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1.
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
2.
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
3.
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
4.
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
5.
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
6.
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
7.
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
8.
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
9.
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
10.
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
11.
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
12.
J Cell Sci ; 137(4)2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38264908

RESUMO

Activator of G-protein signaling 3 (AGS3; also known as GPSM1), a receptor-independent activator of G-protein signaling, oscillates among defined subcellular compartments and biomolecular condensates (BMCs) in a regulated manner that is likely related to the functional diversity of the protein. We determined the influence of cell stress on the cellular distribution of AGS3 and core material properties of AGS3 BMCs. Cellular stress (oxidative, pHi and thermal) induced the formation of AGS3 BMCs in HeLa and COS-7 cells, as determined by fluorescent microscopy. Oxidative stress-induced AGS3 BMCs were distinct from G3BP1 stress granules and from RNA processing BMCs defined by the P-body protein Dcp1a. Immunoblots indicated that cellular stress shifted AGS3, but not the stress granule protein G3BP1 to a membrane pellet fraction following cell lysis. The stress-induced generation of AGS3 BMCs was reduced by co-expression of the signaling protein Gαi3, but not the AGS3-binding partner DVL2. Fluorescent recovery following photobleaching of individual AGS3 BMCs indicated that there are distinct diffusion kinetics and restricted fluidity for AGS3 BMCs. These data suggest that AGS3 BMCs represent a distinct class of stress granules that serve as a previously unrecognized signal processing node.


Assuntos
Condensados Biomoleculares , Proteínas de Transporte , Proteínas de Transporte/metabolismo , DNA Helicases , Proteínas de Ligação ao GTP/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/genética , RNA Helicases/metabolismo , Proteínas com Motivo de Reconhecimento de RNA , Humanos , Animais
13.
Nat Methods ; 21(2): 247-258, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38200227

RESUMO

RNA-binding proteins (RBPs) regulate diverse cellular processes by dynamically interacting with RNA targets. However, effective methods to capture both stable and transient interactions between RBPs and their RNA targets are still lacking, especially when the interaction is dynamic or samples are limited. Here we present an assay of reverse transcription-based RBP binding site sequencing (ARTR-seq), which relies on in situ reverse transcription of RBP-bound RNAs guided by antibodies to identify RBP binding sites. ARTR-seq avoids ultraviolet crosslinking and immunoprecipitation, allowing for efficient and specific identification of RBP binding sites from as few as 20 cells or a tissue section. Taking advantage of rapid formaldehyde fixation, ARTR-seq enables capturing the dynamic RNA binding by RBPs over a short period of time, as demonstrated by the profiling of dynamic RNA binding of G3BP1 during stress granule assembly on a timescale as short as 10 minutes.


Assuntos
RNA , Transcrição Reversa , RNA/genética , RNA/metabolismo , DNA Helicases/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/genética , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , RNA Helicases/genética , RNA Helicases/metabolismo , Proteínas com Motivo de Reconhecimento de RNA/genética , Proteínas com Motivo de Reconhecimento de RNA/metabolismo , Proteínas de Ligação a RNA/metabolismo , Sítios de Ligação/genética , Ligação Proteica
14.
Biochem Biophys Res Commun ; 697: 149497, 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38262290

RESUMO

Stress granule (SG) is a temporary cellular structure that plays a crucial role in the regulation of mRNA and protein sequestration during various cellular stress conditions. SG enables cells to cope with stress more effectively, conserving vital energy and resources. Focusing on the NTF2-like domain of G3BP1, a key protein in SG dynamics, we explore to identify and characterize novel small molecules involved in SG modulation without external stressors. Through in silico molecular docking approach to simulate the interaction between various compounds and the NTF2-like domain of G3BP1, we identified three compounds as potential candidates that could bind to the NTF2-like domain of G3BP1. Subsequent immunofluorescence experiments demonstrated that these compounds induce the formation of SG-like, G3BP1-positive granules. Importantly, the granule formation by these compounds occurs independent from the phosphorylation of eIF2α, a common mechanism in SG formation, suggesting that it might offer a new strategy for influencing SG dynamics implicated in various diseases.


Assuntos
DNA Helicases , RNA Helicases , DNA Helicases/metabolismo , RNA Helicases/metabolismo , Proteínas com Motivo de Reconhecimento de RNA/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Simulação de Acoplamento Molecular , Grânulos Citoplasmáticos/metabolismo
15.
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
16.
J Nanobiotechnology ; 22(1): 35, 2024 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-38243224

RESUMO

BACKGROUND: Most patients with ovarian cancer (OC) treated with platinum-based chemotherapy have a dismal prognosis owing to drug resistance. However, the regulatory mechanisms of circular RNA (circRNA) and p53 ubiquitination are unknown in platinum-resistant OC. We aimed to identify circRNAs associated with platinum-resistant OC to develop a novel treatment strategy. METHODS: Platinum-resistant circRNAs were screened through circRNA sequencing and validated using quantitative reverse-transcription PCR in OC cells and tissues. The characteristics of circNUP50 were analysed using Sanger sequencing, oligo (dT) primers, ribonuclease R and fluorescence in situ hybridisation assays. Functional experimental studies were performed in vitro and in vivo. The mechanism underlying circNUP50-mediated P53 ubiquitination was investigated through circRNA pull-down analysis and mass spectrometry, luciferase reporters, RNA binding protein immunoprecipitation, immunofluorescence assays, cycloheximide chase assays, and ubiquitination experiments. Finally, a platinum and si-circNUP50 co-delivery nanosystem (Psc@DPP) was constructed to treat platinum-resistant OC in an orthotopic animal model. RESULTS: We found that circNUP50 contributes to platinum-resistant conditions in OC by promoting cell proliferation, affecting the cell cycle, and reducing apoptosis. The si-circNUP50 mRNA sequencing and circRNA pull-down analysis showed that circNUP50 mediates platinum resistance in OC by binding p53 and UBE2T, accelerating p53 ubiquitination. By contrast, miRNA sequencing and circRNA pull-down experiments indicated that circNUP50 could serve as a sponge for miR-197-3p, thereby upregulating G3BP1 to mediate p53 ubiquitination, promoting OC platinum resistance. Psc@DPP effectively overcame platinum resistance in an OC tumour model and provided a novel idea for treating platinum-resistant OC using si-circNUP50. CONCLUSIONS: This study reveals a novel molecular mechanism by which circNUP50 mediates platinum resistance in OC by modulating p53 ubiquitination and provides new insights for developing effective therapeutic strategies for platinum resistance in OC.


