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1.
Nat Commun ; 11(1): 4627, 2020 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-33009389

RESUMO

Animals have evolved responses to low oxygen conditions to ensure their survival. Here, we have identified the C. elegans zinc finger transcription factor PQM-1 as a regulator of the hypoxic stress response. PQM-1 is required for the longevity of insulin signaling mutants, but surprisingly, loss of PQM-1 increases survival under hypoxic conditions. PQM-1 functions as a metabolic regulator by controlling oxygen consumption rates, suppressing hypoxic glycogen levels, and inhibiting the expression of the sorbitol dehydrogenase-1 SODH-1, a crucial sugar metabolism enzyme. PQM-1 promotes hypoxic fat metabolism by maintaining the expression of the stearoyl-CoA desaturase FAT-7, an oxygen consuming, rate-limiting enzyme in fatty acid biosynthesis. PQM-1 activity positively regulates fat transport to developing oocytes through vitellogenins under hypoxic conditions, thereby increasing survival rates of arrested progeny during hypoxia. Thus, while pqm-1 mutants increase survival of mothers, ultimately this loss is detrimental to progeny survival. Our data support a model in which PQM-1 controls a trade-off between lipid metabolic activity in the mother and her progeny to promote the survival of the species under hypoxic conditions.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Hipóxia/metabolismo , Metabolismo dos Lipídeos , Transativadores/metabolismo , Animais , Caenorhabditis elegans/embriologia , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Embrião de Mamíferos/metabolismo , Regulação da Expressão Gênica , Glicogênio/metabolismo , Insulina/metabolismo , Larva/metabolismo , Mutação/genética , Consumo de Oxigênio , Transdução de Sinais , Estresse Fisiológico , Análise de Sobrevida , Transativadores/genética , Transcrição Genética , Vitelogeninas/metabolismo
2.
Chemosphere ; 254: 126909, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957299

RESUMO

Soil contamination by heavy metals (HMs) is an environmental problem, and nanoremediation by using zero-valent iron nanoparticles (nZVI) has attracted increasing interest. We used ecotoxicological test and global transcriptome analysis with DNA microarrays to assess the suitability of C. elegans as a useful bioindicator to evaluate such strategy of nanoremediation in a highly polluted soil with Pb, Cd and Zn. The HMs produced devastating effect on C. elegans. nZVI treatment reversed this deleterious effect up to day 30 after application, but the reduction in the relative toxicity of HMs was lower at day 120. We stablished gene expression profile in C. elegans exposed to the polluted soil, treated and untreated with nZVI. The percentage of differentially expressed genes after treatment decreases with exposure time. After application of nZVI we found decreased toxicity, but increased biosynthesis of defensive enzymes responsive to oxidative stress. At day 14, when a decrease in toxicity has occurred, genes related to specific heavy metal detoxification mechanisms or to response to metal stress, were down regulated: gst-genes, encoding for glutathione-S-transferase, htm-1 (heavy metal tolerance factor), and pgp-5 and pgp-7, related to stress response to metals. At day 120, we found increased HMs toxicity compared to day 14, whereas the transcriptional oxidative and metal-induced responses were attenuated. These findings indicate that the profiled gene expression in C. elegans may be considered as an indicator of stress response that allows a reliable evaluation of the nanoremediation strategy.


Assuntos
Caenorhabditis elegans/efeitos dos fármacos , Ferro/química , Metais Pesados/toxicidade , Nanopartículas/química , Estresse Oxidativo/efeitos dos fármacos , Poluentes do Solo/toxicidade , Transcrição Genética/efeitos dos fármacos , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Ecotoxicologia , Nanopartículas Metálicas , Metais Pesados/análise , Estresse Oxidativo/genética , Solo/química , Microbiologia do Solo , Poluentes do Solo/análise , Toxicogenética
3.
Nat Commun ; 11(1): 4639, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32934238

RESUMO

The ability to detect, respond and adapt to mitochondrial stress ensures the development and survival of organisms. Caenorhabditis elegans responds to mitochondrial stress by activating the mitochondrial unfolded protein response (UPRmt) to buffer the mitochondrial folding environment, rewire the metabolic state, and promote innate immunity and lifespan extension. Here we show that HDA-1, the C. elegans ortholog of mammalian histone deacetylase (HDAC) is required for mitochondrial stress-mediated activation of UPRmt. HDA-1 interacts and coordinates with the genome organizer DVE-1 to induce the transcription of a broad spectrum of UPRmt, innate immune response and metabolic reprogramming genes. In rhesus monkey and human tissues, HDAC1/2 transcript levels correlate with the expression of UPRmt genes. Knocking down or pharmacological inhibition of HDAC1/2 disrupts the activation of the UPRmt and the mitochondrial network in mammalian cells. Our results underscore an evolutionarily conserved mechanism of HDAC1/2 in modulating mitochondrial homeostasis and regulating longevity.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/enzimologia , Histona Desacetilase 1/metabolismo , Histona Desacetilase 2/metabolismo , Histona Desacetilases/metabolismo , Longevidade , Mitocôndrias/enzimologia , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Proteínas de Caenorhabditis elegans/genética , Histona Desacetilase 1/genética , Histona Desacetilase 2/genética , Histona Desacetilases/genética , Macaca mulatta , Estresse Fisiológico , Resposta a Proteínas não Dobradas
4.
Nat Commun ; 11(1): 4496, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32901024

