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1.
Genes Chromosomes Cancer ; 63(5): e23238, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38722224

RESUMO

Pleomorphic rhabdomyosarcoma (PRMS) is a rare and highly aggressive sarcoma, occurring mostly in the deep soft tissues of middle-aged adults and showing a variable degree of skeletal muscle differentiation. The diagnosis is challenging as pathologic features overlap with embryonal rhabdomyosarcoma (ERMS), malignant Triton tumor, and other pleomorphic sarcomas. As recurrent genetic alterations underlying PRMS have not been described to date, ancillary molecular diagnostic testing is not useful in subclassification. Herein, we perform genomic profiling of a well-characterized cohort of 14 PRMS, compared to a control group of 23 ERMS and other pleomorphic sarcomas (undifferentiated pleomorphic sarcoma and pleomorphic liposarcoma) using clinically validated DNA-targeted Next generation sequencing (NGS) panels (MSK-IMPACT). The PRMS cohort included eight males and six females, with a median age of 53 years (range 31-76 years). Despite similar tumor mutation burdens, the genomic landscape of PRMS, with a high frequency of TP53 (79%) and RB1 (43%) alterations, stood in stark contrast to ERMS, with 4% and 0%, respectively. CDKN2A deletions were more common in PRMS (43%), compared to ERMS (13%). In contrast, ERMS harbored somatic driver mutations in the RAS pathway and loss of function mutations in BCOR, which were absent in PRMS. Copy number variations in PRMS showed multiple chromosomal arm-level changes, most commonly gains of chr17p and chr22q and loss of chr6q. Notably, gain of chr8, commonly seen in ERMS (61%) was conspicuously absent in PRMS. The genomic profiles of other pleomorphic sarcomas were overall analogous to PRMS, showing shared alterations in TP53, RB1, and CDKN2A. Overall survival and progression-free survival of PRMS were significantly worse (p < 0.0005) than that of ERMS. Our findings revealed that the molecular landscape of PRMS aligns with other adult pleomorphic sarcomas and is distinct from that of ERMS. Thus, NGS assays may be applied in select challenging cases toward a refined classification. Finally, our data corroborate the inclusion of PRMS in the therapeutic bracket of pleomorphic sarcomas, given that their clinical outcomes are comparable.


Assuntos
Rabdomiossarcoma Embrionário , Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Rabdomiossarcoma Embrionário/genética , Rabdomiossarcoma Embrionário/patologia , Rabdomiossarcoma/genética , Rabdomiossarcoma/patologia , Rabdomiossarcoma/classificação , Mutação , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Genômica/métodos , Biomarcadores Tumorais/genética , Proteínas de Ligação a Retinoblastoma/genética , Ubiquitina-Proteína Ligases
2.
Nat Commun ; 15(1): 3969, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38730242

RESUMO

Encephalitis is a rare and potentially fatal manifestation of herpes simplex type 1 infection. Following genome-wide genetic analyses, we identified a previously uncharacterized and very rare heterozygous variant in the E3 ubiquitin ligase WWP2, in a 14-month-old girl with herpes simplex encephalitis. The p.R841H variant (NM_007014.4:c.2522G > A) impaired TLR3 mediated signaling in inducible pluripotent stem cells-derived neural precursor cells and neurons; cells bearing this mutation were also more susceptible to HSV-1 infection compared to control cells. The p.R841H variant increased TRIF ubiquitination in vitro. Antiviral immunity was rescued following the correction of p.R841H by CRISPR-Cas9 technology. Moreover, the introduction of p.R841H in wild type cells reduced such immunity, suggesting that this mutation is linked to the observed phenotypes.


Assuntos
Encefalite por Herpes Simples , Herpesvirus Humano 1 , Mutação , Ubiquitina-Proteína Ligases , Humanos , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Feminino , Encefalite por Herpes Simples/genética , Lactente , Herpesvirus Humano 1/genética , Células-Tronco Pluripotentes Induzidas/metabolismo , Receptor 3 Toll-Like/genética , Receptor 3 Toll-Like/metabolismo , Ubiquitinação , Neurônios/metabolismo , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/virologia , Sistemas CRISPR-Cas
3.
Cell Death Dis ; 15(5): 321, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38719812

