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1.
Nat Commun ; 11(1): 4990, 2020 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-33020478

RESUMO

Neurons are highly compartmentalized cells with tightly controlled subcellular protein organization. While brain transcriptome, connectome and global proteome maps are being generated, system-wide analysis of temporal protein dynamics at the subcellular level are currently lacking. Here, we perform a temporally-resolved surfaceome analysis of primary neuron cultures and reveal dynamic surface protein clusters that reflect the functional requirements during distinct stages of neuronal development. Direct comparison of surface and total protein pools during development and homeostatic synaptic scaling demonstrates system-wide proteostasis-independent remodeling of the neuronal surface, illustrating widespread regulation on the level of surface trafficking. Finally, quantitative analysis of the neuronal surface during chemical long-term potentiation (cLTP) reveals fast externalization of diverse classes of surface proteins beyond the AMPA receptor, providing avenues to investigate the requirement of exocytosis for LTP. Our resource (neurosurfaceome.ethz.ch) highlights the importance of subcellular resolution for systems-level understanding of cellular processes.


Assuntos
Proteínas de Membrana/metabolismo , Plasticidade Neuronal , Neurônios/metabolismo , Sinapses/metabolismo , Animais , Membrana Celular/metabolismo , Células Cultivadas , Potenciais Pós-Sinápticos Excitadores , Homeostase , Potenciação de Longa Duração , Mapas de Interação de Proteínas , Transporte Proteico , Proteostase , Ratos
2.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 28(5): 1704-1709, 2020 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-33067978

RESUMO

OBJECTIVE: To investigate the role of mitochonaria in the regulation of platelet membrane protein GPIbα shedding and its mechanisms. METHODS: The washed platelets were obtained from peripheral blood in healthy volunteers and co-incubated with mitochondrial inhibitor carbonyl cyanide m-chlorophenyl hydrazone (CCCP), mitochondrial protector cyclosporin A (CsA) or matrix metalloproteinases inhibitor GM6001. After the platelets was stimulated, the effect of mitochondria to the shedding in platelet membrane protein GPIbα was detected by flow cytometry. RESULTS: Depolarization of mitochondrial membrane potential and the respiratory function of mitochondrial could be induced and destroyed by the uncoupling agent CCCP. At the same time, the shedding of GPIbα was detected out, and the result showed a statistical significance, which showed that the shedding of GPIbα could be activated by the damaged of mitochondrial in platelets. After the mitochondrial was protected by CsA, the shedding of GPIbα was inhibited significantly. GM6001 could only inhibited the shedding of GPIbα, but showed no inhibitation to the function of mitochondrial, which showed that the shedding of GPIbα was regulated at the mitochondrial, and the regulatory enzyme of receptor shedding (ADAM17) was located in the pathway of downstream of mitochondria. After the oxidative damage in cells was inhibited by NAC, and the changes of GPIbα shedding was detected, the result showed that the GPIbα shedding could be inhibited by NAC, which showed a dose-dependent manner. CONCLUSION: The GPIbα shedding could be caused by abnormality function of metabolic, and the metabolic imbalance of ROS is caused by the abnormallity function of mitochondria.


Assuntos
Plaquetas , Proteínas de Membrana , Humanos , Proteínas de Membrana/metabolismo , Mitocôndrias
3.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 28(5): 1710-1717, 2020 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-33067979

RESUMO

AbstractObjective: To investigate the effect of ALAS2 downregulation on the expression of BNIP3L and erythroid differentiation in K562 cells. METHODS: The expression of ALAS2 was down-regulated by transfection of lentivirus, then quantitative real-time PCR was performed to detect the transfection efficiency. Flow cytometry analysis was applied to evaluate apoptosis of cells, erythroid differentiation, mitochondrial membrane potential and reactive oxygen species (ROS) level. Western blot was used to detect the BNIP3L expression, Co-immunoprecipitation was performed to analyze the relationship between ALAS2 and BNIP3L. RESULTS: Compared with sh-NC group, knockdown of ALAS2 induced downregulation of BNIP3L mRNA and protein expression(P<0.01) and erythroid related transcription factors GATA1, Nrf2 expression, as well as reduction of ROS level(P<0.05). Mitochondrial membrane potential of control (sh-NC) group was lower than that of shALAS2 group(P<0.05), but there was no significant change of cell apoptotic rate in two groups. CD71highCD235ahigh + CD71lowCD235ahigh cells of sh-NC and shALAS2 groups were 53.5%, 92.9% at 96 h after hemin induction, respectively. No direct action between ALAS2 and BNIP3L was observed. CONCLUSION: The intracellular heme level can affect the expression of BNIP3L which may be related with the regulation of ROS and transcription factors GATA1 and Nrf2. Higher BNIP3L facilitates cell differentiation but lower BNIP3L is favorable for cells survival.


