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1.
Biochem Soc Trans ; 52(3): 1393-1404, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38778761

RESUMO

Several biomolecular condensates assemble in mammalian cells in response to viral infection. The most studied of these are stress granules (SGs), which have been proposed to promote antiviral innate immune signaling pathways, including the RLR-MAVS, the protein kinase R (PKR), and the OAS-RNase L pathways. However, recent studies have demonstrated that SGs either negatively regulate or do not impact antiviral signaling. Instead, the SG-nucleating protein, G3BP1, may function to perturb viral RNA biology by condensing viral RNA into viral-aggregated RNA condensates, thus explaining why viruses often antagonize G3BP1 or hijack its RNA condensing function. However, a recently identified condensate, termed double-stranded RNA-induced foci, promotes the activation of the PKR and OAS-RNase L antiviral pathways. In addition, SG-like condensates known as an RNase L-induced bodies (RLBs) have been observed during many viral infections, including SARS-CoV-2 and several flaviviruses. RLBs may function in promoting decay of cellular and viral RNA, as well as promoting ribosome-associated signaling pathways. Herein, we review these recent advances in the field of antiviral biomolecular condensates, and we provide perspective on the role of canonical SGs and G3BP1 during the antiviral response.


Assuntos
RNA Helicases , Proteínas com Motivo de Reconhecimento de RNA , RNA Viral , Grânulos de Estresse , Humanos , Animais , Proteínas com Motivo de Reconhecimento de RNA/metabolismo , RNA Helicases/metabolismo , RNA Viral/metabolismo , Grânulos de Estresse/metabolismo , SARS-CoV-2/fisiologia , Imunidade Inata , Transdução de Sinais , Condensados Biomoleculares/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Viroses/tratamento farmacológico , Viroses/metabolismo , DNA Helicases/metabolismo , eIF-2 Quinase/metabolismo , Endorribonucleases/metabolismo , COVID-19/virologia , COVID-19/imunologia
2.
Toxicol Lett ; 397: 48-54, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38734221

RESUMO

The skin, the organ with the largest surface area in the body, is the most susceptible to chemical exposure from the external environment. In this study, we aimed to establish an in vitro skin toxicity monitoring system that utilizes the mechanism of stress granule (SG) formation induced by various cellular stresses. In HaCaT cells, a keratinocyte cell line that comprises the human skin, a green fluorescent protein (GFP) was knocked in at the C-terminal genomic locus of Ras GTPase-activating protein-binding protein 1 (G3BP1), a representative component of SGs. The G3BP1-GFP knock-in HaCaT cells and wild-type (WT) HaCaT cells formed SGs containing G3BP1-GFP upon exposure to arsenite and household chemicals, such as bisphenol A (BPA) and benzalkonium chloride (BAC), in real-time. In addition, the exposure of G3BP1-GFP knock-in HaCaT cells to BPA and BAC promoted the phosphorylation of eukaryotic initiation factor 2 alpha and protein kinase R-like endoplasmic reticulum kinase, which are cell signaling factors involved in SG formation, similar to WT HaCaT cells. In conclusion, this novel G3BP1-GFP knock-in human skin cell system can monitor SG formation in real-time and be utilized to assess skin toxicity to various substances.


Assuntos
Grânulos Citoplasmáticos , DNA Helicases , Proteínas de Fluorescência Verde , Queratinócitos , Proteínas de Ligação a Poli-ADP-Ribose , RNA Helicases , Proteínas com Motivo de Reconhecimento de RNA , Humanos , Proteínas com Motivo de Reconhecimento de RNA/genética , Proteínas com Motivo de Reconhecimento de RNA/metabolismo , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , RNA Helicases/genética , RNA Helicases/metabolismo , DNA Helicases/genética , DNA Helicases/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/genética , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Grânulos Citoplasmáticos/efeitos dos fármacos , Grânulos Citoplasmáticos/metabolismo , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Arsenitos/toxicidade , Pele/efeitos dos fármacos , Pele/metabolismo , Técnicas de Introdução de Genes , Genes Reporter/efeitos dos fármacos , Fenóis/toxicidade , Células HaCaT , Fosforilação , Compostos Benzidrílicos/toxicidade , Fator de Iniciação 2 em Eucariotos/metabolismo , Fator de Iniciação 2 em Eucariotos/genética , Testes de Toxicidade/métodos
3.
Chemosphere ; 361: 142485, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38821132