RESUMO

RAD18, an important ubiquitin E3 ligase, plays a dual role in translesion DNA synthesis (TLS) and homologous recombination (HR) repair. However, whether and how the regulatory mechanism of O-linked N-acetylglucosamine (O-GlcNAc) modification governing RAD18 and its function during these processes remains unknown. Here, we report that human RAD18, can undergo O-GlcNAcylation at Ser130/Ser164/Thr468, which is important for optimal RAD18 accumulation at DNA damage sites. Mechanistically, abrogation of RAD18 O-GlcNAcylation limits CDC7-dependent RAD18 Ser434 phosphorylation, which in turn significantly reduces damage-induced PCNA monoubiquitination, impairs Polη focus formation and enhances UV sensitivity. Moreover, the ubiquitin and RAD51C binding ability of RAD18 at DNA double-strand breaks (DSBs) is O-GlcNAcylation-dependent. O-GlcNAcylated RAD18 promotes the binding of RAD51 to damaged DNA during HR and decreases CPT hypersensitivity. Our findings demonstrate a novel role of RAD18 O-GlcNAcylation in TLS and HR regulation, establishing a new rationale to improve chemotherapeutic treatment.


Assuntos
Acetilglucosamina , Proteínas de Ligação a DNA , Antígeno Nuclear de Célula em Proliferação , Rad51 Recombinase , Reparo de DNA por Recombinação , Ubiquitina-Proteína Ligases , Humanos , Proteínas de Ligação a DNA/metabolismo , Proteínas de Ligação a DNA/genética , Ubiquitina-Proteína Ligases/metabolismo , Acetilglucosamina/metabolismo , Rad51 Recombinase/metabolismo , Antígeno Nuclear de Célula em Proliferação/metabolismo , Fosforilação , Replicação do DNA , Ubiquitinação , Quebras de DNA de Cadeia Dupla , DNA Polimerase Dirigida por DNA/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Dano ao DNA , DNA/metabolismo , Células HEK293 , Raios Ultravioleta , Ligação Proteica , Glicosilação , Síntese de DNA Translesão
4.
Epigenetics Chromatin ; 17(1): 15, 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38725075

RESUMO

UHRF1 as a member of RING-finger type E3 ubiquitin ligases family, is an epigenetic regulator with five structural domains. It has been involved in the regulation of a series of biological functions, such as DNA replication, DNA methylation, and DNA damage repair. Additionally, aberrant overexpression of UHRF1 has been observed in over ten cancer types, indicating that UHRF1 is a typical oncogene. The overexpression of UHRF1 repressed the transcription of such tumor-suppressor genes as CDKN2A, BRCA1, and CDH1 through DNMT1-mediated DNA methylation. In addition to the upstream transcription factors regulating gene transcription, post-translational modifications (PTMs) also contribute to abnormal overexpression of UHRF1 in cancerous tissues. The types of PTM include phosphorylation, acetylation, methylationand ubiquitination, which regulate protein stability, histone methyltransferase activity, intracellular localization and the interaction with binding partners. Recently, several novel PTM types of UHRF1 have been reported, but the detailed mechanisms remain unclear. This comprehensive review summarized the types of UHRF1 PTMs, as well as their biological functions. A deep understanding of these crucial mechanisms of UHRF1 is pivotal for the development of novel UHRF1-targeted anti-cancer therapeutic strategies in the future.


Assuntos
Proteínas Estimuladoras de Ligação a CCAAT , Neoplasias , Processamento de Proteína Pós-Traducional , Ubiquitina-Proteína Ligases , Humanos , Ubiquitina-Proteína Ligases/metabolismo , Neoplasias/metabolismo , Neoplasias/genética , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Proteínas Estimuladoras de Ligação a CCAAT/genética , Metilação de DNA , Animais , Ubiquitinação , Regulação Neoplásica da Expressão Gênica
5.
Int J Biol Sci ; 20(7): 2686-2697, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38725852

RESUMO

Triple-negative breast cancer (TNBC) is the most malignant subtype of breast cancer. Breast cancer stem cells (BCSCs) are believed to play a crucial role in the carcinogenesis, therapy resistance, and metastasis of TNBC. It is well known that inflammation promotes stemness. Several studies have identified breast cancer-associated gene 2 (BCA2) as a potential risk factor for breast cancer incidence and prognosis. However, whether and how BCA2 promotes BCSCs has not been elucidated. Here, we demonstrated that BCA2 specifically promotes lipopolysaccharide (LPS)-induced BCSCs through LPS induced SOX9 expression. BCA2 enhances the interaction between myeloid differentiation primary response protein 88 (MyD88) and Toll-like receptor 4 (TLR4) and inhibits the interaction of MyD88 with deubiquitinase OTUD4 in the LPS-mediated NF-κB signaling pathway. And SOX9, an NF-κB target gene, mediates BCA2's pro-stemness function in TNBC. Our findings provide new insights into the molecular mechanisms by which BCA2 promotes breast cancer and potential therapeutic targets for the treatment of breast cancer.


