seq) as an alternative to the T7E1 assay.
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69
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Yousfi K, Usongo V, Berry C, Khan RH, Tremblay DM, Moineau S, Mulvey MR, Doualla-Bell F, Fournier E, Nadon C, Goodridge L, Bekal S. Source Tracking Based on Core Genome SNV and CRISPR Typing of Salmonella enterica Serovar Heidelberg Isolates Involved in Foodborne Outbreaks in Québec, 2012. Front Microbiol 2020; 11:1317. [PMID: 32625190 PMCID: PMC7311582 DOI: 10.3389/fmicb.2020.01317] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 05/25/2020] [Indexed: 12/22/2022] Open
Abstract
Whole-genome sequencing (WGS) is the method of choice for bacterial subtyping and it is rapidly replacing the more traditional methods such as pulsed-field gel electrophoresis (PFGE). Here we used the high-resolution core genome single nucleotide variant (cgSNV) typing method to characterize clinical and food from Salmonella enterica serovar Heidelberg isolates in the context of source attribution. Additionally, clustered regularly interspaced short palindromic repeats (CRISPR) analysis was included to further support this method. Our results revealed that cgSNV was highly discriminatory and separated the outbreak isolates into distinct clusters (0-4 SNVs). CRISPR analysis was also able to distinguish outbreak strains from epidemiologically unrelated isolates. Specifically, our data clearly demonstrated the strength of these two methods to determine the probable source(s) of a 2012 epidemiologically characterized outbreak of S. Heidelberg. Using molecular cut-off of 0-10 SNVs, the cgSNV analysis of 246 clinical and food isolates of S. Heidelberg collected in Québec, in the same year of the outbreak event, revealed that retail and abattoir chicken isolates likely represent an important source of human infection to S. Heidelberg. Interestingly, the isolates genetically related by cgSNV also harbored the same CRISPR as outbreak isolates and clusters. This indicates that CRISPR profiles can be useful as a complementary approach to determine source attribution in foodborne outbreaks. Use of the genomic analysis also allowed to identify a large number of cases that were missed by PFGE, indicating that most outbreaks are probably underestimated. Although epidemiological information must still support WGS-based results, cgSNV method is a highly discriminatory method for the resolution of outbreak events and the attribution of these events to their respective sources. CRISPR typing can serve as a complimentary tool to this analysis during source tracking.
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Affiliation(s)
- Khadidja Yousfi
- Laboratoire de Santé Publique du Québec, Institut National de Santé Publique du Québec, Sainte-Anne-de-Bellevue, QC, Canada.,Department of Food Science and Agricultural Chemistry, McGill University, Sainte-Anne-de-Bellevue, QC, Canada
| | - Valentine Usongo
- Laboratoire de Santé Publique du Québec, Institut National de Santé Publique du Québec, Sainte-Anne-de-Bellevue, QC, Canada.,Department of Food Science and Agricultural Chemistry, McGill University, Sainte-Anne-de-Bellevue, QC, Canada
| | - Chrystal Berry
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada
| | - Rufaida H Khan
- Laboratoire de Santé Publique du Québec, Institut National de Santé Publique du Québec, Sainte-Anne-de-Bellevue, QC, Canada.,Department of Food Science and Agricultural Chemistry, McGill University, Sainte-Anne-de-Bellevue, QC, Canada
| | - Denise M Tremblay
- Département de Biochimie, de Microbiologie et de Bio-Informatique, Faculté des Sciences et de Génie, Université Laval, Quebec City, QC, Canada
| | - Sylvain Moineau
- Département de Biochimie, de Microbiologie et de Bio-Informatique, Faculté des Sciences et de Génie, Université Laval, Quebec City, QC, Canada
| | - Michael R Mulvey
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada
| | - Florence Doualla-Bell
- Laboratoire de Santé Publique du Québec, Institut National de Santé Publique du Québec, Sainte-Anne-de-Bellevue, QC, Canada
| | - Eric Fournier
- Laboratoire de Santé Publique du Québec, Institut National de Santé Publique du Québec, Sainte-Anne-de-Bellevue, QC, Canada
| | - Celine Nadon
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada
| | - Lawrence Goodridge
- Department of Food Science and Agricultural Chemistry, McGill University, Sainte-Anne-de-Bellevue, QC, Canada
| | - Sadjia Bekal
- Laboratoire de Santé Publique du Québec, Institut National de Santé Publique du Québec, Sainte-Anne-de-Bellevue, QC, Canada.,Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC, Canada
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70
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Varga M, Csályi K, Bertyák I, Menyhárd DK, Poole RJ, Cerveny KL, Kövesdi D, Barátki B, Rouse H, Vad Z, Hawkins TA, Stickney HL, Cavodeassi F, Schwarz Q, Young RM, Wilson SW. Tissue-Specific Requirement for the GINS Complex During Zebrafish Development. Front Cell Dev Biol 2020; 8:373. [PMID: 32548116 PMCID: PMC7270345 DOI: 10.3389/fcell.2020.00373] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 04/27/2020] [Indexed: 12/13/2022] Open
Abstract
Efficient and accurate DNA replication is particularly critical in stem and progenitor cells for successful proliferation and survival. The replisome, an amalgam of protein complexes, is responsible for binding potential origins of replication, unwinding the double helix, and then synthesizing complimentary strands of DNA. According to current models, the initial steps of DNA unwinding and opening are facilitated by the CMG complex, which is composed of a GINS heterotetramer that connects Cdc45 with the mini-chromosome maintenance (Mcm) helicase. In this work, we provide evidence that in the absence of GINS function DNA replication is cell autonomously impaired, and we also show that gins1 and gins2 mutants exhibit elevated levels of apoptosis restricted to actively proliferating regions of the central nervous system (CNS). Intriguingly, our results also suggest that the rapid cell cycles during early embryonic development in zebrafish may not require the function of the canonical GINS complex as neither zygotic Gins1 nor Gins2 isoforms seem to be present during these stages.
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Affiliation(s)
- Máté Varga
- Department of Genetics, ELTE Eötvös Loránd University, Budapest, Hungary.,Department of Cell and Developmental Biology, Division of Biosciences, University College London, London, United Kingdom
| | - Kitti Csályi
- Department of Genetics, ELTE Eötvös Loránd University, Budapest, Hungary
| | - István Bertyák
- Department of Genetics, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Dóra K Menyhárd
- HAS-ELTE Protein Modeling Research Group and Laboratory of Structural Chemistry and Biology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Richard J Poole
- Department of Cell and Developmental Biology, Division of Biosciences, University College London, London, United Kingdom
| | - Kara L Cerveny
- Biology Department, Reed College, Portland, OR, United States
| | - Dorottya Kövesdi
- Office of Supported Research Groups of the Hungarian Academy of Sciences, Budapest, Hungary.,Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Balázs Barátki
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Hannah Rouse
- Department of Cell and Developmental Biology, Division of Biosciences, University College London, London, United Kingdom
| | - Zsuzsa Vad
- Department of Genetics, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Thomas A Hawkins
- Department of Cell and Developmental Biology, Division of Biosciences, University College London, London, United Kingdom
| | - Heather L Stickney
- Department of Cell and Developmental Biology, Division of Biosciences, University College London, London, United Kingdom
| | - Florencia Cavodeassi
- Department of Cell and Developmental Biology, Division of Biosciences, University College London, London, United Kingdom.,Institute of Medical and Biomedical Education, St. George's University of London, London, United Kingdom
| | - Quenten Schwarz
- Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, SA, Australia
| | - Rodrigo M Young
- Department of Cell and Developmental Biology, Division of Biosciences, University College London, London, United Kingdom
| | - Stephen W Wilson
- Department of Cell and Developmental Biology, Division of Biosciences, University College London, London, United Kingdom
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71
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Wilson-Sánchez D, Lup SD, Sarmiento-Mañús R, Ponce MR, Micol JL. Next-generation forward genetic screens: using simulated data to improve the design of mapping-by-sequencing experiments in Arabidopsis. Nucleic Acids Res 2020; 47:e140. [PMID: 31544937 PMCID: PMC6868388 DOI: 10.1093/nar/gkz806] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 09/07/2019] [Accepted: 09/10/2019] [Indexed: 12/25/2022] Open
Abstract
Forward genetic screens have successfully identified many genes and continue to be powerful tools for dissecting biological processes in Arabidopsis and other model species. Next-generation sequencing technologies have revolutionized the time-consuming process of identifying the mutations that cause a phenotype of interest. However, due to the cost of such mapping-by-sequencing experiments, special attention should be paid to experimental design and technical decisions so that the read data allows to map the desired mutation. Here, we simulated different mapping-by-sequencing scenarios. We first evaluated which short-read technology was best suited for analyzing gene-rich genomic regions in Arabidopsis and determined the minimum sequencing depth required to confidently call single nucleotide variants. We also designed ways to discriminate mutagenesis-induced mutations from background Single Nucleotide Polymorphisms in mutants isolated in Arabidopsis non-reference lines. In addition, we simulated bulked segregant mapping populations for identifying point mutations and monitored how the size of the mapping population and the sequencing depth affect mapping precision. Finally, we provide the computational basis of a protocol that we already used to map T-DNA insertions with paired-end Illumina-like reads, using very low sequencing depths and pooling several mutants together; this approach can also be used with single-end reads as well as to map any other insertional mutagen. All these simulations proved useful for designing experiments that allowed us to map several mutations in Arabidopsis.
