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1.
Nihon Yakurigaku Zasshi ; 156(5): 271-274, 2021.
Artigo em Japonês | MEDLINE | ID: mdl-34470930

RESUMO

Vertebral bone and limb bone are formed by endochondral ossification, which is replaced with bone tissue by osteoblasts after cartilage formation. Bone growth is regulated by the balance between epiphyseal chondrocyte proliferation and ossification. We attempted to elucidate the mechanism of chondrocyte differentiation and maturation regulated by the Extracellular-signal-regulated kinase 5 (Erk5) signal. Erk5 is a serine/threonine kinase belonging to the mitogen-activated protein kinase (MAPK) family, which includes Erk1/2, JNK, and p38. Mesenchymal stem cell-specific Erk5-deficient mice exhibited the phenotype of deformities of the metatarsal bones, enlargement of the long bones in limbs, and overgrowth of cartilage tissue. Based on this result, we searched for factors that directly phosphorylate Erk5, and We demonstrated that Erk5 directly phosphorylates and activates Smurf2 (a ubiquitin E3 ligase) at Thr249 to activate its function and promotes ubiquitination-mediated degradation. The TGF-ß-Smad signal suppresses the proliferation of many cells and regulates the production of extracellular matrix. Our findings may lead to the development of novel drugs targeting TGF-ß associated diseases. In this paper, we investigated the function of Smurf2Thr249 phosphorylation and the possibility as new therapeutic target for various diseases.


Assuntos
Proteína Quinase 7 Ativada por Mitógeno , Fator de Crescimento Transformador beta , Ubiquitina-Proteína Ligases , Animais , Diferenciação Celular , Camundongos , Proteína Quinase 7 Ativada por Mitógeno/genética , Proteína Quinase 7 Ativada por Mitógeno/metabolismo , Fosforilação , Fator de Crescimento Transformador beta/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação
2.
Adv Exp Med Biol ; 1288: 215-240, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34453739

RESUMO

Ubiquitination is one of the most diverse forms of protein post-translational modification that changes the function of the landscape of substrate proteins in response to stimuli, without the need for "de novo" protein synthesis. Ubiquitination is involved in almost all aspects of eukaryotic cell biology, from the best-studied role in promoting the removal of faulty or unnecessary proteins by the way of the ubiquitin proteasome system and autophagy-lysosome pathway to the recruitment of proteins in specific non-proteolytic signaling pathways, as emerged by the more recent discoveries about the protein signature with peculiar types of ubiquitin chains. Spermatogenesis, on its own, is a complex cellular developmental process in which mitosis, meiosis, and cell differentiation coexist so to result in the continuous formation of haploid spermatozoa. Successful spermatogenesis is thus at the same time a mixed result of the precise expression and correct intracellular destination of structural proteins and enzymes, from one hand, and the fine removal by targeted degradation of unfolded or damaged proteins as well as of obsolete, outlived proteins, from the other hand. In this minireview, I will focus on the importance of the ubiquitin system all over the spermatogenic process, discussing both proteolytic and non-proteolytic functions of protein ubiquitination. Alterations in the ubiquitin system have been in fact implicated in pathologies leading to male infertility. Notwithstanding several aspects of the multifaceted world of the ubiquitin system have been clarified, the physiological meaning of the so-called ubiquitin code remains still partially elusive. The studies reviewed in this chapter provide information that could aid the investigators to pursue new promising discoveries in the understanding of human and animal reproductive potential.


Assuntos
Espermatogênese , Ubiquitina , Animais , Humanos , Masculino , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteólise , Ubiquitina/metabolismo , Ubiquitinação
3.
Mol Cell ; 81(16): 3246-3261.e11, 2021 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-34352208

RESUMO

The Wnt/ß-catenin pathway is a highly conserved, frequently mutated developmental and cancer pathway. Its output is defined mainly by ß-catenin's phosphorylation- and ubiquitylation-dependent proteasomal degradation, initiated by the multi-protein ß-catenin destruction complex. The precise mechanisms underlying destruction complex function have remained unknown, largely because of the lack of suitable in vitro systems. Here we describe the in vitro reconstitution of an active human ß-catenin destruction complex from purified components, recapitulating complex assembly, ß-catenin modification, and degradation. We reveal that AXIN1 polymerization and APC promote ß-catenin capture, phosphorylation, and ubiquitylation. APC facilitates ß-catenin's flux through the complex by limiting ubiquitylation processivity and directly interacts with the SCFß-TrCP E3 ligase complex in a ß-TrCP-dependent manner. Oncogenic APC truncation variants, although part of the complex, are functionally impaired. Nonetheless, even the most severely truncated APC variant promotes ß-catenin recruitment. These findings exemplify the power of biochemical reconstitution to interrogate the molecular mechanisms of Wnt/ß-catenin signaling.