Assuntos
Lipopolissacarídeos , Células-Tronco Neoplásicas , Fatores de Transcrição SOX9 , Humanos , Fatores de Transcrição SOX9/metabolismo , Fatores de Transcrição SOX9/genética , Feminino , Lipopolissacarídeos/farmacologia , Células-Tronco Neoplásicas/metabolismo , Linhagem Celular Tumoral , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/patologia , Fator 88 de Diferenciação Mieloide/metabolismo , Fator 88 de Diferenciação Mieloide/genética , NF-kappa B/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética , Regulação para Cima , Transdução de Sinais , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Neoplasias da Mama/genética , Receptor 4 Toll-Like/metabolismo , Receptor 4 Toll-Like/genética , Regulação Neoplásica da Expressão Gênica
6.
J Cell Biol ; 223(7)2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38728007

RESUMO

Activation of PINK1 and Parkin in response to mitochondrial damage initiates a response that includes phosphorylation of RAB7A at Ser72. Rubicon is a RAB7A binding negative regulator of autophagy. The structure of the Rubicon:RAB7A complex suggests that phosphorylation of RAB7A at Ser72 would block Rubicon binding. Indeed, in vitro phosphorylation of RAB7A by TBK1 abrogates Rubicon:RAB7A binding. Pacer, a positive regulator of autophagy, has an RH domain with a basic triad predicted to bind an introduced phosphate. Consistent with this, Pacer-RH binds to phosho-RAB7A but not to unphosphorylated RAB7A. In cells, mitochondrial depolarization reduces Rubicon:RAB7A colocalization whilst recruiting Pacer to phospho-RAB7A-positive puncta. Pacer knockout reduces Parkin mitophagy with little effect on bulk autophagy or Parkin-independent mitophagy. Rescue of Parkin-dependent mitophagy requires the intact pRAB7A phosphate-binding basic triad of Pacer. Together these structural and functional data support a model in which the TBK1-dependent phosphorylation of RAB7A serves as a switch, promoting mitophagy by relieving Rubicon inhibition and favoring Pacer activation.


Assuntos
Mitofagia , Proteínas Serina-Treonina Quinases , Ubiquitina-Proteína Ligases , Proteínas rab de Ligação ao GTP , proteínas de unión al GTP Rab7 , Mitofagia/genética , Humanos , Fosforilação , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas rab de Ligação ao GTP/metabolismo , Proteínas rab de Ligação ao GTP/genética , Células HeLa , Ligação Proteica , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas Relacionadas à Autofagia/metabolismo , Proteínas Relacionadas à Autofagia/genética , Mitocôndrias/metabolismo , Mitocôndrias/genética , Células HEK293
8.
J Cell Biol ; 223(7)2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38722278

RESUMO

Aberrant proteins located in the endoplasmic reticulum (ER) undergo rapid ubiquitination by multiple ubiquitin (Ub) E3 ligases and are retrotranslocated to the cytosol as part of the ER-associated degradation (ERAD). Despite several ERAD branches involving different Ub E3 ligases, the molecular machinery responsible for these ERAD branches in mammalian cells remains not fully understood. Through a series of multiplex knockdown/knockout experiments with real-time kinetic measurements, we demonstrate that HERC3 operates independently of the ER-embedded ubiquitin ligases RNF5 and RNF185 (RNF5/185) to mediate the retrotranslocation and ERAD of misfolded CFTR. While RNF5/185 participates in the ERAD process of both misfolded ABCB1 and CFTR, HERC3 uniquely promotes CFTR ERAD. In vitro assay revealed that HERC3 directly interacts with the exposed membrane-spanning domains (MSDs) of CFTR but not with the MSDs embedded in liposomes. Therefore, HERC3 could play a role in the quality control of MSDs in the cytoplasm and might be crucial for the ERAD pathway of select membrane proteins.


Assuntos
Degradação Associada com o Retículo Endoplasmático , Proteínas de Membrana , Ubiquitina-Proteína Ligases , Humanos , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Proteínas de Ligação a DNA , Retículo Endoplasmático/metabolismo , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Fatores de Troca do Nucleotídeo Guanina/genética , Células HEK293 , Células HeLa , Proteínas de Membrana/química , Proteínas de Membrana/metabolismo , Ligação Proteica , Domínios Proteicos , Dobramento de Proteína , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitinação
9.
J Med Chem ; 67(9): 7569-7584, 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38690687

