Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 474
Filtrar
1.
Mol Med Rep ; 23(5)2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33760179

RESUMO

Burn wounds present an evolutionary progression, in which the initial wound tissue deepens and expands following thermal injury. Progressive tissue damage in the zone of stasis may worsen burn injury, which is associated with oxidative stress and secondary apoptosis, and worsen the prognosis of patients with burn wounds. The mitochondrial apoptotic pathway is involved in receiving oxidative signals and regulating tissue apoptosis. Previously, Abnormal Savda Munziq (ASMq), a natural compound of traditional Uyghur Medicine, which includes ten types of herb, has been reported to exhibit a number of effects, including anti­inflammatory, antioxidative and anti­apoptotic activities. The present study demonstrated that ASMq protected against early burn wound progression following thermal injury in rats; this effect may be mediated by its ability to attenuate oxidative stress­induced mitochondria­associated apoptosis. The present study may provide a novel therapeutic method to prevent early burn wound progression following burn injury.


Assuntos
Queimaduras/tratamento farmacológico , Mitocôndrias/efeitos dos fármacos , Ferimentos e Lesões/tratamento farmacológico , Animais , Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Queimaduras/genética , Queimaduras/patologia , Modelos Animais de Doenças , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Medicina Tradicional/métodos , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/farmacologia , Ratos , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Cicatrização/efeitos dos fármacos , Ferimentos e Lesões/genética , Ferimentos e Lesões/patologia , Proteína de Morte Celular Associada a bcl/genética
2.
Nat Commun ; 12(1): 896, 2021 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-33563994

RESUMO

Histone phosphorylation is a ubiquitous post-translational modification that allows eukaryotic cells to rapidly respond to environmental stimuli. Despite correlative evidence linking histone phosphorylation to changes in gene expression, establishing the causal role of this key epigenomic modification at diverse loci within native chromatin has been hampered by a lack of technologies enabling robust, locus-specific deposition of endogenous histone phosphorylation. To address this technological gap, here we build a programmable chromatin kinase, called dCas9-dMSK1, by directly fusing nuclease-null CRISPR/Cas9 to a hyperactive, truncated variant of the human MSK1 histone kinase. Targeting dCas9-dMSK1 to human promoters results in increased target histone phosphorylation and gene activation and demonstrates that hyperphosphorylation of histone H3 serine 28 (H3S28ph) in particular plays a causal role in the transactivation of human promoters. In addition, we uncover mediators of resistance to the BRAF V600E inhibitor PLX-4720 in human melanoma cells using genome-scale screening with dCas9-dMSK1. Collectively, our findings enable a facile way to reshape human chromatin using CRISPR/Cas9-based epigenome editing and further define the causal link between histone phosphorylation and human gene activation.


Assuntos
Sistemas CRISPR-Cas , Epigenômica/métodos , Histonas/metabolismo , Proteínas Quinases S6 Ribossômicas 90-kDa/metabolismo , Acetilação , Proteína 9 Associada à CRISPR/genética , Proteína 9 Associada à CRISPR/metabolismo , Linhagem Celular Tumoral , Cromatina/genética , Resistencia a Medicamentos Antineoplásicos/genética , Humanos , Indóis/farmacologia , Fosforilação , Regiões Promotoras Genéticas/genética , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Sulfonamidas/farmacologia , Ativação Transcricional
3.
Biochim Biophys Acta Mol Cell Res ; 1868(1): 118892, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33069758

RESUMO

We previously reported that vestigial-like 1 (VGLL1), a cofactor of transcriptional enhanced associate domain 4 (TEAD4), is transcriptionally regulated by PI3K and ß-catenin signaling and is involved in gastric cancer malignancy. However, the precise mechanism underlying the regulation of VGLL1 activation remains unknown. Therefore, we aimed to investigate the molecular mechanism underlying the transforming growth factor-ß (TGF-ß)-mediated activation of VGLL1 and the VGLL1-TEAD4 interaction in gastric cancer cells. We showed that TGF-ß enhanced VGLL1 phosphorylation and that this phosphorylated VGLL1 functioned as a transcription cofactor of TEAD4 in NUGC3 cells. TGF-ß also increased the phosphorylation of ERK and ribosomal S6 kinase 2 (RSK2) in NUGC3 cells, thereby triggering the translocation of phosphorylated RSK2 to the nucleus. Site-directed mutagenesis and immunoprecipitation experiments revealed that RSK2 phosphorylated VGLL1 at S84 in the presence of TGF-ß. Mutation of VGLL1 at S84 suppressed VGLL1-TEAD4 binding and the subsequent transcriptional activation of matrix metalloprotease 9 (MMP9). Moreover, VGLL1 peptide containing S84 suppressed the TGF-ß-induced MMP9 expression and reduced the invasion and proliferation of gastric cancer cells, whereas VGLL1 peptide containing S84A did not. Furthermore, suppression of expression or activation of VGLL1 enhances the therapeutic effects of lapatinib. Collectively, these results indicate that VGLL1 phosphorylation via TGF-ß/ERK/RSK2 signaling plays a crucial role in MMP9-mediated malignancy of gastric cancer. In addition, our study highlights the therapeutic potential of the peptide containing VGLL1 S84 for the treatment of gastric cancer.


