RESUMEN
Structural Maintenance of Chromosomes (SMC) complexes are important for many aspects of the chromosomal organization. Unlike cohesin and condensin, the SMC5/6 complex contains a variant RING domain carried by its Nse1 subunit. RING domains are characteristic for ubiquitin ligases, and human NSE1 has been shown to possess ubiquitin-ligase activity in vitro. However, other studies were unable to show such activity. Here, we confirm Nse1 ubiquitin-ligase activity using purified Schizosaccharomyces pombe proteins. We demonstrate that the Nse1 ligase activity is stimulated by Nse3 and Nse4. We show that Nse1 specifically utilizes Ubc13/Mms2 E2 enzyme and interacts directly with ubiquitin. We identify the Nse1 mutation (R188E) that specifically disrupts its E3 activity and demonstrate that the Nse1-dependent ubiquitination is particularly important under replication stress. Moreover, we determine Nse4 (lysine K181) as the first known SMC5/6-associated Nse1 substrate. Interestingly, abolition of Nse4 modification at K181 leads to suppression of DNA-damage sensitivity of other SMC5/6 mutants. Altogether, this study brings new evidence for Nse1 ubiquitin ligase activity, significantly advancing our understanding of this enigmatic SMC5/6 function.
Asunto(s)
Proteínas Portadoras/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas Cromosómicas no Histona/metabolismo , Ligasas/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Ubiquitina/metabolismo , Ubiquitinación/inmunología , HumanosRESUMEN
Interleukin-3 (IL-3) is a hematopoietic growth factor and critical regulator of inflammatory response such as sepsis. IL-3 binds to IL-3 receptor α (IL-3Rα), which is then associated with IL-3Rß to initiate signaling. How IL-3-triggered physiological and pathological effects are regulated at the receptor level is unclear. Here, we show that the plasma membrane-associated E3 ubiquitin ligase MARCH3 negatively regulates IL-3-triggered signaling. MARCH3 is associated with IL-3Rα, mediates its K48-linked polyubiquitination at K377 and promotes its proteasomal degradation. MARCH3-deficiency promotes IL-3-triggered transcription of downstream effector genes and IL-3-induced expansion of myeloid cells. In the cecal ligation and puncture (CLP) model of sepsis, MARCH3-deficiency aggravates IL-3-ampified expression of inflammatory cytokines, organ damage and inflammatory death. Our findings suggest that regulation of IL-3Rα by MARCH3 plays an important role in IL-3-triggered physiological functions and inflammatory diseases.
Asunto(s)
Subunidad alfa del Receptor de Interleucina-3/inmunología , Interleucina-3/inmunología , Péptidos y Proteínas de Señalización Intracelular/inmunología , Proteolisis , Ubiquitinación/inmunología , Animales , Células HEK293 , Humanos , Inflamación/genética , Inflamación/inmunología , Interleucina-3/genética , Subunidad alfa del Receptor de Interleucina-3/genética , Péptidos y Proteínas de Señalización Intracelular/genética , Ratones , Ubiquitinación/genéticaRESUMEN
Activation-induced cytidine deaminase (AID) initiates class-switch recombination and somatic hypermutation (SHM) in antibody genes. Protein expression and activity are tightly controlled by various mechanisms. However, it remains unknown whether a signal from the extracellular environment directly affects the AID activity in the nucleus where it works. Here, we demonstrated that a deubiquitinase USP10, which specifically stabilizes nuclear AID protein, can translocate into the nucleus after AKT-mediated phosphorylation at its T674 within the NLS domain. Interestingly, the signals from BCR and TLR1/2 synergistically promoted this phosphorylation. The deficiency of USP10 in B cells significantly decreased AID protein levels, subsequently reducing neutralizing antibody production after immunization with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or human immunodeficiency virus type 1 (HIV-1) nanoparticle vaccines. Collectively, we demonstrated that USP10 functions as an integrator for both BCR and TLR signals and directly regulates nuclear AID activity. Its manipulation could be used for the development of vaccines and adjuvants.