RESUMO

Acute stress caused by short-term exposure to deleterious chemicals can induce the aggregation of RNA-binding proteins (RBPs) in the cytosol and the formation of stress granules (SGs). The cytoplasmic RBP, Ras GTPase-activating protein-binding protein 1 (G3BP1) is a critical organizer of SG, and its aggregation is considered a hallmark of cellular stress. However, assembly of SG is a highly dynamic process that involves RBPs; hence, existing methods based on fixation processes or overexpression of RBPs exhibit limited efficacy in detecting the assembly of SG under stress conditions. In this study, we established a G3BP1- Green fluorescent protein (GFP) reporter protein in a human neuroblastoma cell line to overcome these limitations. GFP was introduced into the G3BP1 genomic sequence via homologous recombination to generate a G3BP1-GFP fusion protein and further analyze the aggregation processes. We validated the assembly of SG under stress conditions using the G3BP1-GFP reporter system. Additionally, this system supported the evaluation of bisphenol A-induced SG response in the established human neuroblastoma cell line. In conclusion, the established G3BP1-GFP reporter system enables us to monitor the assembly of the SG complex in a human neuroblastoma cell line in real time and can serve as an efficient tool for assessing potential neurotoxicity associated with short-term exposure to chemicals.


Assuntos
DNA Helicases , Proteínas de Fluorescência Verde , Neuroblastoma , Proteínas de Ligação a Poli-ADP-Ribose , RNA Helicases , Proteínas com Motivo de Reconhecimento de RNA , Humanos , Proteínas com Motivo de Reconhecimento de RNA/genética , Proteínas com Motivo de Reconhecimento de RNA/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/genética , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Linhagem Celular Tumoral , RNA Helicases/genética , RNA Helicases/metabolismo , Neuroblastoma/patologia , DNA Helicases/metabolismo , Grânulos de Estresse , Estresse Fisiológico , Proteínas de Ligação a RNA/metabolismo , Proteínas de Ligação a RNA/genética
4.
Front Immunol ; 15: 1358036, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38690262

RESUMO

Background: It remains unclear whether BPIV3 infection leads to stress granules formation and whether G3BP1 plays a role in this process and in viral replication. This study aims to clarify the association between BPIV3 and stress granules, explore the effect of G3BP1 on BPIV3 replication, and provide significant insights into the mechanisms by which BPIV3 evades the host's antiviral immunity to support its own survival. Methods: Here, we use Immunofluorescence staining to observe the effect of BPIV3 infection on the assembly of stress granules. Meanwhile, the expression changes of eIF2α and G3BP1 were determined. Overexpression or siRNA silencing of intracellular G3BP1 levels was examined for its regulatory control of BPIV3 replication. Results: We identify that the BPIV3 infection elicited phosphorylation of the eIF2α protein. However, it did not induce the assembly of stress granules; rather, it inhibited the formation of stress granules and downregulated the expression of G3BP1. G3BP1 overexpression facilitated the formation of stress granules within cells and hindered viral replication, while G3BP1 knockdown enhanced BPIV3 expression. Conclusion: This study suggest that G3BP1 plays a crucial role in BPIV3 suppressing stress granule formation and viral replication.


Assuntos
DNA Helicases , Proteínas de Ligação a Poli-ADP-Ribose , RNA Helicases , Proteínas com Motivo de Reconhecimento de RNA , Grânulos de Estresse , Replicação Viral , Animais , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/genética , Proteínas com Motivo de Reconhecimento de RNA/metabolismo , DNA Helicases/metabolismo , DNA Helicases/genética , RNA Helicases/metabolismo , RNA Helicases/genética , Grânulos de Estresse/metabolismo , Bovinos , Fator de Iniciação 2 em Eucariotos/metabolismo , Infecções por Respirovirus/imunologia , Infecções por Respirovirus/metabolismo , Interações Hospedeiro-Patógeno/imunologia , Fosforilação , Linhagem Celular , Grânulos Citoplasmáticos/metabolismo
5.
Int J Mol Sci ; 25(10)2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38791594

RESUMO

In plants, nucleotide-binding site and leucine-rich repeat proteins (NLRs) play pivotal roles in effector-triggered immunity (ETI). However, the precise mechanisms underlying NLR-mediated disease resistance remain elusive. Previous studies have demonstrated that the NLR gene pair Pik-H4 confers resistance to rice blast disease by interacting with the transcription factor OsBIHD1, consequently leading to the upregulation of hormone pathways. In the present study, we identified an RNA recognition motif (RRM) protein, OsRRM2, which interacted with Pik1-H4 and Pik2-H4 in vesicles and chloroplasts. OsRRM2 exhibited a modest influence on Pik-H4-mediated rice blast resistance by upregulating resistance genes and genes associated with chloroplast immunity. Moreover, the RNA-binding sequence of OsRRM2 was elucidated using systematic evolution of ligands by exponential enrichment. Transcriptome analysis further indicated that OsRRM2 promoted RNA editing of the chloroplastic gene ndhB. Collectively, our findings uncovered a chloroplastic RRM protein that facilitated the translocation of the NLR gene pair and modulated chloroplast immunity, thereby bridging the gap between ETI and chloroplast immunity.