Assuntos
Proteínas de Ligação a DNA/genética , Proteínas Musculares/genética , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Neoplasias Gástricas/genética , Fatores de Transcrição/genética , Linhagem Celular Tumoral , MAP Quinases Reguladas por Sinal Extracelular/genética , Humanos , Fosfatidilinositol 3-Quinases/genética , Fosforilação/genética , Mapas de Interação de Proteínas/efeitos dos fármacos , Transdução de Sinais/genética , Neoplasias Gástricas/patologia , Ativação Transcricional/genética , Fator de Crescimento Transformador beta/genética
4.
Proc Natl Acad Sci U S A ; 117(28): 16557-16566, 2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32601201

RESUMO

Influenza viruses (IV) exploit a variety of signaling pathways. Previous studies showed that the rapidly accelerated fibrosarcoma/mitogen-activated protein kinase/extracellular signal-regulated kinase (Raf/MEK/ERK) pathway is functionally linked to nuclear export of viral ribonucleoprotein (vRNP) complexes, suggesting that vRNP export is a signaling-induced event. However, the underlying mechanism remained completely enigmatic. Here we have dissected the unknown molecular steps of signaling-driven vRNP export. We identified kinases RSK1/2 as downstream targets of virus-activated ERK signaling. While RSK2 displays an antiviral role, we demonstrate a virus-supportive function of RSK1, migrating to the nucleus to phosphorylate nucleoprotein (NP), the major constituent of vRNPs. This drives association with viral matrix protein 1 (M1) at the chromatin, important for vRNP export. Inhibition or knockdown of MEK, ERK or RSK1 caused impaired vRNP export and reduced progeny virus titers. This work not only expedites the development of anti-influenza strategies, but in addition demonstrates converse actions of different RSK isoforms.


Assuntos
Vírus da Influenza A/metabolismo , Influenza Humana/virologia , Ribonucleoproteínas/metabolismo , Transporte Ativo do Núcleo Celular , Núcleo Celular/metabolismo , Núcleo Celular/virologia , Humanos , Vírus da Influenza A/genética , Influenza Humana/genética , Influenza Humana/metabolismo , Sistema de Sinalização das MAP Quinases , Sinais de Exportação Nuclear , Ribonucleoproteínas/genética , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Proteínas Quinases S6 Ribossômicas 90-kDa/metabolismo , Proteínas da Matriz Viral/genética , Proteínas da Matriz Viral/metabolismo
5.
Proc Natl Acad Sci U S A ; 117(28): 16616-16625, 2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32601203

RESUMO

Enhanced inflammation is believed to contribute to overnutrition-induced metabolic disturbance. Nutrient flux has also been shown to be essential for immune cell activation. Here, we report an unexpected role of nutrient-sensing O-linked ß-N-acetylglucosamine (O-GlcNAc) signaling in suppressing macrophage proinflammatory activation and preventing diet-induced metabolic dysfunction. Overnutrition stimulates an increase in O-GlcNAc signaling in macrophages. O-GlcNAc signaling is down-regulated during macrophage proinflammatory activation. Suppressing O-GlcNAc signaling by O-GlcNAc transferase (OGT) knockout enhances macrophage proinflammatory polarization, promotes adipose tissue inflammation and lipolysis, increases lipid accumulation in peripheral tissues, and exacerbates tissue-specific and whole-body insulin resistance in high-fat-diet-induced obese mice. OGT inhibits macrophage proinflammatory activation by catalyzing ribosomal protein S6 kinase beta-1 (S6K1) O-GlcNAcylation and suppressing S6K1 phosphorylation and mTORC1 signaling. These findings thus identify macrophage O-GlcNAc signaling as a homeostatic mechanism maintaining whole-body metabolism under overnutrition.


