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1.
Nat Commun ; 11(1): 3834, 2020 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-32737309

RESUMO

The transcriptional inducer anhydrotetracycline (aTc) and the bacteriostatic antibiotic tetracycline (Tc) are commonly used in all fields of biology for control of transcription or translation. A drawback of these and other small molecule inducers is the difficulty of their removal from cell cultures, limiting their application for dynamic control. Here, we describe a simple method to overcome this limitation, and show that the natural photosensitivity of aTc/Tc can be exploited to turn them into highly predictable optogenetic transcriptional- and growth-regulators. This new optogenetic class uniquely features both dynamic and setpoint control which act via population-memory adjustable through opto-chemical modulation. We demonstrate this method by applying it for dynamic gene expression control and for enhancing the performance of an existing optogenetic system. We then expand the utility of the aTc system by constructing a new chemical bandpass filter that increases its aTc response range. The simplicity of our method enables scientists and biotechnologists to use their existing systems employing aTc/Tc for dynamic optogenetic experiments without genetic modification.


Assuntos
Escherichia coli/efeitos dos fármacos , Optogenética/métodos , Biossíntese de Proteínas/efeitos dos fármacos , Inibidores da Síntese de Proteínas/farmacologia , Tetraciclina/farmacologia , Tetraciclinas/farmacologia , Transcrição Genética/efeitos dos fármacos , Clonagem Molecular , Relação Dose-Resposta a Droga , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Genes Reporter , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Fotólise , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Raios Ultravioleta
2.
Nat Commun ; 11(1): 4013, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32782250

RESUMO

Antibiotics that interfere with translation, when combined, interact in diverse and difficult-to-predict ways. Here, we explain these interactions by "translation bottlenecks": points in the translation cycle where antibiotics block ribosomal progression. To elucidate the underlying mechanisms of drug interactions between translation inhibitors, we generate translation bottlenecks genetically using inducible control of translation factors that regulate well-defined translation cycle steps. These perturbations accurately mimic antibiotic action and drug interactions, supporting that the interplay of different translation bottlenecks causes these interactions. We further show that growth laws, combined with drug uptake and binding kinetics, enable the direct prediction of a large fraction of observed interactions, yet fail to predict suppression. However, varying two translation bottlenecks simultaneously supports that dense traffic of ribosomes and competition for translation factors account for the previously unexplained suppression. These results highlight the importance of "continuous epistasis" in bacterial physiology.


Assuntos
Antibacterianos/farmacologia , Modelos Teóricos , Biossíntese de Proteínas/efeitos dos fármacos , Inibidores da Síntese de Proteínas/farmacologia , Interações Medicamentosas , Epistasia Genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/fisiologia , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Biossíntese de Proteínas/fisiologia , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , Ribossomos/efeitos dos fármacos , Ribossomos/metabolismo
3.
PLoS Biol ; 18(8): e3000805, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32810152

RESUMO

Antibiotics are losing efficacy due to the rapid evolution and spread of resistance. Treatments targeting bacterial virulence factors have been considered as alternatives because they target virulence instead of pathogen viability, and should therefore exert weaker selection for resistance than conventional antibiotics. However, antivirulence treatments rarely clear infections, which compromises their clinical applications. Here, we explore the potential of combining antivirulence drugs with antibiotics against the opportunistic human pathogen Pseudomonas aeruginosa. We combined two antivirulence compounds (gallium, a siderophore quencher, and furanone C-30, a quorum sensing [QS] inhibitor) together with four clinically relevant antibiotics (ciprofloxacin, colistin, meropenem, tobramycin) in 9×9 drug concentration matrices. We found that drug-interaction patterns were concentration dependent, with promising levels of synergies occurring at intermediate drug concentrations for certain drug pairs. We then tested whether antivirulence compounds are potent adjuvants, especially when treating antibiotic resistant (AtbR) clones. We found that the addition of antivirulence compounds to antibiotics could restore growth inhibition for most AtbR clones, and even abrogate or reverse selection for resistance in five drug combination cases. Molecular analyses suggest that selection against resistant clones occurs when resistance mechanisms involve restoration of protein synthesis, but not when efflux pumps are up-regulated. Altogether, our work provides a first systematic analysis of antivirulence-antibiotic combinatorial treatments and suggests that such combinations have the potential to be both effective in treating infections and in limiting the spread of antibiotic resistance.