Assuntos
Proteína da Polipose Adenomatosa do Colo/genética , Proteína Axina/genética , beta Catenina/genética , Proteína da Polipose Adenomatosa do Colo/ultraestrutura , Proteína Axina/química , Proteína Axina/ultraestrutura , Humanos , Complexos Multiproteicos/genética , Complexos Multiproteicos/ultraestrutura , Fosforilação/genética , Multimerização Proteica/genética , Proteólise , Ubiquitinação/genética , Via de Sinalização Wnt
4.
Int J Mol Sci ; 22(16)2021 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-34445801

RESUMO

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.


Assuntos
Antivirais/imunologia , Proteína DEAD-box 58/imunologia , RNA Helicases DEAD-box/imunologia , Imunidade/imunologia , Receptores Imunológicos/imunologia , Fatores de Transcrição/imunologia , Proteínas com Motivo Tripartido/imunologia , Ubiquitina-Proteína Ligases/imunologia , Linhagem Celular , Regulação da Expressão Gênica/imunologia , Células HEK293 , Humanos , Vírus da Influenza A/imunologia , Interferons/imunologia , Regiões Promotoras Genéticas/imunologia , Ligação Proteica/imunologia , Transdução de Sinais/imunologia , Ubiquitinação/imunologia
5.
FASEB J ; 35(9): e21870, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34436790

RESUMO

COVID-19 is often characterized by dysregulated inflammatory and immune responses. It has been shown that the Traditional Chinese Medicine formulation Qing-Fei-Pai-Du decoction (QFPDD) is effective in the treatment of the disease, especially for patients in the early stage. Our network pharmacology analyses indicated that many inflammation and immune-related molecules were the targets of the active components of QFPDD, which propelled us to examine the effects of the decoction on inflammation. We found in the present study that QFPDD effectively alleviated dextran sulfate sodium-induced intestinal inflammation in mice. It inhibited the production of pro-inflammatory cytokines IL-6 and TNFα, and promoted the expression of anti-inflammatory cytokine IL-10 by macrophagic cells. Further investigations found that QFPDD and one of its active components wogonoside markedly reduced LPS-stimulated phosphorylation of transcription factor ATF2, an important regulator of multiple cytokines expression. Our data revealed that both QFPDD and wogonoside decreased the half-life of ATF2 and promoted its proteasomal degradation. Of note, QFPDD and wogonoside down-regulated deubiquitinating enzyme USP14 along with inducing ATF2 degradation. Inhibition of USP14 with the small molecular inhibitor IU1 also led to the decrease of ATF2 in the cells, indicating that QFPDD and wogonoside may act through regulating USP14 to promote ATF2 degradation. To further assess the importance of ubiquitination in regulating ATF2, we generated mice that were intestinal-specific KLHL5 deficiency, a CUL3-interacting protein participating in substrate recognition of E3s. In these mice, QFPDD mitigated inflammatory reaction in the spleen, but not intestinal inflammation, suggesting CUL3-KLHL5 may function as an E3 for ATF2 degradation.


Assuntos
Fator 2 Ativador da Transcrição/metabolismo , Regulação para Baixo/efeitos dos fármacos , Medicamentos de Ervas Chinesas/farmacologia , Flavanonas/farmacologia , Glucosídeos/farmacologia , Inflamação/tratamento farmacológico , Proteólise/efeitos dos fármacos , Ubiquitina Tiolesterase/deficiência , Animais , Linhagem Celular , Colite/induzido quimicamente , Colite/tratamento farmacológico , Proteínas Culina/metabolismo , Citocinas/metabolismo , Sulfato de Dextrana/farmacologia , Sulfato de Dextrana/uso terapêutico , Medicamentos de Ervas Chinesas/uso terapêutico , Flavanonas/uso terapêutico , Glucosídeos/uso terapêutico , Inflamação/induzido quimicamente , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fosforilação/efeitos dos fármacos , Complexo de Endopeptidases do Proteassoma/efeitos dos fármacos , Complexo de Endopeptidases do Proteassoma/metabolismo , Pirróis/farmacologia , Pirrolidinas/farmacologia , Ubiquitina Tiolesterase/antagonistas & inibidores , Ubiquitinação
6.
Nat Commun ; 12(1): 4794, 2021 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-34373456