RESUMO

Aging is characterized by the loss of homeostasis and the general decline of physiological functions, accompanied by various degenerative diseases and increased rates of mortality. Aging targeting small molecule screens have been performed many times, however, few have focused on endogenous metabolic intermediates-metabolites. Here, using C. elegans lifespan assays, we conducted a worm metabolite screen and identified an eukaryotes conserved metabolite, myo-inositol (MI), to extend lifespan, increase mobility and reduce fat content. Genetic analysis of enzymes in MI metabolic pathway suggest that MI alleviates aging through its derivative PI(4,5)P2. MI and PI(4,5)P2 are precursors of PI(3,4,5)P3, which is negatively related to longevity. The longevity effect of MI is dependent on the tumor suppressor gene, daf-18 (homologous to mouse Pten), independent of its classical pathway downstream genes, akt or daf-16. Furthermore, we found MI effects on aging and lifespan act through mitophagy regulator PTEN induced kinase-1 (pink-1) and mitophagy. MI's anti-aging effect is also conserved in mouse, indicating a conserved mechanism in mammals.


Assuntos
Envelhecimento/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Inositol/metabolismo , Longevidade/fisiologia , PTEN Fosfo-Hidrolase/metabolismo , Envelhecimento/efeitos dos fármacos , Animais , Animais Geneticamente Modificados , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Linhagem Celular Tumoral , Feminino , Fatores de Transcrição Forkhead/genética , Inositol/administração & dosagem , Locomoção/fisiologia , Longevidade/efeitos dos fármacos , Redes e Vias Metabólicas/genética , Metabolômica , Camundongos , Mitofagia/fisiologia , Modelos Animais , Fosfatos de Fosfatidilinositol/metabolismo , Proteínas Quinases/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Interferência de RNA , RNA-Seq
5.
PLoS Pathog ; 16(9): e1008826, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32970778

RESUMO

The nematode Caenorhabditis elegans has been extensively used as a model for the study of innate immune responses against bacterial pathogens. While it is well established that the worm mounts distinct transcriptional responses to different bacterial species, it is still unclear in how far it can fine-tune its response to different strains of a single pathogen species, especially if the strains vary in virulence and infection dynamics. To rectify this knowledge gap, we systematically analyzed the C. elegans response to two strains of Bacillus thuringiensis (Bt), MYBt18247 (Bt247) and MYBt18679 (Bt679), which produce different pore forming toxins (PFTs) and vary in infection dynamics. We combined host transcriptomics with cytopathological characterizations and identified both a common and also a differentiated response to the two strains, the latter comprising almost 10% of the infection responsive genes. Functional genetic analyses revealed that the AP-1 component gene jun-1 mediates the common response to both Bt strains. In contrast, the strain-specific response is mediated by the C. elegans GATA transcription factor ELT-2, a homolog of Drosophila SERPENT and vertebrate GATA4-6, and a known master regulator of intestinal responses in the nematode. elt-2 RNAi knockdown decreased resistance to Bt679, but remarkably, increased survival on Bt247. The elt-2 silencing-mediated increase in survival was characterized by reduced intestinal tissue damage despite a high pathogen burden and might thus involve increased tolerance. Additional functional genetic analyses confirmed the involvement of distinct signaling pathways in the C. elegans defense response: the p38-MAPK pathway acts either directly with or in parallel to elt-2 in mediating resistance to Bt679 infection but is not required for protection against Bt247. Our results further suggest that the elt-2 silencing-mediated increase in survival on Bt247 is multifactorial, influenced by the nuclear hormone receptors NHR-99 and NHR-193, and may further involve lipid metabolism and detoxification. Our study highlights that the nematode C. elegans with its comparatively simple immune defense system is capable of generating a differentiated response to distinct strains of the same pathogen species. Importantly, our study provides a molecular insight into the diversity of biological processes that are influenced by a single master regulator and jointly determine host survival after pathogen infection.


