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1.
PLoS Pathog ; 18(4): e1010425, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35381053

RESUMO

Although Salmonella Typhimurium (STM) and Salmonella Paratyphi A (SPA) belong to the same phylogenetic species, share large portions of their genome and express many common virulence factors, they differ vastly in their host specificity, the immune response they elicit, and the clinical manifestations they cause. In this work, we compared their intracellular transcriptomic architecture and cellular phenotypes during human epithelial cell infection. While transcription induction of many metal transport systems, purines, biotin, PhoPQ and SPI-2 regulons was similar in both intracellular SPA and STM, we identified 234 differentially expressed genes that showed distinct expression patterns in intracellular SPA vs. STM. Surprisingly, clear expression differences were found in SPI-1, motility and chemotaxis, and carbon (mainly citrate, galactonate and ethanolamine) utilization pathways, indicating that these pathways are regulated differently during their intracellular phase. Concurring, on the cellular level, we show that while the majority of STM are non-motile and reside within Salmonella-Containing Vacuoles (SCV), a significant proportion of intracellular SPA cells are motile and compartmentalized in the cytosol. Moreover, we found that the elevated expression of SPI-1 and motility genes by intracellular SPA results in increased invasiveness of SPA, following exit from host cells. These findings demonstrate unexpected flagellum-dependent intracellular motility of a typhoidal Salmonella serovar and intriguing differences in intracellular localization between typhoidal and non-typhoidal salmonellae. We propose that these differences facilitate new cycles of host cell infection by SPA and may contribute to the ability of SPA to disseminate beyond the intestinal lamina propria of the human host during enteric fever.


Assuntos
Quimiotaxia , Salmonella paratyphi A , Proteínas de Bactérias/metabolismo , Carbono/metabolismo , Flagelos/genética , Flagelos/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular , Filogenia , Salmonella paratyphi A/metabolismo , Salmonella typhimurium
2.
PLoS Pathog ; 17(3): e1009451, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33739988

RESUMO

Salmonella enterica is a diverse bacterial pathogen and a primary cause of human and animal infections. While many S. enterica serovars present a broad host-specificity, several specialized pathotypes have been adapted to colonize and cause disease in one or limited numbers of host species. The underlying mechanisms defining Salmonella host-specificity are far from understood. Here, we present genetic analysis, phenotypic characterization and virulence profiling of a monophasic S. enterica serovar Typhimurium strain that was isolated from several wild sparrows in Israel. Whole genome sequencing and complete assembly of its genome demonstrate a unique genetic signature that includes the integration of the BTP1 prophage, loss of the virulence plasmid, pSLT and pseudogene accumulation in multiple T3SS-2 effectors (sseJ, steC, gogB, sseK2, and sseK3), catalase (katE), tetrathionate respiration (ttrB) and several adhesion/ colonization factors (lpfD, fimH, bigA, ratB, siiC and siiE) encoded genes. Correspondingly, this strain demonstrates impaired biofilm formation, intolerance to oxidative stress and compromised intracellular replication within non-phagocytic host cells. Moreover, while this strain showed attenuated pathogenicity in the mouse, it was highly virulent and caused an inflammatory disease in an avian host. Overall, our findings demonstrate a unique phenotypic profile and genetic makeup of an overlooked S. Typhimurium sparrow-associated lineage and present distinct genetic signatures that are likely to contribute to its pathoadaptation to passerine birds.


Assuntos
Doenças das Aves/genética , Especificidade de Hospedeiro/genética , Salmonelose Animal/genética , Salmonella typhimurium/genética , Pardais/microbiologia , Adaptação Fisiológica/genética , Animais , Virulência/genética
3.
Environ Microbiol ; 22(1): 413-432, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31715658

