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1.
Cell ; 184(21): 5391-5404.e17, 2021 10 14.
Artículo en Inglés | MEDLINE | ID: mdl-34597584

RESUMEN

Plant immunity is activated upon pathogen perception and often affects growth and yield when it is constitutively active. How plants fine-tune immune homeostasis in their natural habitats remains elusive. Here, we discover a conserved immune suppression network in cereals that orchestrates immune homeostasis, centering on a Ca2+-sensor, RESISTANCE OF RICE TO DISEASES1 (ROD1). ROD1 promotes reactive oxygen species (ROS) scavenging by stimulating catalase activity, and its protein stability is regulated by ubiquitination. ROD1 disruption confers resistance to multiple pathogens, whereas a natural ROD1 allele prevalent in indica rice with agroecology-specific distribution enhances resistance without yield penalty. The fungal effector AvrPiz-t structurally mimics ROD1 and activates the same ROS-scavenging cascade to suppress host immunity and promote virulence. We thus reveal a molecular framework adopted by both host and pathogen that integrates Ca2+ sensing and ROS homeostasis to suppress plant immunity, suggesting a principle for breeding disease-resistant, high-yield crops.


Asunto(s)
Calcio/metabolismo , Depuradores de Radicales Libres/metabolismo , Proteínas Fúngicas/metabolismo , Oryza/inmunología , Inmunidad de la Planta , Proteínas de Plantas/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Sistemas CRISPR-Cas/genética , Membrana Celular/metabolismo , Resistencia a la Enfermedad/genética , Modelos Biológicos , Oryza/genética , Enfermedades de las Plantas/inmunología , Proteínas de Plantas/genética , Unión Proteica , Estabilidad Proteica , Reproducción , Especificidad de la Especie , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitinación , Zea mays/inmunología
2.
Mol Cell ; 84(7): 1224-1242.e13, 2024 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-38458201

RESUMEN

Although mismatch repair (MMR) is essential for correcting DNA replication errors, it can also recognize other lesions, such as oxidized bases. In G0 and G1, MMR is kept in check through unknown mechanisms as it is error-prone during these cell cycle phases. We show that in mammalian cells, D-type cyclins are recruited to sites of oxidative DNA damage in a PCNA- and p21-dependent manner. D-type cyclins inhibit the proteasomal degradation of p21, which competes with MMR proteins for binding to PCNA, thereby inhibiting MMR. The ability of D-type cyclins to limit MMR is CDK4- and CDK6-independent and is conserved in G0 and G1. At the G1/S transition, the timely, cullin-RING ubiquitin ligase (CRL)-dependent degradation of D-type cyclins and p21 enables MMR activity to efficiently repair DNA replication errors. Persistent expression of D-type cyclins during S-phase inhibits the binding of MMR proteins to PCNA, increases the mutational burden, and promotes microsatellite instability.


Asunto(s)
Ciclinas , Reparación de la Incompatibilidad de ADN , Animales , Ciclinas/genética , Antígeno Nuclear de Célula en Proliferación/genética , Antígeno Nuclear de Célula en Proliferación/metabolismo , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/genética , Interfase , Mamíferos/metabolismo
3.
Mol Cell ; 83(15): 2753-2767.e10, 2023 08 03.
Artículo en Inglés | MEDLINE | ID: mdl-37478846

RESUMEN

Nuclear hormone receptors (NRs) are ligand-binding transcription factors that are widely targeted therapeutically. Agonist binding triggers NR activation and subsequent degradation by unknown ligand-dependent ubiquitin ligase machinery. NR degradation is critical for therapeutic efficacy in malignancies that are driven by retinoic acid and estrogen receptors. Here, we demonstrate the ubiquitin ligase UBR5 drives degradation of multiple agonist-bound NRs, including the retinoic acid receptor alpha (RARA), retinoid x receptor alpha (RXRA), glucocorticoid, estrogen, liver-X, progesterone, and vitamin D receptors. We present the high-resolution cryo-EMstructure of full-length human UBR5 and a negative stain model representing its interaction with RARA/RXRA. Agonist ligands induce sequential, mutually exclusive recruitment of nuclear coactivators (NCOAs) and UBR5 to chromatin to regulate transcriptional networks. Other pharmacological ligands such as selective estrogen receptor degraders (SERDs) degrade their receptors through differential recruitment of UBR5 or RNF111. We establish the UBR5 transcriptional regulatory hub as a common mediator and regulator of NR-induced transcription.