Assuntos
Antibacterianos/farmacologia , Ciprofloxacino/farmacologia , Colistina/farmacologia , Furanos/farmacologia , Gálio/farmacologia , Meropeném/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Tobramicina/farmacologia , Proteínas de Bactérias/antagonistas & inibidores , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/genética , Combinação de Medicamentos , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Sinergismo Farmacológico , Humanos , Testes de Sensibilidade Microbiana , Biossíntese de Proteínas/efeitos dos fármacos , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/crescimento & desenvolvimento , Pseudomonas aeruginosa/metabolismo , Percepção de Quorum/efeitos dos fármacos , Virulência
4.
PLoS One ; 15(8): e0237845, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32813721

RESUMO

Aluminum (Al3+) toxicity is one of the most important limitations to agricultural production worldwide. The overall response of plants to Al3+ stress has been documented, but the contribution of protein phosphorylation to Al3+ detoxicity and tolerance in plants is unclear. Using a combination of tandem mass tag (TMT) labeling, immobilized metal affinity chromatography (IMAC) enrichment and liquid chromatography-tandem mass spectrometry (LC-MS/MS), Al3+-induced phosphoproteomic changes in roots of Tamba black soybean (TBS) were investigated in this study. The Data collected in this study are available via ProteomeXchange with the identifier PXD019807. After the Al3+ treatment, 189 proteins harboring 278 phosphosites were significantly changed (fold change > 1.2 or < 0.83, p < 0.05), with 88 upregulated, 96 downregulated and 5 up-/downregulated. Enrichment and protein interaction analyses revealed that differentially phosphorylated proteins (DPPs) under the Al3+ treatment were mainly related to G-protein-mediated signaling, transcription and translation, transporters and carbohydrate metabolism. Particularly, DPPs associated with root growth inhibition or citric acid synthesis were identified. The results of this study provide novel insights into the molecular mechanisms of TBS post-translational modifications in response to Al3+ stress.


Assuntos
Alumínio/toxicidade , Fosfoproteínas/metabolismo , Proteínas de Plantas/metabolismo , Proteômica , Soja/metabolismo , Citratos/metabolismo , Fosforilação/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Biossíntese de Proteínas/efeitos dos fármacos , Mapas de Interação de Proteínas/efeitos dos fármacos , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Soja/efeitos dos fármacos , Estresse Fisiológico/efeitos dos fármacos , Transcrição Genética/efeitos dos fármacos
5.
Nature ; 584(7820): 252-256, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32760004

RESUMO

A fundamental challenge in developing treatments for autism spectrum disorders is the heterogeneity of the condition. More than one hundred genetic mutations confer high risk for autism, with each individual mutation accounting for only a small fraction of cases1-3. Subsets of risk genes can be grouped into functionally related pathways, most prominently those involving synaptic proteins, translational regulation, and chromatin modifications. To attempt to minimize this genetic complexity, recent therapeutic strategies have focused on the neuropeptides oxytocin and vasopressin4-6, which regulate aspects of social behaviour in mammals7. However, it is unclear whether genetic risk factors predispose individuals to autism as a result of modifications to oxytocinergic signalling. Here we report that an autism-associated mutation in the synaptic adhesion molecule Nlgn3 results in impaired oxytocin signalling in dopaminergic neurons and in altered behavioural responses to social novelty tests in mice. Notably, loss of Nlgn3 is accompanied by a disruption of translation homeostasis in the ventral tegmental area. Treatment of Nlgn3-knockout mice with a new, highly specific, brain-penetrant inhibitor of MAP kinase-interacting kinases resets the translation of mRNA and restores oxytocin signalling and social novelty responses. Thus, this work identifies a convergence between the genetic autism risk factor Nlgn3, regulation of translation, and oxytocinergic signalling. Focusing on such common core plasticity elements might provide a pragmatic approach to overcoming the heterogeneity of autism. Ultimately, this would enable mechanism-based stratification of patient populations to increase the success of therapeutic interventions.


Assuntos
Transtorno Autístico/metabolismo , Transtorno Autístico/psicologia , Modelos Animais de Doenças , Ocitocina/metabolismo , Comportamento Social , Animais , Moléculas de Adesão Celular Neuronais/deficiência , Moléculas de Adesão Celular Neuronais/genética , Fator de Iniciação 4E em Eucariotos/metabolismo , Masculino , Proteínas de Membrana/deficiência , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Proteínas do Tecido Nervoso/deficiência , Proteínas do Tecido Nervoso/genética , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fosforilação/efeitos dos fármacos , Biossíntese de Proteínas/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais/efeitos dos fármacos , Área Tegmentar Ventral/citologia , Área Tegmentar Ventral/efeitos dos fármacos
6.
Chem Biol Interact ; 329: 109222, 2020 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-32771325