RESUMO

The cellular NLRP3 protein level is crucial for assembly and activation of the NLRP3 inflammasome. Various posttranslational modifications (PTMs), including phosphorylation and ubiquitination, control NLRP3 protein degradation and inflammasome activation; however, the function of small ubiquitin-like modifier (SUMO) modification (called SUMOylation) in controlling NLRP3 stability and subsequent inflammasome activation is unclear. Here, we show that the E3 SUMO ligase tripartite motif-containing protein 28 (TRIM28) is an enhancer of NLRP3 inflammasome activation by facilitating NLRP3 expression. TRIM28 binds NLRP3, promotes SUMO1, SUMO2 and SUMO3 modification of NLRP3, and thereby inhibits NLRP3 ubiquitination and proteasomal degradation. Concordantly, Trim28 deficiency attenuates NLRP3 inflammasome activation both in vitro and in vivo. These data identify a mechanism by which SUMOylation controls the cellular NLRP3 level and inflammasome activation, and reveal correlations and interactions of NLRP3 SUMOylation and ubiquitination during inflammasome activation.


Assuntos
Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Sumoilação/fisiologia , Proteína 28 com Motivo Tripartido/metabolismo , Animais , Feminino , Células HEK293 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Fosforilação , Processamento de Proteína Pós-Traducional , Proteólise , Proteína SUMO-1/metabolismo , Proteínas Modificadoras Pequenas Relacionadas à Ubiquitina/metabolismo , Sumoilação/genética , Proteína 28 com Motivo Tripartido/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação , Ubiquitinas/metabolismo
7.
Int J Mol Sci ; 22(15)2021 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-34360702

RESUMO

T-2 toxin is mainly produced by Fusarium species, which is an extremely toxic mycotoxin to humans and animals. It is well known that T-2 toxin induces oxidative stress, but the molecular mechanism is still unknown. In this study, we found that T-2 toxin significantly promoted reactive oxygen species (ROS) accumulation in MCF-7 cells at low doses which maintains cell viability at least 80%. Further analysis showed that T-2 toxin downregulated the expression of the master regulator of antioxidant defense gene, nuclear factor erythroid 2-related factor (Nrf2), and its targeted antioxidant genes. Overexpression of Nrf2 or its target gene heme oxygenase 1 (HO1) significantly blocked the ROS accumulation in MCF-7 cells under T-2 toxin treatment. Moreover, we found that T-2 toxin downregulated the antioxidant genes via inducing the expression of ATF3ΔZip2a/2b. Importantly, overexpression of ATF3ΔZip2a/2b promoted the ubiquitination and degradation of Nrf2. Altogether, our results demonstrated that T-2 toxin-induced ROS accumulation via ATF3ΔZip2a/2b mediated ubiquitination and degradation of Nrf2, which provided a new insight into the mechanism of T-2 toxin-induced oxidative stress.


Assuntos
Fator 3 Ativador da Transcrição/metabolismo , Proteínas de Transporte de Cátions/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo , Toxina T-2/farmacologia , Ubiquitinação , Feminino , Humanos , Células MCF-7 , Transdução de Sinais , Toxina T-2/toxicidade
8.
FASEB J ; 35(9): e21825, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34383978

RESUMO

Ubiquitination is an essential post-translational modification that regulates protein stability or function. Its substrate specificity is dictated by various E3 ligases. The human C-terminal to LisH (CTLH) complex is a newly discovered multi-subunit really interesting new gene (RING) E3 ligase with only a few known ubiquitination targets. Here, we used mass spectrometry-based proteomic techniques to gain insight into CTLH complex function and ubiquitination substrates in HeLa cells. First, global proteomics determined proteins that were significantly increased, and thus may be substrates targeted for degradation, in cells depleted of CTLH complex member RanBPM. RanBPM-dependent ubiquitination determined using diGLY-enriched proteomics and the endogenous RanBPM interactome further revealed candidate ubiquitination targets. Three glycolysis enzymes alpha-enolase, L-lactate dehydrogenase A chain (LDHA), and pyruvate kinase M1/2 (PKM) had decreased ubiquitin sites in shRanBPM cells and were found associated with RanBPM in the interactome. Reduced polyubiquitination was validated for PKM2 and LDHA in cells depleted of RanBPM and CTLH complex RING domain subunit RMND5A. PKM2 and LDHA protein levels were unchanged, yet their activity was increased in extracts of cells with downregulated RanBPM. Finally, RanBPM deficient cells displayed enhanced glycolysis and deregulated central carbon metabolism. Overall, this study identifies potential CTLH complex ubiquitination substrates and uncovers that the CTLH complex inhibits glycolysis via non-degradative ubiquitination of PKM2 and LDHA.