Asunto(s)
Cromatina , Factores de Transcripción , Humanos , Ligandos , Cromatina/genética , Factores de Transcripción/metabolismo , Receptores Citoplasmáticos y Nucleares/genética , Ubiquitinas , Ubiquitina-Proteína Ligasas/genética
4.
Mol Cell ; 81(4): 811-829.e6, 2021 02 18.
Artículo en Inglés | MEDLINE | ID: mdl-33529595

RESUMEN

Eukaryotic cells package their genomes around histone octamers. In response to DNA damage, checkpoint activation in yeast induces core histone degradation resulting in 20%-40% reduction in nucleosome occupancy. To gain insight into this process, we developed a new approach to analyze the chromatin-associated proteome comprehensively before and after damage. This revealed extensive changes in protein composition after Zeocin-induced damage. First, core histones and the H1 homolog Hho1 were partially lost from chromatin along with replication, transcription, and chromatin remodeling machineries, while ubiquitin ligases and the proteasome were recruited. We found that the checkpoint- and INO80C-dependent recruitment of five ubiquitin-conjugating factors (Rad6, Bre1, Pep5, Ufd4, and Rsp5) contributes to core and linker histone depletion, reducing chromatin compaction and enhancing DNA locus mobility. Importantly, loss of Rad6/Bre1, Ufd4/TRIP12, and Pep5/VPS11 compromise DNA strand invasion kinetics during homology-driven repair. Thus we provide a comprehensive overview of a functionally relevant genome-wide chromatin response to DNA damage.


Asunto(s)
Ensamble y Desensamble de Cromatina , Reparación del ADN , ADN de Hongos/metabolismo , Histonas/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , ADN de Hongos/genética , Histonas/genética , Complejo de la Endopetidasa Proteasomal/genética , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Ubiquitina-Proteína Ligasas/genética
5.
Trends Biochem Sci ; 49(10): 875-887, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-38972780

RESUMEN

Neuronal ubiquitin balance impacts the fate of countless cellular proteins, and its disruption is associated with various neurological disorders. The ubiquitin system is critical for proper neuronal cell state transitions and the clearance of misfolded or aggregated proteins that threaten cellular integrity. This article reviews the state of and recent advancements in our understanding of the disruptions to components of the ubiquitin system, in particular E3 ligases and deubiquitylases, in neurodevelopmental and neurodegenerative diseases. Specific focus is on enzymes with recent progress in their characterization, including identifying enzyme-substrate pairs, the use of stem cell and animal models, and the development of therapeutics for ubiquitin-related diseases.


Asunto(s)
Mutación , Enfermedades del Sistema Nervioso , Ubiquitina , Humanos , Ubiquitina/metabolismo , Animales , Enfermedades del Sistema Nervioso/metabolismo , Enfermedades del Sistema Nervioso/genética , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitina-Proteína Ligasas/genética , Enfermedades Neurodegenerativas/genética , Enfermedades Neurodegenerativas/metabolismo
6.
EMBO J ; 42(5): e112351, 2023 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-36762436

RESUMEN

Human cytomegalovirus (CMV) is a ubiquitously distributed pathogen whose rodent counterparts such as mouse and rat CMV serve as common infection models. Here, we conducted global proteome profiling of rat CMV-infected cells and uncovered a pronounced loss of the transcription factor STAT2, which is crucial for antiviral interferon signalling. Via deletion mutagenesis, we found that the viral protein E27 is required for CMV-induced STAT2 depletion. Cellular and in vitro analyses showed that E27 exploits host-cell Cullin4-RING ubiquitin ligase (CRL4) complexes to induce poly-ubiquitylation and proteasomal degradation of STAT2. Cryo-electron microscopy revealed how E27 mimics molecular surface properties of cellular CRL4 substrate receptors called DCAFs (DDB1- and Cullin4-associated factors), thereby displacing them from the catalytic core of CRL4. Moreover, structural analyses showed that E27 recruits STAT2 through a bipartite binding interface, which partially overlaps with the IRF9 binding site. Structure-based mutations in M27, the murine CMV homologue of E27, impair the interferon-suppressing capacity and virus replication in mouse models, supporting the conserved importance of DCAF mimicry for CMV immune evasion.