RESUMO

PTP1B, a promising target for insulin sensitizers in type 2 diabetes treatment, can be effectively degraded using proteolysis-targeting chimera (PROTAC). This approach offers potential for long-acting antidiabetic agents. We report potent bifunctional PROTACs targeting PTP1B through the E3 ubiquitin ligase cereblon. Western blot analysis showed significant PTP1B degradation by PROTACs at concentrations from 5 nM to 5 µM after 48 h. Evaluation of five highly potent PROTACs revealed compound 75 with a longer PEG linker (23 atoms), displaying remarkable degradation activity after 48 and 72 h, with DC50 values of 250 nM and 50 nM, respectively. Compound 75 induced selective degradation of PTP1B, requiring engagement with both the target protein and CRBN E3 ligase, in a ubiquitination and proteasome-dependent manner. It significantly reduced blood glucose AUC0-2h to 29% in an oral glucose tolerance test and activated the IRS-1/PI3K/Akt signaling pathway in HepG2 cells, showing promise for long-term antidiabetic therapy.


Assuntos
Hipoglicemiantes , Proteína Tirosina Fosfatase não Receptora Tipo 1 , Proteólise , Animais , Humanos , Camundongos , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Descoberta de Drogas , Células Hep G2 , Hipoglicemiantes/farmacologia , Hipoglicemiantes/química , Hipoglicemiantes/síntese química , Proteína Tirosina Fosfatase não Receptora Tipo 1/metabolismo , Proteína Tirosina Fosfatase não Receptora Tipo 1/antagonistas & inibidores , Proteólise/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Ubiquitina-Proteína Ligases/metabolismo
10.
J Mol Model ; 30(6): 173, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38767734

RESUMO

CONTEXT: Ubiquitin-like with PHD and RING finger domain containing protein 1 (UHRF1) is responsible for preserving the stability of genomic methylation through the recruitment of DNA methyltransferase 1 (DNMT1). However, the interaction between Developmental pluripotency associated 3 (DPPA3) and the pre-PHD-PHD (PPHD) domain of UHRF1 hinders the nuclear localization of UHRF1. This disruption has implications for potential cancer treatment strategies. Drugs that mimic the binding pattern between DPPA3 and PPHD could offer a promising approach to cancer treatment. Our study reveals that DPPA3 undergoes dissociation from the C-terminal through three different modes of helix unfolding. Furthermore, we have identified key residue pairs involved in this dissociation process and potential drug-targeting residues. These findings offer valuable insights into the dissociation mechanism of DPPA3 from PPHD and have the potential to inform the design of novel drugs targeting UHRF1 for cancer therapy. METHODS: To comprehend the dissociation process and binding patterns of PPHD-DPPA3, we employed enhanced sampling techniques, including steered molecular dynamics (SMD) and conventional molecular dynamics (cMD). Additionally, we utilized self-organizing maps (SOM) and time-resolved force distribution analysis (TRFDA) methodologies. The Gromacs software was used for performing molecular dynamics simulations, and the AMBER FF14SB force field was applied to the protein.


Assuntos
Proteínas Estimuladoras de Ligação a CCAAT , Simulação de Dinâmica Molecular , Ligação Proteica , Ubiquitina-Proteína Ligases , Ubiquitina-Proteína Ligases/química , Ubiquitina-Proteína Ligases/metabolismo , Proteínas Estimuladoras de Ligação a CCAAT/química , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Humanos , Sítios de Ligação
11.
J Tradit Chin Med ; 44(3): 468-477, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38767630

RESUMO

OBJECTIVE: To investigate the effect of acupotomy, on mitophagy and the Pink1-Parkin pathway in chondrocytes from rabbits with knee osteoarthritis (KOA). METHODS: A KOA model was established via the modified Videman method. Rabbits were randomly divided into a control group (CON), KOA group and KOA + acupotomy group (Acu). Rabbits in the acupotomy group were subjected to acupotomy for 4 weeks after model establishment. The behavior of the rabbits before and after intervention was recorded. Cartilage degeneration was evaluated by optical microscopy and fluorescence microscopy. The level of mitophagy was evaluated by transmission electron microscopy, immunofluorescence and enzyme-linked immunosorbent assay (ELISA). The expression of phosphatase and tensin homolog (PTEN)-induced kinase 1 (Pink1)-Parkin mitophagy pathway components was evaluated by immunofluorescence, Western blotting and real-time polymerase chain reaction. RESULTS: In rabbits with KOA, joint pain, mobility disorders and cartilage degeneration were observed, the Mankin score was increased, collagen type Ⅱ (Col-Ⅱ) expression was significantly decreased, mitophagy was inhibited, mitochondrial function was impaired, and factors associated with the Pink1-Parkin pathway were inhibited. Acupotomy regulated the expression of Pink1-Parkin pathway-related proteins, the mitophagy-related protein microtubule-associated protein-1 light chain-3, the translocase of the outer membrane, and the inner mitochondrial membrane 23; increased the colocalization of mitochondria and autophagosomes; promoted the removal of damaged mitochondria; restored mitochondrial adenosine-triphosphate (ATP) production; and alleviated cartilage degeneration in rabbits with KOA. CONCLUSIONS: Acupotomy played a role in alleviating KOA in rabbits by activating mitophagy in chondrocytes via the regulation of proteins that are related to the Pink1-Parkin pathway.