Assuntos
MicroRNAs , Neoplasias Ovarianas , Enzimas de Conjugação de Ubiquitina , Animais , Humanos , Feminino , Cisplatino/farmacologia , Cisplatino/uso terapêutico , MicroRNAs/metabolismo , RNA Circular/genética , RNA Circular/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , DNA Helicases/genética , DNA Helicases/metabolismo , Linhagem Celular Tumoral , Proteínas de Ligação a Poli-ADP-Ribose/genética , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , RNA Helicases/genética , RNA Helicases/metabolismo , RNA Helicases/uso terapêutico , Proteínas com Motivo de Reconhecimento de RNA/genética , Proteínas com Motivo de Reconhecimento de RNA/metabolismo , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Ubiquitinação , Proliferação de Células , Resistencia a Medicamentos Antineoplásicos
17.
J Cell Biol ; 223(3)2024 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-38284934

RESUMO

Stress granule formation is triggered by the release of mRNAs from polysomes and is promoted by the action of the RNA-binding proteins G3BP1/2. Stress granules have been implicated in several disease states, including cancer and neurodegeneration. Consequently, compounds that limit stress granule formation or promote their dissolution have potential as both experimental tools and novel therapeutics. Herein, we describe two small molecules, G3BP inhibitor a and b (G3Ia and G3Ib), designed to bind to a specific pocket in G3BP1/2 that is targeted by viral inhibitors of G3BP1/2 function. In addition to disrupting the co-condensation of RNA, G3BP1, and caprin 1 in vitro, these compounds inhibit stress granule formation in cells treated prior to or concurrent with stress and dissolve pre-existing stress granules. These effects are consistent across multiple cell types and a variety of initiating stressors. Thus, these compounds represent powerful tools to probe the biology of stress granules and hold promise for therapeutic interventions designed to modulate stress granule formation.


Assuntos
DNA Helicases , RNA Helicases , Grânulos de Estresse , DNA Helicases/genética , Proteínas de Ligação a Poli-ADP-Ribose/genética , RNA Helicases/genética , Proteínas com Motivo de Reconhecimento de RNA/genética
18.
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
19.
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
20.
Exp Neurol ; 373: 114678, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38185313

RESUMO

As the main bioactive component of musk, muscone has been reported to have marked protective effects in treating acute ischemic stroke (AIS). However, the specific anti-stroke mechanism of muscone still needs further research. In the current investigation, the PC12 cells OGD/R and the rat transient MCAO/R models were utilized as the AIS models. Serum hepatic and renal functional indexes (ALT, AST, BUN, and Cr) and cell viability were determined to select the appropriate muscone concentrations for in vitro and in vivo experiments. TTC, Hematoxylin and eosin (H&E), and Live/Dead staining were utilized to evaluate the protective effects of muscone in injured tissues and cells. Western blotting analysis, TUNEL staining, propidium iodide, and annexin V staining were applied to detect the anti-apoptotic effect of muscone. Double-label immunofluorescence staining of T-cell intracellular antigen-1 (TIA1) and Ras-GAP SH3 domain-binding protein 1 (G3BP1) was performed to observe whether muscone regulated the SG formation level. Molecular docking, TIA1 silencing and TIA1 overexpression experiments were employed to investigate the molecular mechanism underlying the regulation of SG formation by muscone. The 2, 3, 5-Triphenyl-tetrazolium chloride (TTC) staining and live/dead staining showed the AIS injury level of MCAO/R rat and the OGD/R PC12 cells were attenuated by muscone administration. The muscone significantly minimized the apoptosis rate in MCAO/R rats and OGD/R PC12 cells following flow cytometry analysis, western blotting analysis, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. The double-label immunofluorescence staining data revealed that muscone promoted the SG formation level in OGD/R PC12 cells and the cortex MCAO/R rats. The results of molecular docking, TIA1 silencing and TIA1 overexpression experiments revealed that muscone could bind to TIA1 protein and regulate its expression level, thereby promoting the formation of stress granules and exerting a protective effect against AIS injury. This study indicated that the significant protective effect of muscone in reducing apoptosis levels might be via promoting SG formation under AIS conditions. This study further explores the therapeutic effect and anti-apoptosis mechanism of muscone in AIS, which may provide a potential candidate drug for the clinical treatment of AIS injury.


Assuntos
Isquemia Encefálica , Cicloparafinas , AVC Isquêmico , Traumatismo por Reperfusão , Acidente Vascular Cerebral , Ratos , Animais , AVC Isquêmico/tratamento farmacológico , DNA Helicases , Simulação de Acoplamento Molecular , Grânulos de Estresse , Proteínas de Ligação a Poli-ADP-Ribose , RNA Helicases , Proteínas com Motivo de Reconhecimento de RNA , Apoptose , Acidente Vascular Cerebral/tratamento farmacológico , Traumatismo por Reperfusão/tratamento farmacológico , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/metabolismo
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