Assuntos
Macrófagos/imunologia , N-Acetilglucosaminiltransferases/imunologia , Obesidade/imunologia , Proteínas Quinases S6 Ribossômicas 90-kDa/imunologia , Acetilglucosamina/imunologia , Tecido Adiposo/imunologia , Animais , Humanos , Ativação de Macrófagos , Macrófagos/enzimologia , Camundongos , Camundongos Knockout , N-Acetilglucosaminiltransferases/genética , Obesidade/enzimologia , Obesidade/genética , Obesidade/metabolismo , Fosforilação , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Transdução de Sinais
6.
Nat Commun ; 11(1): 3200, 2020 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-32581239

RESUMO

mTOR activation is essential and sufficient to cause polycystic kidneys in Tuberous Sclerosis Complex (TSC) and other genetic disorders. In disease models, a sharp increase of proliferation and cyst formation correlates with a dramatic loss of oriented cell division (OCD). We find that OCD distortion is intrinsically due to S6 kinase 1 (S6K1) activation. The concomitant loss of S6K1 in Tsc1-mutant mice restores OCD but does not decrease hyperproliferation, leading to non-cystic harmonious hyper growth of kidneys. Mass spectrometry-based phosphoproteomics for S6K1 substrates revealed Afadin, a known component of cell-cell junctions required to couple intercellular adhesions and cortical cues to spindle orientation. Afadin is directly phosphorylated by S6K1 and abnormally decorates the apical surface of Tsc1-mutant cells with E-cadherin and α-catenin. Our data reveal that S6K1 hyperactivity alters centrosome positioning in mitotic cells, affecting oriented cell division and promoting kidney cysts in conditions of mTOR hyperactivity.


Assuntos
Divisão Celular , Cinesina/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Miosinas/metabolismo , Doenças Renais Policísticas/patologia , Proteínas Quinases S6 Ribossômicas 90-kDa/metabolismo , Animais , Linhagem Celular , Cinesina/genética , Camundongos , Camundongos Mutantes , Mutação , Miosinas/genética , Fosforilação , Doenças Renais Policísticas/genética , Doenças Renais Policísticas/metabolismo , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Transdução de Sinais , Esclerose Tuberosa/genética , Esclerose Tuberosa/metabolismo , Esclerose Tuberosa/patologia , Proteína 1 do Complexo Esclerose Tuberosa/genética , Proteína 1 do Complexo Esclerose Tuberosa/metabolismo
7.
J Neurosci ; 40(24): 4644-4660, 2020 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-32376781

RESUMO

Experience powerfully influences neuronal function and cognitive performance, but the cellular and molecular events underlying the experience-dependent enhancement of mental ability have remained elusive. In particular, the mechanisms that couple the external environment to the genomic changes underpinning this improvement are unknown. To address this, we have used male mice harboring an inactivating mutation of mitogen- and stress-activated protein kinase 1 (MSK1), a brain-derived neurotrophic factor (BDNF)-activated enzyme downstream of the mitogen-activated protein kinase (MAPK) pathway. We show that MSK1 is required for the full extent of experience-induced improvement of spatial memory, for the expansion of the dynamic range of synapses, exemplified by the enhancement of hippocampal long-term potentiation (LTP) and long-term depression (LTD), and for the regulation of the majority of genes influenced by enrichment. In addition, and unexpectedly, we show that experience is associated with an MSK1-dependent downregulation of key MAPK and plasticity-related genes, notably of EGR1/Zif268 and Arc/Arg3.1, suggesting the establishment of a novel genomic landscape adapted to experience. By coupling experience to homeostatic changes in gene expression MSK1, represents a prime mechanism through which the external environment has an enduring influence on gene expression, synaptic function, and cognition.SIGNIFICANCE STATEMENT Our everyday experiences strongly influence the structure and function of the brain. Positive experiences encourage the growth and development of the brain and support enhanced learning and memory and resistance to mood disorders such as anxiety. While this has been known for many years, how this occurs is not clear. Here, we show that many of the positive aspects of experience depend on an enzyme called mitogen- and stress-activated protein kinase 1 (MSK1). Using male mice with a mutation in MSK1, we show that MSK1 is necessary for the majority of gene expression changes associated with experience, extending the range over which the communication between neurons occurs, and for both the persistence of memory and the ability to learn new task rules.