Asunto(s)
Infecciones por Citomegalovirus , Muromegalovirus , Animales , Humanos , Ratones , Ratas , Microscopía por Crioelectrón , Infecciones por Citomegalovirus/genética , Subunidad gamma del Factor 3 de Genes Estimulados por el Interferón/metabolismo , Interferones/metabolismo , Factor de Transcripción STAT2/genética , Factor de Transcripción STAT2/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Receptores de Interleucina-17/metabolismo
7.
J Biol Chem ; 300(8): 107545, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38992439

RESUMEN

DNA double-strand breaks (DSBs) elicit an elaborate response to signal damage and trigger repair via two major pathways: nonhomologous end-joining (NHEJ), which functions throughout the interphase, and homologous recombination (HR), restricted to S/G2 phases. The DNA damage response relies, on post-translational modifications of nuclear factors to coordinate the mending of breaks. Ubiquitylation of histones and chromatin-associated factors regulates DSB repair and numerous E3 ubiquitin ligases are involved in this process. Despite significant progress, our understanding of ubiquitin-mediated DNA damage response regulation remains incomplete. Here, we have performed a localization screen to identify RING/U-box E3 ligases involved in genome maintenance. Our approach uncovered 7 novel E3 ligases that are recruited to microirradiation stripes, suggesting potential roles in DNA damage signaling and repair. Among these factors, the DELTEX family E3 ligase DTX2 is rapidly mobilized to lesions in a poly ADP-ribosylation-dependent manner. DTX2 is recruited and retained at DSBs via its WWE and DELTEX conserved C-terminal domains. In cells, both domains are required for optimal binding to mono and poly ADP-ribosylated proteins with WWEs playing a prominent role in this process. Supporting its involvement in DSB repair, DTX2 depletion decreases HR efficiency and moderately enhances NHEJ. Furthermore, DTX2 depletion impeded BRCA1 foci formation and increased 53BP1 accumulation at DSBs, suggesting a fine-tuning role for this E3 ligase in repair pathway choice. Finally, DTX2 depletion sensitized cancer cells to X-rays and PARP inhibition and these susceptibilities could be rescued by DTX2 reexpression. Altogether, our work identifies DTX2 as a novel ADP-ribosylation-dependent regulator of HR-mediated DSB repair.


Asunto(s)
Roturas del ADN de Doble Cadena , Ubiquitina-Proteína Ligasas , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitina-Proteína Ligasas/genética , Humanos , ADP-Ribosilación , Reparación del ADN , Reparación del ADN por Unión de Extremidades , Proteína BRCA1/metabolismo , Proteína BRCA1/genética , Ubiquitinación , Proteína 1 de Unión al Supresor Tumoral P53/metabolismo , Proteína 1 de Unión al Supresor Tumoral P53/genética
8.
Artículo en Inglés | MEDLINE | ID: mdl-39037545

RESUMEN

Membrane-associated RING-CH (MARCH) E3 ubiquitin ligases, a family of RING-type E3 ubiquitin ligases, have garnered increased attention for their indispensable roles in immune regulation, inflammation, mitochondrial dynamics, and lipid metabolism. The MARCH E3 ligase family consists of eleven distinct members, and the dysregulation of many of these members has been documented in several human malignancies. Over the past two decades, extensive research has revealed that MARCH E3 ligases play pivotal roles in cancer progression by ubiquitinating key oncogenes and tumor suppressors and orchestrating various signaling pathways. Some MARCH E3s act as oncogenes, while others act as tumor suppressors, and the majority of MARCH E3s play both oncogenic and tumor suppressive roles in a context-dependent manner. Notably, there is special emphasis on the sole mitochondrial MARCH E3 ligase MARCH5, which regulates mitochondrial homeostasis within cancer cells. In this review, we delve into the diverse functions of MARCH E3 ligases across different cancer types, shedding light on the underlying molecular mechanisms mediating their effects, their regulatory effects on cancer and their potential as therapeutic targets.