Assuntos
Bacillus thuringiensis/metabolismo , Infecções Bacterianas/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Fatores de Transcrição GATA/metabolismo , Sistema de Sinalização das MAP Quinases , Transcrição Genética , Animais , Bacillus thuringiensis/patogenicidade , Infecções Bacterianas/genética , Infecções Bacterianas/microbiologia , Caenorhabditis elegans/genética , Caenorhabditis elegans/microbiologia , Proteínas de Caenorhabditis elegans/genética , Fatores de Transcrição GATA/genética
6.
Nat Commun ; 11(1): 4869, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32978394

RESUMO

Poly(ADP-ribosyl)ation is a reversible post-translational modification synthetized by ADP-ribose transferases and removed by poly(ADP-ribose) glycohydrolase (PARG), which plays important roles in DNA damage repair. While well-studied in somatic tissues, much less is known about poly(ADP-ribosyl)ation in the germline, where DNA double-strand breaks are introduced by a regulated program and repaired by crossover recombination to establish a tether between homologous chromosomes. The interaction between the parental chromosomes is facilitated by meiotic specific adaptation of the chromosome axes and cohesins, and reinforced by the synaptonemal complex. Here, we uncover an unexpected role for PARG in coordinating the induction of meiotic DNA breaks and their homologous recombination-mediated repair in Caenorhabditis elegans. PARG-1/PARG interacts with both axial and central elements of the synaptonemal complex, REC-8/Rec8 and the MRN/X complex. PARG-1 shapes the recombination landscape and reinforces the tightly regulated control of crossover numbers without requiring its catalytic activity. We unravel roles in regulating meiosis, beyond its enzymatic activity in poly(ADP-ribose) catabolism.


Assuntos
Caenorhabditis elegans/metabolismo , Quebras de DNA de Cadeia Dupla , Reparo do DNA/fisiologia , DNA/metabolismo , Glicosídeo Hidrolases/metabolismo , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Núcleo Celular/metabolismo , Células Germinativas , Glicosídeo Hidrolases/genética , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Poli ADP Ribosilação , Poli Adenosina Difosfato Ribose/metabolismo , Processamento de Proteína Pós-Traducional
7.
Nat Commun ; 11(1): 4865, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32978396

RESUMO

The metabolic state of an organism instructs gene expression modalities, leading to changes in complex life history traits, such as longevity. Dietary restriction (DR), which positively affects health and life span across species, leads to metabolic reprogramming that enhances utilisation of fatty acids for energy generation. One direct consequence of this metabolic shift is the upregulation of cytoprotective (CyTP) genes categorized in the Gene Ontology (GO) term of "Xenobiotic Detoxification Program" (XDP). How an organism senses metabolic changes during nutritional stress to alter gene expression programs is less known. Here, using a genetic model of DR, we show that the levels of polyunsaturated fatty acids (PUFAs), especially linoleic acid (LA) and eicosapentaenoic acid (EPA), are increased following DR and these PUFAs are able to activate the CyTP genes. This activation of CyTP genes is mediated by the conserved p38 mitogen-activated protein kinase (p38-MAPK) pathway. Consequently, genes of the PUFA biosynthesis and p38-MAPK pathway are required for multiple paradigms of DR-mediated longevity, suggesting conservation of mechanism. Thus, our study shows that PUFAs and p38-MAPK pathway function downstream of DR to help communicate the metabolic state of an organism to regulate expression of CyTP genes, ensuring extended life span.


Assuntos
Ácidos Graxos Insaturados/genética , Ácidos Graxos Insaturados/metabolismo , Regulação da Expressão Gênica , Proteínas Quinases p38 Ativadas por Mitógeno/genética , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Fenômenos Bioquímicos , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Ácido Eicosapentaenoico/análogos & derivados , Regulação da Expressão Gênica/genética , Técnicas de Silenciamento de Genes , Ácido Linoleico/metabolismo , Longevidade , Redes e Vias Metabólicas/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo
8.
PLoS Genet ; 16(8): e1008975, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32750056

RESUMO

The C. elegans proteins PAQR-2 (a homolog of the human seven-transmembrane domain AdipoR1 and AdipoR2 proteins) and IGLR-2 (a homolog of the mammalian LRIG proteins characterized by a single transmembrane domain and the presence of immunoglobulin domains and leucine-rich repeats in their extracellular portion) form a complex that protects against plasma membrane rigidification by promoting the expression of fatty acid desaturases and the incorporation of polyunsaturated fatty acids into phospholipids, hence increasing membrane fluidity. In the present study, we leveraged a novel gain-of-function allele of PAQR-1, a PAQR-2 paralog, to carry out structure-function studies. We found that the transmembrane domains of PAQR-2 are responsible for its functional requirement for IGLR-2, that PAQR-1 does not require IGLR-2 but acts via the same pathway as PAQR-2, and that the divergent N-terminal cytoplasmic domains of the PAQR-1 and PAQR-2 proteins serve a regulatory function and may regulate access to the catalytic site of these proteins. We also show that overexpression of human AdipoR1 or AdipoR2 alone is sufficient to confer increased palmitic acid resistance in HEK293 cells, and thus act in a manner analogous to the PAQR-1 gain-of-function allele.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/genética , Proteínas de Membrana/genética , Receptores de Adiponectina/genética , Alelos , Animais , Caenorhabditis elegans/metabolismo , Membrana Celular/genética , Membrana Celular/metabolismo , Mutação com Ganho de Função/genética , Células HEK293 , Humanos , Fluidez de Membrana/genética , Fenótipo , Fosfolipídeos/genética , Fosfolipídeos/metabolismo
9.
PLoS Genet ; 16(8): e1008505, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32776934