Assuntos
Cognição/fisiologia , Hipocampo/metabolismo , Plasticidade Neuronal/fisiologia , Proteínas Quinases S6 Ribossômicas 90-kDa/metabolismo , Memória Espacial/fisiologia , Sinapses/metabolismo , Animais , Espinhas Dendríticas/metabolismo , Técnicas de Silenciamento de Genes , Masculino , Memória de Curto Prazo/fisiologia , Camundongos , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Transmissão Sináptica/fisiologia
8.
Nat Commun ; 11(1): 1168, 2020 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-32127537

RESUMO

Telomerase deficiency leads to age-related diseases and shorter lifespans. Inhibition of the mechanistic target of rapamycin (mTOR) delays aging and age-related pathologies. Here, we show that telomerase deficient mice with short telomeres (G2-Terc-/-) have an hyper-activated mTOR pathway with increased levels of phosphorylated ribosomal S6 protein in liver, skeletal muscle and heart, a target of mTORC1. Transcriptional profiling confirms mTOR activation in G2-Terc-/- livers. Treatment of G2-Terc-/- mice with rapamycin, an inhibitor of mTORC1, decreases survival, in contrast to lifespan extension in wild-type controls. Deletion of mTORC1 downstream S6 kinase 1 in G3-Terc-/- mice also decreases longevity, in contrast to lifespan extension in single S6K1-/- female mice. These findings demonstrate that mTOR is important for survival in the context of short telomeres, and that its inhibition is deleterious in this setting. These results are of clinical interest in the case of human syndromes characterized by critically short telomeres.


Assuntos
Envelhecimento/genética , RNA/genética , Serina-Treonina Quinases TOR/metabolismo , Telomerase/genética , Telômero/genética , Envelhecimento/efeitos dos fármacos , Animais , Dano ao DNA/efeitos dos fármacos , Feminino , Longevidade/efeitos dos fármacos , Longevidade/genética , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neoplasias/genética , Fosforilação , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Sirolimo/farmacologia , Taxa de Sobrevida , Serina-Treonina Quinases TOR/genética , Telômero/efeitos dos fármacos , Telômero/metabolismo
9.
Am J Physiol Cell Physiol ; 318(5): C836-C847, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32159363

RESUMO

Prostate cancer (PCa) is a leading cause of cancer death in men. Despite the antiproliferative effects of 1α,25-dihydroxyvitamin D3 [1,25(OH)2D3] on PCa, accumulating evidence indicates that 1,25(OH)2D3 promotes cancer progression by increasing genome plasticity. Our investigation of epigenetic changes associated with vitamin D insensitivity found that 1,25(OH)2D3 treatment reduced the expression levels and activities of DNA methyltransferases 1 and 3B (DNMT1 and DNMT3B, respectively). In silico analysis and reporter assay confirmed that 1,25(OH)2D3 downregulated transcriptional activation of the DNMT3B promoter and upregulated microRNAs targeting the 3'-untranslated regions of DNMT3B. We then profiled DNA methylation in the vitamin D-resistant PC-3 cells and a resistant PCa cell model generated by long-term 1,25(OH)2D3 exposure. Several candidate genes were found to be hypomethylated and overexpressed in vitamin D-resistant PCa cells compared with vitamin D-sensitive cells. Most of the identified genes were associated with mammalian target of rapamycin (mTOR) signaling activation, which is known to promote cancer progression. Among them, we found that inhibition of ribosomal protein S6 kinase A1 (RPS6KA1) promoted vitamin D sensitivity in PC-3 cells. Furthermore, The Cancer Genome Atlas (TCGA) prostate cancer data set demonstrated that midline 1 (MID1) expression is positively correlated with tumor stage. Overall, our study reveals an inhibitory mechanism of 1,25(OH)2D3 on DNMT3B, which may contribute to vitamin D resistance in PCa.


Assuntos
DNA (Citosina-5-)-Metiltransferase 1/genética , DNA (Citosina-5-)-Metiltransferases/genética , Neoplasias da Próstata/genética , Vitamina D/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Metilação de DNA/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Masculino , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Serina-Treonina Quinases TOR/genética , Ubiquitina-Proteína Ligases/genética , Vitamina D/análogos & derivados , Vitamina D/genética , Vitamina D/farmacologia
10.
PLoS One ; 15(1): e0227340, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31910234