Assuntos
Terapia por Acupuntura , Condrócitos , Mitofagia , Osteoartrite do Joelho , Proteínas Quinases , Ubiquitina-Proteína Ligases , Animais , Coelhos , Mitofagia/genética , Osteoartrite do Joelho/metabolismo , Osteoartrite do Joelho/genética , Osteoartrite do Joelho/terapia , Condrócitos/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética , Proteínas Quinases/metabolismo , Proteínas Quinases/genética , Masculino , Humanos , Transdução de Sinais , Mitocôndrias/metabolismo , Mitocôndrias/genética
12.
Cell Mol Life Sci ; 81(1): 223, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38767677

RESUMO

Parkinson's disease (PD) is a common and incurable neurodegenerative disorder that arises from the loss of dopaminergic neurons in the substantia nigra and is mainly characterized by progressive loss of motor function. Monogenic familial PD is associated with highly penetrant variants in specific genes, notably the PRKN gene, where homozygous or compound heterozygous loss-of-function variants predominate. PRKN encodes Parkin, an E3 ubiquitin-protein ligase important for protein ubiquitination and mitophagy of damaged mitochondria. Accordingly, Parkin plays a central role in mitochondrial quality control but is itself also subject to a strict protein quality control system that rapidly eliminates certain disease-linked Parkin variants. Here, we summarize the cellular and molecular functions of Parkin, highlighting the various mechanisms by which PRKN gene variants result in loss-of-function. We emphasize the importance of high-throughput assays and computational tools for the clinical classification of PRKN gene variants and how detailed insights into the pathogenic mechanisms of PRKN gene variants may impact the development of personalized therapeutics.


Assuntos
Doença de Parkinson , Ubiquitina-Proteína Ligases , Humanos , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Doença de Parkinson/genética , Doença de Parkinson/patologia , Doença de Parkinson/metabolismo , Mitocôndrias/metabolismo , Mitocôndrias/genética , Mitocôndrias/patologia , Ubiquitinação/genética , Mitofagia/genética , Animais
13.
Nat Commun ; 15(1): 4296, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38769295

RESUMO

Therapeutic resistance represents a bottleneck to treatment in advanced gastric cancer (GC). Ferroptosis is an iron-dependent form of non-apoptotic cell death and is associated with anti-cancer therapeutic efficacy. Further investigations are required to clarify the underlying mechanisms. Ferroptosis-resistant GC cell lines are constructed. Dysregulated mRNAs between ferroptosis-resistant and parental cell lines are identified. The expression of SOX13/SCAF1 is manipulated in GC cell lines where relevant biological and molecular analyses are performed. Molecular docking and computational screening are performed to screen potential inhibitors of SOX13. We show that SOX13 boosts protein remodeling of electron transport chain (ETC) complexes by directly transactivating SCAF1. This leads to increased supercomplexes (SCs) assembly, mitochondrial respiration, mitochondrial energetics and chemo- and immune-resistance. Zanamivir, reverts the ferroptosis-resistant phenotype via directly targeting SOX13 and promoting TRIM25-mediated ubiquitination and degradation of SOX13. Here we show, SOX13/SCAF1 are important in ferroptosis-resistance, and targeting SOX13 with zanamivir has therapeutic potential.


Assuntos
Resistencia a Medicamentos Antineoplásicos , Ferroptose , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/genética , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/patologia , Ferroptose/efeitos dos fármacos , Ferroptose/genética , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/genética , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Transporte de Elétrons/efeitos dos fármacos , Simulação de Acoplamento Molecular , Mitocôndrias/metabolismo , Mitocôndrias/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Animais , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética , Camundongos
14.
Nat Commun ; 15(1): 4292, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38769345

RESUMO

Deficiencies in the BRCA1 tumor suppressor gene are the main cause of hereditary breast and ovarian cancer. BRCA1 is involved in the Homologous Recombination DNA repair pathway and, together with BARD1, forms a heterodimer with ubiquitin E3 activity. The relevance of the BRCA1/BARD1 ubiquitin E3 activity for tumor suppression and DNA repair remains controversial. Here, we observe that the BRCA1/BARD1 ubiquitin E3 activity is not required for Homologous Recombination or resistance to Olaparib. Using TULIP2 methodology, which enables the direct identification of E3-specific ubiquitination substrates, we identify substrates for BRCA1/BARD1. We find that PCNA is ubiquitinated by BRCA1/BARD1 in unperturbed conditions independently of RAD18. PCNA ubiquitination by BRCA1/BARD1 avoids the formation of ssDNA gaps during DNA replication and promotes continuous DNA synthesis. These results provide additional insight about the importance of BRCA1/BARD1 E3 activity in Homologous Recombination.