RESUMO

Dynamic gene expression in neurons shapes fundamental processes in the nervous systems of animals. However, how neuronal activation by different stimuli can lead to distinct transcriptional responses is not well understood. We have been studying how microbial metabolites modulate gene expression in chemosensory neurons of Caenorhabditis elegans. Considering the diverse environmental stimuli that can activate chemosensory neurons of C. elegans, we sought to understand how specific transcriptional responses can be generated in these neurons in response to distinct cues. We have focused on the mechanism of rapid (<6 min) and selective transcriptional induction of daf-7, a gene encoding a TGF-ß ligand, in the ASJ chemosensory neurons in response to the pathogenic bacterium Pseudomonas aeruginosa. DAF-7 is required for the protective behavioral avoidance of P. aeruginosa by C. elegans. Here, we define the involvement of two distinct cyclic GMP (cGMP)-dependent pathways that are required for daf-7 expression in the ASJ neuron pair in response to P. aeruginosa. We show that a calcium-independent pathway dependent on the cGMP-dependent protein kinase G (PKG) EGL-4, and a canonical calcium-dependent signaling pathway dependent on the activity of a cyclic nucleotide-gated channel subunit CNG-2, function in parallel to activate rapid, selective transcription of daf-7 in response to P. aeruginosa metabolites. Our data suggest that fast, selective early transcription of neuronal genes require PKG in shaping responses to distinct microbial stimuli in a pair of C. elegans chemosensory neurons.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Células Quimiorreceptoras/metabolismo , GMP Cíclico/metabolismo , Pseudomonas aeruginosa/metabolismo , Fator de Crescimento Transformador beta/genética , Animais , Caenorhabditis elegans , Proteínas de Caenorhabditis elegans/metabolismo , Sinalização do Cálcio , Proteínas Quinases Dependentes de GMP Cíclico/metabolismo , Canais de Cátion Regulados por Nucleotídeos Cíclicos/metabolismo , Ativação Transcricional , Fator de Crescimento Transformador beta/metabolismo
10.
PLoS Genet ; 16(8): e1008644, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32776941

RESUMO

Correct regulation of cell contractility is critical for the function of many biological systems. The reproductive system of the hermaphroditic nematode C. elegans contains a contractile tube of myoepithelial cells known as the spermatheca, which stores sperm and is the site of oocyte fertilization. Regulated contraction of the spermatheca pushes the embryo into the uterus. Cell contractility in the spermatheca is dependent on actin and myosin and is regulated, in part, by Ca2+ signaling through the phospholipase PLC-1, which mediates Ca2+ release from the endoplasmic reticulum. Here, we describe a novel role for GSA-1/Gαs, and protein kinase A, composed of the catalytic subunit KIN-1/PKA-C and the regulatory subunit KIN-2/PKA-R, in the regulation of Ca2+ release and contractility in the C. elegans spermatheca. Without GSA-1/Gαs or KIN-1/PKA-C, Ca2+ is not released, and oocytes become trapped in the spermatheca. Conversely, when PKA is activated through either a gain of function allele in GSA-1 (GSA-1(GF)) or by depletion of KIN-2/PKA-R, the transit times and total numbers, although not frequencies, of Ca2+ pulses are increased, and Ca2+ propagates across the spermatheca even in the absence of oocyte entry. In the spermathecal-uterine valve, loss of GSA-1/Gαs or KIN-1/PKA-C results in sustained, high levels of Ca2+ and a loss of coordination between the spermathecal bag and sp-ut valve. Additionally, we show that depleting phosphodiesterase PDE-6 levels alters contractility and Ca2+ dynamics in the spermatheca, and that the GPB-1 and GPB-2 Gß subunits play a central role in regulating spermathecal contractility and Ca2+ signaling. This work identifies a signaling network in which Ca2+ and cAMP pathways work together to coordinate spermathecal contractions for successful ovulations.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Sinalização do Cálcio , Subunidades Catalíticas da Proteína Quinase Dependente de AMP Cíclico/metabolismo , Contração Muscular , 3',5'-AMP Cíclico Fosfodiesterases/metabolismo , Animais , Caenorhabditis elegans , Proteínas de Caenorhabditis elegans/genética , Subunidades Catalíticas da Proteína Quinase Dependente de AMP Cíclico/genética , Células Epiteliais/metabolismo , Células Epiteliais/fisiologia , Subunidades beta da Proteína de Ligação ao GTP/metabolismo , Mutação com Ganho de Função , Células Musculares/metabolismo , Células Musculares/fisiologia , Oócitos/fisiologia
11.
PLoS Genet ; 16(8): e1008982, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32841230