9.
Bioessays ; 45(12): e2300139, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37890275

RESUMEN

The dynamic structure and composition of lipid membranes need to be tightly regulated to control the vast array of cellular processes from cell and organelle morphology to protein-protein interactions and signal transduction pathways. To maintain membrane integrity, sense-and-response systems monitor and adjust membrane lipid composition to the ever-changing cellular environment, but only a relatively small number of control systems have been described. Here, we explore the emerging role of the ubiquitin-proteasome system in monitoring and maintaining membrane lipid composition. We focus on the ER-resident RNF145 E3 ubiquitin ligase, its role in regulating adiponectin receptor 2 (ADIPOR2), its lipid hydrolase substrate, and the broader implications for understanding the homeostatic processes that fine-tune cellular membrane composition.


Asunto(s)
Ubiquitina-Proteína Ligasas , Ubiquitina , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitinación , Ubiquitina/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo , Lípidos de la Membrana
10.
Biochem J ; 481(10): 653-666, 2024 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-38666590

RESUMEN

E3 ubiquitin ligase, ring finger protein 138 (RNF138) is involved in several biological processes; however, its role in myeloid differentiation or tumorigenesis remains unclear. RNAseq data from TNMplot showed that RNF138 mRNA levels are highly elevated in acute myeloid leukemia (AML) bone marrow samples as compared with bone marrow of normal volunteers. Here, we show that RNF138 serves as an E3 ligase for the tumor suppressor CCAAT/enhancer binding protein (C/EBPα) and promotes its degradation leading to myeloid differentiation arrest in AML. Wild-type RNF138 physically interacts with C/EBPα and promotes its ubiquitin-dependent proteasome degradation while a mutant RNF-138 deficient in ligase activity though interacts with C/EBPα, fails to down-regulate it. We show that RNF138 depletion enhances endogenous C/EBPα levels in peripheral blood mononuclear cells (PBMCs) isolated from healthy volunteers. Our data further shows that RNF138-mediated degradation of C/EBPα negatively affects its transactivation potential on its target genes. Furthermore, RNF138 overexpression inhibits all-trans-retinoic acid-induced differentiation of HL-60 cells whereas RNF138 RNAi enhances. In line with RNF138 inhibiting C/EBPα protein turnover, we also observed that RNF138 overexpression inhibited ß-estradiol (E2)-induced C/EBPα driven granulocytic differentiation in C/EBPα inducible K562-p42C/EBPα-estrogen receptor cells. Furthermore, we also recapitulated these findings in PBMCs isolated from AML patients where depletion of RNF138 increased the expression of myeloid differentiation marker CD11b. These results suggest that RNF138 inhibits myeloid differentiation by targeting C/EBPα for proteasomal degradation and may provide a plausible mechanism for loss of C/EBPα expression often observed in myeloid leukemia. Also, targeting RNF138 may resolve differentiation arrest by restoring C/EBPα expression in AML.


Asunto(s)
Proteína alfa Potenciadora de Unión a CCAAT , Diferenciación Celular , Leucemia Mieloide Aguda , Ubiquitina-Proteína Ligasas , Humanos , Proteína alfa Potenciadora de Unión a CCAAT/metabolismo , Proteína alfa Potenciadora de Unión a CCAAT/genética , Proteínas Potenciadoras de Unión a CCAAT , Diferenciación Celular/genética , Células HEK293 , Células HL-60 , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patología , Proteolisis , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismo
11.
Mol Plant Microbe Interact ; 37(6): 520-529, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38470518

RESUMEN

E3 ubiquitin ligases play a critical role in plant disease resistance. Among them, the Skp1-Cullin-F-box protein (SCF) ubiquitin ligase complex is the largest family and regulates the ubiquitination of a wide range of proteins. Apple Valsa canker (AVC) is a fungal disease of apple trees caused by the fungus Valsa mali, which can lead to significant economic losses. However, the function of the SCF complex in apple resistance to this disease is still largely unknown. In this study, we identified an SCF ubiquitin ligase complex that can enhance resistance to Valsa canker in apple. Disease evaluation experiments demonstrated that MdSkp1 increased apple resistance to AVC. Furthermore, MdSkp1 interacted with an F-box protein, MdSKIP14, and interacted with a cullin-1 protein, MdCUL1, to form an SCF ubiquitin ligase complex. Additionally, we revealed both MdSKIP14 and MdCUL1 as positive regulators of AVC resistance. In conclusion, our results identified an SCF complex capable of contributing to apple resistance against AVC, providing a theoretical basis for apple disease resistance and the sustainable development of the industry. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.