Asunto(s)
Vacunas contra el SIDA/inmunología , Factor Activador de Células B/inmunología , Vacunas contra la COVID-19/inmunología , Citidina Desaminasa/inmunología , VIH-1/inmunología , Nanopartículas , SARS-CoV-2/inmunología , Transducción de Señal/inmunología , Ubiquitina Tiolesterasa/inmunología , Ubiquitinación/inmunología , Vacunas contra el SIDA/genética , Animales , Factor Activador de Células B/genética , Vacunas contra la COVID-19/genética , Citidina Desaminasa/genética , Células HEK293 , VIH-1/genética , Humanos , Ratones , Ratones Noqueados , SARS-CoV-2/genética , Transducción de Señal/genética , Ubiquitina Tiolesterasa/genéticaRESUMEN
CONTEXT: Circulating adiponectin levels are decreased in pregnant women with obesity or gestational diabetes, and this is believed to contribute to the insulin resistance and increased risk of fetal overgrowth associated with these conditions. However, the molecular mechanisms regulating adiponectin secretion from maternal adipose tissues in pregnancy are poorly understood. OBJECTIVE: We tested the hypothesis that obesity in pregnancy is associated with adipose tissue insulin resistance and increased adiponectin ubiquitination and degradation, caused by inflammation and endoplasmic reticulum (ER) stress. METHODS: Visceral adipose tissues were collected from lean and obese pregnant humans and mice. Total and ubiquitinated adiponectin, and markers of inflammation, ER stress, and insulin resistance were examined in adipose tissues. The role of insulin, inflammation, and ER stress in mediating adiponectin ubiquitination and degradation was examined using 3T3L-1 adipocytes. RESULTS: Obesity in pregnancy is associated with adipose tissue inflammation, ER stress, insulin resistance, increased adiponectin ubiquitination, and decreased total abundance of adiponectin. Adiponectin ubiquitination was increased in visceral fat of obese pregnant women as compared to lean pregnant women. We further observed that insulin prevents, whereas ER stress and inflammation promote, adiponectin ubiquitination and degradation in differentiated 3T3-L1 adipocytes. CONCLUSION: We have identified adiponectin ubiquitination as a key mechanism by which obesity diminishes adiponectin secretion in pregnancy. This information will help us better understand the mechanisms controlling maternal insulin resistance and fetal growth in pregnancy and may provide a foundation for the development of strategies aimed at improving adiponectin production in pregnant women with obesity or gestational diabetes.
Asunto(s)
Adiponectina/metabolismo , Diabetes Gestacional/metabolismo , Insulina/metabolismo , Obesidad Materna/metabolismo , Células 3T3-L1 , Adipocitos/metabolismo , Adiponectina/análisis , Adulto , Animales , Estudios de Cohortes , Diabetes Gestacional/inmunología , Modelos Animales de Enfermedad , Femenino , Humanos , Recién Nacido , Resistencia a la Insulina/inmunología , Grasa Intraabdominal/inmunología , Grasa Intraabdominal/patología , Masculino , Ratones , Obesidad Materna/inmunología , Obesidad Materna/patología , Embarazo , Proteolisis , Ubiquitinación/inmunologíaRESUMEN
Inflammatory bowel disease (IBD), which include Crohn's disease (CD) and ulcerative colitis (UC), exhibits a complex multifactorial pathogenesis involving genetic susceptibility, imbalance of gut microbiota, mucosal immune disorder and environmental factors. Recent studies reported associations between ubiquitination and deubiquitination and the occurrence and development of inflammatory bowel disease. Ubiquitination modification, one of the most important types of post-translational modifications, is a multi-step enzymatic process involved in the regulation of various physiological processes of cells, including cell cycle progression, cell differentiation, apoptosis, and innate and adaptive immune responses. Alterations in ubiquitination and deubiquitination can lead to various diseases, including IBD. Here, we review the role of E3 ubiquitin ligases and deubiquitinases (DUBs) and their mediated ubiquitination and deubiquitination modifications in the pathogenesis of IBD. We highlight the importance of this type of posttranslational modification in the development of inflammation, and provide guidance for the future development of targeted therapeutics in IBD.