RESUMO

High glucose diets are unhealthy, although the mechanisms by which elevated glucose is harmful to whole animal physiology are not well understood. In Caenorhabditis elegans, high glucose shortens lifespan, while chemically inflicted glucose restriction promotes longevity. We investigated the impact of glucose metabolism on aging quality (maintained locomotory capacity and median lifespan) and found that, in addition to shortening lifespan, excess glucose negatively impacts locomotory healthspan. Conversely, disrupting glucose utilization by knockdown of glycolysis-specific genes results in large mid-age physical improvements via a mechanism that requires the FOXO transcription factor DAF-16. Adult locomotory capacity is extended by glycolysis disruption, but maximum lifespan is not, indicating that limiting glycolysis can increase the proportion of life spent in mobility health. We also considered the largely ignored role of glucose biosynthesis (gluconeogenesis) in adult health. Directed perturbations of gluconeogenic genes that specify single direction enzymatic reactions for glucose synthesis decrease locomotory healthspan, suggesting that gluconeogenesis is needed for healthy aging. Consistent with this idea, overexpression of the central gluconeogenic gene pck-2 (encoding PEPCK) increases health measures via a mechanism that requires DAF-16 to promote pck-2 expression in specific intestinal cells. Dietary restriction also features DAF-16-dependent pck-2 expression in the intestine, and the healthspan benefits conferred by dietary restriction require pck-2. Together, our results describe a new paradigm in which nutritional signals engage gluconeogenesis to influence aging quality via DAF-16. These data underscore the idea that promotion of gluconeogenesis might be an unappreciated goal for healthy aging and could constitute a novel target for pharmacological interventions that counter high glucose consequences, including diabetes.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/genética , Fatores de Transcrição Forkhead/genética , Gluconeogênese/genética , Envelhecimento Saudável/genética , Animais , Restrição Calórica , Regulação da Expressão Gênica no Desenvolvimento/genética , Glucose/metabolismo , Humanos , Expectativa de Vida , Longevidade/genética , Fosfoenolpiruvato Carboxiquinase (ATP)/genética , Transdução de Sinais/genética
12.
Nat Commun ; 11(1): 4242, 2020 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-32843637

RESUMO

Membraneless organelles are sites for RNA biology including small non-coding RNA (ncRNA) mediated gene silencing. How small ncRNAs utilise phase separated environments for their function is unclear. We investigated how the PIWI-interacting RNA (piRNA) pathway engages with the membraneless organelle P granule in Caenorhabditis elegans. Proteomic analysis of the PIWI protein PRG-1 reveals an interaction with the constitutive P granule protein DEPS-1. DEPS-1 is not required for piRNA biogenesis but piRNA-dependent silencing: deps-1 mutants fail to produce the secondary endo-siRNAs required for the silencing of piRNA targets. We identify a motif on DEPS-1 which mediates a direct interaction with PRG-1. DEPS-1 and PRG-1 form intertwining clusters to build elongated condensates in vivo which are dependent on the Piwi-interacting motif of DEPS-1. Additionally, we identify EDG-1 as an interactor of DEPS-1 and PRG-1. Our study reveals how specific protein-protein interactions drive the spatial organisation and piRNA-dependent silencing within membraneless organelles.


Assuntos
Proteínas Argonauta/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Inativação Gênica , RNA Interferente Pequeno/metabolismo , Animais , Proteínas Argonauta/genética , Sítios de Ligação , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/química , Proteínas de Caenorhabditis elegans/genética , Grânulos Citoplasmáticos/metabolismo , Células Germinativas/metabolismo , Mutação , Ligação Proteica , Proteômica , Interferência de RNA , RNA de Cadeia Dupla/metabolismo , RNA Interferente Pequeno/genética
13.
PLoS Biol ; 18(8): e3000817, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32813728