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Affiliation(s)
- David Wilson-Sánchez
- Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, 03202 Elche, Spain
| | - Samuel Daniel Lup
- Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, 03202 Elche, Spain
| | - Raquel Sarmiento-Mañús
- Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, 03202 Elche, Spain
| | - María Rosa Ponce
- Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, 03202 Elche, Spain
| | - José Luis Micol
- Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, 03202 Elche, Spain
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72
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Flynn SM, Chen C, Artan M, Barratt S, Crisp A, Nelson GM, Peak-Chew SY, Begum F, Skehel M, de Bono M. MALT-1 mediates IL-17 neural signaling to regulate C. elegans behavior, immunity and longevity. Nat Commun 2020; 11:2099. [PMID: 32350248 PMCID: PMC7190641 DOI: 10.1038/s41467-020-15872-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 03/26/2020] [Indexed: 12/27/2022] Open
Abstract
Besides pro-inflammatory roles, the ancient cytokine interleukin-17 (IL-17) modulates neural circuit function. We investigate IL-17 signaling in neurons, and the extent it can alter organismal phenotypes. We combine immunoprecipitation and mass spectrometry to biochemically characterize endogenous signaling complexes that function downstream of IL-17 receptors in C. elegans neurons. We identify the paracaspase MALT-1 as a critical output of the pathway. MALT1 mediates signaling from many immune receptors in mammals, but was not previously implicated in IL-17 signaling or nervous system function. C. elegans MALT-1 forms a complex with homologs of Act1 and IRAK and appears to function both as a scaffold and a protease. MALT-1 is expressed broadly in the C. elegans nervous system, and neuronal IL-17-MALT-1 signaling regulates multiple phenotypes, including escape behavior, associative learning, immunity and longevity. Our data suggest MALT1 has an ancient role modulating neural circuit function downstream of IL-17 to remodel physiology and behavior.
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Affiliation(s)
- Sean M Flynn
- Cell Biology Division, Medical Research Council Laboratory of Molecular Biology, Cambridge, CB2 0QH, United Kingdom
| | - Changchun Chen
- Cell Biology Division, Medical Research Council Laboratory of Molecular Biology, Cambridge, CB2 0QH, United Kingdom
- Umeå Center for Molecular Medicine, Wallenberg Center for Molecular Medicine, Umeå University, SE-901 87, Umeå, Sweden
| | - Murat Artan
- Cell Biology Division, Medical Research Council Laboratory of Molecular Biology, Cambridge, CB2 0QH, United Kingdom
| | - Stephen Barratt
- Cell Biology Division, Medical Research Council Laboratory of Molecular Biology, Cambridge, CB2 0QH, United Kingdom
| | - Alastair Crisp
- Cell Biology Division, Medical Research Council Laboratory of Molecular Biology, Cambridge, CB2 0QH, United Kingdom
| | - Geoffrey M Nelson
- Cell Biology Division, Medical Research Council Laboratory of Molecular Biology, Cambridge, CB2 0QH, United Kingdom
- Department of Biomedical Informatics, Harvard Medical School, Boston, MA, 02115, USA
| | - Sew-Yeu Peak-Chew
- Biological Mass Spectrometry and Proteomics, Cell Biology Division, Medical Research Council Laboratory of Molecular Biology, Cambridge, CB2 0QH, United Kingdom
| | - Farida Begum
- Biological Mass Spectrometry and Proteomics, Cell Biology Division, Medical Research Council Laboratory of Molecular Biology, Cambridge, CB2 0QH, United Kingdom
| | - Mark Skehel
- Biological Mass Spectrometry and Proteomics, Cell Biology Division, Medical Research Council Laboratory of Molecular Biology, Cambridge, CB2 0QH, United Kingdom
| | - Mario de Bono
- Cell Biology Division, Medical Research Council Laboratory of Molecular Biology, Cambridge, CB2 0QH, United Kingdom.
- Institute of Science and Technology Austria (IST Austria), Am Campus 1, 3400, Klosterneuburg, Austria.
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73
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Fan J, Ji T, Wang K, Huang J, Wang M, Manning L, Dong X, Shi Y, Zhang X, Shao Z, Colón-Ramos DA. A muscle-epidermis-glia signaling axis sustains synaptic specificity during allometric growth in Caenorhabditis elegans. eLife 2020; 9:55890. [PMID: 32255430 PMCID: PMC7164957 DOI: 10.7554/elife.55890] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 04/05/2020] [Indexed: 02/06/2023] Open
Abstract
Synaptic positions underlie precise circuit connectivity. Synaptic positions can be established during embryogenesis and sustained during growth. The mechanisms that sustain synaptic specificity during allometric growth are largely unknown. We performed forward genetic screens in C. elegans for regulators of this process and identified mig-17, a conserved ADAMTS metalloprotease. Proteomic mass spectrometry, cell biological and genetic studies demonstrate that MIG-17 is secreted from cells like muscles to regulate basement membrane proteins. In the nematode brain, the basement membrane does not directly contact synapses. Instead, muscle-derived basement membrane coats one side of the glia, while glia contact synapses on their other side. MIG-17 modifies the muscle-derived basement membrane to modulate epidermal-glial crosstalk and sustain glia location and morphology during growth. Glia position in turn sustains the synaptic pattern established during embryogenesis. Our findings uncover a muscle-epidermis-glia signaling axis that sustains synaptic specificity during the organism's allometric growth.
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Affiliation(s)
- Jiale Fan
- Department of Neurosurgery, the State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, the Institutes of Brain Science, and Zhongshan Hospital, Fudan University Shanghai, Shanghai, China
| | - Tingting Ji
- Department of Neurosurgery, the State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, the Institutes of Brain Science, and Zhongshan Hospital, Fudan University Shanghai, Shanghai, China
| | - Kai Wang
- Department of Neurosurgery, the State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, the Institutes of Brain Science, and Zhongshan Hospital, Fudan University Shanghai, Shanghai, China
| | - Jichang Huang
- State Key Laboratory of Genetic Engineering, Department of Biochemistry, School of Life Sciences, Fudan University, Shanghai, China
| | - Mengqing Wang
- Department of Neurosurgery, the State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, the Institutes of Brain Science, and Zhongshan Hospital, Fudan University Shanghai, Shanghai, China
| | - Laura Manning
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine, New Haven, United States
| | - Xiaohua Dong
- Department of Neurosurgery, the State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, the Institutes of Brain Science, and Zhongshan Hospital, Fudan University Shanghai, Shanghai, China
| | - Yanjun Shi
- Department of Neurosurgery, the State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, the Institutes of Brain Science, and Zhongshan Hospital, Fudan University Shanghai, Shanghai, China
| | - Xumin Zhang
- State Key Laboratory of Genetic Engineering, Department of Biochemistry, School of Life Sciences, Fudan University, Shanghai, China
| | - Zhiyong Shao
- Department of Neurosurgery, the State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, the Institutes of Brain Science, and Zhongshan Hospital, Fudan University Shanghai, Shanghai, China
| | - Daniel A Colón-Ramos
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine, New Haven, United States.,Instituto de Neurobiología, Recinto de Ciencias Médicas, Universidad de Puerto Rico, San Juan, Puerto Rico
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74
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Foster KJ, Cheesman HK, Liu P, Peterson ND, Anderson SM, Pukkila-Worley R. Innate Immunity in the C. elegans Intestine Is Programmed by a Neuronal Regulator of AWC Olfactory Neuron Development. Cell Rep 2020; 31:107478. [PMID: 32268082 PMCID: PMC7215899 DOI: 10.1016/j.celrep.2020.03.042] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 01/15/2020] [Accepted: 03/13/2020] [Indexed: 12/22/2022] Open
Abstract
Olfactory neurons allow animals to discriminate nutritious food sources from potential pathogens. From a forward genetic screen, we uncovered a surprising requirement for the olfactory neuron gene olrn-1 in the regulation of intestinal epithelial immunity in Caenorhabditis elegans. During nematode development, olrn-1 is required to program the expression of odorant receptors in the AWC olfactory neuron pair. Here, we show that olrn-1 also functions in AWC neurons in the cell non-autonomous suppression of the canonical p38 MAPK PMK-1 immune pathway in the intestine. Low activity of OLRN-1, which activates the p38 MAPK signaling cassette in AWC neurons during larval development, also de-represses the p38 MAPK PMK-1 pathway in the intestine to promote immune effector transcription, increased clearance of an intestinal pathogen, and resistance to bacterial infection. These data reveal an unexpected connection between olfactory receptor development and innate immunity and show that anti-pathogen defenses in the intestine are developmentally programmed.