Asunto(s)
Enzimas Desubicuitinizantes/inmunología , Enfermedades Inflamatorias del Intestino/inmunología , Procesamiento Proteico-Postraduccional/inmunología , Transducción de Señal/inmunología , Ubiquitina-Proteína Ligasas/inmunología , Ubiquitinación/inmunología , Inmunidad Adaptativa/inmunología , Colitis Ulcerosa/enzimología , Colitis Ulcerosa/inmunología , Colitis Ulcerosa/metabolismo , Enfermedad de Crohn/enzimología , Enfermedad de Crohn/inmunología , Enfermedad de Crohn/metabolismo , Enzimas Desubicuitinizantes/metabolismo , Humanos , Inmunidad Innata/inmunología , Inflamación/enzimología , Inflamación/inmunología , Inflamación/metabolismo , Enfermedades Inflamatorias del Intestino/enzimología , Enfermedades Inflamatorias del Intestino/metabolismo , Ubiquitina-Proteína Ligasas/metabolismoRESUMEN
Acute lung injury (ALI) is an inflammatory disorder of the lung that causes high mortality and lacks any pharmacological intervention. Ubiquitination plays a critical role in the pathogenesis of ALI as it regulates the alveolocapillary barrier and the inflammatory response. Tripartite motif (TRIM) proteins are one of the subfamilies of the RING-type E3 ubiquitin ligases, which contains more than 80 distinct members in humans involved in a broad range of biological processes including antivirus innate immunity, development, and tumorigenesis. Recently, some studies have shown that several members of TRIM family proteins play important regulatory roles in inflammation and ALI. Herein, we integrate emerging evidence regarding the roles of TRIMs in ALI. Articles were selected from the searches of PubMed database that had the terms "acute lung injury," "ubiquitin ligases," "tripartite motif protein," "inflammation," and "ubiquitination" using both MeSH terms and keywords. Better understanding of these mechanisms may ultimately lead to novel therapeutic approaches by targeting TRIMs for ALI treatment.
Asunto(s)
Lesión Pulmonar Aguda/inmunología , Antiinflamatorios/farmacología , Pulmón/patología , Proteínas de Motivos Tripartitos/metabolismo , Lesión Pulmonar Aguda/tratamiento farmacológico , Lesión Pulmonar Aguda/patología , Antiinflamatorios/uso terapéutico , Humanos , Inflamación/tratamiento farmacológico , Inflamación/inmunología , Inflamación/patología , Pulmón/efectos de los fármacos , Pulmón/inmunología , Dominios RING Finger , Proteínas de Motivos Tripartitos/antagonistas & inhibidores , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitinación/efectos de los fármacos , Ubiquitinación/inmunologíaRESUMEN
Acute pancreatitis (AP) is an inflammatory disease of the pancreas. Accumulating studies have revealed the involvement of tumor necrosis factor alpha-induced protein 3 (TNFAIP3) in the progression of AP. Here, the current study was conducted to elucidate the role of TNFAIP3 and the underlying molecular mechanisms on the progression of AP. The in vivo animal model and in vitro cell model of AP were generated by retrograde injection of sodium taurocholate and stimulation of cerulein into AR42J cells, respectively. Relationships among TNFAIP3, receptor interacting protein 3 (RIP3) and nod-like receptor protein 3 (NLRP3) were predicted on bioinformatics websites and verified by co-immunoprecipitation. AR42J cells were transfected with overexpressing plasmid or shRNA to study the effects of TNFAIP3/RIP3/NLRP3 axis on cell proliferation and apoptosis, secretion of inflammatory cytokines and production of ROS. The effect of TNFAIP3/RIP3/NLRP3 axis in AP was further confirmed in vivo. High expression of TNFAIP3 was observed in AP pancreatic tissues and AP cell model. TNFAIP3 increased RIP phosphorylation through deubiquitination. RIP activated the NLRP3 inflammasome. Silencing of TNFAIP3 or RIP3T led to elevated proliferation and inhibited apoptosis in AR42J cells, accompanied by decreased inflammatory cytokine levels and ROS production. The protective role of inhibited TNFAIP3 in AP was confirmed evidenced by reduced levels of AMY, LIPA, and ROS in vivo. Collectively, overexpressed TNFAIP3 could contribute to the progression of AP by activating RIP3/NLRP3 axis, providing a potential therapeutic target for AP treatment.