RESUMO

The PI3K/Akt pathway is interconnected to protein kinase CK2, which directly phosphorylates Akt1 at S129. We have previously found that, in HK-2 renal cells, downregulation of the CK2 regulatory subunit ß (shCK2ß cells) reduces S129 Akt phosphorylation. Here, we investigated in more details how the different CK2 isoforms impact on Akt and other signaling pathways. We found that all CK2 isoforms phosphorylate S129 in vitro, independently of CK2ß. However, in HK-2 cells the dependence on CK2ß was confirmed by rescue experiments (CK2ß re-expression in shCK2ß HK-2 cells), suggesting the presence of additional components that drive Akt recognition by CK2 in cells. We also found that CK2ß downregulation altered the phosphorylation ratio between the two canonical Akt activation sites (pT308 strongly reduced, pS473 slightly increased) in HK-2 cells. Similar results were found in other cell lines where CK2ß was stably knocked out by CRISPR-Cas9 technology. The phosphorylation of rpS6 S235/S236, a downstream effector of Akt, was strongly reduced in shCK2ß HK-2 cells, while the phosphorylation of two Akt direct targets, PRAS40 T246 and GSK3ß S9, was increased. Differently to what observed in response to CK2ß down-regulation, the chemical inhibition of CK2 activity by cell treatment with the specific inhibitor CX-4945 reduced both the Akt canonical sites, pT308 and pS473. In CX-4945-treated cells, the changes in rpS6 pS235/S236 and GSK3ß pS9 mirrored those induced by CK2ß knock-down (reduction and slight increase, respectively); on the contrary, the effect on PRAS40 pT246 phosphorylation was sharply different, being strongly reduced by CK2 inhibition; this suggests that this Akt target might be dependent on Akt pS473 status in HK-2 cells. Since PI3K/Akt and ERK1/2/p90rsk pathways are known to be interconnected and both modulated by CK2, with GSK3ß pS9 representing a convergent point, we investigated if ERK1/2/p90rsk signaling was affected by CK2ß knock-down and CX-4945 treatment in HK-2 cells. We found that p90rsk was insensitive to any kind of CK2 targeting; therefore, the observation that, similarly, GSK3ß pS9 was not reduced by CK2 blockade suggests that GSK3ß phosphorylation is mainly under the control of p90rsk in these cells. However, we found that the PI3K inhibitor LY294002 reduced GSK3ß pS9, and concomitantly decreased Snail1 levels (a GSK3ß target and Epithelial-to-Mesenchymal transition marker). The effects of LY294002 were observed also in CK2ß-downregulated cells, suggesting that reducing GSK3ß pS9 could be a strategy to control Snail1 levels in any situation where CK2ß is defective, as possibly occurring in cancer cells.


Assuntos
Caseína Quinase II/genética , Glicogênio Sintase Quinase 3 beta/genética , Proteína Oncogênica v-akt/genética , Fatores de Transcrição da Família Snail/genética , Sistemas CRISPR-Cas/genética , Linhagem Celular , Cromonas/farmacologia , Transição Epitelial-Mesenquimal/genética , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Técnicas de Inativação de Genes , Humanos , Rim/efeitos dos fármacos , Rim/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Morfolinas/farmacologia , Naftiridinas/farmacologia , Fosfatidilinositol 3-Quinases/genética , Fosforilação/efeitos dos fármacos , Isoformas de Proteínas , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Transdução de Sinais/efeitos dos fármacos
11.
Sci Rep ; 10(1): 152, 2020 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-31932636

RESUMO

Consanguineous populations of the Arabian Peninsula, which has seen an uncontrolled rise in type 2 diabetes incidence, are underrepresented in global studies on diabetes genetics. We performed a genome-wide association study on the quantitative trait of fasting plasma glucose (FPG) in unrelated Arab individuals from Kuwait (discovery-cohort:n = 1,353; replication-cohort:n = 1,196). Genome-wide genotyping in discovery phase was performed for 632,375 markers from Illumina HumanOmniExpress Beadchip; and top-associating markers were replicated using candidate genotyping. Genetic models based on additive and recessive transmission modes were used in statistical tests for associations in discovery phase, replication phase, and meta-analysis that combines data from both the phases. A genome-wide significant association with high FPG was found at rs1002487 (RPS6KA1) (p-discovery = 1.64E-08, p-replication = 3.71E-04, p-combined = 5.72E-11; ß-discovery = 8.315; ß-replication = 3.442; ß-combined = 6.551). Further, three suggestive associations (p-values < 8.2E-06) with high FPG were observed at rs487321 (CADPS), rs707927 (VARS and 2Kb upstream of VWA7), and rs12600570 (DHX58); the first two markers reached genome-wide significance in the combined analysis (p-combined = 1.83E-12 and 3.07E-09, respectively). Significant interactions of diabetes traits (serum triglycerides, FPG, and glycated hemoglobin) with homeostatic model assessment of insulin resistance were identified for genotypes heterozygous or homozygous for the risk allele. Literature reports support the involvement of these gene loci in type 2 diabetes etiology.