RESUMO

Extensive application of methylene blue (MB) for therapeutic and diagnostic purposes, and reports for unwanted side effects, demand better understanding of the mechanisms of biological action of this thiazine dye. Because MB is redox-active, its biological activities have been attributed to transfer of electrons, generation of reactive oxygen species, and antioxidant action. Results of this study show that MB is more toxic to a superoxide dismutase-deficient Escherichia coli mutant than to its SOD-proficient parent, which indicates that superoxide anion radical is involved. Incubation of E. coli with MB induced the enzymes fumarase C, SOD, nitroreductase A, and glucose-6-phosphate dehydrogenase, all controlled by the soxRS regulon. Induction of these enzymes was prevented by blocking protein synthesis with chloramphenicol and was not observed when soxRS-negative mutants were incubated with MB. These results show that MB is capable of inducing the soxRS regulon of E. coli, which plays a key role in protecting bacteria against oxidative stress and redox-cycling compounds. Irrespective of the abundance of heme-containing proteins in living cells, which are preferred acceptors of electrons from the reduced form of MB, reduction of oxygen to superoxide radical still takes place. Induction of the soxRS regulon suggests that in humans, beneficial effects of MB could be attributed to activation of redox-sensitive transcription factors like Nrf2 and FoxO. If defense systems are compromised or genes coding for protective proteins are not induced, MB would have deleterious effects.


Assuntos
Proteínas de Bactérias/metabolismo , Proteínas de Escherichia coli/metabolismo , Escherichia coli/metabolismo , Azul de Metileno/farmacologia , Regulon/efeitos dos fármacos , Transativadores/metabolismo , Fatores de Transcrição/metabolismo , Proteínas de Bactérias/genética , Cloranfenicol/farmacologia , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Fumarato Hidratase/genética , Fumarato Hidratase/metabolismo , Glucosefosfato Desidrogenase/metabolismo , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Biossíntese de Proteínas/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Superóxidos/metabolismo , Transativadores/genética , Fatores de Transcrição/genética
7.
Proc Natl Acad Sci U S A ; 117(31): 18591-18599, 2020 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-32690681

RESUMO

Repeat associated non-AUG (RAN) translation is found in a growing number of microsatellite expansion diseases, but the mechanisms remain unclear. We show that RAN translation is highly regulated by the double-stranded RNA-dependent protein kinase (PKR). In cells, structured CAG, CCUG, CAGG, and G4C2 expansion RNAs activate PKR, which leads to increased levels of multiple RAN proteins. Blocking PKR using PKR-K296R, the TAR RNA binding protein or PKR-KO cells, reduces RAN protein levels. p-PKR is elevated in C9orf72 ALS/FTD human and mouse brains, and inhibiting PKR in C9orf72 BAC transgenic mice using AAV-PKR-K296R or the Food and Drug Administration (FDA)-approved drug metformin, decreases RAN proteins, and improves behavior and pathology. In summary, targeting PKR, including by use of metformin, is a promising therapeutic approach for C9orf72 ALS/FTD and other expansion diseases.


Assuntos
Esclerose Amiotrófica Lateral/metabolismo , Proteína C9orf72 , Metformina/farmacologia , Biossíntese de Proteínas/efeitos dos fármacos , eIF-2 Quinase , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Proteína C9orf72/genética , Proteína C9orf72/metabolismo , Modelos Animais de Doenças , Demência Frontotemporal/metabolismo , Humanos , Camundongos , Camundongos Transgênicos , Repetições de Microssatélites/genética , eIF-2 Quinase/genética , eIF-2 Quinase/metabolismo
8.
Proc Natl Acad Sci U S A ; 117(30): 18029-18036, 2020 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-32665437

RESUMO

Memory reconsolidation occurs when a retrieving event destabilizes transiently a consolidated memory, triggering thereby a new process of restabilization that ensures memory persistence. Although this phenomenon has received wide attention, the effect of new information cooccurring with the reconsolidation process has been less explored. Here we demonstrate that a memory-retrieving event sets a neural tag, which enables the reconsolidation of memory after binding proteins provided by the original or a different contiguous experience. We characterized the specific temporal window during which this association is effective and identified the protein kinase A (PKA) and the extracellular signal-regulated kinase 1 and 2 (ERK 1/2) pathways as the mechanisms related to the setting of the reconsolidation tag and the synthesis of proteins. Our results show, therefore, that memory reconsolidation is mediated by a "behavioral tagging" process, which is common to different memory forms. They represent a significant advance in understanding the fate of memories reconsolidated while being adjacent to other events, and provide a tool for designing noninvasive strategies to attenuate (pathological/traumatic) or improve (education-related) memories.


Assuntos
Comportamento , Consolidação da Memória/fisiologia , Memória/fisiologia , Animais , Biomarcadores , Masculino , Memória/efeitos dos fármacos , Consolidação da Memória/efeitos dos fármacos , Biossíntese de Proteínas/efeitos dos fármacos , Inibidores da Síntese de Proteínas/farmacologia , Ratos
9.
PLoS One ; 15(7): e0235033, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32639961

RESUMO

Lithium Chloride (LiCl) toxicity, mode of action and cellular responses have been the subject of active investigations over the past decades. In yeast, LiCl treatment is reported to reduce the activity and alters the expression of PGM2, a gene that encodes a phosphoglucomutase involved in sugar metabolism. Reduced activity of phosphoglucomutase in the presence of galactose causes an accumulation of intermediate metabolites of galactose metabolism leading to a number of phenotypes including growth defect. In the current study, we identify two understudied yeast genes, YTA6 and YPR096C that when deleted, cell sensitivity to LiCl is increased when galactose is used as a carbon source. The 5'-UTR of PGM2 mRNA is structured. Using this region, we show that YTA6 and YPR096C influence the translation of PGM2 mRNA.