Asunto(s)
Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Pancreatitis/inmunología , Proteína Serina-Treonina Quinasas de Interacción con Receptores/metabolismo , Proteína 3 Inducida por el Factor de Necrosis Tumoral alfa/metabolismo , Animales , Línea Celular Tumoral , Modelos Animales de Enfermedad , Perfilación de la Expresión Génica , Humanos , Inflamasomas/inmunología , Inflamasomas/metabolismo , Masculino , Páncreas/inmunología , Páncreas/patología , Pancreatitis/inducido químicamente , Pancreatitis/patología , Fosforilación/inmunología , Ratas , Ácido Taurocólico/administración & dosificación , Ácido Taurocólico/toxicidad , Proteína 3 Inducida por el Factor de Necrosis Tumoral alfa/genética , Ubiquitinación/inmunologíaRESUMEN
The cytoplasmic retinoic acid-inducible gene-I (RIG-I)-like receptors (RLRs) initiate interferon (IFN) production and antiviral gene expression in response to RNA virus infection. Consequently, RLR signalling is tightly regulated by both host and viral factors. Tripartite motif protein 25 (TRIM25) is an E3 ligase that ubiquitinates multiple substrates within the RLR signalling cascade, playing both ubiquitination-dependent and -independent roles in RIG-I-mediated IFN induction. However, additional regulatory roles are emerging. Here, we show a novel interaction between TRIM25 and another protein in the RLR pathway that is essential for type I IFN induction, DEAD-box helicase 3X (DDX3X). In vitro assays and knockdown studies reveal that TRIM25 ubiquitinates DDX3X at lysine 55 (K55) and that TRIM25 and DDX3X cooperatively enhance IFNB1 induction following RIG-I activation, but the latter is independent of TRIM25's catalytic activity. Furthermore, we found that the influenza A virus non-structural protein 1 (NS1) disrupts the TRIM25:DDX3X interaction, abrogating both TRIM25-mediated ubiquitination of DDX3X and cooperative activation of the IFNB1 promoter. Thus, our results reveal a new interplay between two RLR-host proteins that cooperatively enhance IFN-ß production. We also uncover a new and further mechanism by which influenza A virus NS1 suppresses host antiviral defence.
Asunto(s)
Antivirales/inmunología , Proteína 58 DEAD Box/inmunología , ARN Helicasas DEAD-box/inmunología , Inmunidad/inmunología , Receptores Inmunológicos/inmunología , Factores de Transcripción/inmunología , Proteínas de Motivos Tripartitos/inmunología , Ubiquitina-Proteína Ligasas/inmunología , Línea Celular , Regulación de la Expresión Génica/inmunología , Células HEK293 , Humanos , Virus de la Influenza A/inmunología , Interferones/inmunología , Regiones Promotoras Genéticas/inmunología , Unión Proteica/inmunología , Transducción de Señal/inmunología , Ubiquitinación/inmunologíaRESUMEN
Proper regulation of B-cell function is essential for effective humoral immunity and maintenance of immune tolerance. Here, we found that FBW7 (F-box/WD40 repeat-containing protein 7) is highly expressed in germinal centre B and B1 cells, and confirmed that it has an intrinsic role in maintaining homeostasis of mature B cells and B-1 cells. FBW7 deletion led to an impairment of antibody response, and although germinal centre formation was not affected, antibody class-switch recombination and affinity maturation processes were defective. Likewise, memory immune response was severely impaired. Moreover, FBW7 ablation ameliorated the pathogenesis of an autoimmune disease model, collagen-induced arthritis, by reducing the production of anti-collagen II autoantibodies. Taken together, these data suggest that FBW7 may be an attractive target for developing new therapeutics for the treatment of autoimmune diseases.