Asunto(s)
Ascomicetos , Resistencia a la Enfermedad , Malus , Enfermedades de las Plantas , Proteínas de Plantas , Proteínas Ligasas SKP Cullina F-box , Malus/microbiología , Malus/genética , Malus/inmunología , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/inmunología , Resistencia a la Enfermedad/genética , Proteínas Ligasas SKP Cullina F-box/metabolismo , Proteínas Ligasas SKP Cullina F-box/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Ascomicetos/fisiología , Regulación de la Expresión Génica de las Plantas , Proteínas F-Box/metabolismo , Proteínas F-Box/genética , Plantas Modificadas Genéticamente
12.
Apoptosis ; 29(5-6): 663-680, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38598070

RESUMEN

Cancer cachexia-associated muscle wasting as a multifactorial wasting syndrome, is an important factor affecting the long-term survival rate of tumor patients. Photobiomodulation therapy (PBMT) has emerged as a promising tool to cure and prevent many diseases. However, the effect of PBMT on skeletal muscle atrophy during cancer progression has not been fully demonstrated yet. Here, we found PBMT alleviated the atrophy of myotube diameter induced by cancer cells in vitro, and prevented cancer-associated muscle atrophy in mice bearing tumor. Mechanistically, the alleviation of muscle wasting by PBMT was found to be involved in inhibiting E3 ubiquitin ligases MAFbx and MuRF-1. In addition, transcriptomic analysis using RNA-seq and GSEA revealed that PI3K/AKT pathway might be involved in PBMT-prevented muscle cachexia. Next, we showed the protective effect of PBMT against muscle cachexia was totally blocked by AKT inhibitor in vitro and in vivo. Moreover, PBMT-activated AKT promoted FoxO3a phosphorylation and thus inhibiting the nucleus entry of FoxO3a. Lastly, in cisplatin-treated muscle cachexia model, PBMT had also been shown to ameliorate muscle atrophy through enhancing PI3K/AKT pathway to suppress MAFbx and MuRF-1 expression. These novel findings revealed that PBMT could be a promising therapeutic approach in treating muscle cachexia induced by cancer.


Asunto(s)
Caquexia , Proteína Forkhead Box O3 , Enfermedades Musculares , Neoplasias , Fosfatidilinositol 3-Quinasas , Proteínas Proto-Oncogénicas c-akt , Síndrome Debilitante , Caquexia/etiología , Caquexia/metabolismo , Caquexia/terapia , Enfermedades Musculares/etiología , Enfermedades Musculares/metabolismo , Enfermedades Musculares/terapia , Neoplasias/complicaciones , Redes y Vías Metabólicas , Fosfatidilinositol 3-Quinasas/genética , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proteína Forkhead Box O3/genética , Proteína Forkhead Box O3/metabolismo , Síndrome Debilitante/etiología , Síndrome Debilitante/metabolismo , Síndrome Debilitante/terapia , Animales , Modelos Animales de Enfermedad , Ratones , Línea Celular , Masculino , Ratones Endogámicos BALB C , Perfilación de la Expresión Génica
13.
J Virol ; 97(11): e0138923, 2023 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-37888983

RESUMEN

IMPORTANCE: Kaposi's sarcoma-associated herpesvirus (KSHV) is a cancer-causing human herpesvirus that establishes a persistent infection in humans. The lytic viral cycle plays a crucial part in lifelong infection as it is involved in the viral dissemination. The master regulator of the KSHV lytic replication cycle is the viral replication and transcription activator (RTA) protein, which is necessary and sufficient to push the virus from latency into the lytic phase. Thus, the identification of host factors utilized by RTA for controlling the lytic cycle can help to find novel targets that could be used for the development of antiviral therapies against KSHV. Using a proteomics approach, we have identified a novel interaction between RTA and the cellular E3 ubiquitin ligase complex RNF20/40, which we have shown to be necessary for promoting RTA-induced KSHV lytic cycle.