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Affiliation(s)
- Kyle J Foster
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Hilary K Cheesman
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Pengpeng Liu
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Nicholas D Peterson
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Sarah M Anderson
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Read Pukkila-Worley
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01655, USA; Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01655, USA.
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75
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Hart MP, Hobert O. A missense mutation separates distinct functions of the Zic-family transcription factor REF-2. MICROPUBLICATION BIOLOGY 2020; 2020:10.17912/micropub.biology.000232. [PMID: 32550516 PMCID: PMC7252410 DOI: 10.17912/micropub.biology.000232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Michael P. Hart
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | - Oliver Hobert
- Columbia University, Howard Hughes Medical Institute,
Correspondence to: Oliver Hobert ()
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76
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Sensory cilia as the Achilles heel of nematodes when attacked by carnivorous mushrooms. Proc Natl Acad Sci U S A 2020; 117:6014-6022. [PMID: 32123065 DOI: 10.1073/pnas.1918473117] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Fungal predatory behavior on nematodes has evolved independently in all major fungal lineages. The basidiomycete oyster mushroom Pleurotus ostreatus is a carnivorous fungus that preys on nematodes to supplement its nitrogen intake under nutrient-limiting conditions. Its hyphae can paralyze nematodes within a few minutes of contact, but the mechanism had remained unclear. We demonstrate that the predator-prey relationship is highly conserved between multiple Pleurotus species and a diversity of nematodes. To further investigate the cellular and molecular mechanisms underlying rapid nematode paralysis, we conducted genetic screens in Caenorhabditis elegans and isolated mutants that became resistant to P. ostreatus We found that paralysis-resistant mutants all harbored loss-of-function mutations in genes required for ciliogenesis, demonstrating that the fungus induced paralysis via the cilia of nematode sensory neurons. Furthermore, we observed that P. ostreatus caused excess calcium influx and hypercontraction of the head and pharyngeal muscle cells, ultimately resulting in rapid necrosis of the entire nervous system and muscle cells throughout the entire organism. This cilia-dependent predatory mechanism is evolutionarily conserved in Pristionchus pacificus, a nematode species estimated to have diverged from C. elegans 280 to 430 million y ago. Thus, P. ostreatus exploits a nematode-killing mechanism that is distinct from widely used anthelmintic drugs such as ivermectin, levamisole, and aldicarb, representing a potential route for targeting parasitic nematodes in plants, animals, and humans.
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77
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Romanelli-Credrez L, Doitsidou M, Alkema MJ, Salinas G. HIF-1 Has a Central Role in Caenorhabditis elegans Organismal Response to Selenium. Front Genet 2020; 11:63. [PMID: 32161616 PMCID: PMC7052493 DOI: 10.3389/fgene.2020.00063] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 01/17/2020] [Indexed: 11/13/2022] Open
Abstract
Selenium is a trace element for most organisms; its deficiency and excess are detrimental. Selenium beneficial effects are mainly due to the role of the 21st genetically encoded amino acid selenocysteine (Sec). Selenium also exerts Sec-independent beneficial effects. Its harmful effects are thought to be mainly due to non-specific incorporation in protein synthesis. Yet the selenium response in animals is poorly understood. In Caenorhabditis elegans, Sec is genetically incorporated into a single selenoprotein. Similar to mammals, a 20-fold excess of the optimal selenium requirement is harmful. Sodium selenite (Na2SeO3) excess causes development retardation, impaired growth, and neurodegeneration of motor neurons. To study the organismal response to selenium we performed a genetic screen for C. elegans mutants that are resistant to selenite. We isolated non-sense and missense egl-9/EGLN mutants that confer robust resistance to selenium. In contrast, hif-1/HIF null mutant was highly sensitive to selenium, establishing a role for this transcription factor in the selenium response. We showed that EGL-9 regulates HIF-1 activity through VHL-1, and identified CYSL-1 as a key sensor that transduces the selenium signal. Finally, we showed that the key enzymes involved in sulfide and sulfite stress (sulfide quinone oxidoreductase and sulfite oxidase) are not required for selenium resistance. In contrast, knockout strains in the persulfide dioxygenase ETHE-1 and the sulfurtransferase MPST-7 affect the organismal response to selenium. In sum, our results identified a transcriptional pathway as well as enzymes possibly involved in the organismal selenium response.
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Affiliation(s)
- Laura Romanelli-Credrez
- Laboratorio de Biología de Gusanos. Unidad Mixta, Departamento de Biociencias, Facultad de Química, Universidad de la República-Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Maria Doitsidou
- Centre for Discovery Brain Sciences (CDBS), University of Edinburgh, Edinburgh, United Kingdom
| | - Mark J Alkema
- Neurobiology Department, University of Massachusetts Medical School, Worcester, MA, United States
| | - Gustavo Salinas
- Laboratorio de Biología de Gusanos. Unidad Mixta, Departamento de Biociencias, Facultad de Química, Universidad de la República-Institut Pasteur de Montevideo, Montevideo, Uruguay
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78
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Alexander-Floyd J, Haroon S, Ying M, Entezari AA, Jaeger C, Vermulst M, Gidalevitz T. Unexpected cell type-dependent effects of autophagy on polyglutamine aggregation revealed by natural genetic variation in C. elegans. BMC Biol 2020; 18:18. [PMID: 32093691 PMCID: PMC7038566 DOI: 10.1186/s12915-020-0750-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 02/13/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Monogenic protein aggregation diseases, in addition to cell selectivity, exhibit clinical variation in the age of onset and progression, driven in part by inter-individual genetic variation. While natural genetic variants may pinpoint plastic networks amenable to intervention, the mechanisms by which they impact individual susceptibility to proteotoxicity are still largely unknown. RESULTS We have previously shown that natural variation modifies polyglutamine (polyQ) aggregation phenotypes in C. elegans muscle cells. Here, we find that a genomic locus from C. elegans wild isolate DR1350 causes two genetically separable aggregation phenotypes, without changing the basal activity of muscle proteostasis pathways known to affect polyQ aggregation. We find that the increased aggregation phenotype was due to regulatory variants in the gene encoding a conserved autophagy protein ATG-5. The atg-5 gene itself conferred dosage-dependent enhancement of aggregation, with the DR1350-derived allele behaving as hypermorph. Surprisingly, increased aggregation in animals carrying the modifier locus was accompanied by enhanced autophagy activation in response to activating treatment. Because autophagy is expected to clear, not increase, protein aggregates, we activated autophagy in three different polyQ models and found a striking tissue-dependent effect: activation of autophagy decreased polyQ aggregation in neurons and intestine, but increased it in the muscle cells. CONCLUSIONS Our data show that cryptic natural variants in genes encoding proteostasis components, although not causing detectable phenotypes in wild-type individuals, can have profound effects on aggregation-prone proteins. Clinical applications of autophagy activators for aggregation diseases may need to consider the unexpected divergent effects of autophagy in different cell types.
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Affiliation(s)
- J Alexander-Floyd
- Biology Department, Drexel University, Philadelphia, PA, 19104, USA
- Present Address: Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - S Haroon
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - M Ying
- Biology Department, Drexel University, Philadelphia, PA, 19104, USA
| | - A A Entezari
- Biology Department, Drexel University, Philadelphia, PA, 19104, USA
- Current Address: Department of Pharmacology and Experimental Therapeutics, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - C Jaeger
- Biology Department, Drexel University, Philadelphia, PA, 19104, USA
- Current Address: Department of Neuroradiology, Technical University of Munich, Munich, Germany
| | - M Vermulst
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Current Address: Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, 90089, USA
| | - T Gidalevitz
- Biology Department, Drexel University, Philadelphia, PA, 19104, USA.