Assuntos
Cloroplastos , Regulação da Expressão Gênica de Plantas , Oryza , Imunidade Vegetal , Proteínas de Plantas , Cloroplastos/metabolismo , Cloroplastos/genética , Imunidade Vegetal/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Oryza/genética , Oryza/metabolismo , Oryza/imunologia , Proteínas de Repetições Ricas em Leucina , Sítios de Ligação , Proteínas com Motivo de Reconhecimento de RNA/metabolismo , Proteínas com Motivo de Reconhecimento de RNA/genética , Doenças das Plantas/genética , Doenças das Plantas/imunologia , Resistência à Doença/genética , Proteínas NLR/metabolismo , Proteínas NLR/genética , Edição de RNA
6.
Nat Commun ; 15(1): 4127, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38750080

RESUMO

Stress granules (SGs) are induced by various environmental stressors, resulting in their compositional and functional heterogeneity. SGs play a crucial role in the antiviral process, owing to their potent translational repressive effects and ability to trigger signal transduction; however, it is poorly understood how these antiviral SGs differ from SGs induced by other environmental stressors. Here we identify that TRIM25, a known driver of the ubiquitination-dependent antiviral innate immune response, is a potent and critical marker of the antiviral SGs. TRIM25 undergoes liquid-liquid phase separation (LLPS) and co-condenses with the SG core protein G3BP1 in a dsRNA-dependent manner. The co-condensation of TRIM25 and G3BP1 results in a significant enhancement of TRIM25's ubiquitination activity towards multiple antiviral proteins, which are mainly located in SGs. This co-condensation is critical in activating the RIG-I signaling pathway, thus restraining RNA virus infection. Our studies provide a conceptual framework for better understanding the heterogeneity of stress granule components and their response to distinct environmental stressors.


Assuntos
DNA Helicases , Proteínas de Ligação a Poli-ADP-Ribose , RNA Helicases , Proteínas com Motivo de Reconhecimento de RNA , Transdução de Sinais , Grânulos de Estresse , Proteínas com Motivo Tripartido , Ubiquitina-Proteína Ligases , Ubiquitinação , Humanos , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/genética , Proteínas com Motivo Tripartido/metabolismo , Proteínas com Motivo Tripartido/genética , Proteínas com Motivo de Reconhecimento de RNA/metabolismo , Proteínas com Motivo de Reconhecimento de RNA/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética , Grânulos de Estresse/metabolismo , RNA Helicases/metabolismo , DNA Helicases/metabolismo , Proteína DEAD-box 58/metabolismo , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Imunidade Inata , RNA de Cadeia Dupla/metabolismo , Células HEK293 , Células HeLa , Grânulos Citoplasmáticos/metabolismo , Infecções por Vírus de RNA/virologia , Infecções por Vírus de RNA/metabolismo , Infecções por Vírus de RNA/imunologia , Receptores Imunológicos/metabolismo
7.
Cancer Sci ; 115(6): 1851-1865, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38581120

RESUMO

Aberrant expression of forkhead box transcription factor 1 (FOXM1) plays critical roles in a variety of human malignancies and predicts poor prognosis. However, little is known about the crosstalk between FOXM1 and long noncoding RNAs (lncRNAs) in tumorigenesis. The present study identifies a previously uncharacterized lncRNA XLOC_008672 in gastric cancer (GC), which is regulated by FOXM1 and possesses multiple copies of tandem repetitive sequences. LncRNA microarrays are used to screen differentially expressed lncRNAs in FOXM1 knockdown GC cells, and then the highest fold downregulation lncRNA XLOC_008672 is screened out. Sequence analysis reveals that the new lncRNA contains 62 copies of 37-bp tandem repeats. It is transcriptionally activated by FOXM1 and functions as a downstream effector of FOXM1 in GC cells through in vitro and in vivo functional assays. Elevated expression of XLOC_008672 is found in GC tissues and indicates worse prognosis. Mechanistically, XLOC_008672 can bind to small nuclear ribonucleoprotein polypeptide A (SNRPA), thereby enhancing mRNA stability of Ras-GTPase-activating protein SH3 domain-binding protein 1 (G3BP1) and, consequently, facilitating GC cell proliferation and migration. Our study discovers a new uncharacterized lncRNA XLOC_008672 involved in GC carcinogenesis and progression. Targeting FOXM1/XLOC_008672/SNRPA/G3BP1 signaling axis might be a promising therapeutic strategy for GC.