Assuntos
Glicólise/fisiologia , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação/fisiologia , Animais , Linhagem Celular Tumoral , Células HeLa , Humanos , L-Lactato Desidrogenase/metabolismo , Camundongos , Proteômica/métodos , Especificidade por Substrato , Ubiquitina/metabolismo
9.
Nat Commun ; 12(1): 5016, 2021 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-34408138

RESUMO

DNA damage prompts a diverse range of alterations to the chromatin landscape. The RNF168 E3 ubiquitin ligase catalyzes the mono-ubiquitination of histone H2A at lysine (K)13/15 (mUb-H2A), forming a binding module for DNA repair proteins. BRCA1 promotes homologous recombination (HR), in part, through its interaction with PALB2, and the formation of a larger BRCA1-PALB2-BRCA2-RAD51 (BRCA1-P) complex. The mechanism by which BRCA1-P is recruited to chromatin surrounding DNA breaks is unclear. In this study, we reveal that an RNF168-governed signaling pathway is responsible for localizing the BRCA1-P complex to DNA damage. Using mice harboring a Brca1CC (coiled coil) mutation that blocks the Brca1-Palb2 interaction, we uncovered an epistatic relationship between Rnf168- and Brca1CC alleles, which disrupted development, and reduced the efficiency of Palb2-Rad51 localization. Mechanistically, we show that RNF168-generated mUb-H2A recruits BARD1 through a BRCT domain ubiquitin-dependent recruitment motif (BUDR). Subsequently, BARD1-BRCA1 accumulate PALB2-RAD51 at DNA breaks via the CC domain-mediated BRCA1-PALB2 interaction. Together, these findings establish a series of molecular interactions that connect the DNA damage signaling and HR repair machinery.


Assuntos
Proteína BRCA1/metabolismo , Dano ao DNA , Proteína do Grupo de Complementação N da Anemia de Fanconi/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Animais , Proteína BRCA1/genética , Núcleo Celular/genética , Núcleo Celular/metabolismo , DNA/genética , DNA/metabolismo , Proteína do Grupo de Complementação N da Anemia de Fanconi/genética , Histonas/genética , Histonas/metabolismo , Humanos , Camundongos , Ligação Proteica , Transporte Proteico , Rad51 Recombinase/genética , Rad51 Recombinase/metabolismo , Reparo de DNA por Recombinação , Proteínas Supressoras de Tumor/genética , Ubiquitina-Proteína Ligases/genética , Ubiquitinação
10.
Nat Commun ; 12(1): 5010, 2021 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-34408146

RESUMO

Poly(ADP)-ribosylation (PARylation) regulates chromatin structure and recruits DNA repair proteins. Using single-molecule fluorescence microscopy to track topoisomerase I (TOP1) in live cells, we found that sustained PARylation blocked the repair of TOP1 DNA-protein crosslinks (TOP1-DPCs) in a similar fashion as inhibition of the ubiquitin-proteasome system (UPS). PARylation of TOP1-DPC was readily revealed by inhibiting poly(ADP-ribose) glycohydrolase (PARG), indicating the otherwise transient and reversible PARylation of the DPCs. As the UPS is a key repair mechanism for TOP1-DPCs, we investigated the impact of TOP1-DPC PARylation on the proteasome and found that the proteasome is unable to associate with and digest PARylated TOP1-DPCs. In addition, PARylation recruits the deubiquitylating enzyme USP7 to reverse the ubiquitylation of PARylated TOP1-DPCs. Our work identifies PARG as repair factor for TOP1-DPCs by enabling the proteasomal digestion of TOP1-DPCs. It also suggests the potential regulatory role of PARylation for the repair of a broad range of DPCs.