Assuntos
Adenosina Trifosfatases/genética , Antimaníacos/farmacologia , Cloreto de Lítio/farmacologia , RNA Mensageiro/genética , Saccharomyces cerevisiae/efeitos dos fármacos , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Fosfoglucomutase/genética , Biossíntese de Proteínas/efeitos dos fármacos , Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/genética
10.
Nat Commun ; 11(1): 3244, 2020 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-32591520

RESUMO

Bioorthogonal chemistry introduces affinity-labels into biomolecules with minimal disruption to the original system and is widely applicable in a range of contexts. In proteomics, immobilized metal affinity chromatography (IMAC) enables enrichment of phosphopeptides with extreme sensitivity and selectivity. Here, we adapt and combine these superb assets in a new enrichment strategy using phosphonate-handles, which we term PhosID. In this approach, click-able phosphonate-handles are introduced into proteins via 1,3-dipolar Huisgen-cycloaddition to azido-homo-alanine (AHA) and IMAC is then used to enrich exclusively for phosphonate-labeled peptides. In interferon-gamma (IFNγ) stimulated cells, PhosID enabled the identification of a large number of IFN responsive newly synthesized proteins (NSPs) whereby we monitored the differential synthesis of these proteins over time. Collectively, these data validate the excellent performance of PhosID with efficient analysis and quantification of hundreds of NSPs by single LC-MS/MS runs. We envision PhosID as an attractive and alternative tool for studying stimuli-sensitive proteome subsets.


Assuntos
Organofosfonatos/metabolismo , Biossíntese de Proteínas , Animais , Biotina/metabolismo , Bovinos , Células HeLa , Humanos , Interferon gama/farmacologia , Células Jurkat , Organofosfonatos/química , Peptídeos/metabolismo , Biossíntese de Proteínas/efeitos dos fármacos , Soroalbumina Bovina/metabolismo , Coloração e Rotulagem , Estreptavidina/metabolismo
11.
Nature ; 583(7816): 469-472, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32408336

RESUMO

A new coronavirus was recently discovered and named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Infection with SARS-CoV-2 in humans causes coronavirus disease 2019 (COVID-19) and has been rapidly spreading around the globe1,2. SARS-CoV-2 shows some similarities to other coronaviruses; however, treatment options and an understanding of how SARS-CoV-2 infects cells are lacking. Here we identify the host cell pathways that are modulated by SARS-CoV-2 and show that inhibition of these pathways prevents viral replication in human cells. We established a human cell-culture model for infection with a clinical isolate of SARS-CoV-2. Using this cell-culture system, we determined the infection profile of SARS-CoV-2 by translatome3 and proteome proteomics at different times after infection. These analyses revealed that SARS-CoV-2 reshapes central cellular pathways such as translation, splicing, carbon metabolism, protein homeostasis (proteostasis) and nucleic acid metabolism. Small-molecule inhibitors that target these pathways prevented viral replication in cells. Our results reveal the cellular infection profile of SARS-CoV-2 and have enabled the identification of drugs that inhibit viral replication. We anticipate that our results will guide efforts to understand the molecular mechanisms that underlie the modulation of host cells after infection with SARS-CoV-2. Furthermore, our findings provide insights for the development of therapies for the treatment of COVID-19.


Assuntos
Betacoronavirus/efeitos dos fármacos , Betacoronavirus/metabolismo , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/metabolismo , Terapia de Alvo Molecular , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/metabolismo , Proteômica , Betacoronavirus/genética , Betacoronavirus/crescimento & desenvolvimento , Células CACO-2 , Carbono/metabolismo , Infecções por Coronavirus/genética , Infecções por Coronavirus/virologia , Avaliação Pré-Clínica de Medicamentos , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Interações Hospedeiro-Patógeno/genética , Humanos , Técnicas In Vitro , Cinética , Pandemias , Pneumonia Viral/genética , Pneumonia Viral/virologia , Biossíntese de Proteínas/efeitos dos fármacos , Proteoma/metabolismo , Proteostase , Processamento de RNA , Fatores de Tempo , Replicação Viral/efeitos dos fármacos
12.
Am J Chin Med ; 48(3): 651-678, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32349518