RESUMO

Non-typhoidal Salmonella enterica (NTS) are diverse and important bacterial pathogens consisting of more than 2600 different serovars, with varying host-specificity. Here, we characterized the poultry-associated serovars in Israel, analysed their resistome and illuminated the molecular mechanisms underlying common multidrug resistance (MDR) patterns. We show that at least four serovars including Infantis, Muenchen, Newport and Virchow present a strong epidemiological association between their temporal trends in poultry and humans. Worrisomely, 60% from all of the poultry isolates tested (n = 188) were multidrug resistant, mediated by chromosomal SNPs and different mobile genetics elements. A novel streptomycin-azithromycin resistance island and previously uncharacterized versions of the mobilized Salmonella genomic island 1 (SGI1) were identified and characterized in S. Blockley and S. Kentucky isolates respectively. Moreover, we demonstrate that the acquisition of SGI1 does not impose fitness cost during growth under nutrient-limited conditions or in the context of Salmonella infection in the mouse model. Overall, our data emphasize the role of the poultry production as a pool of specific epidemic MDR strains and autonomous genetic elements, which confer resistance to heavy metals and medically relevant antibiotics. These are likely to disseminate to humans via the food chain and fuel the increasing global antibiotic resistance crisis.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Aves Domésticas/microbiologia , Salmonelose Animal/microbiologia , Salmonella enterica/efeitos dos fármacos , Salmonella enterica/genética , Animais , Azitromicina/farmacologia , Ilhas Genômicas/genética , Humanos , Sequências Repetitivas Dispersas/genética , Israel , Camundongos , Testes de Sensibilidade Microbiana , Polimorfismo de Nucleotídeo Único/genética , Salmonella enterica/isolamento & purificação , Estreptomicina/farmacologia
4.
Nucleic Acids Res ; 45(4): 2081-2098, 2017 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-28204614

RESUMO

MicroRNAs (miRNAs) impinge on the translation and stability of their target mRNAs, and play key roles in development, homeostasis and disease. The gene regulation mechanisms they instigate are largely mediated through the CCR4­NOT deadenylase complex, but the molecular events that occur on target mRNAs are poorly resolved. We observed a broad convergence of interactions of germ granule and P body mRNP components on AIN-1/GW182 and NTL-1/CNOT1 in Caenorhabditis elegans embryos. We show that the miRISC progressively matures on the target mRNA from a scanning form into an effector mRNP particle by sequentially recruiting the CCR4­NOT complex, decapping and decay, or germ granule proteins. Finally, we implicate intrinsically disordered proteins, key components in mRNP architectures, in the embryonic function of lsy-6 miRNA. Our findings define dynamic steps of effector mRNP assembly in miRNA-mediated silencing, and identify a functional continuum between germ granules and P bodies in the C. elegans embryo.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , MicroRNAs/metabolismo , Interferência de RNA , Ribonucleoproteínas/metabolismo , Animais , Caenorhabditis elegans/embriologia , Caenorhabditis elegans/enzimologia , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Grânulos Citoplasmáticos/metabolismo , Embrião não Mamífero/metabolismo , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Proteínas Intrinsicamente Desordenadas/metabolismo , RNA Mensageiro/metabolismo , Complexo de Inativação Induzido por RNA/metabolismo , Ribonucleases/metabolismo
5.
Nucleic Acids Res ; 43(W1): W154-9, 2015 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-25958392

RESUMO

Proteins that function in the same pathways, protein complexes or the same environmental conditions can show similar patterns of sequence conservation across phylogenetic clades. In species that no longer require a specific protein complex or pathway, these proteins, as a group, tend to be lost or diverge. Analysis of the similarity in patterns of sequence conservation across a large set of eukaryotes can predict functional associations between different proteins, identify new pathway members and reveal the function of previously uncharacterized proteins. We used normalized phylogenetic profiling to predict protein function and identify new pathway members and disease genes. The phylogenetic profiles of tens of thousands conserved proteins in the human, mouse, Caenorhabditis elegans and Drosophila genomes can be queried on our new web server, PhyloGene. PhyloGene provides intuitive and user-friendly platform to query the patterns of conservation across 86 animal, fungal, plant and protist genomes. A protein query can be submitted either by selecting the name from whole-genome protein sets of the intensively studied species or by entering a protein sequence. The graphic output shows the profile of sequence conservation for the query and the most similar phylogenetic profiles for the proteins in the genome of choice. The user can also download this output in numerical form.