Asunto(s)
Herpesvirus Humano 8 , Interacciones Microbiota-Huesped , Proteínas Inmediatas-Precoces , Ubiquitina-Proteína Ligasas , Proteínas Virales , Activación Viral , Latencia del Virus , Replicación Viral , Humanos , Herpesvirus Humano 8/crecimiento & desarrollo , Herpesvirus Humano 8/fisiología , Proteínas Inmediatas-Precoces/metabolismo , Unión Proteica , Proteómica , Transactivadores/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Proteínas Virales/metabolismo
14.
Biochem Soc Trans ; 2024 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-39222407

RESUMEN

E3 ubiquitin ligases regulate the composition of the proteome. These enzymes mono- or poly-ubiquitinate their substrates, directly altering protein function or targeting proteins for degradation by the proteasome. In this review, we discuss the opposing roles of human E3 ligases as effectors and targets in the evolutionary battle between host and pathogen, specifically in the context of SARS-CoV-2 infection. Through complex effects on transcription, translation, and protein trafficking, human E3 ligases can either attenuate SARS-CoV-2 infection or become vulnerabilities that are exploited by the virus to suppress the host's antiviral defenses. For example, the human E3 ligase RNF185 regulates the stability of SARS-CoV-2 envelope protein through the ubiquitin-proteasome pathway, and depletion of RNF185 significantly increases SARS-CoV-2 viral titer (iScience (2023) 26, 106601). We highlight recent advances that identify functions for numerous human E3 ligases in the SARS-CoV-2 life cycle and we assess their potential as novel antiviral agents.

15.
Biochem J ; 480(22): 1817-1831, 2023 11 29.
Artículo en Inglés | MEDLINE | ID: mdl-37870100

RESUMEN

Protein ubiquitylation typically involves isopeptide bond formation between the C-terminus of ubiquitin to the side-chain amino group on Lys residues. However, several ubiquitin ligases (E3s) have recently been identified that ubiquitylate proteins on non-Lys residues. For instance, HOIL-1 belongs to the RING-in-between RING (RBR) class of E3s and has an established role in Ser ubiquitylation. Given the homology between HOIL-1 and ARIH1, an RBR E3 that functions with the large superfamily of cullin-RING E3 ligases (CRLs), a biochemical investigation was undertaken, showing ARIH1 catalyzes Ser ubiquitylation to CRL-bound substrates. However, the efficiency of ubiquitylation was exquisitely dependent on the location and chemical environment of the Ser residue within the primary structure of the substrate. Comprehensive mutagenesis of the ARIH1 Rcat domain identified residues whose mutation severely impacted both oxyester and isopeptide bond formation at the preferred site for Ser ubiquitylation while only modestly affecting Lys ubiquitylation at the physiological site. The results reveal dual isopeptide and oxyester protein ubiquitylation activities of ARIH1 and set the stage for physiological investigations into this function of emerging importance.


Asunto(s)
Ubiquitina-Proteína Ligasas , Ubiquitina , Ubiquitina/genética , Ubiquitina/metabolismo , Ubiquitinación , Ubiquitina-Proteína Ligasas/metabolismo , Proteínas/metabolismo , Catálisis
16.
Int J Mol Sci ; 25(14)2024 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-39062881

RESUMEN

Ubiquitination, a post-translational modification, refers to the covalent attachment of ubiquitin molecules to substrates. This modification plays a critical role in diverse cellular processes such as protein degradation. The specificity of ubiquitination for substrates is regulated by E3 ubiquitin ligases. Dysregulation of ubiquitination has been associated with numerous diseases, including cancers. In our study, we first investigated the protein expression patterns of E3 ligases across 12 cancer types. Our findings indicated that E3 ligases tend to be up-regulated and exhibit reduced tissue specificity in tumors. Moreover, the correlation of protein expression between E3 ligases and substrates demonstrated significant changes in cancers, suggesting that E3-substrate specificity alters in tumors compared to normal tissues. By integrating transcriptome, proteome, and ubiquitylome data, we further characterized the E3-substrate regulatory patterns in lung squamous cell carcinoma. Our analysis revealed that the upregulation of the SKP2 E3 ligase leads to excessive degradation of BRCA2, potentially promoting tumor cell proliferation and metastasis. Furthermore, the upregulation of E3 ubiquitin-protein ligase TRIM33 was identified as a biomarker associated with a favorable prognosis by inhibiting the cell cycle. This work exemplifies how leveraging multi-omics data to analyze E3 ligases across various cancers can unveil prognosis biomarkers and facilitate the identification of potential drug targets for cancer therapy.