Assuntos
Carcinogênese , Proliferação de Células , Proteína Forkhead Box M1 , Regulação Neoplásica da Expressão Gênica , Proteínas de Ligação a Poli-ADP-Ribose , Proteínas com Motivo de Reconhecimento de RNA , RNA Longo não Codificante , Neoplasias Gástricas , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Humanos , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Neoplasias Gástricas/metabolismo , Proteína Forkhead Box M1/genética , Proteína Forkhead Box M1/metabolismo , Linhagem Celular Tumoral , Proteínas com Motivo de Reconhecimento de RNA/genética , Proteínas com Motivo de Reconhecimento de RNA/metabolismo , Carcinogênese/genética , Proliferação de Células/genética , Animais , Camundongos , Proteínas de Ligação a Poli-ADP-Ribose/genética , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Movimento Celular/genética , Sequências de Repetição em Tandem/genética , Prognóstico , Camundongos Nus , Masculino , Feminino , DNA Helicases , RNA Helicases
8.
Int J Mol Sci ; 25(7)2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38612449

RESUMO

Stress granules (SGs) are membraneless ribonucleoprotein (RNP)-based cellular foci formed in response to stress, facilitating cell survival by protecting against damage. Mammalian spermatogenesis should be maintained below body temperature for proper development, indicating its vulnerability to heat stress (HS). In this study, biotin tracer permeability assays showed that the inhibition of heat-induced SG assembly in the testis by 4-8 mg/kg cycloheximide significantly increased the percentage of seminiferous tubules with a damaged blood-testis barrier (BTB). Western blot results additionally revealed that the suppression of heat-induced SG assembly in Sertoli cell line, TM4 cells, by RNA inference of G3bp1/2 aggravated the decline in the BTB-related proteins ZO-1, ß-Catenin and Claudin-11, indicating that SGs could protect the BTB against damage caused by HS. The protein components that associate with SGs in Sertoli cells were isolated by sequential centrifugation and immunoprecipitation, and were identified by liquid chromatography with tandem mass spectrometry. Gene Ontology and KEGG pathway enrichment analysis revealed that their corresponding genes were mainly involved in pathways related to proteasomes, nucleotide excision repair, mismatch repair, and DNA replication. Furthermore, a new SG component, the ubiquitin associated protein 2 (UBAP2), was found to translocate to SGs upon HS in TM4 cells by immunofluorescence. Moreover, SG assembly was significantly diminished after UBAP2 knockdown by RNA inference during HS, suggesting the important role of UBAP2 in SG assembly. In addition, UBAP2 knockdown reduced the expression of ZO-1, ß-Catenin and Claudin-11, which implied its potential role in the function of the BTB. Overall, our study demonstrated the role of SGs in maintaining BTB functions during HS and identified a new component implicated in SG formation in Sertoli cells. These findings not only offer novel insights into the biological functions of SGs and the molecular mechanism of low fertility in males in summer, but also potentially provide an experimental basis for male fertility therapies.


Assuntos
Barreira Hematotesticular , DNA Helicases , Masculino , Animais , Camundongos , Proteínas de Ligação a Poli-ADP-Ribose , RNA Helicases , Proteínas com Motivo de Reconhecimento de RNA , Grânulos de Estresse , beta Catenina , RNA , Claudinas , Mamíferos
9.
J Gen Virol ; 105(4)2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38572740

RESUMO

The herpes simplex virus 1 (HSV1) virion host shutoff (vhs) protein is an endoribonuclease that regulates the translational environment of the infected cell, by inducing the degradation of host mRNA via cellular exonuclease activity. To further understand the relationship between translational shutoff and mRNA decay, we have used ectopic expression to compare HSV1 vhs (vhsH) to its homologues from four other alphaherpesviruses - varicella zoster virus (vhsV), bovine herpesvirus 1 (vhsB), equine herpesvirus 1 (vhsE) and Marek's disease virus (vhsM). Only vhsH, vhsB and vhsE induced degradation of a reporter luciferase mRNA, with poly(A)+ in situ hybridization indicating a global depletion of cytoplasmic poly(A)+ RNA and a concomitant increase in nuclear poly(A)+ RNA and the polyA tail binding protein PABPC1 in cells expressing these variants. By contrast, vhsV and vhsM failed to induce reporter mRNA decay and poly(A)+ depletion, but rather, induced cytoplasmic G3BP1 and poly(A)+ mRNA- containing granules and phosphorylation of the stress response proteins eIF2α and protein kinase R. Intriguingly, regardless of their apparent endoribonuclease activity, all vhs homologues induced an equivalent general blockade to translation as measured by single-cell puromycin incorporation. Taken together, these data suggest that the activities of translational arrest and mRNA decay induced by vhs are separable and we propose that they represent sequential steps of the vhs host interaction pathway.