Asunto(s)
Artritis Experimental/inmunología , Linfocitos B/inmunología , Proteína 7 que Contiene Repeticiones F-Box-WD/metabolismo , Animales , Artritis Experimental/diagnóstico , Artritis Experimental/patología , Linfocitos B/metabolismo , Colágeno/administración & dosificación , Colágeno/inmunología , Proteína 7 que Contiene Repeticiones F-Box-WD/genética , Femenino , Centro Germinal/citología , Centro Germinal/inmunología , Centro Germinal/metabolismo , Humanos , Cambio de Clase de Inmunoglobulina/genética , Memoria Inmunológica , Masculino , Ratones , Ratones Noqueados , Índice de Severidad de la Enfermedad , Ubiquitinación/inmunologíaRESUMEN
The membrane-associated RING-CH (MARCH) proteins are E3 ligases that regulate the stability of various cellular membrane proteins. MARCH8 has been reported to inhibit the infection of HIV-1 and a few other viruses, thus plays an important role in host antiviral defense. However, the antiviral spectrum and the underlying mechanisms of MARCH8 are incompletely defined. Here, we demonstrate that MARCH8 profoundly inhibits influenza A virus (IAV) replication both in vitro and in mice. Mechanistically, MARCH8 suppresses IAV release through redirecting viral M2 protein from the plasma membrane to lysosomes for degradation. Specifically, MARCH8 catalyzes the K63-linked polyubiquitination of M2 at lysine residue 78 (K78). A recombinant A/Puerto Rico/8/34 virus carrying the K78R M2 protein shows greater replication and more severe pathogenicity in cells and mice. More importantly, we found that the M2 protein of the H1N1 IAV has evolved to acquire non-lysine amino acids at positions 78/79 to resist MARCH8-mediated ubiquitination and degradation. Together, our data support the important role of MARCH8 in host anti-IAV intrinsic immune defense by targeting M2, and suggest the inhibitory pressure of MARCH8 on H1N1 IAV transmission in the human population.
Asunto(s)
Subtipo H1N1 del Virus de la Influenza A/inmunología , Gripe Humana/inmunología , Ubiquitina-Proteína Ligasas/metabolismo , Proteínas de la Matriz Viral/metabolismo , Células A549 , Secuencia de Aminoácidos , Animales , Modelos Animales de Enfermedad , Perros , Técnicas de Silenciamiento del Gen , Células HEK293 , Células HeLa , Glicoproteínas Hemaglutininas del Virus de la Influenza/metabolismo , Interacciones Microbiota-Huesped/genética , Interacciones Microbiota-Huesped/inmunología , Humanos , Subtipo H1N1 del Virus de la Influenza A/genética , Subtipo H1N1 del Virus de la Influenza A/metabolismo , Subtipo H1N1 del Virus de la Influenza A/patogenicidad , Gripe Humana/virología , Lisina/genética , Lisina/metabolismo , Lisosomas/metabolismo , Lisosomas/virología , Células de Riñón Canino Madin Darby , Masculino , Ratones , Ubiquitina-Proteína Ligasas/genética , Ubiquitinación/genética , Ubiquitinación/inmunología , Proteínas de la Matriz Viral/genética , Replicación ViralRESUMEN
Plant pathogenic Gram-negative bacteria evade the host plant immune system by secreting Type III (T3E) and Type IV effector (T4E) proteins into the plant cytoplasm. Mostly T3Es are secreted into the plant cells to establish pathogenicity by affecting the vital plant process viz. metabolic pathways, signal transduction and hormonal regulation. Ubiquitin-26S proteasome system (UPS) exists as one of the important pathways in plants to control plant immunity and various cellular processes by employing several enzymes and enzyme components. Pathogenic and non-pathogenic bacteria are found to secrete effectors into plants with structural and/or functional similarity to UPS pathway components like ubiquitin E3 ligases, F-box domains, cysteine proteases, inhibitor of host UPS or its components, etc. The bacterial effectors mimic UPS components and target plant resistance proteins for degradation by proteasomes, thereby taking control over the host cellular activities as a strategy to exert virulence. Thus, the bacterial effectors circumvent plant cellular pathways leading to infection and disease development. This review highlights known bacterial T3E and T4E proteins that function and interfere with the ubiquitination pathway to regulate the immune system of plants.
Asunto(s)
Bacterias/metabolismo , Proteínas Bacterianas/metabolismo , Interacciones Huésped-Patógeno , Inmunidad de la Planta , Plantas/microbiología , Complejo de la Endopetidasa Proteasomal/inmunología , Ubiquitinación/inmunología , Bacterias/genética , Proteínas Bacterianas/genética , Proteínas de Plantas/metabolismo , Complejo de la Endopetidasa Proteasomal/genética , Ubiquitinación/genéticaRESUMEN
Shrimp aquaculture is an essential economic venture globally, but the industry faces numerous challenges, especially pathogenic infections. As invertebrates, shrimp rely mainly on their innate immune system for protection. An increasing number of studies have shown that ubiquitination plays a vital role in the innate immune response to microbial pathogens. As an important form of posttranslational modification (PTM), both hosts and pathogens have exploited ubiquitination and the ubiquitin system as an immune response strategy to outwit the other. This short review brings together recent findings on ubiquitination and how this PTM plays a critical role in immune modulation in penaeid shrimps. Key findings inferred from other species would help guide further studies on ubiquitination as an immune response strategy in shrimp-pathogen interactions.