Assuntos
DNA Topoisomerases Tipo I/metabolismo , DNA/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , DNA/química , DNA/metabolismo , Dano ao DNA , Reparo do DNA , DNA Topoisomerases Tipo I/química , DNA Topoisomerases Tipo I/genética , Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/metabolismo , Células HEK293 , Humanos , Poli ADP Ribosilação , Complexo de Endopeptidases do Proteassoma/química , Complexo de Endopeptidases do Proteassoma/genética , Proteólise , Ubiquitinação
11.
Int J Mol Sci ; 22(16)2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34445478

RESUMO

Peptide-based target protein degradation inducers called PROTACs/SNIPERs have low cell penetrability and poor intracellular stability as drawbacks. These shortcomings can be overcome by easily modifying these peptides by conjugation with cell penetrating peptides and side-chain stapling. In this study, we succeeded in developing the stapled peptide stPERML-R7, which is based on the estrogen receptor alpha (ERα)-binding peptide PERML and composed of natural amino acids. stPERML-R7, which includes a hepta-arginine motif and a hydrocarbon stapling moiety, showed increased α-helicity and similar binding affinity toward ERα when compared with those of the parent peptide PERML. Furthermore, we used stPERML-R7 to develop a peptide-based degrader LCL-stPERML-R7 targeting ERα by conjugating stPERML-R7 with a small molecule LCL161 (LCL) that recruits the E3 ligase IAPs to induce proteasomal degradation via ubiquitylation. The chimeric peptide LCL-stPERML-R7 induced sustained degradation of ERα and potently inhibited ERα-mediated transcription more effectively than the unstapled chimera LCL-PERML-R7. These results suggest that a stapled structure is effective in maintaining the intracellular activity of peptide-based degraders.


Assuntos
Peptídeos Penetradores de Células/metabolismo , Receptor alfa de Estrogênio/metabolismo , Tiazóis/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Receptor alfa de Estrogênio/genética , Humanos , Células MCF-7 , Ligação Proteica , Ubiquitinação
12.
Int J Mol Sci ; 22(16)2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34445480

RESUMO

Multivesicular body (MVB)-mediated endosomal sorting and macroautophagy are the main pathways mediating the transport of cellular components to the vacuole and are essential for maintaining cellular homeostasis. The interplay of these two pathways remains poorly understood in plants. In this study, we show that FYVE DOMAIN PROTEIN REQUIRED FOR ENDOSOMAL SORTING 1 (FREE1), which was previously identified as a plant-specific component of the endosomal sorting complex required for transport (ESCRT), essential for MVB biogenesis and plant growth, can be transported to the vacuole for degradation in response to iron deficiency. The vacuolar transport of ubiquitinated FREE1 protein is mediated by the autophagy pathway. As a consequence, the autophagy deficient mutants, atg5-1 and atg7-2, accumulate more endogenous FREE1 protein and display hypersensitivity to iron deficiency. Furthermore, under iron-deficient growth condition autophagy related genes are upregulated to promote the autophagic degradation of FREE1, thereby possibly relieving the repressive effect of FREE1 on iron absorption. Collectively, our findings demonstrate a unique regulatory mode of protein turnover of the ESCRT machinery through the autophagy pathway to respond to iron deficiency in plants.


Assuntos
Proteínas de Arabidopsis/química , Arabidopsis/metabolismo , Proteínas Relacionadas à Autofagia/genética , Ferro/metabolismo , Proteínas de Transporte Vesicular/química , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Autofagia , Transporte Biológico , Complexos Endossomais de Distribuição Requeridos para Transporte , Endossomos/metabolismo , Mutação , Proteólise , Ubiquitinação
13.
Int J Mol Sci ; 22(16)2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34445484

RESUMO

In response to diverse pathogenic and danger signals, the cytosolic activation of the NLRP3 (NOD-, LRR-, and pyrin domain-containing (3)) inflammasome complex is a critical event in the maturation and release of some inflammatory cytokines in the state of an inflammatory response. After activation of the NLRP3 inflammasome, a series of cellular events occurs, including caspase 1-mediated proteolytic cleavage and maturation of the IL-1ß and IL-18, followed by pyroptotic cell death. Therefore, the NLRP3 inflammasome has become a prime target for the resolution of many inflammatory disorders. Since NLRP3 inflammasome activation can be triggered by a wide range of stimuli and the activation process occurs in a complex, it is difficult to target the NLRP3 inflammasome. During the activation process, various post-translational modifications (PTM) of the NLRP3 protein are required to form a complex with other components. The regulation of ubiquitination and deubiquitination of NLRP3 has emerged as a potential therapeutic target for NLRP3 inflammasome-associated inflammatory disorders. In this review, we discuss the ubiquitination and deubiquitination system for NLRP3 inflammasome activation and the inhibitors that can be used as potential therapeutic agents to modulate the activation of the NLRP3 inflammasome.