Assuntos
Filogenia , Proteínas/classificação , Homologia de Sequência de Aminoácidos , Software , Algoritmos , Animais , Gráficos por Computador , Genômica , Humanos , Internet , Camundongos , Proteínas/química , Proteínas/genética
6.
Mol Cell Neurosci ; 59: 85-96, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24518198

RESUMO

Polymodal nociceptors sense and integrate information on injurious mechanical, thermal, and chemical stimuli. Chemical signals either activate nociceptors or modulate their responses to other stimuli. One chemical known to activate or modulate responses of nociceptors is acetylcholine (ACh). Across evolution nociceptors express subunits of the nicotinic acetylcholine receptor (nAChR) family, a family of ACh-gated ion channels. The roles of ACh and nAChRs in nociceptor function are, however, poorly understood. Caenorhabditis elegans polymodal nociceptors, PVD, express nAChR subunits on their sensory arbor. Here we show that mutations reducing ACh synthesis and mutations in nAChR subunits lead to defects in PVD function and morphology. A likely cause for these defects is a reduction in cytosolic calcium measured in ACh and nAChR mutants. Indeed, overexpression of a calcium pump in PVD mimics defects in PVD function and morphology found in nAChR mutants. Our results demonstrate, for the first time, a central role for nAChRs and ACh in nociceptor function and suggest that calcium permeating via nAChRs facilitates activity of several signaling pathways within this neuron.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Nociceptividade , Receptores Nicotínicos/metabolismo , Acetilcolina/metabolismo , Animais , Caenorhabditis elegans/fisiologia , Proteínas de Caenorhabditis elegans/genética , Mutação , Nociceptores/metabolismo , Receptores Nicotínicos/genética
7.
Microbes Infect ; 26(3): 105249, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37956735

RESUMO

Salmonella enterica is a ubiquitous and clinically-important bacterial pathogen, able to infect and cause different diseases in a wide range of hosts. Here, we report the isolation and characterization of a new S. enterica serovar (13,23:i:-; S. Tirat-Zvi), belonging to the Havana supper-lineage that was isolated from a wild house sparrow (Passer domesticus) in Israel. Whole genome sequencing and complete assembly of its genome indicated a plasmid-free, 4.7 Mb genome that carries the Salmonella pathogenicity islands 1-6, 9, 19 and an integrative and conjugative element (ICE), encoding arsenic resistance genes. Phenotypically, S. Tirat-Zvi isolate TZ282 was motile, readily formed biofilm, more versatile in carbon source utilization than S. Typhimurium and highly tolerant to arsenic, but impaired in host cell invasion. In-vivo infection studies indicated that while S. Tirat-Zvi was able to infect and cause an acute inflammatory enterocolitis in young chicks, it was compromised in mice colonization and did not cause an inflammatory colitis in mice compared to S. Typhimurium. We suggest that these phenotypes reflect the distinctive ecological niche of this new serovar and its evolutionary adaptation to passerine birds, as a permissive host. Moreover, these results further illuminate the genetic, phenotypic and ecological diversity of S. enterica pathovars.


Assuntos
Arsênio , Salmonelose Animal , Salmonella enterica , Pardais , Animais , Camundongos , Salmonella enterica/genética , Salmonella typhimurium/genética , Sorogrupo , Salmonelose Animal/microbiologia , Virulência/genética
8.
J Exp Biol ; 215(Pt 20): 3639-48, 2012 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-22811252

RESUMO

The simple and well-characterized nervous system of C. elegans facilitates the analysis of mechanisms controlling behavior. Locomotion is a major behavioral output governed by multiple external and internal signals. Here, we examined the roles of low- and high-threshold mechanosensors in locomotion, using high-resolution and detailed analysis of locomotion and its dynamics. This analysis revealed a new role for touch receptor neurons in suppressing an intrinsic direction bias of locomotion. We also examined the response to noxious mechanical stimuli, which was found to involve several locomotion properties and to last several minutes. Effects on different locomotion properties have different half-lives and depend on different, partly overlapping sets of sensory neurons. PVD and FLP, high-threshold mechanosensors, play a major role in some of these responses. Overall, our results demonstrate the power of detailed, prolonged and high-resolution analysis of locomotion and locomotion dynamics in enabling better understanding of gene and neuron function.


Assuntos
Caenorhabditis elegans/fisiologia , Mecanotransdução Celular , Células Receptoras Sensoriais/fisiologia , Animais , Comportamento Animal/fisiologia , Locomoção
9.
Clin Microbiol Infect ; 28(11): 1499.e7-1499.e14, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35654317