RESUMO

Cinobufagin is a Na+/K+-ATPase (NKA) inhibitor with excellent anticancer effects to prolong the survival of patients. The purpose of the present study was to clarify the underlying mechanism of the anticancer effects of cinobufagin using overexpression or inhibition of aurora kinase A (AURKA) signaling. First, high expression of Na+/K+-ATPase alpha 1 subunit (ATP1A1) and AURAK resulted in increased malignant transformation in hepatocellular carcinoma (HCC) patients using the cancer genome atlas (TCGA) data and tissue samples. After treatment with cinobufagin, we successfully screened 202, 249, and 335 changing expression proteins in Huh-7 cells under normal, overexpression, and inhibition of AURKA using tandem mass tags (TMT)-labeled quantitative proteomics coupled to 2D liquid chromatography-tandem mass spectrometry (LC-MS/MS). Bioinformatics analysis revealed that these molecules were closely associated with chromosome segregation, DNA damage, and regulation of translation processes. We further confirmed that cinobufagin induced DNA damage and chromosome segregation disorders and suppresses translational processing in oncogenes by decreasing the expression of AURKA, mechanistic target of rapamycin kinase (mTOR), p-mTOR, p-extracellular regulated protein kinases (ERK), eukaryotic translation initiation factor 4E (eIF4E), and p-eIF4E, while increasing the expression of p-eukaryotic translation initiation factor 4E binding protein 1 (4E-BP1) (S65, T37, T46, T45) and increasing the interaction between eIF4 and 4E-BP1. Our results suggested that cinobufagin performed an antitumor effects in liver cancer cells by inhibiting the AURKA-mTOR-eIF4E axis.


Assuntos
Antineoplásicos Fitogênicos , Aurora Quinase A/metabolismo , Bufanolídeos/farmacologia , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Proteínas de Ligação a DNA/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Biossíntese de Proteínas/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo , Fatores de Transcrição/metabolismo , Segregação de Cromossomos/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Expressão Gênica/efeitos dos fármacos , Oncogenes/genética , ATPase Trocadora de Sódio-Potássio/metabolismo , Células Tumorais Cultivadas
13.
PLoS One ; 15(5): e0231894, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32365111

RESUMO

Stress granules (SG) are cytoplasmic RNA granules that form during various types of stress known to inhibit general translation, including oxidative stress, hypoxia, endoplasmic reticulum stress (ER), ionizing radiations or viral infection. Induction of these SG promotes cell survival in part through sequestration of proapoptotic molecules, resulting in the inactivation of cell death pathways. SG also form in cancer cells, but studies investigating their formation upon treatment with chemotherapeutics are very limited. Here we identified Lapatinib (Tykerb / Tyverb®), a tyrosine kinase inhibitor used for the treatment of breast cancers as a new inducer of SG in breast cancer cells. Lapatinib-induced SG formation correlates with the inhibition of general translation initiation which involves the phosphorylation of the translation initiation factor eIF2α through the kinase PERK. Disrupting PERK-SG formation by PERK depletion experiments sensitizes resistant breast cancer cells to Lapatinib. This study further supports the assumption that treatment with anticancer drugs activates the SG pathway, which may constitute an intrinsic stress response used by cancer cells to resist treatment.


Assuntos
Grânulos Citoplasmáticos/efeitos dos fármacos , Lapatinib/uso terapêutico , Neoplasias/tratamento farmacológico , Biossíntese de Proteínas/efeitos dos fármacos , Linhagem Celular Tumoral , Grânulos Citoplasmáticos/metabolismo , Grânulos Citoplasmáticos/patologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Estresse do Retículo Endoplasmático/genética , Fator de Iniciação 2 em Eucariotos/metabolismo , Humanos , Lapatinib/farmacologia , Células MCF-7 , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patologia , Fosforilação/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genética , eIF-2 Quinase/metabolismo
14.
J Int Soc Sports Nutr ; 17(1): 26, 2020 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-32460884