Assuntos
Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Citosol/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Terapia de Alvo Molecular , Ubiquitinação/efeitos dos fármacos
14.
Int J Mol Sci ; 22(15)2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34360546

RESUMO

Promyelocytic leukemia (PML) protein is the core component of subnuclear structures called PML nuclear bodies that are known to play important roles in cell survival, DNA damage responses, and DNA repair. Fanconi anemia (FA) proteins are required for repairing interstrand DNA crosslinks (ICLs). Here we report a novel role of PML proteins, regulating the ICL repair pathway. We found that depletion of the PML protein led to the significant reduction of damage-induced FANCD2 mono-ubiquitination and FANCD2 foci formation. Consistently, the cells treated with siRNA against PML showed enhanced sensitivity to a crosslinking agent, mitomycin C. Further studies showed that depletion of PML reduced the protein expression of FANCA, FANCG, and FANCD2 via reduced transcriptional activity. Interestingly, we observed that damage-induced CHK1 phosphorylation was severely impaired in cells with depleted PML, and we demonstrated that CHK1 regulates FANCA, FANCG, and FANCD2 transcription. Finally, we showed that inhibition of CHK1 phosphorylation further sensitized cancer cells to mitomycin C. Taken together, these findings suggest that the PML is critical for damage-induced CHK1 phosphorylation, which is important for FA gene expression and for repairing ICLs.


Assuntos
Quinase 1 do Ponto de Checagem/metabolismo , Proteína do Grupo de Complementação A da Anemia de Fanconi/metabolismo , Proteína do Grupo de Complementação D2 da Anemia de Fanconi/metabolismo , Proteína do Grupo de Complementação G da Anemia de Fanconi/metabolismo , Anemia de Fanconi/patologia , Regulação da Expressão Gênica , Quinase 1 do Ponto de Checagem/genética , Dano ao DNA , Reparo do DNA , Anemia de Fanconi/genética , Anemia de Fanconi/metabolismo , Proteína do Grupo de Complementação A da Anemia de Fanconi/genética , Proteína do Grupo de Complementação D2 da Anemia de Fanconi/genética , Proteína do Grupo de Complementação G da Anemia de Fanconi/genética , Células HeLa , Humanos , Fosforilação , Ubiquitinação
15.
Int J Mol Sci ; 22(15)2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34360560

RESUMO

Among autophagy-related molecules, p62/SQSTM1 is an adaptor for identifying and delivering intracellular cargo for degradation. Since ubiquitination is reversible, it has a switch role in autophagy. Ubiquitination is also involved in regulating autophagy in a timely manner. This study aimed to elucidate how p62-mediated autophagy is regulated in human endothelial cells and macrophages under atherosclerotic conditions, focusing on the lysosomal and proteasomal pathways. Co-cultured HUVECs and THP-1 cells were exposed to oxLDL (50 µg/mL) and autophagy was assessed. To downregulate p62, siRNA was administered, and the E3 ligases were inhibited by Heclin or MLN4924 treatment under the condition that cellular inflammatory processes were stimulated by oxLDL simultaneously initiated autophagy. Downregulating p62 induced an alternative degradation system, and the E3 ligases were found to be involved in the progression of atherosclerosis. Collectively, the present study demonstrated that the endothelial lipid accumulation under atherosclerotic conditions was caused by lysosomal dysfunction associated with autophagy.


Assuntos
Aterosclerose/patologia , Autofagia , Células Endoteliais/patologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteólise , Proteína Sequestossoma-1/metabolismo , Ubiquitinação , Aterosclerose/metabolismo , Células Endoteliais/metabolismo , Humanos , Complexo de Endopeptidases do Proteassoma/genética , Proteína Sequestossoma-1/genética , Transdução de Sinais , Ubiquitina/metabolismo
16.
Viruses ; 13(7)2021 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-34372566

RESUMO

Infection by RNA viruses causes extensive cellular reorganization, including hijacking of membranes to create membranous structures termed replication organelles, which support viral RNA synthesis and virion assembly. In this study, we show that infection with coxsackievirus B3 entails a profound impairment of the protein homeostasis at virus-utilized membranes, reflected by an accumulation of ubiquitinylated proteins, including K48-linked polyubiquitin conjugates, known to direct proteins to proteasomal degradation. The enrichment of membrane-bound ubiquitin conjugates is attributed to the presence of the non-structural viral proteins 2B and 3A, which are known to perturb membrane integrity and can cause an extensive rearrangement of cellular membranes. The locally increased abundance of ubiquitinylated proteins occurs without an increase of oxidatively damaged proteins. During the exponential phase of replication, the oxidative damage of membrane proteins is even diminished, an effect we attribute to the recruitment of glutathione, which is known to be required for the formation of infectious virus particles. Furthermore, we show that the proteasome contributes to the processing of viral precursor proteins. Taken together, we demonstrate how an infection with coxsackievirus B3 affects the cellular protein and redox homeostasis locally at the site of viral replication and virus assembly.