RESUMO

OBJECTIVES: Horizontal acquisition of mobile genetic elements is a powerful evolutionary driving force that can profoundly affect pathogens epidemiology and their interactions with the environment and host. In the last decade, the role of the epidemic megaplasmid, pESI was demonstrated in the global emergence of multi-drug resistant (MDR) Salmonella enterica serovar Infantis strains, but it was unknown if this was a one-time phenomenon, or that pESI can drive the emergence of other pathogens. METHODS: Epidemiological, molecular, whole genome sequencing, de-novo assembly, bioinformatics and genetic approaches were used to analyze the emergence of a pESI-positive Salmonella enterica serovar Muenchen strain in Israel. RESULTS: Since 2018, we report the emergence and high prevalence of S. Muenchen in Israel, which consisted at 2020, 40% (1055/2671) of all clinical Salmonella isolates. We show that the emergence of S. Muenchen is dominated by a clonal MDR strain, report its complete assembled genome sequence, and demonstrate that in contrast to preemergent strains, it harbors the epidemic megaplasmid, pESI, which can be self-mobilized into E. coli and other Salmonella serovars. Additionally, we identified bioinformatically highly similar genomes of clinical isolates that were recently collected in South Africa, UK and USA. CONCLUSIONS: This is a second documented case of a pathogen emergence associated with pESI acquisition. Considering the genetic cargo of pESI that enhances resistance, stress tolerance and virulence, and its ability to conjugate into prevalent Salmonella serovars, we provide further support that pESI facilities the emergence and spreading of new Salmonella strains.


Assuntos
Farmacorresistência Bacteriana Múltipla , Salmonella enterica , Humanos , Sorogrupo , Farmacorresistência Bacteriana Múltipla/genética , Escherichia coli , Israel/epidemiologia , Plasmídeos/genética , Salmonella/genética , Antibacterianos/farmacologia
10.
Gut Microbes ; 14(1): 1997294, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34923900

RESUMO

DksA is a conserved RNA polymerase-binding protein known to play a key role in the stringent response of proteobacteria species, including many gastrointestinal pathogens. Here, we used RNA-sequencing of Escherichia coli, Salmonella bongori and Salmonella enterica serovar Typhimurium, together with phenotypic comparison to study changes in the DksA regulon, during Salmonella evolution. Comparative RNA-sequencing showed that under non-starved conditions, DksA controls the expression of 25%, 15%, and 20% of the E. coli, S. bongori, and S. enterica genes, respectively, indicating that DksA is a pleiotropic regulator, expanding its role beyond the canonical stringent response. We demonstrate that DksA is required for the growth of these three enteric bacteria species in minimal medium and controls the expression of the TCA cycle, glycolysis, pyrimidine biosynthesis, and quorum sensing. Interestingly, at multiple steps during Salmonella evolution, the type I fimbriae and various virulence genes encoded within SPIs 1, 2, 4, 5, and 11 have been transcriptionally integrated under the ancestral DksA regulon. Consequently, we show that DksA is necessary for host cells invasion by S. Typhimurium and S. bongori and for intracellular survival of S. Typhimurium in bone marrow-derived macrophages (BMDM). Moreover, we demonstrate regulatory inversion of the conserved motility-chemotaxis regulon by DksA, which acts as a negative regulator in E. coli, but activates this pathway in S. bongori and S. enterica. Overall, this study demonstrates the regulatory assimilation of multiple horizontally acquired virulence genes under the DksA regulon and provides new insights into the evolution of virulence genes regulation in Salmonella spp.


Assuntos
Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Evolução Molecular , Salmonella typhimurium/genética , Salmonella/genética , Salmonella/metabolismo , Fatores de Virulência/genética , Fatores de Virulência/metabolismo , Ciclo do Ácido Cítrico , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/classificação , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Regulação Bacteriana da Expressão Gênica , Transferência Genética Horizontal , Glicólise , Humanos , Pirimidinas/biossíntese , Regulon , Salmonella/citologia , Salmonella/patogenicidade , Infecções por Salmonella/microbiologia , Salmonella typhimurium/citologia , Salmonella typhimurium/metabolismo , Salmonella typhimurium/patogenicidade , Virulência
11.
Genome Biol Evol ; 12(3): 151-159, 2020 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-32145019

RESUMO

Salmonella enterica serovar Infantis (S. Infantis) is one of the dominant serovars of the bacterial pathogen S. enterica. In recent years, the number of human infections caused by S. Infantis has been increasing in many countries, and often the emerging population harbors a unique virulence-resistant megaplasmid called plasmid of emerging S. Infantis (pESI). Here, we report the complete gap-free genome sequence of the S. Infantis Israeli emerging clone and compare its chromosome and pESI sequences with other complete S. Infantis genomes. We show a conserved presence of the Salmonella pathogenicity islands 1-6, 9, 11, 12, and CS54 and a common integration of five bacteriophages in the S. Infantis chromosome. In contrast, we found variable presence of additionally three chromosomally integrated phages and eight modular regions in pESI, which contribute to the genetic and phenotypic diversity (including antimicrobial resistance) of this ubiquitous foodborne pathogen.