Assuntos
Proteína BRCA1 , Replicação do DNA , Ftalazinas , Piperazinas , Antígeno Nuclear de Célula em Proliferação , Proteínas Supressoras de Tumor , Ubiquitina-Proteína Ligases , Ubiquitinação , Humanos , Proteína BRCA1/metabolismo , Proteína BRCA1/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética , Antígeno Nuclear de Célula em Proliferação/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Proteínas Supressoras de Tumor/genética , Ftalazinas/farmacologia , Piperazinas/farmacologia , Recombinação Homóloga , Feminino , Células HEK293 , Linhagem Celular Tumoral , DNA/metabolismo
15.
Elife ; 122024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38771316

RESUMO

Rab GTPases are representative targets of manipulation by intracellular bacterial pathogens for hijacking membrane trafficking. Legionella pneumophila recruits many Rab GTPases to its vacuole and exploits their activities. Here, we found that infection-associated regulation of Rab10 dynamics involves ubiquitin signaling cascades mediated by the SidE and SidC families of Legionella ubiquitin ligases. Phosphoribosyl-ubiquitination of Rab10 catalyzed by the SidE ligases is crucial for its recruitment to the bacterial vacuole. SdcB, the previously uncharacterized SidC-family effector, resides on the vacuole and contributes to retention of Rab10 at the late stages of infection. We further identified MavC as a negative regulator of SdcB. By the transglutaminase activity, MavC crosslinks ubiquitin to SdcB and suppresses its function, resulting in elimination of Rab10 from the vacuole. These results demonstrate that the orchestrated actions of many L. pneumophila effectors fine-tune the dynamics of Rab10 during infection.


Assuntos
Proteínas de Bactérias , Legionella pneumophila , Vacúolos , Proteínas rab de Ligação ao GTP , Proteínas rab de Ligação ao GTP/metabolismo , Proteínas rab de Ligação ao GTP/genética , Legionella pneumophila/metabolismo , Legionella pneumophila/genética , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Humanos , Vacúolos/metabolismo , Vacúolos/microbiologia , Interações Hospedeiro-Patógeno , Ubiquitinação , Animais , Ubiquitina/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética
16.
Nutrients ; 16(9)2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38732549

RESUMO

Oleocanthal (OC) is a monophenol of extra-virgin olive oil (EVOO) endowed with antibiotic, cardioprotective and anticancer effects, among others, mainly in view of its antioxidant and anti-inflammatory properties. OC has been largely investigated in terms of its anticancer activity, in Alzheimer disease and in collagen-induced arthritis; however, the possibility that it can also affect muscle biology has been totally overlooked so far. This study is the first to describe that OC modulates alterations induced in C2C12 myotubes by stimuli known to induce muscle wasting in vivo, namely TNF-α, or in the medium conditioned by the C26 cachexia-inducing tumor (CM-C26). C2C12 myotubes were exposed to CM-C26 or TNF-α in the presence or absence of OC for 24 and 48 h and analyzed by immunofluorescence and Western blotting. In combination with TNF-α or CM-C26, OC was revealed to be able to restore both the myotube's original size and morphology and normal levels of both atrogin-1 and MuRF1. OC seems unable to impinge on the autophagic-lysosomal proteolytic system or protein synthesis. Modulations towards normal levels of the expression of molecules involved in myogenesis, such as Pax7, myogenin and MyHC, were also observed in the myotube cultures exposed to OC and TNF-α or CM-C26. In conclusion, the data presented here show that OC exerts a protective action in C2C12 myotubes exposed to TNF-α or CM-C26, with mechanisms likely involving the downregulation of ubiquitin-proteasome-dependent proteolysis and the partial relief of myogenic differentiation impairment.