Assuntos
Árabes/genética , Biomarcadores/análise , Glicemia/análise , Diabetes Mellitus Tipo 2/genética , Regulação da Expressão Gênica , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , Proteínas de Ligação ao Cálcio/genética , Estudos de Casos e Controles , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/patologia , Jejum , Feminino , Perfilação da Expressão Gênica , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Resistência à Insulina , Kuweit/epidemiologia , Masculino , Fenótipo , Prognóstico , RNA Helicases/genética , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Valina-tRNA Ligase/genética , Proteínas de Transporte Vesicular/genética
12.
Nat Commun ; 11(1): 258, 2020 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-31937753

RESUMO

BET bromodomain inhibitors (BETi), such as JQ1, have been demonstrated to effectively kill multiple types of cancer cells. However, the underlying mechanisms for BETi resistance remain largely unknown. Our evidences show that JQ1 treatment evicts BRD4 from the FOXD3-localized MIR548D1 gene promoter, leading to repression of miR-548d-3p. The loss of miRNA restores JunD expression and subsequent JunD-dependent transcription of RPS6KA2 gene. ERK1/2/5 kinases phosphorylate RSK3 (RPS6KA2), resulting in the enrichment of activated RSK3 and blockade of JQ1 killing effect. Dual inhibition of MEKs/ERKs or single EGFR inhibition are able to mimic the effect of JunD/RSK3-knockdown to reverse BETi resistance. Collectively, our study indicates that loss of BRD4/FOXD3/miR-548d-3p axis enhances JunD/RSK3 signalling and determines BET inhibition resistance, which can be reversed by targeting EGFR-MEK1/2/5-ERK1/2/5 signalling.


Assuntos
Proteínas de Ciclo Celular/antagonistas & inibidores , Proteínas de Ciclo Celular/metabolismo , Resistencia a Medicamentos Antineoplásicos , Fatores de Transcrição Forkhead/metabolismo , MicroRNAs/genética , Proteínas Proto-Oncogênicas c-jun/metabolismo , Proteínas Quinases S6 Ribossômicas 90-kDa/metabolismo , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/metabolismo , Antineoplásicos/farmacologia , Azepinas/farmacologia , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Fatores de Transcrição Forkhead/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Humanos , Quinases de Proteína Quinase Ativadas por Mitógeno/antagonistas & inibidores , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Fosforilação , Regiões Promotoras Genéticas , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-jun/genética , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Transdução de Sinais/efeitos dos fármacos , Fatores de Transcrição/genética , Triazóis/farmacologia
13.
Sci Rep ; 10(1): 591, 2020 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-31953410

RESUMO

The activation of the majority of AGC kinases is regulated by two phosphorylation events on two conserved serine/threonine residues located on the activation loop and on the hydrophobic motif, respectively. In AGC kinase family, phosphomimetic substitutions with aspartate or glutamate, leading to constitutive activation, have frequently occurred at the hydrophobic motif site. On the contrary, phosphomimetic substitutions in the activation loop are absent across the evolution of AGC kinases. This observation is explained by the failure of aspartate and glutamate to mimic phosphorylatable serine/threonine in this regulatory site. By detailed 3D structural simulations of RSK2 and further biochemical evaluation in cells, we show that the phosphomimetic residue on the activation loop fails to form a critical salt bridge with R114, necessary to reorient the αC-helix and to activate the protein. By a phylogenetic analysis, we point at a possible coevolution of a phosphorylatable activation loop and the presence of a conserved positively charged amino acid on the αC-helix. In sum, our analysis leads to the unfeasibility of phosphomimetic substitution in the activation loop of RSK and, at the same time, highlights the peculiar structural role of activation loop phosphorylation.


Assuntos
Substituição de Aminoácidos , Proteínas Quinases S6 Ribossômicas 90-kDa/química , Proteínas Quinases S6 Ribossômicas 90-kDa/metabolismo , Motivos de Aminoácidos , Ativação Enzimática , Evolução Molecular , Células HEK293 , Células HeLa , Humanos , Modelos Moleculares , Simulação de Dinâmica Molecular , Mimetismo Molecular , Fosforilação , Filogenia , Estrutura Secundária de Proteína , Proteínas Quinases S6 Ribossômicas 90-kDa/genética
14.
Sci Rep ; 10(1): 608, 2020 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-31953461

RESUMO

Multiple kinases converge on the transcription factor cAMP response element-binding protein (CREB) to enhance the expression of proteins essential for long-term synaptic plasticity and memory. The p90 ribosomal S6 kinase (RSK) is one of these kinases, although its role is poorly understood. The present study exploited the technical advantages of the Aplysia sensorimotor culture system to examine the role of RSK in long-term synaptic facilitation (LTF) and long-term enhancement of neuronal excitability (LTEE), two correlates of long-term memory (LTM). Inhibition of RSK expression or RSK activity both significantly reduced CREB1 phosphorylation, LTF, and LTEE, suggesting RSK is required for learning-related synaptic plasticity and enhancement in neuronal excitability. In addition, knock down of RSK by RNAi in Aplysia sensory neurons impairs LTF, suggesting that this may be a useful single-cell system to study aspects of defective synaptic plasticity in Coffin-Lowry Syndrome (CLS), a cognitive disorder that is caused by mutations in rsk2 and associated with deficits in learning and memory. We found that the impairments in LTF and LTEE can be rescued by a computationally designed spaced training protocol, which was previously demonstrated to augment normal LTF and LTM.