Asunto(s)
Neoplasias , Ubiquitina-Proteína Ligasas , Ubiquitinación , Humanos , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitina-Proteína Ligasas/genética , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patología , Regulación Neoplásica de la Expresión Génica , Biomarcadores de Tumor/metabolismo , Biomarcadores de Tumor/genética , Proteínas Quinasas Asociadas a Fase-S/metabolismo , Proteínas Quinasas Asociadas a Fase-S/genética , Proteómica/métodos , Transcriptoma , Proteoma/metabolismo , Pronóstico , Proteínas de Motivos Tripartitos/metabolismo , Proteínas de Motivos Tripartitos/genética , Multiómica
17.
Angew Chem Int Ed Engl ; : e202413651, 2024 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-39363740

RESUMEN

The chemical synthesis of histones with homogeneous modifications is a potent approach for quantitatively deciphering the functional crosstalk between different post-translational modifications (PTMs). Here, we developed an expedient site-specific (poly)ubiquitylation strategy (CAEPL, Cysteine-Aminoethylation coupled with Enzymatic Protein Ligation), which integrates the Cys-aminoethylation reaction with the process of ubiquitin-activating enzyme UBA1-assisted native chemical ligation. Using this strategy, we successfully prepared monoubiquitylated and K63-linked di- and tri-ubiquitylated linker histone H1.0 proteins, which were incorporated into individual chromatosomes. Quantitative biochemical analysis of different RNF168 constructs on ubiquitylated chromatosomes with different ubiquitin chain lengths demonstrated that K63-linked polyubiquitylated H1.0 could directly stimulate RNF168 ubiquitylation activity by enhancing the affinity between RNF168 and chromatosome. Subsequent cryo-EM structural analysis of the RNF168/UbcH5c-Ub/H1.0-K63-Ub3 chromatosome complex revealed the potential recruitment orientation between RNF168 UDM1 domain and K63-linked ubiquitin chain on H1.0. Finally, we explored the impact of H1.0 ubiquitylation on RNF168 activity in the context of asymmetric H1.0-K63-Ub3 di-nucleosome substrate, revealing a comparable stimulation effect of both the inter- and intra-nucleosomal crosstalk. Overall, our study highlights the significance of access to structurally-defined polyubiquitylated H1.0 by CAEPL strategy, enabling in-depth mechanistic investigations of in-trans PTM crosstalk between linker histone H1.0 and core histone H2A ubiquitylation.

18.
Trends Biochem Sci ; 44(12): 1057-1075, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31610939

RESUMEN

Ubiquitination, a post-translational modification that involves a covalent attachment of ubiquitin to a protein substrate, is essential for cellular homeostatic maintenance. At the end of a three-enzyme cascade, E3 ubiquitin ligases (E3s) recruit substrates and promote or directly catalyze ubiquitin transfer to targets. These enzymes largely determine the specificity of the ubiquitination reaction. Genetic alteration, abnormal expression, or dysfunction of E3s account for the occurrence and progression of human cancers. Indeed, excessive degradation of relevant tumor-suppressor molecules and impaired disposal of oncogenic proteins have been linked to tumorigenesis. This review focuses on the emerging roles of HECT-type E3s in tumorigenesis, and emphasizes how perturbations of these enzymes contribute to cancer pathogenesis.


Asunto(s)
Carcinogénesis , Neoplasias , Proteolisis , Ubiquitina-Proteína Ligasas , Ubiquitinación , Animales , Carcinogénesis/genética , Carcinogénesis/metabolismo , Humanos , Neoplasias/enzimología , Neoplasias/genética , Ubiquitina/genética , Ubiquitina/metabolismo , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismo
19.
J Cell Physiol ; 238(3): 582-596, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36791253