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79
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Coakley S, Ritchie FK, Galbraith KM, Hilliard MA. Epidermal control of axonal attachment via β-spectrin and the GTPase-activating protein TBC-10 prevents axonal degeneration. Nat Commun 2020; 11:133. [PMID: 31919407 PMCID: PMC6952388 DOI: 10.1038/s41467-019-13795-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 11/28/2019] [Indexed: 12/28/2022] Open
Abstract
Neurons are subjected to strain due to body movement and their location within organs and tissues. However, how they withstand these forces over the lifetime of an organism is still poorly understood. Here, focusing on touch receptor neuron-epidermis interactions using Caenorhabditis elegans as a model system, we show that UNC-70/β-spectrin and TBC-10, a conserved GTPase-activating protein, function non-cell-autonomously within the epidermis to dynamically maintain attachment of the axon. We reveal that, in response to strain, UNC-70/β-spectrin and TBC-10 stabilize trans-epidermal hemidesmosome attachment structures which otherwise become lost, causing axonal breakage and degeneration. Furthermore, we show that TBC-10 regulates axonal attachment and maintenance by inactivating RAB-35, and reveal functional conservation of these molecules with their vertebrate orthologs. Finally, we demonstrate that β-spectrin functions in this context non-cell-autonomously. We propose a model in which mechanically resistant epidermal attachment structures are maintained by UNC-70/β-spectrin and TBC-10 during movement, preventing axonal detachment and degeneration.
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Affiliation(s)
- Sean Coakley
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Fiona K Ritchie
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Kate M Galbraith
- 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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80
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Marques F, Saro G, Lia AS, Poole RJ, Falquet L, Glauser DA. Identification of avoidance genes through neural pathway-specific forward optogenetics. PLoS Genet 2019; 15:e1008509. [PMID: 31891575 PMCID: PMC6938339 DOI: 10.1371/journal.pgen.1008509] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 11/05/2019] [Indexed: 11/19/2022] Open
Abstract
Understanding how the nervous system bridges sensation and behavior requires the elucidation of complex neural and molecular networks. Forward genetic approaches, such as screens conducted in C. elegans, have successfully identified genes required to process natural sensory stimuli. However, functional redundancy within the underlying neural circuits, which are often organized with multiple parallel neural pathways, limits our ability to identify 'neural pathway-specific genes', i.e. genes that are essential for the function of some, but not all of these redundant neural pathways. To overcome this limitation, we developed a 'forward optogenetics' screening strategy in which natural stimuli are initially replaced by the selective optogenetic activation of a specific neural pathway. We used this strategy to address the function of the polymodal FLP nociceptors mediating avoidance of noxious thermal and mechanical stimuli. According to our expectations, we identified both mutations in 'general' avoidance genes that broadly impact avoidance responses to a variety of natural noxious stimuli (unc-4, unc-83, and eat-4) and mutations that produce a narrower impact, more restricted to the FLP pathway (syd-2, unc-14 and unc-68). Through a detailed follow-up analysis, we further showed that the Ryanodine receptor UNC-68 acts cell-autonomously in FLP to adjust heat-evoked calcium signals and aversive behaviors. As a whole, our work (i) reveals the importance of properly regulated ER calcium release for FLP function, (ii) provides new entry points for new nociception research and (iii) demonstrates the utility of our forward optogenetic strategy, which can easily be transposed to analyze other neural pathways.
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Affiliation(s)
- Filipe Marques
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Gabriella Saro
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Andrei-Stefan Lia
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Richard J. Poole
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Laurent Falquet
- Department of Biology, University of Fribourg, Fribourg, Switzerland
- Swiss Institute of Bioinformatics, Fribourg, Switzerland
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81
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A universal transportin protein drives stochastic choice of olfactory neurons via specific nuclear import of a sox-2-activating factor. Proc Natl Acad Sci U S A 2019; 116:25137-25146. [PMID: 31767767 DOI: 10.1073/pnas.1908168116] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Stochastic neuronal cell fate choice involving notch-independent mechanisms is a poorly understood biological process. The Caenorhabditis elegans AWC olfactory neuron pair asymmetrically differentiates into the default AWCOFF and induced AWCON subtypes in a stochastic manner. Stochastic choice of the AWCON subtype is established using gap junctions and SLO BK potassium channels to repress a calcium-activated protein kinase pathway. However, it is unknown how the potassium channel-repressed calcium signaling is translated into the induction of the AWCON subtype. Here, we identify a detailed working mechanism of how the homeodomain-like transcription factor NSY-7, previously described as a repressor in the maintenance of AWC asymmetry, couples SLO BK potassium channels to transactivation of sox-2 expression for the induction of the AWCON subtype through the identification of a unique imb-2 (transportin 1) allele. imb-2 loss-of-function mutants are not viable; however, we identify a viable imb-2 allele from an unbiased forward genetic screen that reveals a specific role of imb-2 in AWC olfactory neuron asymmetry. IMB-2 specifically drives nuclear import of NSY-7 within AWC neurons to transactivate the expression of the high mobility group (HMG)-box transcription factor SOX-2 for the specification of the AWCON subtype. This study provides mechanistic insight into how NSY-7 couples SLO BK potassium channels to transactivation of sox-2 expression for the induction of the AWCON subtype. Our findings also provide structure-function insight into a conserved amino acid residue of transportins in brain development and suggest its dysfunction may lead to human neurological disorders.
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82
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Klingseisen A, Ristoiu AM, Kegel L, Sherman DL, Rubio-Brotons M, Almeida RG, Koudelka S, Benito-Kwiecinski SK, Poole RJ, Brophy PJ, Lyons DA. Oligodendrocyte Neurofascin Independently Regulates Both Myelin Targeting and Sheath Growth in the CNS. Dev Cell 2019; 51:730-744.e6. [PMID: 31761670 PMCID: PMC6912162 DOI: 10.1016/j.devcel.2019.10.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 09/10/2019] [Accepted: 10/17/2019] [Indexed: 01/06/2023]
Abstract
Selection of the correct targets for myelination and regulation of myelin sheath growth are essential for central nervous system (CNS) formation and function. Through a genetic screen in zebrafish and complementary analyses in mice, we find that loss of oligodendrocyte Neurofascin leads to mistargeting of myelin to cell bodies, without affecting targeting to axons. In addition, loss of Neurofascin reduces CNS myelination by impairing myelin sheath growth. Time-lapse imaging reveals that the distinct myelinating processes of individual oligodendrocytes can engage in target selection and sheath growth at the same time and that Neurofascin concomitantly regulates targeting and growth. Disruption to Caspr, the neuronal binding partner of oligodendrocyte Neurofascin, also impairs myelin sheath growth, likely reflecting its association in an adhesion complex at the axon-glial interface with Neurofascin. Caspr does not, however, affect myelin targeting, further indicating that Neurofascin independently regulates distinct aspects of CNS myelination by individual oligodendrocytes in vivo. Single oligodendrocytes coordinate myelin targeting and growth at the same time Oligodendrocyte Neurofascin prevents myelination of cell bodies Oligodendrocyte Neurofascin promotes myelin sheath growth The neuronal binding partner of Neurofascin, Caspr, promotes myelin sheath growth
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Affiliation(s)
- Anna Klingseisen
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Ana-Maria Ristoiu
- 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
| | - Diane L Sherman
- 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
| | - Rafael G Almeida
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Sigrid Koudelka
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | | | - Richard J Poole
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK
| | - Peter J Brophy
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - David A Lyons
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK.