Asunto(s)
Interacciones Huésped-Patógeno/inmunología , Penaeidae/inmunología , Ubiquitinación/inmunología , Animales , Acuicultura , Inmunidad Innata , Modelos Inmunológicos , Penaeidae/microbiología , Penaeidae/virología , Especificidad de la EspecieRESUMEN
Pattern recognition receptors (PRRs) are a kind of recognition molecules mainly expressed on innate immune cells. PRRs recognize one or more kinds of pathogen-associated molecular patterns (PAMPs), inducing the production of interleukin (IL), tumor necrosis factor (TNF), interferon (IFN) and other related cytokines to aggravate immune-related diseases. PPR signaling pathways play an important role in both innate and adaptive immune system, and they are easy to be activated or regulated. Tripartite motif (TRIM) proteins are a group of highly conserved proteins in structure. Most of TRIM proteins contain RING domain, which is thought to play a role in ubiquitination. TRIM proteins are involved in viral immunity, inflammatory response, autophagy, and tumor growth. In this review, we focus on the regulation of TRIM proteins on PRR signaling pathways and their roles in immune-related diseases.
Asunto(s)
Citocinas/metabolismo , Enfermedades del Sistema Inmune/inmunología , Receptores de Reconocimiento de Patrones/metabolismo , Transducción de Señal/inmunología , Proteínas de Motivos Tripartitos/metabolismo , Animales , Modelos Animales de Enfermedad , Humanos , Enfermedades del Sistema Inmune/patología , Inmunidad Innata , Dominios RING Finger , Proteínas de Motivos Tripartitos/ultraestructura , Ubiquitinación/inmunologíaRESUMEN
Nuclear factor 90 (NF90) is a novel virus sensor that serves to initiate antiviral innate immunity by triggering stress granule (SG) formation. However, the regulation of the NF90-SG pathway remains largely unclear. We found that Tim-3, an immune checkpoint inhibitor, promotes the ubiquitination and degradation of NF90 and inhibits NF90-SG-mediated antiviral immunity. Vesicular stomatitis virus (VSV) infection induces the up-regulation and activation of Tim-3 in macrophages, which in turn recruit the E3 ubiquitin ligase TRIM47 to the zinc finger domain of NF90 and initiate a proteasome-dependent degradation via K48-linked ubiquitination at Lys297. Targeted inactivation of Tim-3 enhances the NF90 downstream SG formation by selectively increasing the phosphorylation of protein kinase R and eukaryotic translation initiation factor 2α, the expression of SG markers G3BP1 and TIA-1, and protecting mice from VSV challenge. These findings provide insights into the crosstalk between Tim-3 and other receptors in antiviral innate immunity and its related clinical significance.
Asunto(s)
Receptor 2 Celular del Virus de la Hepatitis A , Inmunidad Innata/inmunología , Proteínas del Factor Nuclear 90 , Ubiquitinación/inmunología , Virosis/inmunología , Animales , Gránulos Citoplasmáticos/inmunología , Gránulos Citoplasmáticos/metabolismo , Receptor 2 Celular del Virus de la Hepatitis A/inmunología , Receptor 2 Celular del Virus de la Hepatitis A/metabolismo , Macrófagos/inmunología , Macrófagos/metabolismo , Ratones , Proteínas del Factor Nuclear 90/inmunología , Proteínas del Factor Nuclear 90/metabolismo , Infecciones por Rhabdoviridae/inmunología , VesiculovirusRESUMEN
The antiviral innate immune responses are crucial steps during host defense and must be strictly regulated, but the molecular mechanisms of control remain unclear. In this study, we report increased expression of human ATPase Na+/K+ transporting subunit ß 1(ATP1B1) after DNA and RNA virus infections. We found that the expression of ATP1B1 can inhibit viral replication and increase the levels of IFNs, IFN-stimulated genes, and inflammatory cytokines. Knockdown of ATP1B1 by specific short hairpin RNA had the opposite effects. Upon viral infection, ATP1B1 was induced, interacted with TRAF3 and TRAF6, and potentiated the ubiquitination of these proteins, leading to increased phosphorylation of downstream molecules, including TGF-ß-activated kinase 1 (TAK1) and TANK-binding kinase 1 (TBK1). These results reveal a previously unrecognized role of ATP1B1 in antiviral innate immunity and suggest a novel mechanism for the induction of IFNs and proinflammatory cytokines during viral infection.