Assuntos
Aplysia/fisiologia , Memória de Longo Prazo/fisiologia , Proteínas Quinases S6 Ribossômicas 90-kDa/metabolismo , Células Receptoras Sensoriais/citologia , Animais , Aplysia/metabolismo , Células Cultivadas , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Plasticidade Neuronal , Fosforilação , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Células Receptoras Sensoriais/metabolismo , Serotonina/farmacologia
16.
Mol Cell Biochem ; 465(1-2): 13-26, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31782083

RESUMO

Cellular signals that influence Cap-dependent translation have assumed significant relevance in the backdrop of their enforced dysregulation during oncogenesis. Eukaryotic initiation factor 4E(eIF4E), the mRNA cap-binding protein, has emerged as a key player to facilitate tumor progression through upregulated cap-dependent translation synchronized with enhanced cell division. We provide evidence that eIF4E phosphorylation is regulated by mTORC1 by virtue of its interaction with Raptor through a novel TPTPNPP motif and consequent phosphorylation invitro and in vivo in a Rapamycin-sensitive manner. While we show that phosphorylation pattern of eIF4E responds faithfully to Rapamycin inhibition, the prolonged exposure to Rapamycin rescues the loss of eIF4E phosphorylation through Mnk1 activation. We also present evidence that eIF4E interacts with the amino terminal domain of S6K1 in a phospho-dependent manner, and this interaction is instrumental in overriding Rapamycin inhibition of S6K1. The data endorses eIF4E as a regulatory subunit that modulates the functional attributes of mTOR effectors to synchronize cap-dependent translation with growth assertion.


Assuntos
Fator de Iniciação 4E em Eucariotos/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Motivos de Aminoácidos , Animais , Fator de Iniciação 4E em Eucariotos/genética , Células HEK293 , Células HeLa , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Camundongos , Células NIH 3T3 , Fosforilação/efeitos dos fármacos , Fosforilação/genética , Proteínas Serina-Treonina Quinases/genética , Proteína Regulatória Associada a mTOR/genética , Proteína Regulatória Associada a mTOR/metabolismo , Proteínas Quinases S6 Ribossômicas 70-kDa/genética , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Proteínas Quinases S6 Ribossômicas 90-kDa/metabolismo , Sirolimo/farmacologia
17.
Mol Cell Proteomics ; 19(1): 50-64, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31678930

RESUMO

The RAS/mitogen-activated protein kinase (MAPK) signaling pathway regulates various biological functions, including cell survival, proliferation and migration. This pathway is frequently deregulated in cancer, including melanoma, which is the most aggressive form of skin cancer. RSK (p90 ribosomal S6 kinase) is a MAPK-activated protein kinase required for melanoma growth and proliferation, but relatively little is known about its function and the nature of its cellular partners. In this study, we used a proximity-based labeling approach to identify RSK proximity partners in cells. We identified many potential RSK-interacting proteins, including p120ctn (p120-catenin), which is an essential component of adherens junction (AJ). We found that RSK phosphorylates p120ctn on Ser320, which appears to be constitutively phosphorylated in melanoma cells. We also found that RSK inhibition increases melanoma cell-cell adhesion, suggesting that constitutive RAS/MAPK signaling negatively regulates AJ integrity. Together, our results indicate that RSK plays an important role in the regulation of melanoma cell-cell adhesion.


Assuntos
Cateninas/metabolismo , Adesão Celular/genética , Melanoma/metabolismo , Proteômica/métodos , Proteínas Quinases S6 Ribossômicas 90-kDa/metabolismo , Cateninas/genética , Linhagem Celular Tumoral , Células HEK293 , Humanos , Sistema de Sinalização das MAP Quinases/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fosforilação , Interferência de RNA , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Transdução de Sinais/genética
18.
Anim Genet ; 51(1): 122-126, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31691328

RESUMO

A GWAS was performed for inborn X-linked facial dysmorphia with severe growth retardation in Labrador Retrievers. This lethal condition was mapped on the X chromosome at 17-21 Mb and supported by eight SNPs in complete LD. Dams of affected male puppies were heterozygous for the significantly associated SNPs and male affected puppies carried the associated alleles hemizygously. In the near vicinity to the associated region, RPS6KA3 was identified as a candidate gene causing facial dysmorphia in humans and mice known as Coffin-Lowry syndrome. Haplotype analysis showed significant association with the phenotypes of all 18 animals under study. This haplotype was validated through normal male progeny from a dam with the not-associated haplotype on both X chromosomes but male affected full-sibs with the associated haplotype.