Assuntos
Enterovirus Humano B/metabolismo , Ubiquitinação/fisiologia , Replicação Viral/fisiologia , Citoplasma/metabolismo , Enterovirus Humano B/patogenicidade , Células HeLa , Humanos , Proteínas de Membrana/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Ligação Proteica/fisiologia , RNA Viral/genética , Ubiquitina/metabolismo , Proteínas Virais/metabolismo , Vírion/metabolismo , Montagem de Vírus/genética , Montagem de Vírus/fisiologia , Replicação Viral/genética
17.
Science ; 373(6558): 998-1004, 2021 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-34446601

RESUMO

In eukaryotic cells, half of all proteins function as subunits within multiprotein complexes. Imbalanced synthesis of subunits leads to unassembled intermediates that must be degraded to minimize cellular toxicity. Here, we found that excess PSMC5, a subunit of the proteasome base, was targeted for degradation by the HERC1 ubiquitin ligase in mammalian cells. HERC1 identified unassembled PSMC5 by its cognate assembly chaperone PAAF1. Because PAAF1 only dissociates after assembly, HERC1 could also engage later assembly intermediates such as the PSMC4-PSMC5-PAAF1 complex. A missense mutant of HERC1 that causes neurodegeneration in mice was impaired in the recognition and ubiquitination of the PSMC5-PAAF1 complex. Thus, proteasome assembly factors can serve as adaptors for ubiquitin ligases to facilitate elimination of unassembled intermediates and maintain protein homeostasis.


Assuntos
ATPases Associadas a Diversas Atividades Celulares/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Animais , Calmodulina/metabolismo , Humanos , Células MCF-7 , Camundongos , Mutação , Mutação de Sentido Incorreto , Doenças Neurodegenerativas/genética , Mutação Puntual , Domínios e Motivos de Interação entre Proteínas , Subunidades Proteicas/metabolismo , Proteólise , Proteínas Proto-Oncogênicas/metabolismo , Ubiquitina-Proteína Ligases/química , Ubiquitina-Proteína Ligases/genética , Ubiquitinação
18.
Int J Mol Sci ; 22(15)2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34360709

RESUMO

Toxoplasma gondii (T. gondii) is an important human and veterinary pathogen causing life-threatening disease in immunocompromised patients. The UBL-UBA shuttle protein family are important components of the ubiquitin-proteasome system. Here, we identified a novel UBL-UBA shuttle protein DSK2b that is charactered by an N-terminal ubiquitin-like domain (UBL) and a C-terminal ubiquitin-associated domain (UBA). DSK2b was localized in the cytoplasm and nucleus. The deletion of dsk2b did not affect the degradation of ubiquitinated proteins, parasite growth in vitro or virulence in mice. The double-gene knockout of dsk2b and its paralogs dsk2a (ΔΔdsk2adsk2b) results in a significant accumulation of ubiquitinated proteins and the asynchronous division of T. gondii. The growth of ΔΔdsk2adsk2b was significantly inhibited in vitro, while virulence in mice was not attenuated. In addition, autophagy occurred in the ΔΔdsk2adsk2b, which was speculated to degrade the accumulated ubiquitinated proteins in the parasites. Overall, DSK2b is a novel UBL-UBA shuttle protein contributing to the degradation of ubiquitinated proteins and is important for the synchronous cell division of T. gondii.