Assuntos
Genoma Bacteriano , Salmonella enterica/genética , Ilhas Genômicas , Genômica , Plasmídeos/genética , Virulência/genética
12.
iScience ; 23(7): 101262, 2020 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-32585595

RESUMO

PhenolaTi is an advanced non-toxic anticancer chemotherapy; this inert bis(phenolato)bis(alkoxo) Ti(IV) complex demonstrates the intriguing combination of high and wide efficacy with no detected toxicity in animals. Here we unravel the cellular pathways involved in its mechanism of action by a first genome study on Ti(IV)-treated cells, using an attuned RNA sequencing-based available technology. First, phenolaTi induced apoptosis and cell-cycle arrest at the G2/M phase in MCF7 cells. Second, the transcriptome of the treated cells was analyzed, identifying alterations in pathways relating to protein translation, DNA damage, and mitochondrial eruption. Unlike for common metallodrugs, electrophoresis assay showed no inhibition of DNA polymerase activity. Reduced in vitro cytotoxicity with added endoplasmic reticulum (ER) stress inhibitor supported the ER as a putative cellular target. Altogether, this paper reveals a distinct ER-related mechanism by the Ti(IV) anticancer coordination complex, paving the way for wider applicability of related techniques in mechanistic analyses of metallodrugs.

13.
Front Pharmacol ; 10: 1567, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-32009965

RESUMO

C. elegans PVD neurons are conserved for morphology, function and molecular determinants with mammalian polymodal nociceptors. Functions of polymodal nociceptors require activities of multiple ion channels and receptors including members of the TRP family. GTL-1, a member of the TRPM subclass of TRP channels, was previously shown to amplify PVD-mediated responses to optogenetic stimuli. Here we characterize effects of GTL-1 on PVD-mediated behavioral responses to noxious stimuli. We show that GTL-1 is required within PVD for the immediate and enduring response to thermal (cold) stimuli. But, find no significant reduction in percent animals responding to single or to repeated noxious mechanical stimuli. Nevertheless, PVD specific knockdown of gtl-1expression reduces the magnitude of responses to noxious mechanical stimuli. To understand GTL-1's mechanism of action we expressed it in HEK293 cells. Our results show GTL-1-dependent currents induced by activation of a Gαq-coupled Designer Receptor Exclusively Activated by Designer Drugs (DREADD). In addition, using excised patches we show that GTL-1 can be activated by internal calcium. Our results are consistent with indirect, calcium dependent, activation of GTL-1 by noxious stimuli. This mechanism explains the GTL-1-dependent amplification of responses to multiple stimuli optogenetic and sensory in PVD.

14.
J Mol Biol ; 431(9): 1711-1728, 2019 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-30878478

RESUMO

Myotonic dystrophy type 1 is an autosomal-dominant inherited disorder caused by the expansion of CTG repeats in the 3' untranslated region of the DMPK gene. The RNAs bearing these expanded repeats have a range of toxic effects. Here we provide evidence from a Caenorhabditis elegans myotonic dystrophy type 1 model that the RNA interference (RNAi) machinery plays a key role in causing RNA toxicity and disease phenotypes. We show that the expanded repeats systematically affect a range of endogenous genes bearing short non-pathogenic repeats and that this mechanism is dependent on the small RNA pathway. Conversely, by perturbating the RNA interference machinery, we reversed the RNA toxicity effect and reduced the disease pathogenesis. Our results unveil a role for RNA repeats as templates (based on sequence homology) for moderate but constant gene silencing. Such a silencing effect affects the cell steady state over time, with diverse impacts depending on tissue, developmental stage, and the type of repeat. Importantly, such a mechanism may be common among repeats and similar in human cells with different expanded repeat diseases.