Assuntos
Herpesvirus Humano 1 , Proteínas Virais , Proteínas Virais/genética , Proteínas Virais/metabolismo , Ribonucleases , DNA Helicases , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , RNA Helicases , Proteínas com Motivo de Reconhecimento de RNA/metabolismo , Herpesvirus Humano 1/genética , Endorribonucleases/metabolismo , Estabilidade de RNA , Vírion/genética , Vírion/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
10.
Vet Microbiol ; 293: 110070, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38593624

RESUMO

Stress granules (SGs), the main component is GTPase-activating protein-binding protein 1 (G3BP1), which are assembled during viral infection and function to sequester host and viral mRNAs and proteins, are part of the antiviral responses. In this study, we found that porcine deltacoronavirus (PDCoV) infection induced stable formation of robust SGs in cells through a PERK (protein kinase R-like endoplasmic reticulum kinase)-dependent mechanism. Overexpression of SGs marker proteins G3BP1 significantly reduced PDCoV replication in vitro, while inhibition of endogenous G3BP1 enhanced PDCoV replication. Moreover, PDCoV infected LLC-PK1 cells raise the phosphorylation level of G3BP1. By overexpression of the G3BP1 phosphorylated protein or the G3BP1 dephosphorylated protein, we found that phosphorylation of G3BP1 is involved in the regulation of PDCoV-induced inflammatory response. Taken together, our study presents a vital aspect of the host innate response to invading pathogens and reveals attractive host targets for antiviral target.


Assuntos
DNA Helicases , Inflamação , Proteínas de Ligação a Poli-ADP-Ribose , RNA Helicases , Proteínas com Motivo de Reconhecimento de RNA , Animais , Suínos , Proteínas com Motivo de Reconhecimento de RNA/genética , Proteínas com Motivo de Reconhecimento de RNA/metabolismo , Fosforilação , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/genética , RNA Helicases/metabolismo , RNA Helicases/genética , DNA Helicases/metabolismo , DNA Helicases/genética , Replicação Viral , Coronavirus/imunologia , Coronavirus/fisiologia , Linhagem Celular , Doenças dos Suínos/virologia , Doenças dos Suínos/imunologia , Doenças dos Suínos/genética , Imunidade Inata
11.
Signal Transduct Target Ther ; 9(1): 98, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38609366

RESUMO

Evidence suggests associations between COVID-19 patients or vaccines and glycometabolic dysfunction and an even higher risk of the occurrence of diabetes. Herein, we retrospectively analyzed pancreatic lesions in autopsy tissues from 67 SARS-CoV-2 infected non-human primates (NHPs) models and 121 vaccinated and infected NHPs from 2020 to 2023 and COVID-19 patients. Multi-label immunofluorescence revealed direct infection of both exocrine and endocrine pancreatic cells by the virus in NHPs and humans. Minor and limited phenotypic and histopathological changes were observed in adult models. Systemic proteomics and metabolomics results indicated metabolic disorders, mainly enriched in insulin resistance pathways, in infected adult NHPs, along with elevated fasting C-peptide and C-peptide/glucose ratio levels. Furthermore, in elder COVID-19 NHPs, SARS-CoV-2 infection causes loss of beta (ß) cells and lower expressed-insulin in situ characterized by islet amyloidosis and necrosis, activation of α-SMA and aggravated fibrosis consisting of lower collagen in serum, an increase of pancreatic inflammation and stress markers, ICAM-1 and G3BP1, along with more severe glycometabolic dysfunction. In contrast, vaccination maintained glucose homeostasis by activating insulin receptor α and insulin receptor ß. Overall, the cumulative risk of diabetes post-COVID-19 is closely tied to age, suggesting more attention should be paid to blood sugar management in elderly COVID-19 patients.


Assuntos
COVID-19 , Diabetes Mellitus , Adulto , Animais , Humanos , Idoso , SARS-CoV-2 , Receptor de Insulina , Peptídeo C , DNA Helicases , Estudos Retrospectivos , Proteínas de Ligação a Poli-ADP-Ribose , RNA Helicases , Proteínas com Motivo de Reconhecimento de RNA , Glucose
12.
Cell Rep ; 43(3): 113965, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38492217

RESUMO

G3BP1/2 are paralogous proteins that promote stress granule formation in response to cellular stresses, including viral infection. The nucleocapsid (N) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) inhibits stress granule assembly and interacts with G3BP1/2 via an ITFG motif, including residue F17, in the N protein. Prior studies examining the impact of the G3PB1-N interaction on SARS-CoV-2 replication have produced inconsistent findings, and the role of this interaction in pathogenesis is unknown. Here, we use structural and biochemical analyses to define the residues required for G3BP1-N interaction and structure-guided mutagenesis to selectively disrupt this interaction. We find that N-F17A mutation causes highly specific loss of interaction with G3BP1/2. SARS-CoV-2 N-F17A fails to inhibit stress granule assembly in cells, has decreased viral replication, and causes decreased pathology in vivo. Further mechanistic studies indicate that the N-F17-mediated G3BP1-N interaction promotes infection by limiting sequestration of viral genomic RNA (gRNA) into stress granules.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , DNA Helicases/metabolismo , RNA Helicases/metabolismo , Proteínas com Motivo de Reconhecimento de RNA/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Virulência , RNA Guia de Sistemas CRISPR-Cas , Proteínas do Nucleocapsídeo , Replicação Viral , RNA Viral/genética
13.
J Biochem ; 175(6): 629-641, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38299728