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83
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Beets I, Zhang G, Fenk LA, Chen C, Nelson GM, Félix MA, de Bono M. Natural Variation in a Dendritic Scaffold Protein Remodels Experience-Dependent Plasticity by Altering Neuropeptide Expression. Neuron 2019; 105:106-121.e10. [PMID: 31757604 PMCID: PMC6953435 DOI: 10.1016/j.neuron.2019.10.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Revised: 08/18/2019] [Accepted: 09/28/2019] [Indexed: 12/13/2022]
Abstract
The extent to which behavior is shaped by experience varies between individuals. Genetic differences contribute to this variation, but the neural mechanisms are not understood. Here, we dissect natural variation in the behavioral flexibility of two Caenorhabditis elegans wild strains. In one strain, a memory of exposure to 21% O2 suppresses CO2-evoked locomotory arousal; in the other, CO2 evokes arousal regardless of previous O2 experience. We map that variation to a polymorphic dendritic scaffold protein, ARCP-1, expressed in sensory neurons. ARCP-1 binds the Ca2+-dependent phosphodiesterase PDE-1 and co-localizes PDE-1 with molecular sensors for CO2 at dendritic ends. Reducing ARCP-1 or PDE-1 activity promotes CO2 escape by altering neuropeptide expression in the BAG CO2 sensors. Variation in ARCP-1 alters behavioral plasticity in multiple paradigms. Our findings are reminiscent of genetic accommodation, an evolutionary process by which phenotypic flexibility in response to environmental variation is reset by genetic change. Behavioral flexibility varies across Caenorhabditis and C. elegans wild isolates A natural polymorphism in ARCP-1 underpins inter-individual variation in plasticity ARCP-1 is a dendritic scaffold protein localizing cGMP signaling machinery to cilia Disrupting ARCP-1 alters behavioral plasticity by changing neuropeptide expression
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Affiliation(s)
- Isabel Beets
- Cell Biology Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Gaotian Zhang
- Institut de Biologie de l'École Normale Supérieure, CNRS, Inserm, PSL Research University, Paris 75005, France
| | - Lorenz A Fenk
- Cell Biology Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Changchun Chen
- Cell Biology Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Geoffrey M Nelson
- Cell Biology Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Marie-Anne Félix
- Institut de Biologie de l'École Normale Supérieure, CNRS, Inserm, PSL Research University, Paris 75005, France.
| | - Mario de Bono
- Cell Biology Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK.
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84
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Zhao Y, Wang H, Poole RJ, Gems D. A fln-2 mutation affects lethal pathology and lifespan in C. elegans. Nat Commun 2019; 10:5087. [PMID: 31704915 PMCID: PMC6841690 DOI: 10.1038/s41467-019-13062-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 10/15/2019] [Indexed: 12/12/2022] Open
Abstract
Differences in genetic background in model organisms can have complex effects on phenotypes of interest. We previously reported a difference in hermaphrodite lifespan between two wild-type lines widely used by C. elegans researchers (N2 hermaphrodite and male stocks). Here, using pathology-based approaches and genome sequencing, we identify the cause of this difference as a nonsense mutation in the filamin gene fln-2 in the male stock, which reduces early mortality caused by pharyngeal infection. We show how fln-2 variation explains previous discrepancies involving effects of sir-2.1 (sirtuin deacetylase) on ageing, and show that in a fln-2(+) background, sir-2.1 over-expression causes an FUDR (DNA synthesis inhibitor)-dependent reduction in pharyngeal infection and increase in lifespan. In addition we show how fln-2 variation confounds effects on lifespan of daf-2 (insulin/IGF-1 signalling), daf-12 (steroid hormone signalling), and eat-2 (putative dietary restriction). These findings underscore the importance of identifying and controlling genetic background variation.
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Affiliation(s)
- Yuan Zhao
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, London, WC1E 6BT, UK
| | - Hongyuan Wang
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, London, WC1E 6BT, UK
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, China
| | - Richard J Poole
- Department of Cell and Developmental Biology, University College London, London, WC1E 6BT, UK
| | - David Gems
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, London, WC1E 6BT, UK.
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85
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Ravikumar S, Devanapally S, Jose AM. Gene silencing by double-stranded RNA from C. elegans neurons reveals functional mosaicism of RNA interference. Nucleic Acids Res 2019; 47:10059-10071. [PMID: 31501873 PMCID: PMC6821342 DOI: 10.1093/nar/gkz748] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 08/12/2019] [Accepted: 08/20/2019] [Indexed: 12/12/2022] Open
Abstract
Delivery of double-stranded RNA (dsRNA) into animals can silence genes of matching sequence in diverse cell types through mechanisms that have been collectively called RNA interference. In the nematode Caenorhabditis elegans, dsRNA from multiple sources can trigger the amplification of silencing signals. Amplification occurs through the production of small RNAs by two RNA-dependent RNA polymerases (RdRPs) that are thought to be tissue-specific - EGO-1 in the germline and RRF-1 in somatic cells. Here we demonstrate that EGO-1 can compensate for the lack of RRF-1 when dsRNA from neurons is used to silence genes in intestinal cells. However, the lineal origins of cells that can use EGO-1 varies. This variability could be because random sets of cells can either receive different amounts of dsRNA from the same source or use different RdRPs to perform the same function. Variability is masked in wild-type animals, which show extensive silencing by neuronal dsRNA. As a result, cells appear similarly functional despite underlying differences that vary from animal to animal. This functional mosaicism cautions against inferring uniformity of mechanism based on uniformity of outcome. We speculate that functional mosaicism could contribute to escape from targeted therapies and could allow developmental systems to drift over evolutionary time.
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Affiliation(s)
- Snusha Ravikumar
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Sindhuja Devanapally
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Antony M Jose
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
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86
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Minevich G, Bernstein A, Mei K, Poole R, Hobert O. Nibbling 405 kb off the X: Viable deletion alleles eliminating 50 protein coding genes, including a chromatin factor involved in neuronal development. MICROPUBLICATION BIOLOGY 2019; 2019. [PMID: 32550431 PMCID: PMC7252304 DOI: 10.17912/micropub.biology.000187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Gregory Minevich
- Department of Biochemistiry and Molecular Biophysics, Columbia University
| | - Alex Bernstein
- Department of Biochemistiry and Molecular Biophysics, Columbia University
| | - Kevin Mei
- Department of Biochemistiry and Molecular Biophysics, Columbia University
| | - Richard Poole
- Department of Biochemistiry and Molecular Biophysics, Columbia University.,present address: Department of Cell and Developmental Biology, University College London
| | - Oliver Hobert
- Department of Biochemistiry and Molecular Biophysics, Columbia University.,Department of Biological Sciences, HHMI, Columbia University
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87
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Horsman JW, Heinis FI, Miller DL. A Novel Mechanism To Prevent H 2S Toxicity in Caenorhabditis elegans. Genetics 2019; 213:481-490. [PMID: 31371406 PMCID: PMC6781907 DOI: 10.1534/genetics.119.302326] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 07/24/2019] [Indexed: 11/18/2022] Open
Abstract
Hydrogen sulfide (H2S) is an endogenously produced signaling molecule that can be cytoprotective, especially in conditions of ischemia/reperfusion injury. However, H2S is also toxic, and unregulated accumulation or exposure to environmental H2S can be lethal. In Caenorhabditis elegans, the hypoxia inducible factor (hif-1) coordinates the initial transcriptional response to H2S, and is essential to survive exposure to low concentrations of H2S. We performed a forward genetic screen to identify mutations that suppress the lethality of hif-1 mutant animals in H2S. The mutations we recovered are specific for H2S, as they do not suppress embryonic lethality or reproductive arrest of hif-1 mutant animals in hypoxia, nor can they prevent the death of hif-1 mutant animals exposed to hydrogen cyanide. The majority of hif-1 suppressor mutations we recovered activate the skn-1/Nrf2 transcription factor. Activation of SKN-1 by hif-1 suppressor mutations increased the expression of a subset of H2S-responsive genes, consistent with previous findings that skn-1 plays a role in the transcriptional response to H2S. Using transgenic rescue, we show that overexpression of a single gene, rhy-1, is sufficient to protect hif-1 mutant animals in H2S. The rhy-1 gene encodes a predicated O-acyltransferase enzyme that has previously been shown to negatively regulate HIF-1 activity. Our data indicate that RHY-1 has novel, hif-1 independent, function that promotes survival in H2S.
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Affiliation(s)
- Joseph W Horsman
- Department of Biochemistry, University of Washington School of Medicine, Seattle, Washington 98195
| | - Frazer I Heinis
- Department of Biochemistry, University of Washington School of Medicine, Seattle, Washington 98195
| | - Dana L Miller
- Department of Biochemistry, University of Washington School of Medicine, Seattle, Washington 98195
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88
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Rajan M, Anderson CP, Rindler PM, Romney SJ, Ferreira dos Santos MC, Gertz J, Leibold EA. NHR-14 loss of function couples intestinal iron uptake with innate immunity in C. elegans through PQM-1 signaling. eLife 2019; 8:e44674. [PMID: 31532389 PMCID: PMC6777940 DOI: 10.7554/elife.44674] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 09/17/2019] [Indexed: 02/06/2023] Open
Abstract
Iron is essential for survival of most organisms. All organisms have thus developed mechanisms to sense, acquire and sequester iron. In C. elegans, iron uptake and sequestration are regulated by HIF-1. We previously showed that hif-1 mutants are developmentally delayed when grown under iron limitation. Here we identify nhr-14, encoding a nuclear receptor, in a screen conducted for mutations that rescue the developmental delay of hif-1 mutants under iron limitation. nhr-14 loss upregulates the intestinal metal transporter SMF-3 to increase iron uptake in hif-1 mutants. nhr-14 mutants display increased expression of innate immune genes and DAF-16/FoxO-Class II genes, and enhanced resistance to Pseudomonas aeruginosa. These responses are dependent on the transcription factor PQM-1, which localizes to intestinal cell nuclei in nhr-14 mutants. Our data reveal how C. elegans utilizes nuclear receptors to regulate innate immunity and iron availability, and show iron sequestration as a component of the innate immune response.