RESUMO

BACKGROUND: A previous clinical study reported that the addition of an amylopectin/chromium complex (ACr; Velositol®) to 6 g of whey protein (WP) significantly enhanced muscle protein synthesis (MPS). Branched-chain amino acids (BCAAs) are also well-known to enhance MPS. The aim of this study was to determine if the addition of ACr to BCAAs can enhance MPS and activate expression of the mammalian target of the rapamycin (mTOR) pathway compared to BCAAs and exercise alone in exercise-trained rats. METHODS: Twenty-four male Wistar rats were randomly divided into three groups (n = 8 per group): (I) Exercise control, (II) Exercise plus BCAAs (0.465 g/kg BW, a 6 g human equivalent dose (HED)), and (III) Exercise plus BCAAs (0.465 g/kg BW) and ACr (0.155 g/kg BW, a 2 g HED). All animals were trained with treadmill exercise for 10 days. On the day of the single-dose experiment, rats were exercised at 26 m/min for 2 h and then fed, via oral gavage, study product. One hour after the consumption of study product, rats were injected with a bolus dose (250 mg/kg BW, 25 g/L) of phenylalanine labeled with deuterium to measure the fractional rate of protein synthesis (FSR). Ten minutes later, muscle tissue samples were taken to determine MPS measured by FSR and the phosphorylation of proteins involved in the mTOR pathway including mTOR, S6K1, and 4E-BP1. RESULTS: ACr combined with BCAAs increased MPS by 71% compared to the exercise control group, while BCAAs alone increased MPS by 57% over control (p < 0.05). ACr plus BCAAs significantly enhanced phosphorylation of mTOR, S6K1 and 4E-BP1 compared to exercise control rats (p < 0.05). The addition of ACr to BCAAs enhanced insulin levels, mTOR and S6K1 phosphorylation compared to BCAAs alone (p < 0.05). Serum insulin concentration was positively correlated with the levels of mTOR, (r = 0.923), S6K1 (r = 0.814) and 4E-BP1 (r = 0.953). CONCLUSIONS: In conclusion, the results of this study provide evidence that the addition of ACr to BCAAs significantly enhances exercise-induced MPS, and the phosphorylation of mTOR signaling proteins, compared to BCAAs and exercise alone.


Assuntos
Aminoácidos de Cadeia Ramificada/farmacologia , Amilopectina/farmacologia , Cromo/farmacologia , Proteínas Musculares/metabolismo , Músculo Esquelético/metabolismo , Biossíntese de Proteínas/efeitos dos fármacos , Animais , Masculino , Ratos , Ratos Wistar
15.
Nature ; 583(7816): 459-468, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32353859

RESUMO

A newly described coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is the causative agent of coronavirus disease 2019 (COVID-19), has infected over 2.3 million people, led to the death of more than 160,000 individuals and caused worldwide social and economic disruption1,2. There are no antiviral drugs with proven clinical efficacy for the treatment of COVID-19, nor are there any vaccines that prevent infection with SARS-CoV-2, and efforts to develop drugs and vaccines are hampered by the limited knowledge of the molecular details of how SARS-CoV-2 infects cells. Here we cloned, tagged and expressed 26 of the 29 SARS-CoV-2 proteins in human cells and identified the human proteins that physically associated with each of the SARS-CoV-2 proteins using affinity-purification mass spectrometry, identifying 332 high-confidence protein-protein interactions between SARS-CoV-2 and human proteins. Among these, we identify 66 druggable human proteins or host factors targeted by 69 compounds (of which, 29 drugs are approved by the US Food and Drug Administration, 12 are in clinical trials and 28 are preclinical compounds). We screened a subset of these in multiple viral assays and found two sets of pharmacological agents that displayed antiviral activity: inhibitors of mRNA translation and predicted regulators of the sigma-1 and sigma-2 receptors. Further studies of these host-factor-targeting agents, including their combination with drugs that directly target viral enzymes, could lead to a therapeutic regimen to treat COVID-19.


Assuntos
Betacoronavirus/efeitos dos fármacos , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/metabolismo , Reposicionamento de Medicamentos , Terapia de Alvo Molecular , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/metabolismo , Mapas de Interação de Proteínas , Proteínas Virais/metabolismo , Animais , Antivirais/classificação , Antivirais/farmacologia , Betacoronavirus/genética , Betacoronavirus/metabolismo , Betacoronavirus/patogenicidade , Chlorocebus aethiops , Clonagem Molecular , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Avaliação Pré-Clínica de Medicamentos , Células HEK293 , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Humanos , Imunidade Inata , Espectrometria de Massas , Pandemias , Pneumonia Viral/imunologia , Pneumonia Viral/virologia , Ligação Proteica , Biossíntese de Proteínas/efeitos dos fármacos , Domínios Proteicos , Mapeamento de Interação de Proteínas , Receptores sigma/metabolismo , Proteínas Ligases SKP Culina F-Box/metabolismo , Células Vero , Proteínas Virais/genética
16.
Nucleic Acids Res ; 48(10): 5201-5216, 2020 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-32382758

RESUMO

High-throughput methods, such as ribosome profiling, have revealed the complexity of translation regulation in Bacteria and Eukarya with large-scale effects on cellular functions. In contrast, the translational landscape in Archaea remains mostly unexplored. Here, we developed ribosome profiling in a model archaeon, Haloferax volcanii, elucidating, for the first time, the translational landscape of a representative of the third domain of life. We determined the ribosome footprint of H. volcanii to be comparable in size to that of the Eukarya. We linked footprint lengths to initiating and elongating states of the ribosome on leadered transcripts, operons, and on leaderless transcripts, the latter representing 70% of H. volcanii transcriptome. We manipulated ribosome activity with translation inhibitors to reveal ribosome pausing at specific codons. Lastly, we found that the drug harringtonine arrested ribosomes at initiation sites in this archaeon. This drug treatment allowed us to confirm known translation initiation sites and also reveal putative novel initiation sites in intergenic regions and within genes. Ribosome profiling revealed an uncharacterized complexity of translation in this archaeon with bacteria-like, eukarya-like, and potentially novel translation mechanisms. These mechanisms are likely to be functionally essential and to contribute to an expanded proteome with regulatory roles in gene expression.