RESUMO

Proper regulation of cellular response to environmental stress is crucial for maintaining biological homeostasis and is achieved by the balance between cell death processes, such as the formation of the pyroptosis-inducing NLRP3 inflammasome, and pro-survival processes, such as stress granule (SG) assembly. However, the functional interplay between these two stress-responsive organelles remains elusive. Here, we identified DHX33, a viral RNA sensor for the NLRP3 inflammasome, as a SG component, and the SG-nucleating protein G3BP as an NLRP3 inflammasome component. We also found that a decrease in intracellular potassium (K+) concentration, a key 'common' step in NLRP3 inflammasome activation, markedly inhibited SG assembly. Therefore, when macrophages are exposed to stress stimuli with the potential to induce both SGs and the NLRP3 inflammasome, such as cytoplasmic poly(I:C) stimulation, they preferentially form the NLRP3 inflammasome but avoid SG assembly by sequestering G3BP into the inflammasome and by inducing a reduction in intracellular K+ levels. Thus, under such conditions, DHX33 is primarily utilized as a viral RNA sensor for the inflammasome. Our data reveal the functional crosstalk between NLRP3 inflammasome-mediated pyroptosis and SG-mediated cell survival pathways and delineate a molecular mechanism that regulates cell-fate decisions and anti-viral innate immunity under stress.


Assuntos
Inflamassomos , Proteína 3 que Contém Domínio de Pirina da Família NLR , Grânulos de Estresse , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Inflamassomos/metabolismo , Humanos , Grânulos de Estresse/metabolismo , Camundongos , Animais , Potássio/metabolismo , RNA Helicases DEAD-box/metabolismo , RNA Helicases DEAD-box/genética , Piroptose , RNA Helicases/metabolismo , Macrófagos/metabolismo , Macrófagos/virologia , Proteínas com Motivo de Reconhecimento de RNA/metabolismo , Poli I-C/farmacologia , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/genética , DNA Helicases
14.
Adv Sci (Weinh) ; 11(16): e2306174, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38368261

RESUMO

Patients with concurrent intrahepatic cholangiocarcinoma (ICC) and hepatolithiasis generally have poor prognoses. Hepatolithiasis is once considered the primary cause of ICC, although recent insights indicate that bacteria in the occurrence of hepatolithiasis can promote the progression of ICC. By constructing in vitro and in vivo ICC models and patient-derived organoids (PDOs), it is shown that Escherichia coli induces the production of a novel RNA, circGLIS3 (cGLIS3), which promotes tumor growth. cGLIS3 binds to hnRNPA1 and G3BP1, resulting in the assembly of stress granules (SGs) and suppression of hnRNPA1 and G3BP1 ubiquitination. Consequently, the IKKα mRNA is blocked in SGs, decreasing the production of IKKα and activating the NF-κB pathway, which finally results in chemoresistance and produces metastatic phenotypes of ICC. This study shows that a combination of Icaritin (ICA) and gemcitabine plus cisplatin (GP) chemotherapy can be a promising treatment strategy for ICC.


Assuntos
Neoplasias dos Ductos Biliares , Colangiocarcinoma , Progressão da Doença , Escherichia coli , NF-kappa B , Grânulos de Estresse , Animais , Humanos , Camundongos , Neoplasias dos Ductos Biliares/metabolismo , Neoplasias dos Ductos Biliares/genética , Neoplasias dos Ductos Biliares/patologia , Colangiocarcinoma/metabolismo , Colangiocarcinoma/genética , Colangiocarcinoma/patologia , Modelos Animais de Doenças , DNA Helicases , Escherichia coli/genética , Escherichia coli/metabolismo , Gencitabina , NF-kappa B/metabolismo , NF-kappa B/genética , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/genética , RNA Helicases , Proteínas com Motivo de Reconhecimento de RNA/metabolismo , Proteínas com Motivo de Reconhecimento de RNA/genética , Transdução de Sinais/genética , Grânulos de Estresse/metabolismo , Grânulos de Estresse/genética
15.
Cell Rep ; 43(2): 113769, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38363675

RESUMO

Although the composition and assembly of stress granules (SGs) are well understood, the molecular mechanisms underlying SG disassembly remain unclear. Here, we identify that heterogeneous nuclear ribonucleoprotein A2/B1 (hnRNPA2B1) is associated with SGs and that its absence specifically enhances the disassembly of arsenite-induced SGs depending on the ubiquitination-proteasome system but not the autophagy pathway. hnRNPA2B1 interacts with many core SG proteins, including G3BP1, G3BP2, USP10, and Caprin-1; USP10 can deubiquitinate G3BP1; and hnRNPA2B1 depletion attenuates the G3BP1-USP10/Caprin-1 interaction but elevates the G3BP1 ubiquitination level under arsenite treatment. Moreover, the disease-causing mutation FUSR521C also disassembles faster from SGs in HNRNPA2B1 mutant cells. Furthermore, knockout of hnRNPA2B1 in mice leads to Sertoli cell-only syndrome (SCOS), causing complete male infertility. Consistent with this, arsenite-induced SGs disassemble faster in Hnrnpa2b1 knockout (KO) mouse Sertoli cells as well. These findings reveal the essential roles of hnRNPA2B1 in regulating SG disassembly and male mouse fertility.