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Affiliation(s)
- Malini Rajan
- Department of Medicine, Division of HematologyUniversity of UtahSalt Lake CityUnited States
- Molecular Medicine ProgramUniversity of UtahSalt Lake CityUnited States
| | - Cole P Anderson
- Molecular Medicine ProgramUniversity of UtahSalt Lake CityUnited States
- Department of Oncological SciencesUniversity of UtahSalt Lake CityUnited States
| | - Paul M Rindler
- Department of Medicine, Division of HematologyUniversity of UtahSalt Lake CityUnited States
- Molecular Medicine ProgramUniversity of UtahSalt Lake CityUnited States
| | - Steven Joshua Romney
- Department of Medicine, Division of HematologyUniversity of UtahSalt Lake CityUnited States
- Molecular Medicine ProgramUniversity of UtahSalt Lake CityUnited States
| | - Maria C Ferreira dos Santos
- Department of Medicine, Division of HematologyUniversity of UtahSalt Lake CityUnited States
- Molecular Medicine ProgramUniversity of UtahSalt Lake CityUnited States
| | - Jason Gertz
- Department of Oncological SciencesUniversity of UtahSalt Lake CityUnited States
- Huntsman Cancer InstituteUniversity of UtahSalt Lake CityUnited States
| | - Elizabeth A Leibold
- Department of Medicine, Division of HematologyUniversity of UtahSalt Lake CityUnited States
- Molecular Medicine ProgramUniversity of UtahSalt Lake CityUnited States
- Department of Oncological SciencesUniversity of UtahSalt Lake CityUnited States
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89
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Reduction of mRNA export unmasks different tissue sensitivities to low mRNA levels during Caenorhabditis elegans development. PLoS Genet 2019; 15:e1008338. [PMID: 31525188 PMCID: PMC6762213 DOI: 10.1371/journal.pgen.1008338] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Revised: 09/26/2019] [Accepted: 07/31/2019] [Indexed: 12/25/2022] Open
Abstract
Animal development requires the execution of specific transcriptional programs in different sets of cells to build tissues and functional organs. Transcripts are exported from the nucleus to the cytoplasm where they are translated into proteins that, ultimately, carry out the cellular functions. Here we show that in Caenorhabditis elegans, reduction of mRNA export strongly affects epithelial morphogenesis and germline proliferation while other tissues remain relatively unaffected. Epithelialization and gamete formation demand a large number of transcripts in the cytoplasm for the duration of these processes. In addition, our findings highlight the existence of a regulatory feedback mechanism that activates gene expression in response to low levels of cytoplasmic mRNA. We expand the genetic characterization of nuclear export factor NXF-1 to other members of the mRNA export pathway to model mRNA export and recycling of NXF-1 back to the nucleus. Our model explains how mutations in genes involved in general processes, such as mRNA export, may result in tissue-specific developmental phenotypes. The Central Dogma of Biology schematically highlights the transmission of genetic information stored in DNA, through RNA, to the formation of proteins. This general flow implicates RNA export from the nucleus to the cytoplasm and proper protein localization within the eukaryotic cell. Ultimately, proteins are the cell’s structural and catalytic functional units. As a result, cells differentiate into one cell type or another (such as epithelial, muscle, neuron…) and exhibit specific shape and functionality. Here we describe, in a C. elegans model, how mutations in genes involved in a general and ubiquitous mechanism, such as mRNA export, may result in tissue-specific developmental phenotypes that show up in processes that are highly demanding of cytoplasmic transcripts like epithelialization and gamete formation. A deep understanding of the mechanisms underlying the "connectors" shown in the Central Dogma of Biology is key both to unravel the general genetic control of an organism’s development and, at the same time, contribute to a better understanding of tissue-specific diseases.
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90
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Gong J, Liu J, Ronan EA, He F, Cai W, Fatima M, Zhang W, Lee H, Li Z, Kim GH, Pipe KP, Duan B, Liu J, Xu XZS. A Cold-Sensing Receptor Encoded by a Glutamate Receptor Gene. Cell 2019; 178:1375-1386.e11. [PMID: 31474366 DOI: 10.1016/j.cell.2019.07.034] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 05/31/2019] [Accepted: 07/17/2019] [Indexed: 12/11/2022]
Abstract
In search of the molecular identities of cold-sensing receptors, we carried out an unbiased genetic screen for cold-sensing mutants in C. elegans and isolated a mutant allele of glr-3 gene that encodes a kainate-type glutamate receptor. While glutamate receptors are best known to transmit chemical synaptic signals in the CNS, we show that GLR-3 senses cold in the peripheral sensory neuron ASER to trigger cold-avoidance behavior. GLR-3 transmits cold signals via G protein signaling independently of its glutamate-gated channel function, suggesting GLR-3 as a metabotropic cold receptor. The vertebrate GLR-3 homolog GluK2 from zebrafish, mouse, and human can all function as a cold receptor in heterologous systems. Mouse DRG sensory neurons express GluK2, and GluK2 knockdown in these neurons suppresses their sensitivity to cold but not cool temperatures. Our study identifies an evolutionarily conserved cold receptor, revealing that a central chemical receptor unexpectedly functions as a thermal receptor in the periphery.
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Affiliation(s)
- Jianke Gong
- College of Life Science and Technology, Key Laboratory of Molecular Biophysics of MOE, and International Research Center for Sensory Biology and Technology of MOST, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China; Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA; Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jinzhi Liu
- College of Life Science and Technology, Key Laboratory of Molecular Biophysics of MOE, and International Research Center for Sensory Biology and Technology of MOST, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China; Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA; Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Elizabeth A Ronan
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA; Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Feiteng He
- College of Life Science and Technology, Key Laboratory of Molecular Biophysics of MOE, and International Research Center for Sensory Biology and Technology of MOST, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China; Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA; Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Wei Cai
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA; Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Mahar Fatima
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Wenyuan Zhang
- College of Life Science and Technology, Key Laboratory of Molecular Biophysics of MOE, and International Research Center for Sensory Biology and Technology of MOST, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China; Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA; Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Hankyu Lee
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Zhaoyu Li
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA; Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Gun-Ho Kim
- Department of Mechanical Engineering, Ulsan National Institute of Science and Technology, 50 UNIST-gil, South Korea
| | - Kevin P Pipe
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA; Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI 48109, USA
| | - Bo Duan
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jianfeng Liu
- College of Life Science and Technology, Key Laboratory of Molecular Biophysics of MOE, and International Research Center for Sensory Biology and Technology of MOST, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China.
| | - X Z Shawn Xu
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA; Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA.
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91
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Wang D, Stoveken HM, Zucca S, Dao M, Orlandi C, Song C, Masuho I, Johnston C, Opperman KJ, Giles AC, Gill MS, Lundquist EA, Grill B, Martemyanov KA. Genetic behavioral screen identifies an orphan anti-opioid system. Science 2019; 365:1267-1273. [PMID: 31416932 DOI: 10.1126/science.aau2078] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 02/22/2019] [Accepted: 08/05/2019] [Indexed: 12/12/2022]
Abstract
Opioids target the μ-opioid receptor (MOR) to produce unrivaled pain management, but their addictive properties can lead to severe abuse. We developed a whole-animal behavioral platform for unbiased discovery of genes influencing opioid responsiveness. Using forward genetics in Caenorhabditis elegans, we identified a conserved orphan receptor, GPR139, with anti-opioid activity. GPR139 is coexpressed with MOR in opioid-sensitive brain circuits, binds to MOR, and inhibits signaling to heterotrimeric guanine nucleotide-binding proteins (G proteins). Deletion of GPR139 in mice enhanced opioid-induced inhibition of neuronal firing to modulate morphine-induced analgesia, reward, and withdrawal. Thus, GPR139 could be a useful target for increasing opioid safety. These results also demonstrate the potential of C. elegans as a scalable platform for genetic discovery of G protein-coupled receptor signaling principles.