Assuntos
Catecóis , Monoterpenos Ciclopentânicos , Fibras Musculares Esqueléticas , Proteínas Musculares , Atrofia Muscular , Fator de Necrose Tumoral alfa , Animais , Fibras Musculares Esqueléticas/efeitos dos fármacos , Fibras Musculares Esqueléticas/metabolismo , Camundongos , Fator de Necrose Tumoral alfa/metabolismo , Atrofia Muscular/prevenção & controle , Atrofia Muscular/metabolismo , Proteínas Musculares/metabolismo , Monoterpenos Ciclopentânicos/farmacologia , Catecóis/farmacologia , Linhagem Celular , Proteínas Ligases SKP Culina F-Box/metabolismo , Proteínas Ligases SKP Culina F-Box/genética , Desenvolvimento Muscular/efeitos dos fármacos , Proteínas com Motivo Tripartido/metabolismo , Proteínas com Motivo Tripartido/genética , Ubiquitina-Proteína Ligases/metabolismo , Autofagia/efeitos dos fármacos , Fenóis/farmacologia , Caquexia/prevenção & controle , Meios de Cultivo Condicionados/farmacologia , Aldeídos
17.
Rev Assoc Med Bras (1992) ; 70(4): e20231358, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38716944

RESUMO

OBJECTIVE: This prospective study aimed to provide a comprehensive analysis of the methylation status of two pivotal genes, CDKN2A/p16INK4A (cyclin-dependent kinase inhibitor 2A) and RB1 (retinoblastoma transcriptional corepressor 1), in breast cancer patients. METHODS: Samples were obtained from 15 women diagnosed with breast cancer and who underwent a total mastectomy. DNA was extracted from the tumor, non-tumor tissue, and peripheral blood (circulating cell-free DNA). The methylation pattern of cell-free DNA extracted from blood collected on the day of mastectomy was compared with the methylation pattern of cell-free DNA from blood collected 1 year post-surgery. The methylation analysis was carried out by sodium bisulfite conversion and polymerase chain reaction, followed by electrophoresis. RESULTS: Methylation of CDKN2A/p16INK4A was identified in 13 tumor samples and 12 non-tumor tissue samples. Two patients exhibited CDKN2A/p16INK4A methylation in the cell-free DNA of the first blood collection, while another showed methylation only in the cell-free DNA of the subsequent blood collection. Regarding RB1, 11 tumors and 8 non-tumor tissue samples presented methylation of the gene. CONCLUSION: This study presents a novel approach for monitoring breast cancer patients through the analysis of cell-free DNA methylation. This analysis can detect changes in methylation patterns before any visible sign of cancer appears in breast tissue and could help predict the recurrence of malignant breast tumors.


Assuntos
Neoplasias da Mama , Inibidor p16 de Quinase Dependente de Ciclina , Metilação de DNA , Proteínas de Ligação a Retinoblastoma , Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/sangue , Neoplasias da Mama/genética , Ácidos Nucleicos Livres/genética , Ácidos Nucleicos Livres/sangue , Ácidos Nucleicos Livres/análise , Inibidor p16 de Quinase Dependente de Ciclina/genética , Metilação de DNA/genética , Mastectomia , Reação em Cadeia da Polimerase , Estudos Prospectivos , Proteínas de Ligação a Retinoblastoma/genética , Ubiquitina-Proteína Ligases/genética
18.
Int J Mol Sci ; 25(9)2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38731820

RESUMO

A significant number of patients with genetic epilepsy do not obtain seizure freedom, despite developments in new antiseizure drugs, suggesting a need for novel therapeutic approaches. Many genetic epilepsies are associated with misfolded mutant proteins, including GABRG2(Q390X)-associated Dravet syndrome, which we have previously shown to result in intracellular accumulation of mutant GABAA receptor γ2(Q390X) subunit protein. Thus, a potentially promising therapeutic approach is modulation of proteostasis, such as increasing endoplasmic reticulum (ER)-associated degradation (ERAD). To that end, we have here identified an ERAD-associated E3 ubiquitin ligase, HRD1, among other ubiquitin ligases, as a strong modulator of wildtype and mutant γ2 subunit expression. Overexpressing HRD1 or knockdown of HRD1 dose-dependently reduced the γ2(Q390X) subunit. Additionally, we show that zonisamide (ZNS)-an antiseizure drug reported to upregulate HRD1-reduces seizures in the Gabrg2+/Q390X mouse. We propose that a possible mechanism for this effect is a partial rescue of surface trafficking of GABAA receptors, which are otherwise sequestered in the ER due to the dominant-negative effect of the γ2(Q390X) subunit. Furthermore, this partial rescue was not due to changes in ER chaperones BiP and calnexin, as total expression of these chaperones was unchanged in γ2(Q390X) models. Our results here suggest that leveraging the endogenous ERAD pathway may present a potential method to degrade neurotoxic mutant proteins like the γ2(Q390X) subunit. We also demonstrate a pharmacological means of regulating proteostasis, as ZNS alters protein trafficking, providing further support for the use of proteostasis regulators for the treatment of genetic epilepsies.