Assuntos
Arsenitos , Masculino , Animais , Camundongos , Arsenitos/toxicidade , DNA Helicases , Proteínas de Ligação a Poli-ADP-Ribose , RNA Helicases , Proteínas com Motivo de Reconhecimento de RNA , Grânulos de Estresse , Fertilidade
16.
Nat Commun ; 15(1): 640, 2024 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-38245532

RESUMO

Considerable progress has been made in understanding the molecular host-virus battlefield during SARS-CoV-2 infection. Nevertheless, the assembly and egress of newly formed virions are less understood. To identify host proteins involved in viral morphogenesis, we characterize the proteome of SARS-CoV-2 virions produced from A549-ACE2 and Calu-3 cells, isolated via ultracentrifugation on sucrose cushion or by ACE-2 affinity capture. Bioinformatic analysis unveils 92 SARS-CoV-2 virion-associated host factors, providing a valuable resource to better understand the molecular environment of virion production. We reveal that G3BP1 and G3BP2 (G3BP1/2), two major stress granule nucleators, are embedded within virions and unexpectedly favor virion production. Furthermore, we show that G3BP1/2 participate in the formation of cytoplasmic membrane vesicles, that are likely virion assembly sites, consistent with a proviral role of G3BP1/2 in SARS-CoV-2 dissemination. Altogether, these findings provide new insights into host factors required for SARS-CoV-2 assembly with potential implications for future therapeutic targeting.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/metabolismo , Replicação Viral , DNA Helicases/metabolismo , Proteômica , Proteínas com Motivo de Reconhecimento de RNA/metabolismo , COVID-19/metabolismo , RNA Helicases/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Montagem de Vírus , Vírion/metabolismo
17.
Int J Mol Sci ; 25(2)2024 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-38279260

RESUMO

Donation after circulatory death (DCD) hearts are predominantly maintained by normothermic blood perfusion (NBP). Nevertheless, it was shown that hypothermic crystalloid perfusion (HCP) is superior to blood perfusion to recondition left ventricular (LV) contractility. However, transcriptomic changes in the myocardium and coronary artery in DCD hearts after HCP and NBP have not been investigated yet. In a pig model, DCD hearts were harvested and maintained for 4 h by NBP (DCD-BP group, N = 8) or HCP with oxygenated histidine-tryptophane-ketoglutarate (HTK) solution (DCD-HTK, N = 8) followed by reperfusion with fresh blood for 2 h. In the DCD group (N = 8), hearts underwent reperfusion immediately after procurement. In the control group (N = 7), no circulatory death was induced. We performed transcriptomics from LV myocardial and left anterior descending (LAD) samples using microarrays (25,470 genes). We applied the Boruta algorithm for variable selection to identify relevant genes. In the DCD-BP group, compared to DCD, six genes were regulated in the myocardium and 1915 genes were regulated in the LAD. In the DCD-HTK group, 259 genes were downregulated in the myocardium and 27 in the LAD; and 52 genes were upregulated in the myocardium and 765 in the LAD, compared to the DCD group. We identified seven genes of relevance for group identification: ITPRIP, G3BP1, ARRDC3, XPO6, NOP2, SPTSSA, and IL-6. NBP resulted in the upregulation of genes involved in mitochondrial calcium accumulation and ROS production, the reduction in microvascular endothelial sprouting, and inflammation. HCP resulted in the downregulation of genes involved in NF-κB-, STAT3-, and SASP-activation and inflammation.


Assuntos
Transplante de Coração , Suínos , Animais , Humanos , Transplante de Coração/métodos , Vasos Coronários , Transcriptoma , DNA Helicases , Doadores de Tecidos , Proteínas de Ligação a Poli-ADP-Ribose , RNA Helicases , Proteínas com Motivo de Reconhecimento de RNA , Miocárdio , Perfusão/métodos , Perfilação da Expressão Gênica , Inflamação , Preservação de Órgãos/métodos , Morte
18.
Sci Adv ; 10(5): eadk8152, 2024 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-38295168

RESUMO

G3BP1 is an RNA binding protein that condenses untranslating messenger RNAs into stress granules (SGs). G3BP1 is inactivated by multiple viruses and is thought to antagonize viral replication by SG-enhanced antiviral signaling. Here, we show that neither G3BP1 nor SGs generally alter the activation of innate immune pathways. Instead, we show that the RNAs encoded by West Nile virus, Zika virus, and severe acute respiratory syndrome coronavirus 2 are prone to G3BP1-dependent RNA condensation, which is enhanced by limiting translation initiation and correlates with the disruption of viral replication organelles and viral RNA replication. We show that these viruses counteract condensation of their RNA genomes by inhibiting the RNA condensing function of G3BP proteins, hijacking the RNA decondensing activity of eIF4A, and/or maintaining efficient translation. These findings argue that RNA condensation can function as an intrinsic antiviral mechanism, which explains why many viruses inactivate G3BP proteins and suggests that SGs may have arisen as a vestige of this antiviral mechanism.