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Affiliation(s)
- Dandan Wang
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Hannah M Stoveken
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Stefano Zucca
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Maria Dao
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Cesare Orlandi
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Chenghui Song
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Ikuo Masuho
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Caitlin Johnston
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Karla J Opperman
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Andrew C Giles
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Matthew S Gill
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Erik A Lundquist
- Department of Molecular Biosciences, The University of Kansas, Lawrence, KS 66045, USA
| | - Brock Grill
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA.
| | - Kirill A Martemyanov
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA.
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92
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Forward Genetic Screen for Caenorhabditis elegans Mutants with a Shortened Locomotor Healthspan. G3-GENES GENOMES GENETICS 2019; 9:2415-2423. [PMID: 31213517 PMCID: PMC6686916 DOI: 10.1534/g3.119.400241] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Two people with the same lifespan do not necessarily have the same healthspan. One person may retain locomotor and cognitive abilities until the end of life, while another person may lose them during adulthood. Unbiased searches for genes that are required to maintain locomotor ability during adulthood may uncover key regulators of locomotor healthspan. Here, we take advantage of the relatively short lifespan of the nematode Caenorhabditis elegans and develop a novel screening procedure to collect mutants with locomotor deficits that become apparent in adulthood. After ethyl methanesulfonate mutagenesis, we isolated five C. elegans mutant strains that progressively lose adult locomotor ability. In one of the mutant strains, a nonsense mutation in elpc-2, which encodes Elongator Complex Protein Component 2, causes a progressive decline in locomotor ability during adulthood. Mutants and mutations identified in the present screen may provide insights into mechanisms of age-related locomotor impairment and the maintenance of locomotor healthspan.
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93
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Thompson M, Bixby R, Dalton R, Vandenburg A, Calarco JA, Norris AD. Splicing in a single neuron is coordinately controlled by RNA binding proteins and transcription factors. eLife 2019; 8:46726. [PMID: 31322498 PMCID: PMC6641836 DOI: 10.7554/elife.46726] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 06/20/2019] [Indexed: 12/22/2022] Open
Abstract
Single-cell transcriptomes are established by transcription factors (TFs), which determine a cell's gene-expression complement. Post-transcriptional regulation of single-cell transcriptomes, and the RNA binding proteins (RBPs) responsible, are more technically challenging to determine, and combinatorial TF-RBP coordination of single-cell transcriptomes remains unexplored. We used fluorescent reporters to visualize alternative splicing in single Caenorhabditis elegans neurons, identifying complex splicing patterns in the neuronal kinase sad-1. Most neurons express both isoforms, but the ALM mechanosensory neuron expresses only the exon-included isoform, while its developmental sister cell the BDU neuron expresses only the exon-skipped isoform. A cascade of three cell-specific TFs and two RBPs are combinatorially required for sad-1 exon inclusion. Mechanistically, TFs combinatorially ensure expression of RBPs, which interact with sad-1 pre-mRNA. Thus a combinatorial TF-RBP code controls single-neuron sad-1 splicing. Additionally, we find ‘phenotypic convergence,’ previously observed for TFs, also applies to RBPs: different RBP combinations generate similar splicing outcomes in different neurons. All the cells in the human nervous system contain the same genetic information, and yet there are many kinds of neurons, each with different features and roles in the body. Proteins known as transcription factors help to establish this diversity by switching on different genes in different types of cells. A mechanism known as RNA splicing, which is regulated by RNA binding proteins, can also provide another layer of regulation. When a gene is switched on, a faithful copy of its sequence is produced in the form of an RNA molecule, which will then be ‘read’ to create a protein. However, the RNA molecules may first be processed to create templates that can differ between cell types: this means that a single gene can code for slightly different proteins, some of them specific to a given cell type. Yet, very little is known about how RNA splicing can generate more diversity in the nervous system. To investigate, Thompson et al. developed a fluorescent reporter system that helped them track how the RNA of a gene called sad-1 is spliced in individual neurons of the worm Caenorhabditis elegans. This showed that sad-1 was turned on in all neurons, but the particular spliced versions varied widely between different types of nerve cells. Additional experiments combined old school and cutting-edge genetics technics such as CRISPR/Cas9 to identify the proteins that control the splicing of sad-1 in different kinds of neurons. Despite not directly participating in RNA splicing, a number of transcription factors were shown to be involved. These molecular switches were turning on genes that code for RNA binding proteins differently between types of neurons, which in turn led sad-1 to be spliced according to neuron-specific patterns. The findings by Thompson et al. could provide some insight into how mammals can establish many types of neurons; however, a technical hurdle stands in the way of this line of research, as it is still difficult to detect splicing in single neurons in these species.
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Affiliation(s)
- Morgan Thompson
- Biological Sciences, Southern Methodist University, Dallas, United States
| | - Ryan Bixby
- Biological Sciences, Southern Methodist University, Dallas, United States
| | - Robert Dalton
- Biological Sciences, Southern Methodist University, Dallas, United States
| | - Alexa Vandenburg
- Biological Sciences, Southern Methodist University, Dallas, United States
| | - John A Calarco
- Cell & Systems Biology, University of Toronto, Toronto, Canada
| | - Adam D Norris
- Biological Sciences, Southern Methodist University, Dallas, United States
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94
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Van Sciver N, Pulkowski J, Politz S. Three C. elegans srf-6 mutants carry nsy-1 mutations ( srf-6 is nsy-1 I). MICROPUBLICATION BIOLOGY 2019; 2019. [PMID: 32550407 PMCID: PMC7252240 DOI: 10.17912/micropub.biology.000127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Affiliation(s)
- Nicholas Van Sciver
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA.,Present address: McArdle Laboratory for Cancer Research, University of Wisconsin, Madison, WI
| | - Jennifer Pulkowski
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA
| | - Samuel Politz
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA
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95
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Ipson BR, Green RA, Wilson JT, Watson JN, Faull KF, Fisher AL. Tyrosine aminotransferase is involved in the oxidative stress response by metabolizing meta-tyrosine in Caenorhabditis elegans. J Biol Chem 2019; 294:9536-9554. [PMID: 31043480 PMCID: PMC6579467 DOI: 10.1074/jbc.ra118.004426] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 04/24/2019] [Indexed: 12/11/2022] Open
Abstract
Under oxidative stress conditions, hydroxyl radicals can oxidize the phenyl ring of phenylalanine, producing the abnormal tyrosine isomer meta-tyrosine (m-tyrosine). m-Tyrosine levels are commonly used as a biomarker of oxidative stress, and its accumulation has recently been reported to adversely affect cells, suggesting a direct role for m-tyrosine in oxidative stress effects. We found that the Caenorhabditis elegans ortholog of tyrosine aminotransferase (TATN-1)-the first enzyme involved in the metabolic degradation of tyrosine-is up-regulated in response to oxidative stress and directly activated by the oxidative stress-responsive transcription factor SKN-1. Worms deficient in tyrosine aminotransferase activity displayed increased sensitivity to multiple sources of oxidative stress. Biochemical assays revealed that m-tyrosine is a substrate for TATN-1-mediated deamination, suggesting that TATN-1 also metabolizes m-tyrosine. Consistent with a toxic effect of m-tyrosine and a protective function of TATN-1, tatn-1 mutant worms exhibited delayed development, marked reduction in fertility, and shortened lifespan when exposed to m-tyrosine. A forward genetic screen identified a mutation in the previously uncharacterized gene F01D4.5-homologous with human transcription factor 20 (TCF20) and retinoic acid-induced 1 (RAI1)-that suppresses the adverse phenotypes observed in m-tyrosine-treated tatn-1 mutant worms. RNA-Seq analysis of F01D4.5 mutant worms disclosed a significant reduction in the expression of specific isoforms of genes encoding ribosomal proteins, suggesting that alterations in protein synthesis or ribosome structure could diminish the adverse effects of m-tyrosine. Our findings uncover a critical role for tyrosine aminotransferase in the oxidative stress response via m-tyrosine metabolism.