RESUMO

During meiosis, chromosomes adopt a specialized organization involving assembly of a cohesin-based axis along their lengths, with DNA loops emanating from this axis. We applied novel, quantitative, and widely applicable cytogenetic strategies to elucidate the molecular bases of this organization using Caenorhabditis elegans. Analyses of wild-type (WT) chromosomes and de novo circular minichromosomes revealed that meiosis-specific HORMA-domain proteins assemble into cohorts in defined numbers and co-organize the axis together with 2 functionally distinct cohesin complexes (REC-8 and COH-3/4) in defined stoichiometry. We further found that REC-8 cohesins, which load during S phase and mediate sister-chromatid cohesion, usually occur as individual complexes, supporting a model wherein sister cohesion is mediated locally by a single cohesin ring. REC-8 complexes are interspersed in an alternating pattern with cohorts of axis-organizing COH-3/4 complexes (averaging 3 per cohort), which are insufficient to confer cohesion but can bind to individual chromatids, suggesting a mechanism to enable formation of asymmetric sister-chromatid loops. Indeed, immunofluorescence/fluorescence in situ hybridization (immuno-FISH) assays demonstrate frequent asymmetry in genomic content between the loops formed on sister chromatids. We discuss how features of chromosome axis/loop architecture inferred from our data can help to explain enigmatic, yet essential, aspects of the meiotic program.


Assuntos
Caenorhabditis elegans/genética , Proteínas de Ciclo Celular/genética , Cromátides/ultraestrutura , Proteínas Cromossômicas não Histona/genética , Cromossomos/ultraestrutura , Meiose , Complexo Sinaptonêmico/ultraestrutura , Animais , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Ciclo Celular/metabolismo , Cromátides/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Segregação de Cromossomos , Cromossomos/metabolismo , Análise Citogenética , Hibridização in Situ Fluorescente , Fase S/genética , Complexo Sinaptonêmico/metabolismo
14.
PLoS Pathog ; 16(8): e1008766, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32857822

RESUMO

Pathogens commonly disrupt the intestinal epithelial barrier; however, how the epithelial immune system senses the loss of intestinal barrier as a danger signal to activate self-defense is unclear. Through an unbiased approach in the model nematode Caenorhabditis elegans, we found that the EGL-44/TEAD transcription factor and its transcriptional activator YAP-1/YAP (Yes-associated protein) were activated when the intestinal barrier was disrupted by infections with the pathogenic bacterium Pseudomonas aeruginosa PA14. Gene Ontology enrichment analysis of the genes containing the TEAD-binding sites revealed that "innate immune response" and "defense response to Gram-negative bacterium" were two top significantly overrepresented terms. Genetic inactivation of yap-1 and egl-44 significantly reduced the survival rate and promoted bacterial accumulation in worms after bacterial infections. Furthermore, we found that disturbance of the E-cadherin-based adherens junction triggered the nuclear translocation and activation of YAP-1/YAP in the gut of worms. Although YAP is a major downstream effector of the Hippo signaling, our study revealed that the activation of YAP-1/YAP was independent of the Hippo pathway during disruption of intestinal barrier. After screening 10 serine/threonine phosphatases, we identified that PP2A phosphatase was involved in the activation of YAP-1/YAP after intestinal barrier loss induced by bacterial infections. Additionally, our study demonstrated that the function of YAP was evolutionarily conserved in mice. Our study highlights how the intestinal epithelium recognizes the loss of the epithelial barrier as a danger signal to deploy defenses against pathogens, uncovering an immune surveillance program in the intestinal epithelium.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Permeabilidade da Membrana Celular , Células Epiteliais/imunologia , Microbioma Gastrointestinal/imunologia , Salmonelose Animal/imunologia , Salmonella typhimurium/imunologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Caenorhabditis elegans , Proteínas de Caenorhabditis elegans/genética , Células Epiteliais/metabolismo , Células Epiteliais/microbiologia , Células Epiteliais/patologia , Camundongos , Salmonelose Animal/metabolismo , Salmonelose Animal/microbiologia , Salmonelose Animal/patologia , Transdução de Sinais
15.
Sci Total Environ ; 745: 141047, 2020 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-32758726

RESUMO

TGF-ß signaling pathway is important for the regulation of stress response in organisms. We here used Caenorhabditis elegans to determine the function of DBL-1/TGF-ß signaling pathway in the control of response to nanopolystyrene (100 nm). In DBL-1/TGF-ß signaling pathway, exposure to 1-1000 µg/L nanopolystyrene significantly increased the expressions of dbl-1 encoding a TGF-ß ligand, sma-6 encoding a TGF-ß receptor, sma-4 encoding a Co-Smad, and two genes (mab-31 and sma-9) encoding transcriptional factors. DBL-1 acted in the neurons to control the response to nanopolystyrene. In the neurons, the expression and the function of DBL-1 were under the control of two signaling cascades (SMOC-1-ZAG-1 and SMOC-1-ADT-2). TGF-ß receptor SMA-6 acted in the intestine to control the response to nanopolystyrene. The downstream Co-Smad/SMA-4 and two transcriptional factors (MAB-31 and SMA-9) of SMA-6 in the intestine were further identified to be required for the control of response to nanopolystyrene. In nanopolystyrene exposed nematodes, intestinal MAB-31 activated the mitochondrial Mn-SOD/SOD-3 by modulating DAF-16 activity, and intestinal SMA-9 activated the mitochondrial unfolded protein response by affecting ELT-2 activity. Therefore, the DBL-1/TGF-ß signaling pathway mediated an important neuron-intestine communication in nanopolystyrene exposed nematodes.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Neuropeptídeos , Animais , Caenorhabditis elegans , Fatores de Transcrição GATA , Intestinos , Neurônios , Poliestirenos , Transdução de Sinais , Fatores de Transcrição , Fator de Crescimento Transformador beta
16.
Int J Nanomedicine ; 15: 5227-5237, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32801688