Assuntos
Códon/metabolismo , Haloferax volcanii/genética , Haloferax volcanii/metabolismo , Biossíntese de Proteínas , Ribossomos/metabolismo , Regiões 5' não Traduzidas/genética , Códon/genética , Haloferax volcanii/efeitos dos fármacos , Harringtoninas/farmacologia , Elongação Traducional da Cadeia Peptídica/efeitos dos fármacos , Elongação Traducional da Cadeia Peptídica/genética , Iniciação Traducional da Cadeia Peptídica/efeitos dos fármacos , Iniciação Traducional da Cadeia Peptídica/genética , Biossíntese de Proteínas/efeitos dos fármacos , Pegadas de Proteínas , Fases de Leitura/genética , Ribossomos/efeitos dos fármacos , Transcriptoma/efeitos dos fármacos
17.
Nat Commun ; 11(1): 1990, 2020 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-32332749

RESUMO

Up-regulation of utrophin in muscles represents a promising therapeutic strategy for the treatment of Duchenne Muscular Dystrophy. We previously demonstrated that eEF1A2 associates with the 5'UTR of utrophin A to promote IRES-dependent translation. Here, we examine whether eEF1A2 directly regulates utrophin A expression and identify via an ELISA-based high-throughput screen, FDA-approved drugs that upregulate both eEF1A2 and utrophin A. Our results show that transient overexpression of eEF1A2 in mouse muscles causes an increase in IRES-mediated translation of utrophin A. Through the assessment of our screen, we reveal 7 classes of FDA-approved drugs that increase eEF1A2 and utrophin A protein levels. Treatment of mdx mice with the 2 top leads results in multiple improvements of the dystrophic phenotype. Here, we report that IRES-mediated translation of utrophin A via eEF1A2 is a critical mechanism of regulating utrophin A expression and reveal the potential of repurposed drugs for treating DMD via this pathway.


Assuntos
Distrofia Muscular de Duchenne/tratamento farmacológico , Fator 1 de Elongação de Peptídeos/antagonistas & inibidores , Biossíntese de Proteínas/efeitos dos fármacos , Utrofina/genética , Regiões 5' não Traduzidas/genética , Animais , Betaxolol/farmacologia , Betaxolol/uso terapêutico , Linhagem Celular , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Reposicionamento de Medicamentos , Humanos , Sítios Internos de Entrada Ribossomal/genética , Camundongos , Camundongos Endogâmicos mdx , Camundongos Knockout , Distrofia Muscular de Duchenne/genética , Mioblastos , Fator 1 de Elongação de Peptídeos/genética , Fator 1 de Elongação de Peptídeos/metabolismo , Pravastatina/farmacologia , Pravastatina/uso terapêutico , Biossíntese de Proteínas/genética , Regulação para Cima/efeitos dos fármacos , Utrofina/metabolismo
18.
RNA ; 26(6): 715-723, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32144191

RESUMO

Macrolides are one of the most successful and widely used classes of antibacterials, which kill or stop the growth of pathogenic bacteria by binding near the active site of the ribosome and interfering with protein synthesis. Dirithromycin is a derivative of the prototype macrolide erythromycin with additional hydrophobic side chain. In our recent study, we have discovered that the side chain of dirithromycin forms lone pair-π stacking interaction with the aromatic imidazole ring of the His69 residue in ribosomal protein uL4 of the Thermus thermophilus 70S ribosome. In the current work, we found that neither the presence of the side chain, nor the additional contact with the ribosome, improve the binding affinity of dirithromycin to the ribosome. Nevertheless, we found that dirithromycin is a more potent inhibitor of in vitro protein synthesis in comparison with its parent compound, erythromycin. Using high-resolution cryo-electron microscopy, we determined the structure of the dirithromycin bound to the translating Escherichia coli 70S ribosome, which suggests that the better inhibitory properties of the drug could be rationalized by the side chain of dirithromycin pointing into the lumen of the nascent peptide exit tunnel, where it can interfere with the normal passage of the growing polypeptide chain.