Assuntos
Craniossinostoses/veterinária , Doenças do Cão/genética , Cães/genética , Genes Letais , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Animais , Craniossinostoses/genética , Feminino , Estudos de Associação Genética/veterinária , Haplótipos , Masculino , Linhagem , Fenótipo , Polimorfismo de Nucleotídeo Único , Cromossomo X/genética
19.
BMB Rep ; 52(12): 706-711, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31818359

RESUMO

Cisplatin (Cis-DDP) is one of the most widely used anti-cancer drugs. It is applicable to many types of cancer, including lung, bladder, and breast cancer. However, its use is now limited because of drug resistance. p90 ribosomal S6 kinase (p90RSK) is one of the downstream effectors in the extracellular signalregulated protein kinases 1 and 2 (ERK1/2) pathway and high expression of p90RSK is observed in human breast cancer tissues. Therefore, we investigated the role of p90RSK in the Cis-DDP resistance-related signaling pathway and epithelialmesenchymal transition (EMT) in breast cancer cells. First, we discovered that MDA-MB-231 cells exhibited more Cis-DDP resistance than other breast cancer cells, including MCF-7 and BT549 cells. Cis-DDP increased p90RSK activation, whereas the inactivation of p90RSK using a small interfering RNA (siRNA) or dominant-negative kinase mutant plasmid overexpression significantly reduced Cis-DDP-induced cell proliferation and migration via the inhibition of matrix metallopeptidase (MMP)2 and MMP9 in MDA-MB-231 cells. In addition, p90RSK activation was involved in EMT via the upregulation of mRNA expression, including that of Snail, Twist, ZEB1, N-cadherin, and vimentin. We also investigated NF-κB, the upstream regulator of EMT markers, and discovered that Cis-DDP treatment led to NF-κB translocation in the nucleus as well as its promoter activity. Our results suggest that targeting p90RSK would be a good strategy to increase Cis-DDP sensitivity in triple-negative breast cancers. [BMB Reports 2019; 52(12): 706-711].


Assuntos
Antineoplásicos/farmacologia , Cisplatino/farmacologia , Proteínas Quinases S6 Ribossômicas 90-kDa/antagonistas & inibidores , Proteínas Quinases S6 Ribossômicas 90-kDa/metabolismo , Neoplasias de Mama Triplo Negativas/enzimologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Células MCF-7 , NF-kappa B/metabolismo , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Transdução de Sinais/efeitos dos fármacos , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/metabolismo
20.
Sci Rep ; 9(1): 16133, 2019 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-31695068

RESUMO

Huntington's disease (HD) is a fatal inherited autosomal dominant neurodegenerative disorder caused by an expansion in the number of CAG trinucleotide repeats in the huntingtin gene. The disease is characterized by motor, behavioural and cognitive symptoms for which at present there are no disease altering treatments. It has been shown that manipulating the mTOR (mammalian target of rapamycin) pathway using rapamycin or its analogue CCI-779 can improve the cellular and behavioural phenotypes of HD models. Ribosomal protein S6 kinase 1 (S6K1) is a major downstream signalling molecule of mTOR, and its activity is reduced by rapamycin suggesting that deregulation of S6K1 activity may be beneficial in HD. Furthermore, S6k1 knockout mice have increased lifespan and improvement in age-related phenotypes. To evalute the potential benefit of S6k1 loss on HD-related phenotypes, we crossed the R6/2 HD model with the long-lived S6k1 knockout mouse line. We found that S6k1 knockout does not ameliorate behavioural or physiological phenotypes in the R6/2 mouse model. Additionally, no improvements were seen in brain mass reduction or mutant huntingtin protein aggregate levels. Therefore, these results suggest that while a reduction in S6K1 signalling has beneficial effects on ageing it is unlikely to be a therapeutic strategy for HD patients.


Assuntos
Deleção de Genes , Doença de Huntington/genética , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Animais , Modelos Animais de Doenças , Feminino , Humanos , Proteína Huntingtina/genética , Proteína Huntingtina/metabolismo , Doença de Huntington/metabolismo , Masculino , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Fenótipo , Proteínas Quinases S6 Ribossômicas 90-kDa/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...