RESUMO

Background: Large-scale production and application of amorphous silica nanoparticles (SiNPs) have enhanced the risk of human exposure to SiNPs. However, the toxic effects and the underlying biological mechanisms of SiNPs on Caenorhabditis elegans remain largely unclear. Purpose: This study was to investigate the genome-wide transcriptional alteration of SiNPs on C. elegans. Methods and Results: In this study, a total number of 3105 differentially expressed genes were identified in C. elegans. Among them, 1398 genes were significantly upregulated and 1707 genes were notably downregulated in C. elegans. Gene ontology analysis revealed that the significant change of gene functional categories triggered by SiNPs was focused on locomotion, determination of adult lifespan, reproduction, body morphogenesis, multicellular organism development, endoplasmic reticulum unfolded protein response, oocyte development, and nematode larval development. Meanwhile, we explored the regulated effects between microRNA and genes or signaling pathways. Pathway enrichment analysis and miRNA-gene-pathway-network displayed that 23 differential expression microRNA including cel-miR-85-3p, cel-miR-793, cel-miR-241-5p, and cel-miR-5549-5p could regulate the longevity-related pathways and inflammation signaling pathways, etc. Additionally, our data confirmed that SiNPs could disrupt the locomotion behavior and reduce the longevity by activating ins-7, daf-16, ftt-2, fat-5, and rho-1 genes in C. elegans. Conclusion: Our study showed that SiNPs induced the change of the whole transcriptome in C. elegans, and triggered negative effects on longevity, development, reproduction, and body morphogenesis. These data provide abundant clues to understand the molecular mechanisms of SiNPs in C. elegans.


Assuntos
Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Nanopartículas/toxicidade , Animais , Proteínas de Caenorhabditis elegans/genética , Redes Reguladoras de Genes/efeitos dos fármacos , Genoma Helmíntico , Humanos , Longevidade/efeitos dos fármacos , MicroRNAs/genética , Testes de Mutagenicidade/métodos , Nanopartículas/química , Reprodução/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Dióxido de Silício/química , Dióxido de Silício/toxicidade , Transcriptoma , Resposta a Proteínas não Dobradas/genética
17.
PLoS Genet ; 16(7): e1008904, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32730253

RESUMO

The conserved ATPase, PCH-2/TRIP13, is required during both the spindle checkpoint and meiotic prophase. However, its specific role in regulating meiotic homolog pairing, synapsis and recombination has been enigmatic. Here, we report that this enzyme is required to proofread meiotic homolog interactions. We generated a mutant version of PCH-2 in C. elegans that binds ATP but cannot hydrolyze it: pch-2E253Q. In vitro, this mutant can bind a known substrate but is unable to remodel it. This mutation results in some non-homologous synapsis and impaired crossover assurance. Surprisingly, worms with a null mutation in PCH-2's adapter protein, CMT-1, the ortholog of p31comet, localize PCH-2 to meiotic chromosomes, exhibit non-homologous synapsis and lose crossover assurance. The similarity in phenotypes between cmt-1 and pch-2E253Q mutants suggest that PCH-2 can bind its meiotic substrates in the absence of CMT-1, in contrast to its role during the spindle checkpoint, but requires its adapter to hydrolyze ATP and remodel them.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Ciclo Celular/genética , Meiose/genética , Proteínas Nucleares/genética , Adenosina Trifosfatases/genética , Trifosfato de Adenosina/genética , Animais , Caenorhabditis elegans/genética , Pareamento Cromossômico/genética , Segregação de Cromossomos/genética , Cromossomos/genética , Humanos , Mutação/genética , Fuso Acromático/genética
18.
Nat Commun ; 11(1): 3615, 2020 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-32680986