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Affiliation(s)
- Brett R Ipson
- From the Department of Cell Systems and Anatomy
- the Center for Healthy Aging, and
| | - Rebecca A Green
- the Ludwig Institute for Cancer Research, San Diego, La Jolla, California 92093
| | | | | | - Kym F Faull
- the Pasarow Mass Spectrometry Laboratory, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, UCLA, Los Angeles, California 90095, and
| | - Alfred L Fisher
- the Center for Healthy Aging, and
- the Division of Geriatrics, Gerontology, and Palliative Medicine, Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
- Geriatric Research, Education and Clinical Center (GRECC), South Texas Veterans Affairs Healthcare System, San Antonio, Texas 78229
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96
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Regulation of Caenorhabditis elegans neuronal polarity by heterochronic genes. Proc Natl Acad Sci U S A 2019; 116:12327-12336. [PMID: 31164416 DOI: 10.1073/pnas.1820928116] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Many neurons display characteristic patterns of synaptic connections that are under genetic control. The Caenorhabditis elegans DA cholinergic motor neurons form synaptic connections only on their dorsal axons. We explored the genetic pathways that specify this polarity by screening for gene inactivations and mutations that disrupt this normal polarity of a DA motorneuron. A RAB-3::GFP fusion protein that is normally localized to presynaptic terminals along the dorsal axon of the DA9 motorneuron was used to screen for gene inactivations that disrupt the DA9 motorneuron polarity. This screen identified heterochronic genes as major regulators of DA neuron presynaptic polarity. In many heterochronic mutants, presynapses of this cholinergic motoneuron are mislocalized to the dendrite at the ventral side: inactivation of the blmp-1 transcription factor gene, the lin-29/Zn finger transcription factor, lin-28/RNA binding protein, and the let-7miRNA gene all disrupt the presynaptic polarity of this DA cholinergic neuron. We also show that the dre-1/F box heterochronic gene functions early in development to control maintenance of polarity at later stages, and that a mutation in the let-7 heterochronic miRNA gene causes dendritic misplacement of RAB-3 presynaptic markers that colocalize with muscle postsynaptic terminals ectopically. We propose that heterochronic genes are components in the UNC-6/Netrin pathway of synaptic polarity of these neurons. These findings highlight the role of heterochronic genes in postmitotic neuronal patterning events.
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97
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Javorka P, Raxwal VK, Najvarek J, Riha K. artMAP: A user-friendly tool for mapping ethyl methanesulfonate-induced mutations in Arabidopsis. PLANT DIRECT 2019; 3:e00146. [PMID: 31245783 PMCID: PMC6560221 DOI: 10.1002/pld3.146] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 05/14/2019] [Accepted: 05/14/2019] [Indexed: 05/27/2023]
Abstract
Mapping-by-sequencing is a rapid method for identifying both natural as well as induced variations in the genome. However, it requires extensive bioinformatics expertise along with the computational infrastructure to analyze the sequencing data and these requirements have limited its widespread adoption. In the current study, we develop an easy to use tool, artMAP, to discover ethyl methanesulfonate (EMS) induced mutations in the Arabidopsis genome. The artMAP pipeline consists of well-established tools including TrimGalore, BWA, BEDTools, SAMtools, and SnpEff which were integrated in a Docker container. artMAP provides a graphical user interface and can be run on a regular laptop and desktop, thereby limiting the bioinformatics expertise required. artMAP can process input sequencing files generated from single or paired-end sequencing. The results of the analysis are presented in interactive graphs which display the annotation details of each mutation. Due to its ease of use, artMAP makes the identification of EMS-induced mutations in Arabidopsis possible with only a few mouse click. The source code of artMAP is available on Github (https://github.com/RihaLab/artMAP).
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Affiliation(s)
| | | | | | - Karel Riha
- CEITECMasaryk UniversityBrnoCzech Republic
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98
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Lehrbach NJ, Ruvkun G. Endoplasmic reticulum-associated SKN-1A/Nrf1 mediates a cytoplasmic unfolded protein response and promotes longevity. eLife 2019; 8:44425. [PMID: 30973820 PMCID: PMC6459674 DOI: 10.7554/elife.44425] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 03/29/2019] [Indexed: 01/21/2023] Open
Abstract
Unfolded protein responses (UPRs) safeguard cellular function during proteotoxic stress and aging. In a previous paper (Lehrbach and Ruvkun, 2016) we showed that the ER-associated SKN-1A/Nrf1 transcription factor activates proteasome subunit expression in response to proteasome dysfunction, but it was not established whether SKN-1A/Nrf1 adjusts proteasome capacity in response to other proteotoxic insults. Here, we reveal that misfolded endogenous proteins and the human amyloid beta peptide trigger activation of proteasome subunit expression by SKN-1A/Nrf1. SKN-1A activation is protective against age-dependent defects caused by accumulation of misfolded and aggregation-prone proteins. In a C. elegans Alzheimer’s disease model, SKN-1A/Nrf1 slows accumulation of the amyloid beta peptide and delays adult-onset cellular dysfunction. Our results indicate that SKN-1A surveys cellular protein folding and adjusts proteasome capacity to meet the demands of protein quality control pathways, revealing a new arm of the cytosolic UPR. This regulatory axis is critical for healthy aging and may be a target for therapeutic modulation of human aging and age-related disease.
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Affiliation(s)
- Nicolas J Lehrbach
- Department of Molecular Biology, Massachusetts General Hospital, Boston, United States.,Department of Genetics, Harvard Medical School, Boston, United States
| | - Gary Ruvkun
- Department of Molecular Biology, Massachusetts General Hospital, Boston, United States.,Department of Genetics, Harvard Medical School, Boston, United States
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99
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Molybdenum cofactor transfer from bacteria to nematode mediates sulfite detoxification. Nat Chem Biol 2019; 15:480-488. [PMID: 30911177 PMCID: PMC6470025 DOI: 10.1038/s41589-019-0249-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 02/14/2019] [Indexed: 11/26/2022]
Abstract
The kingdoms of life share many small molecule cofactors and coenzymes. Molybdenum cofactor (Moco) is synthesized by many archaea, bacteria, and eukaryotes, and is essential for human viability. The genome of the animal Caenorhabditis elegans contains all of the Moco biosynthesis genes, and surprisingly these genes are not essential if animals are fed a bacterial diet that synthesizes Moco. C. elegans lacking both endogenous Moco synthesis and dietary Moco from bacteria arrest development, demonstrating interkingdom Moco transfer. Our screen of E. coli mutants identified genes necessary for synthesis of bacterial Moco or transfer to C. elegans. Moco-deficient C. elegans developmental arrest is caused by loss of sulfite oxidase, a Moco-requiring enzyme, and is suppressed by mutations in either C. elegans cystathionine gamma-lyase or cysteine dioxygenase, blocking toxic sulfite production from cystathionine. Thus, we define the genetic pathways for an interkingdom dialogue focused on sulfur homeostasis.
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100
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Hill SE, Kauffman KJ, Krout M, Richmond JE, Melia TJ, Colón-Ramos DA. Maturation and Clearance of Autophagosomes in Neurons Depends on a Specific Cysteine Protease Isoform, ATG-4.2. Dev Cell 2019; 49:251-266.e8. [PMID: 30880001 DOI: 10.1016/j.devcel.2019.02.013] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Revised: 12/17/2018] [Accepted: 02/12/2019] [Indexed: 12/31/2022]
Abstract
In neurons, defects in autophagosome clearance have been associated with neurodegenerative disease. Yet, the mechanisms that coordinate trafficking and clearance of synaptic autophagosomes are poorly understood. Here, we use genetic screens and in vivo imaging in single neurons of C. elegans to identify mechanisms necessary for clearance of synaptic autophagosomes. We observed that autophagy at the synapse can be modulated in vivo by the state of neuronal activity, that autophagosomes undergo UNC-16/JIP3-mediated retrograde transport, and that autophagosomes containing synaptic material mature in the cell body. Through forward genetic screens, we then determined that autophagosome maturation in the cell body depends on the protease ATG-4.2, but not the related ATG-4.1, and that ATG-4.2 can cleave LGG-1/Atg8/GABARAP from membranes. Our studies revealed that ATG-4.2 is specifically necessary for the maturation and clearance of autophagosomes and that defects in transport and ATG-4.2-mediated maturation genetically interact to enhance abnormal accumulation of autophagosomes in neurons.
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Affiliation(s)
- Sarah E Hill
- Department of Neuroscience, Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT 06510, USA; Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Karlina J Kauffman
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Mia Krout
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Janet E Richmond
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Thomas J Melia
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Daniel A Colón-Ramos
- Department of Neuroscience, Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT 06510, USA; Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06510, USA; Instituto de Neurobiología, Recinto de Ciencias Médicas, Universidad de Puerto Rico, 201 Blvd del Valle, San Juan 00901, Puerto Rico.
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