Assuntos
Retículo Endoplasmático , Epilepsias Mioclônicas , Proteólise , Receptores de GABA-A , Epilepsias Mioclônicas/metabolismo , Epilepsias Mioclônicas/genética , Receptores de GABA-A/metabolismo , Receptores de GABA-A/genética , Animais , Retículo Endoplasmático/metabolismo , Camundongos , Humanos , Convulsões Febris/metabolismo , Convulsões Febris/genética , Degradação Associada com o Retículo Endoplasmático , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética , Chaperonas Moleculares/metabolismo , Chaperonas Moleculares/genética , Mutação , Células HEK293 , Chaperona BiP do Retículo Endoplasmático/metabolismo
19.
PLoS Biol ; 22(5): e3002550, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38768083

RESUMO

Alkenyl oxindoles have been characterized as autophagosome-tethering compounds (ATTECs), which can target mutant huntingtin protein (mHTT) for lysosomal degradation. In order to expand the application of alkenyl oxindoles for targeted protein degradation, we designed and synthesized a series of heterobifunctional compounds by conjugating different alkenyl oxindoles with bromodomain-containing protein 4 (BRD4) inhibitor JQ1. Through structure-activity relationship study, we successfully developed JQ1-alkenyl oxindole conjugates that potently degrade BRD4. Unexpectedly, we found that these molecules degrade BRD4 through the ubiquitin-proteasome system, rather than the autophagy-lysosomal pathway. Using pooled CRISPR interference (CRISPRi) screening, we revealed that JQ1-alkenyl oxindole conjugates recruit the E3 ubiquitin ligase complex CRL4DCAF11 for substrate degradation. Furthermore, we validated the most potent heterobifunctional molecule HL435 as a promising drug-like lead compound to exert antitumor activity both in vitro and in a mouse xenograft tumor model. Our research provides new employable proteolysis targeting chimera (PROTAC) moieties for targeted protein degradation, providing new possibilities for drug discovery.


Assuntos
Proteínas de Ciclo Celular , Oxindóis , Proteólise , Ubiquitina-Proteína Ligases , Humanos , Animais , Proteólise/efeitos dos fármacos , Camundongos , Ubiquitina-Proteína Ligases/metabolismo , Oxindóis/farmacologia , Oxindóis/metabolismo , Oxindóis/química , Proteínas de Ciclo Celular/metabolismo , Fatores de Transcrição/metabolismo , Linhagem Celular Tumoral , Ensaios Antitumorais Modelo de Xenoenxerto , Camundongos Nus , Células HEK293 , Relação Estrutura-Atividade , Complexo de Endopeptidases do Proteassoma/metabolismo , Azepinas/farmacologia , Azepinas/química , Azepinas/metabolismo , Antineoplásicos/farmacologia , Antineoplásicos/química , Feminino , Proteínas que Contêm Bromodomínio , Receptores de Interleucina-17
20.
BMC Plant Biol ; 24(1): 432, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38773389

RESUMO

The VIM (belonged to E3 ubiquitin ligase) gene family is crucial for plant growth, development, and stress responses, yet their role in salt stress remains unclear. We analyzed phylogenetic relationships, chromosomal localization, conserved motifs, gene structure, cis-acting elements, and gene expression patterns of the VIM gene family in four cotton varieties. Our findings reveal 29, 29, 17, and 14 members in Gossypium hirsutum (G.hirsutum), Gossypium barbadense (G.barbadense), Gossypium arboreum (G.arboreum), and Gossypium raimondii (G. raimondii), respectively, indicating the maturity and evolution of this gene family. motifs among GhVIMs genes were observed, along with the presence of stress-responsive, hormone-responsive, and growth-related elements in their promoter regions. Gene expression analysis showed varying patterns and tissue specificity of GhVIMs genes under abiotic stress. Silencing GhVIM28 via virus-induced gene silencing revealed its role as a salt-tolerant negative regulator. This work reveals a mechanism by which the VIM gene family in response to salt stress in cotton, identifying a potential negative regulator, GhVIM28, which could be targeted for enhancing salt tolerance in cotton. The objective of this study was to explore the evolutionary relationship of the VIM gene family and its potential function in salt stress tolerance, and provide important genetic resources for salt tolerance breeding of cotton.


Assuntos
Regulação da Expressão Gênica de Plantas , Gossypium , Família Multigênica , Filogenia , Proteínas de Plantas , Estresse Salino , Gossypium/genética , Gossypium/fisiologia , Estresse Salino/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Genes de Plantas , Tolerância ao Sal/genética
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