Assuntos
Antibacterianos/química , Eritromicina/análogos & derivados , Inibidores da Síntese de Proteínas/química , Ribossomos/química , Antibacterianos/farmacologia , Microscopia Crioeletrônica , Eritromicina/química , Eritromicina/farmacologia , Escherichia coli/genética , Modelos Moleculares , Biossíntese de Proteínas/efeitos dos fármacos , Inibidores da Síntese de Proteínas/farmacologia , RNA Ribossômico 23S/química
19.
Stroke ; 51(5): 1570-1577, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32212900

RESUMO

Background and Purpose- Ischemic stroke impairs endoplasmic reticulum (ER) function, causes ER stress, and activates the unfolded protein response. The unfolded protein response consists of 3 branches controlled by ER stress sensor proteins, which include PERK (protein kinase RNA-like ER kinase). Activated PERK phosphorylates eIF2α (eukaryotic initiation factor 2 alpha), resulting in inhibition of global protein synthesis. Here, we aimed to clarify the role of the PERK unfolded protein response branch in stroke. Methods- Neuron-specific and tamoxifen-inducible PERK conditional knockout (cKO) mice were generated by cross-breeding Camk2a-CreERT2 with Perkf/f mice. Transient middle cerebral artery occlusion was used to induce stroke. Short- and long-term stroke outcomes were evaluated. Protein synthesis in the brain was assessed using a surface-sensing-of-translation approach. Results- After tamoxifen-induced deletion of Perk in forebrain neurons was confirmed in PERK-cKO mice, PERK-cKO and control mice were subjected to transient middle cerebral artery occlusion and 3 days or 3 weeks recovery. PERK-cKO mice had larger infarcts and worse neurological outcomes compared with control mice, suggesting that PERK-induced eIF2α phosphorylation and subsequent suppression of translation protects neurons from ischemic stress. Indeed, better stroke outcomes were observed in PERK-cKO mice that received postischemic treatment with salubrinal, which can restore the ischemia-induced increase in phosphorylated eIF2α in these mice. Finally, our data showed that post-treatment with salubrinal improved functional recovery after stroke. Conclusions- Here, we presented the first evidence that postischemic suppression of translation induced by PERK activation promotes recovery of neurological function after stroke. This confirms and further extends our previous observations that recovery of ER function impaired by ischemic stress critically contributes to stroke outcome. Therefore, future research should include strategies to improve stroke outcome by targeting unfolded protein response branches to restore protein homeostasis in neurons.


Assuntos
Estresse do Retículo Endoplasmático/genética , Fator de Iniciação 2 em Eucariotos/metabolismo , Infarto da Artéria Cerebral Média/metabolismo , Neurônios/metabolismo , Neuroproteção/genética , Resposta a Proteínas não Dobradas/genética , eIF-2 Quinase/genética , Animais , Isquemia Encefálica/metabolismo , Isquemia Encefálica/fisiopatologia , Cinamatos/farmacologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Fator de Iniciação 2 em Eucariotos/efeitos dos fármacos , Infarto da Artéria Cerebral Média/fisiopatologia , Camundongos , Camundongos Knockout , Fosforilação , Biossíntese de Proteínas/efeitos dos fármacos , Biossíntese de Proteínas/genética , Acidente Vascular Cerebral/metabolismo , Acidente Vascular Cerebral/fisiopatologia , Tioureia/análogos & derivados , Tioureia/farmacologia , Resposta a Proteínas não Dobradas/efeitos dos fármacos
20.
RNA ; 26(5): 541-549, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32014999

RESUMO

The PI3K/Akt/mTOR kinase pathway is extensively deregulated in human cancers. One critical node under regulation of this signaling axis is eukaryotic initiation factor (eIF) 4F, a complex involved in the control of translation initiation rates. eIF4F-dependent addictions arise during tumor initiation and maintenance due to increased eIF4F activity-generally in response to elevated PI3K/Akt/mTOR signaling flux. There is thus much interest in exploring eIF4F as a small molecule target for the development of new anticancer drugs. The DEAD-box RNA helicase, eIF4A, is an essential subunit of eIF4F, and several potent small molecules (rocaglates, hippuristanol, pateamine A) affecting its activity have been identified and shown to demonstrate anticancer activity in vitro and in vivo in preclinical models. Recently, a number of new small molecules have been reported as having the capacity to target and inhibit eIF4A. Here, we undertook a comparative analysis of their biological activity and specificity relative to the eIF4A inhibitor, hippuristanol.


Assuntos
Antineoplásicos/química , Fator de Iniciação 4A em Eucariotos/química , Neoplasias/tratamento farmacológico , Bibliotecas de Moléculas Pequenas/química , Esteróis/química , Antineoplásicos/farmacologia , Benzofuranos/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Compostos de Epóxi/química , Fator de Iniciação 4A em Eucariotos/antagonistas & inibidores , Fator de Iniciação 4F em Eucariotos/antagonistas & inibidores , Fator de Iniciação 4F em Eucariotos/química , Humanos , Macrolídeos/química , Neoplasias/genética , Fosfatidilinositol 3-Quinases/genética , Biossíntese de Proteínas/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/genética , Bibliotecas de Moléculas Pequenas/farmacologia , Esteróis/farmacologia , Serina-Treonina Quinases TOR/genética , Tiazóis/química
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