Asunto(s)
Inmunidad Innata/inmunología , Péptidos y Proteínas de Señalización Intracelular/inmunología , ATPasa Intercambiadora de Sodio-Potasio/inmunología , Factor 3 Asociado a Receptor de TNF/inmunología , Regulación hacia Arriba/inmunología , Animales , Células Cultivadas , Chlorocebus aethiops , Infecciones por Virus ADN/inmunología , Virus ADN/inmunología , Humanos , Infecciones por Virus ARN/inmunología , Virus ARN/inmunología , ATPasa Intercambiadora de Sodio-Potasio/genética , Ubiquitinación/inmunología , Replicación ViralRESUMEN
Oncogenic histone lysine-to-methionine mutations block the methylation of their corresponding lysine residues on wild-type histones. One attractive model is that these mutations sequester histone methyltransferases, but genome-wide studies show that mutant histones and histone methyltransferases often do not colocalize. Using chromatin immunoprecipitation sequencing (ChIP-seq), here, we show that, in fission yeast, even though H3K9M-containing nucleosomes are broadly distributed across the genome, the histone H3K9 methyltransferase Clr4 is mainly sequestered at pericentric repeats. This selective sequestration of Clr4 depends not only on H3K9M but also on H3K14 ubiquitylation (H3K14ub), a modification deposited by a Clr4-associated E3 ubiquitin ligase complex. In vitro, H3K14ub synergizes with H3K9M to interact with Clr4 and potentiates the inhibitory effects of H3K9M on Clr4 enzymatic activity. Moreover, binding kinetics show that H3K14ub overcomes the Clr4 aversion to H3K9M and reduces its dissociation. The selective sequestration model reconciles previous discrepancies and demonstrates the importance of protein-interaction kinetics in regulating biological processes.
Asunto(s)
Proteínas de Ciclo Celular/metabolismo , Heterocromatina/metabolismo , Histona Metiltransferasas/metabolismo , N-Metiltransferasa de Histona-Lisina/metabolismo , Histonas/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Ubiquitinación/inmunología , MutaciónRESUMEN
Activation of MAVS, an adaptor molecule in Rig-I-like receptor (RLR) signaling, is indispensable for antiviral immunity, yet the molecular mechanisms modulating MAVS activation are not completely understood. Ubiquitination has a central function in regulating the activity of MAVS. Here, we demonstrate that a mitochondria-localized deubiquitinase USP18 specifically interacts with MAVS, promotes K63-linked polyubiquitination and subsequent aggregation of MAVS. USP18 upregulates the expression and production of type I interferon following infection with Sendai virus (SeV) or Encephalomyocarditis virus (EMCV). Mice with a deficiency of USP18 are more susceptible to RNA virus infection. USP18 functions as a scaffold protein to facilitate the re-localization of TRIM31 and enhances the interaction between TRIM31 and MAVS in mitochondria. Our results indicate that USP18 functions as a post-translational modulator of MAVS-mediated antiviral signaling.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Infecciones por Cardiovirus/inmunología , Infecciones por Respirovirus/inmunología , Ubiquitina Tiolesterasa/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Adaptadoras Transductoras de Señales/aislamiento & purificación , Animales , Infecciones por Cardiovirus/virología , Línea Celular Tumoral , Modelos Animales de Enfermedad , Virus de la Encefalomiocarditis/inmunología , Técnicas de Silenciamiento del Gen , Células HEK293 , Humanos , Inmunidad Innata , Interferón Tipo I/metabolismo , Lisina/metabolismo , Masculino , Ratones , Ratones Noqueados , Procesamiento Proteico-Postraduccional/inmunología , Células RAW 264.7 , Proteínas Recombinantes/genética , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/metabolismo , Infecciones por Respirovirus/virología , Virus Sendai/inmunología , Transducción de Señal/inmunología , Proteínas de Motivos Tripartitos/metabolismo , Ubiquitina Tiolesterasa/genética , Ubiquitina Tiolesterasa/aislamiento & purificación , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitinación/inmunologíaRESUMEN
Alterations in the cGAS-STING DNA-sensing pathway affect intestinal homeostasis. We sought to delineate the functional role of STING in intestinal inflammation. Increased STING expression was a feature of intestinal inflammation in mice with colitis and in humans afflicted with inflammatory bowel disease. Mice bearing an allele rendering STING constitutively active exhibited spontaneous colitis and dysbiosis, as well as progressive chronic intestinal inflammation and fibrosis. Bone marrow chimera experiments revealed STING accumulation in intestinal macrophages and monocytes as the initial driver of inflammation. Depletion of Gram-negative bacteria prevented STING accumulation in these cells and alleviated intestinal inflammation. STING accumulation occurred at the protein rather than transcript level, suggesting post-translational stabilization. We found that STING was ubiquitinated in myeloid cells, and this K63-linked ubiquitination could be elicited by bacterial products, including cyclic di-GMP. Our findings suggest a positive feedback loop wherein dysbiosis foments the accumulation of STING in intestinal myeloid cells, driving intestinal inflammation.