Assuntos
Divisão Celular , Proteólise , Proteínas de Protozoários/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Toxoplasma/metabolismo , Ubiquitinação , Animais , Deleção de Genes , Humanos , Camundongos , Proteínas de Protozoários/genética , Receptores Citoplasmáticos e Nucleares/genética , Toxoplasma/genética , Toxoplasma/patogenicidade
19.
FASEB J ; 35(9): e21332, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34423867

RESUMO

Emerging research has highlighted the capacity of microRNA-23a-3p (miR-23a-3p) to alleviate inflammatory pain. However, the molecular mechanism by which miR-23a-3p attenuates inflammatory pain is yet to be fully understood. Hence, the current study aimed to elucidate the mechanism by which miR-23a-3p influences inflammatory pain. Bioinformatics was initially performed to predict the inflammatory pain related downstream targets of miR-23a-3p in macrophage-derived extracellular vesicles (EVs). An animal inflammatory pain model was established using Complete Freund's Adjuvant (CFA). The miR-23a-3p expression was downregulated in the microglia of CFA-induced mice, after which the inflammatory factors were determined by ELISA. FISH and immunofluorescence were performed to analyze the co-localization of miR-23a-3p and microglia. Interestingly, miR-23a-3p was transported to the microglia via M2 macrophage-EVs, which elevated the mechanical allodynia and the thermal hyperalgesia thresholds in mice model. The miR-23a-3p downstream target, USP5, was found to stabilize HDAC2 via deubiquitination to promote its expression while inhibiting the expression of NRF2. Taken together, the key findings of the current study demonstrate that macrophage-derived EVs containing miR-23a-3p regulates the HDAC2/NRF2 axis by decreasing USP5 expression to alleviate inflammatory pain, which may provide novel therapeutic targets for the treatment of inflammatory pain.


Assuntos
Vesículas Extracelulares/metabolismo , Histona Desacetilase 2/metabolismo , Inflamação/metabolismo , Macrófagos/citologia , Fator 2 Relacionado a NF-E2/metabolismo , Dor/metabolismo , Proteases Específicas de Ubiquitina/metabolismo , Animais , Linhagem Celular , Enzimas Desubiquitinantes/metabolismo , Modelos Animais de Doenças , Regulação para Baixo , Estabilidade Enzimática , Vesículas Extracelulares/genética , Inflamação/genética , Inflamação/terapia , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microglia/citologia , Microglia/metabolismo , Modelos Biológicos , Dor/genética , Manejo da Dor , Proteases Específicas de Ubiquitina/genética , Ubiquitinação
20.
Theranostics ; 11(16): 8112-8128, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34335983

RESUMO

The coiled-coil domain containing protein members have been well documented for their roles in many diseases including cancers. However, the function of the coiled-coil domain containing 65 (CCDC65) remains unknown in tumorigenesis including gastric cancer. Methods: CCDC65 expression and its correlation with clinical features and prognosis of gastric cancer were analyzed in tissue. The biological role and molecular basis of CCDC65 were performed via in vitro and in vivo assays and a various of experimental methods including co-immunoprecipitation (Co-IP), GST-pull down and ubiquitination analysis et al. Finally, whether metformin affects the pathogenesis of gastric cancer by regulating CCDC65 and its-mediated signaling was investigated. Results: Here, we found that downregulated CCDC65 level was showed as an unfavourable factor in gastric cancer patients. Subsequently, CCDC65 or its domain (a.a. 130-484) was identified as a significant suppressor in GC growth and metastasis in vitro and in vivo. Molecular basis showed that CCDC65 bound to ENO1, an oncogenic factor has been widely reported to promote the tumor pathogenesis, by its domain (a.a. 130-484) and further promoted ubiquitylation and degradation of ENO1 by recruiting E3 ubiquitin ligase FBXW7. The downregulated ENO1 decreased the binding with AKT1 and further inactivated AKT1, which led to the loss of cell proliferation and EMT signal. Finally, we observed that metformin, a new anti-cancer drug, can significantly induce CCDC65 to suppress ENO1-AKT1 complex-mediated cell proliferation and EMT signals and finally suppresses the malignant phenotypes of gastric cancer cells. Conclusion: These results firstly highlight a critical role of CCDC65 in suppressing ENO1-AKT1 pathway to reduce the progression of gastric cancer and reveals a new molecular mechanism for metformin in suppressing gastric cancer. Our present study provides a new insight into the mechanism and therapy for gastric cancer.


Assuntos
Biomarcadores Tumorais/metabolismo , Proteínas de Ligação a DNA/metabolismo , Glicoproteínas/metabolismo , Fosfopiruvato Hidratase/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Neoplasias Gástricas/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Animais , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , China , Feminino , Expressão Gênica/genética , Regulação Neoplásica da Expressão Gênica/genética , Genes Supressores de Tumor/fisiologia , Glicoproteínas/genética , Humanos , Masculino , Metformina/metabolismo , Metformina/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Oncogenes , Prognóstico , Proteínas Proto-Oncogênicas c-akt/fisiologia , Transdução de Sinais/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação
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