Assuntos
Envelhecimento/genética , Caenorhabditis elegans/genética , Distrofia Miotônica/genética , Interferência de RNA , RNA de Cadeia Dupla/genética , Repetições de Trinucleotídeos , Regiões 3' não Traduzidas , Animais , Animais Geneticamente Modificados , Caenorhabditis elegans/crescimento & desenvolvimento , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Modelos Animais de Doenças , Genes Reporter , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Proteínas de Choque Térmico HSP70/genética , Proteínas de Choque Térmico HSP70/metabolismo , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Temperatura Alta , Humanos , Distrofia Miotônica/metabolismo , Distrofia Miotônica/patologia , Ligação Proteica , RNA de Cadeia Dupla/metabolismo , RNA de Helmintos/genética , RNA de Helmintos/metabolismo
15.
Mol Brain ; 9(1): 47, 2016 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-27129882

RESUMO

BACKGROUND: The nicotinic acetylcholine receptors form a large and diverse family of acetylcholine gated ion channels having diverse roles in the central nervous system. Maturation of nicotinic acetylcholine receptors is a complex and inefficient process requiring assistance from multiple cellular factors including RIC-3, a functionally conserved endoplasmic reticulum-resident protein and nicotinic acetylcholine receptor-specific chaperone. In mammals and in Drosophila melanogaster RIC-3 is alternatively spliced to produce multiple isoforms. RESULTS: We used electrophysiological analysis in Xenopus laevis oocytes, in situ hybridization, and quantitative real-time polymerase chain reaction assays to investigate regulation of RIC-3's expression and splicing and its effects on the expression of three major neuronal nicotinic acetylcholine receptors. We found that RIC-3 expression level and splicing affect nicotinic acetylcholine receptor functional expression and that two conserved RIC-3 isoforms express in the brain differentially. Moreover, in immune cells RIC-3 expression and splicing are regulated by inflammatory signals. CONCLUSIONS: Regulation of expression level and splicing of RIC-3 in brain and in immune cells following inflammation enables regulation of nicotinic acetylcholine receptor functional expression. Specifically, in immune cells such regulation via effects on α7 nicotinic acetylcholine receptor, known to function in the cholinergic anti-inflammatory pathway, may have a role in neuroinflammatory diseases.


Assuntos
Processamento Alternativo/genética , Proteínas de Membrana/genética , Chaperonas Moleculares/genética , Receptor Nicotínico de Acetilcolina alfa7/metabolismo , Acetilcolina/farmacologia , Processamento Alternativo/efeitos dos fármacos , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Hibridização In Situ , Inflamação/patologia , Ativação do Canal Iônico/efeitos dos fármacos , Proteínas de Membrana/metabolismo , Camundongos , Chaperonas Moleculares/metabolismo , Domínios Proteicos , Isoformas de Proteínas/metabolismo , Subunidades Proteicas/metabolismo , Células RAW 264.7 , Baço/metabolismo , Xenopus laevis
16.
J Cell Sci ; 122(Pt 6): 807-12, 2009 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-19223395

RESUMO

RIC-3 is a member of a conserved family of proteins that affect nicotinic acetylcholine receptor maturation. In yeast and in vitro, BATH-42, a BTB- and MATH-domain-containing protein, interacts with RIC-3. BATH-42 is also known to interact with the CUL-3 ubiquitin ligase complex. Loss of BATH-42 function leads to increased RIC-3 expression and decreased activity of nicotinic acetylcholine receptors in Caenorhabditis elegans vulva muscles. Increased expression of RIC-3 is deleterious for activity and distribution of nicotinic acetylcholine receptors, and thus the effects of BATH-42 loss of function on RIC-3 expression explain the associated reduction in receptor activity. Overexpression of BATH-42 is also detrimental to nicotinic acetylcholine receptor function, leading to decreased pharyngeal pumping. This effect depends on the C-terminus of RIC-3 and on CUL-3. Thus, our work suggests that BATH-42 targets RIC-3 to degradation via CUL-3-mediated ubiquitylation. This demonstrates the importance of regulation of RIC-3 levels, and identifies a mechanism that protects cells from the deleterious effects of excess RIC-3.


Assuntos
Proteínas de Caenorhabditis elegans/química , Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Proteínas de Transporte/química , Proteínas de Transporte/metabolismo , Receptores Nicotínicos/metabolismo , Animais , Caenorhabditis elegans/citologia , Caenorhabditis elegans/efeitos dos fármacos , Feminino , Levamisol/farmacologia , Músculos/citologia , Músculos/efeitos dos fármacos , Músculos/metabolismo , Mutação/genética , Faringe/citologia , Faringe/metabolismo , Ligação Proteica , Estrutura Terciária de Proteína , Transporte Proteico/efeitos dos fármacos , Vulva/citologia , Vulva/efeitos dos fármacos , Vulva/metabolismo
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