Asunto(s)
Colitis/inmunología , Disbiosis/inmunología , Inmunidad Innata/inmunología , Proteínas de la Membrana/inmunología , Células Mieloides/inmunología , Ubiquitinación/inmunología , Animales , Estudios de Casos y Controles , Femenino , Humanos , Inflamación/inmunología , Intestinos/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL , Monocitos/inmunologíaRESUMEN
The rapid and dynamic activation of the innate immune system is achieved through complex signaling networks regulated by post-translational modifications modulating the subcellular localization, activity, and abundance of signaling molecules. Many constitutively expressed signaling molecules are present in the cell in inactive forms, and become functionally activated once they are modified with ubiquitin, and, in turn, inactivated by removal of the same post-translational mark. Moreover, upon infection resolution a rapid remodeling of the proteome needs to occur, ensuring the removal of induced response proteins to prevent hyperactivation. This review discusses the current knowledge on the negative regulation of innate immune signaling pathways by deubiquitinating enzymes, and through degradative ubiquitination. It focusses on spatiotemporal regulation of deubiquitinase and E3 ligase activities, mechanisms for re-establishing proteostasis, and degradation through immune-specific feedback mechanisms vs. general protein quality control pathways.
Asunto(s)
Regulación de la Expresión Génica/inmunología , Inmunidad Innata/genética , Complejo de la Endopetidasa Proteasomal/metabolismo , Ubiquitinación/fisiología , Humanos , Complejo de la Endopetidasa Proteasomal/genética , Complejo de la Endopetidasa Proteasomal/inmunología , Unión Proteica , Procesamiento Proteico-Postraduccional , Transporte de Proteínas , Transducción de Señal/genética , Transducción de Señal/inmunología , Ubiquitinación/genética , Ubiquitinación/inmunologíaRESUMEN
Various autoimmune diseases are associated with defects in protein degradation and NETosis. This review aims to examine defects in ubiquitination and NETosis and their associations with human disease. This study involved a systematic search of electronic databases, including PubMed, EBSCO, and LILACS, to locate articles on the relationship between human disease and defects in protein degradation and NETosis. Ubiquitination and NETosis can trigger a cascade of events that affect immune system function and impact the body's ability to fight disease. Ubiquitination is implicated in various disorders, such as Liddle's syndrome, Alzheimer's disease, and other neurodegenerative disorders, whereas NETosis has been linked to antineutrophil cytoplasmic antibody associated vasculitis, accelerated atherosclerosis, thrombosis, rheumatoid arthritis, antiphospholipid antibody syndrome, type 1 diabetes mellitus, and renal inflammatory complications. Researchers have attempted for years to identify the link between neurodegenerative disease and ubiquitination. Previous studies analysed the relationships between different autoimmune disorders and NETosis and identified various ubiquitin conjugates and NET remnants that trigger disease development and progression. Ubiquitination and NETosis play key roles in the emergence and progression of neurodegenerative and autoimmune disorders. Further investigation is needed to elucidate the mechanisms underlying the relationships between these disorders and biological processes.