RESUMO

Failure to preserve the integrity of the genome is a hallmark of cancer. Recent studies have revealed that loss of the capacity to repair DNA breaks via homologous recombination (HR) results in a mutational profile termed BRCAness. The enzymatic activity that repairs HR substrates in BRCA-deficient conditions to produce this profile is currently unknown. We here show that the mutational landscape of BRCA1 deficiency in C. elegans closely resembles that of BRCA1-deficient tumours. We identify polymerase theta-mediated end-joining (TMEJ) to be responsible: knocking out polq-1 suppresses the accumulation of deletions and tandem duplications in brc-1 and brd-1 animals. We find no additional back-up repair in HR and TMEJ compromised animals; non-homologous end-joining does not affect BRCAness. The notion that TMEJ acts as an alternative to HR, promoting the genome alteration of HR-deficient cells, supports the idea that polymerase theta is a promising therapeutic target for HR-deficient tumours.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/genética , Reparo do DNA por Junção de Extremidades , DNA Polimerase Dirigida por DNA/metabolismo , Proteínas Supressoras de Tumor/genética , Ubiquitina-Proteína Ligases/genética , Animais , Animais Geneticamente Modificados , Análise Mutacional de DNA , DNA Polimerase Dirigida por DNA/genética , Técnicas de Inativação de Genes , Mutação
19.
Nucleic Acids Res ; 48(15): 8782-8795, 2020 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-32633758

RESUMO

The stability and processing of cellular RNA transcripts are efficiently controlled via non-templated addition of single or multiple nucleotides, which is catalyzed by various nucleotidyltransferases including poly(A) polymerases (PAPs). Germline development defective 2 (GLD-2) is among the first reported cytoplasmic non-canonical PAPs that promotes the translation of germline-specific mRNAs by extending their short poly(A) tails in metazoan, such as Caenorhabditis elegans and Xenopus. On the other hand, the function of mammalian GLD-2 seems more diverse, which includes monoadenylation of certain microRNAs. To understand the structural basis that underlies the difference between mammalian and non-mammalian GLD-2 proteins, we determine crystal structures of two rodent GLD-2s. Different from C. elegans GLD-2, mammalian GLD-2 is an intrinsically robust PAP with an extensively positively charged surface. Rodent and C. elegans GLD-2s have a topological difference in the ß-sheet region of the central domain. Whereas C. elegans GLD-2 prefers adenosine-rich RNA substrates, mammalian GLD-2 can work on RNA oligos with various sequences. Coincident with its activity on microRNAs, mammalian GLD-2 structurally resembles the mRNA and miRNA processor terminal uridylyltransferase 7 (TUT7). Our study reveals how GLD-2 structurally evolves to a more versatile nucleotidyltransferase, and provides important clues in understanding its biological function in mammals.


Assuntos
Proteínas de Caenorhabditis elegans/genética , MicroRNAs/genética , Nucleotidiltransferases/genética , Polinucleotídeo Adenililtransferase/genética , Estabilidade de RNA/genética , RNA Mensageiro/genética , Proteínas de Xenopus/genética , Animais , Caenorhabditis elegans/genética , Citoplasma/genética , Células Germinativas/crescimento & desenvolvimento , Mamíferos , Poli A/genética , Interferência de RNA
20.
PLoS One ; 15(6): e0233991, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32497060

RESUMO

Neuropeptides are secreted molecules that have conserved roles modulating many processes, including mood, reproduction, and feeding. Dysregulation of neuropeptide signaling is also implicated in neurological disorders such as epilepsy. However, much is unknown about the mechanisms regulating specific neuropeptides to mediate behavior. Here, we report that the expression levels of dozens of neuropeptides are up-regulated in response to circuit activity imbalance in C. elegans. acr-2 encodes a homolog of human nicotinic receptors, and functions in the cholinergic motoneurons. A hyperactive mutation, acr-2(gf), causes an activity imbalance in the motor circuit. We performed cell-type specific transcriptomic analysis and identified genes differentially expressed in acr-2(gf), compared to wild type. The most over-represented class of genes are neuropeptides, with insulin-like-peptides (ILPs) the most affected. Moreover, up-regulation of neuropeptides occurs in motoneurons, as well as sensory neurons. In particular, the induced expression of the ILP ins-29 occurs in the BAG neurons, which were previously shown to function in gas-sensing. We also show that this up-regulation of ins-29 in acr-2(gf) animals is activity-dependent. Our genetic and molecular analyses support cooperative effects for ILPs and other neuropeptides in promoting motor circuit activity in the acr-2(gf) background. Together, this data reveals that a major transcriptional response to motor circuit dysregulation is in up-regulation of multiple neuropeptides, and suggests that BAG sensory neurons can respond to intrinsic activity states to feedback on the motor circuit.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/genética , Neuropeptídeos/genética , Receptores Nicotínicos/genética , Transcriptoma , Animais , Caenorhabditis elegans/fisiologia , Perfilação da Expressão Gênica , Neurônios Motores/metabolismo , Mutação , Células Receptoras Sensoriais/metabolismo
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