Assuntos
Infecção por Zika virus , Zika virus , Humanos , DNA Helicases , RNA Helicases , Proteínas de Ligação a Poli-ADP-Ribose , RNA Viral , Proteínas com Motivo de Reconhecimento de RNA , Antivirais
19.
J Mol Med (Berl) ; 102(3): 287-311, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38183492

RESUMO

Lysosomes function as critical signaling hubs that govern essential enzyme complexes. LGALS proteins (LGALS3, LGALS8, and LGALS9) are integral to the endomembrane damage response. If ESCRT fails to rectify damage, LGALS-mediated ubiquitination occurs, recruiting autophagy receptors (CALCOCO2, TRIM16, and SQSTM1) and VCP/p97 complex containing UBXN6, PLAA, and YOD1, initiating selective autophagy. Lysosome replenishment through biogenesis is regulated by TFEB. LGALS3 interacts with TFRC and TRIM16, aiding ESCRT-mediated repair and autophagy-mediated removal of damaged lysosomes. LGALS8 inhibits MTOR and activates TFEB for ATG and lysosomal gene transcription. LGALS9 inhibits USP9X, activates PRKAA2, MAP3K7, ubiquitination, and autophagy. Conjugation of ATG8 to single membranes (CASM) initiates damage repair mediated by ATP6V1A, ATG16L1, ATG12, ATG5, ATG3, and TECPR1. ATG8ylation or CASM activates the MERIT system (ESCRT-mediated repair, autophagy-mediated clearance, MCOLN1 activation, Ca2+ release, RRAG-GTPase regulation, MTOR modulation, TFEB activation, and activation of GTPase IRGM). Annexins ANAX1 and ANAX2 aid damage repair. Stress granules stabilize damaged membranes, recruiting FLCN-FNIP1/2, G3BP1, and NUFIP1 to inhibit MTOR and activate TFEB. Lysosomes coordinate the synergistic response to endomembrane damage and are vital for innate and adaptive immunity. Future research should unveil the collaborative actions of ATG proteins, LGALSs, TRIMs, autophagy receptors, and lysosomal proteins in lysosomal damage response.


Assuntos
DNA Helicases , Galectina 3 , Galectina 3/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , RNA Helicases/metabolismo , Proteínas com Motivo de Reconhecimento de RNA/metabolismo , Autofagia/genética , Serina-Treonina Quinases TOR/metabolismo , Lisossomos/metabolismo , GTP Fosfo-Hidrolases/metabolismo , Complexos Endossomais de Distribuição Requeridos para Transporte/metabolismo , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo
20.
Int J Biol Sci ; 20(1): 94-112, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38164170

RESUMO

Ras-GTPase-activating protein (GAP)-binding protein 1 (G3BP1) is an RNA-binding protein implicated in various malignancies. However, its role in nasopharyngeal carcinoma (NPC) remains elusive. This study elucidates the potential regulation mechanisms of G3BP1 and its significance in NPC advancement. Through knockdown and overexpression approaches, we validate G3BP1's oncogenic role by promoting proliferation, migration, and invasion in vitro and in vivo. Moreover, G3BP1 emerges as a key regulator of the JAK2/STAT3 signaling pathway, augmenting JAK2 expression via mRNA binding. Notably, epigallocatechin gallate (EGCG), a green tea-derived antioxidant, counteracts G3BP1-mediated pathway activation. Clinical analysis reveals heightened G3BP1, JAK2, and p-STAT3 as powerful prognostic markers, with G3BP1's expression standing as an independent indicator of poorer outcomes for NPC patients. In conclusion, the study unveils the oncogenic prowess of G3BP1, its orchestration of the JAK2/STAT3 signaling pathway, and its pivotal role in NPC progression.


Assuntos
DNA Helicases , Neoplasias Nasofaríngeas , Humanos , Carcinoma Nasofaríngeo/genética , DNA Helicases/metabolismo , RNA Helicases/genética , RNA Helicases/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Linhagem Celular Tumoral , Proteínas com Motivo de Reconhecimento de RNA/genética , Proteínas com Motivo de Reconhecimento de RNA/metabolismo , Transdução de Sinais/genética , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/patologia , Proliferação de Células/genética , Janus Quinase 2/genética , Janus Quinase 2/metabolismo
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