RESUMEN

Endoplasmic reticulum (ER) stress is involved in skeletal muscle atrophy in various conditions, but the role of ER stress in sepsis-induced muscle atrophy is not well understood. In this study, we conducted experiments in wild-type (WT) mice and C/EBP homologous protein knockout (CHOP KO) mice to explore the role and mechanism of ER stress in sepsis-induced muscle atrophy. Cecal ligation and puncture (CLP) was used to establish a mouse model of sepsis. In WT mice, the body weight, muscle mass, and cross-sectional area of muscle fibers in CLP group both decreased significantly compared with sham group, which revealed that sepsis-induced dramatic muscle atrophy. Additionally, sepsis activated the ubiquitin-proteasome system (UPS), accompanied by the activation of ER stress. In vitro, inhibition of ER stress suppressed the activity of E3 ubiquitin ligases and alleviated the myotube atrophy. In vivo, CHOP KO also reduced the expression of E3 ubiquitin ligases and UPS-mediated protein degradation, and significantly attenuated sepsis-induced muscle atrophy. Deletion of CHOP also decreased the phosphorylation of signal transducer and activator of transcription 3 (STAT3) and Smad3, and inhibition of STAT3 and Smad3 partly reduced proteolysis caused by ER stress in vitro. These findings confirm that ER stress activates UPS-mediated proteolysis and promotes sepsis-induced muscle atrophy, which is partly achieved by activating STAT3 and Smad3.


Asunto(s)
Estrés del Retículo Endoplásmico , Atrofia Muscular , Factor de Transcripción STAT3 , Sepsis , Proteína smad3 , Animales , Ratones , Ratones Noqueados , Músculo Esquelético/metabolismo , Músculo Esquelético/patología , Atrofia Muscular/etiología , Atrofia Muscular/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo , Sepsis/complicaciones , Sepsis/metabolismo , Factor de Transcripción STAT3/antagonistas & inhibidores , Factor de Transcripción STAT3/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Proteína smad3/antagonistas & inhibidores , Proteína smad3/metabolismo , Modelos Animales de Enfermedad , Ubiquitina/metabolismo , Proteolisis , Fosforilación
20.
BMC Genomics ; 24(1): 549, 2023 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-37723489

RESUMEN

E2 ubiquitin conjugating enzymes and E3 ubiquitin ligases play important roles in the growth and development of plants and animals. To date, the systematic analysis of E2 and E3 genes in Rhodophyta is limited. In this study, 14 E2 genes and 51 E3 genes were identified in Gracilariopsis lemaneiformis, an economically important red alga. E2 genes were classified into four classes according to the structure of the conserved domain, UBC. E3 genes were classified into 12 subfamilies according to individual conserved domains. A phylogenetic tree of seven algae species showed that functional differentiation of RING-type E3s was the highest, and the similarity between orthologous genes was high except in Chlamydomonas reinhardtii and Chara braunii. RNA-seq data analysis showed significant differential expression levels of E2 and E3 genes under the life stages of tetraspore formation and release, especially GlUBCN and GlAPC3. According to GO and KEGG analysis of two transcriptomes, GlUBCN and GlAPC3 were involved in ubiquitin-mediated proteolysis, and other subunits of the anaphase promoting complex or cyclosome (APC/C) and its activators GlCDC20 and GlCDH1 were also enriched into this process. The CDH1 and CDC20 in 981 were down-regulated during tetraspores formation and release, with the down-regulation of CDH1 being particularly significant; CDH1 and CDC20 in WLP-1, ZC, and WT were up-regulated during tetraspores formation and release, with CDC20 being more significantly up-regulated. Therefore, GlCDH1, rather than GlCDC20, in '981' might play the leading role in the activation of the APC/C, and GlCDC20 might play the leading role rather than GlCDH1 in strains WLP-1, ZC and wild type. The low fertility of cultivar 981 might be highly correlated with the inactivity of activators CDH1 and CDC20. This study provided a basic and comprehensive understanding of characteristic of E2 and E3 genes in Gp. lemaneiformis and set a foundation for further understanding of E2 ubiquitin conjugating enzymes and E3 ubiquitin ligase in regulating tetrasporophytes development of Gp. lemaneiformis.


Asunto(s)
Rhodophyta , Enzimas Ubiquitina-Conjugadoras , Animales , Filogenia , Enzimas Ubiquitina-Conjugadoras/genética , Genes cdc , Proteínas de Ciclo Celular , Rhodophyta/genética , Ubiquitinas
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