Assuntos
Proteínas de Transporte , Mitofagia , 5-Aminolevulinato Sintetase/metabolismo , Apoptose , Diferenciação Celular , Humanos , Células K562 , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Proteínas Proto-Oncogênicas/genética , Proteínas Supressoras de Tumor
4.
Nat Commun ; 11(1): 4913, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-33004813

RESUMO

Reprograming of proline metabolism is critical for tumor growth. Here we show that PINCH-1 is highly expressed in lung adenocarcinoma and promotes proline synthesis through regulation of mitochondrial dynamics. Knockout (KO) of PINCH-1 increases dynamin-related protein 1 (DRP1) expression and mitochondrial fragmentation, which suppresses kindlin-2 mitochondrial translocation and interaction with pyrroline-5-carboxylate reductase 1 (PYCR1), resulting in inhibition of proline synthesis and cell proliferation. Depletion of DRP1 reverses PINCH-1 deficiency-induced defects on mitochondrial dynamics, proline synthesis and cell proliferation. Furthermore, overexpression of PYCR1 in PINCH-1 KO cells restores proline synthesis and cell proliferation, and suppresses DRP1 expression and mitochondrial fragmentation. Finally, ablation of PINCH-1 from lung adenocarcinoma in mouse increases DRP1 expression and inhibits PYCR1 expression, proline synthesis, fibrosis and tumor growth. Our results identify a signaling axis consisting of PINCH-1, DRP1 and PYCR1 that regulates mitochondrial dynamics and proline synthesis, and suggest an attractive strategy for alleviation of tumor growth.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Adenocarcinoma de Pulmão/patologia , Proteínas com Domínio LIM/metabolismo , Neoplasias Pulmonares/patologia , Proteínas de Membrana/metabolismo , Células A549 , Proteínas Adaptadoras de Transdução de Sinal/genética , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/mortalidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Proliferação de Células/genética , Proteínas do Citoesqueleto/metabolismo , Modelos Animais de Doenças , Dinaminas/metabolismo , Feminino , Técnicas de Inativação de Genes , Humanos , Proteínas com Domínio LIM/genética , Pulmão/citologia , Pulmão/patologia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/mortalidade , Masculino , Proteínas de Membrana/genética , Camundongos , Camundongos Transgênicos , Pessoa de Meia-Idade , Mitocôndrias/metabolismo , Dinâmica Mitocondrial , Proteínas Musculares/metabolismo , Proteínas de Neoplasias/metabolismo , Prolina/biossíntese , Proteínas Proto-Oncogênicas p21(ras)/genética , Pirrolina Carboxilato Redutases/metabolismo , Análise de Sobrevida
5.
Nat Commun ; 11(1): 5065, 2020 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-33033237

RESUMO

The type VI protein secretion system (T6SS) is a powerful needle-like machinery found in Gram-negative bacteria that can penetrate the cytosol of receiving cells in milliseconds by physical force. Anchored by its membrane-spanning complex (MC) and a baseplate (BP), the T6SS sheath-tube is assembled in a stepwise process primed by TssA and terminated by TagA. However, the molecular details of its assembly remain elusive. Here, we systematically examined the initiation and termination of contractile and non-contractile T6SS sheaths in MC-BP, tssA and tagA mutants by fluorescence microscopy. We observe long pole-to-pole sheath-tube structures in the non-contractile MC-BP defective mutants but not in the Hcp tube or VgrG spike mutants. Combining overexpression and genetic mutation data, we demonstrate complex effects of TssM, TssA and TagA interactions on T6SS sheath-tube dynamics. We also report promiscuous interactions of TagA with multiple T6SS components, similar to TssA. Our results demonstrate that priming of the T6SS sheath-tube assembly is not dependent on TssA, nor is the assembly termination dependent on the distal end TssA-TagA interaction, and highlight the tripartite control of TssA-TssM-TagA on sheath-tube initiation and termination.


Assuntos
Proteínas de Bactérias/metabolismo , Sistemas de Secreção Tipo VI/metabolismo , Vibrio cholerae/metabolismo , Proteínas de Bactérias/química , Membrana Celular/metabolismo , Escherichia coli/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Proteínas de Membrana/metabolismo , Viabilidade Microbiana , Modelos Biológicos , Mutação/genética , Ligação Proteica , Domínios Proteicos
6.
Nat Commun ; 11(1): 4866, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32978391

RESUMO

Mitochondria house evolutionarily conserved pathways of carbon and nitrogen metabolism that drive cellular energy production. Mitochondrial bioenergetics is regulated by calcium uptake through the mitochondrial calcium uniporter (MCU), a multi-protein complex whose assembly in the inner mitochondrial membrane is facilitated by the scaffold factor MCUR1. Intriguingly, many fungi that lack MCU contain MCUR1 homologs, suggesting alternate functions. Herein, we characterize Saccharomyces cerevisiae homologs Put6 and Put7 of MCUR1 as regulators of mitochondrial proline metabolism. Put6 and Put7 are tethered to the inner mitochondrial membrane in a large hetero-oligomeric complex, whose abundance is regulated by proline. Loss of this complex perturbs mitochondrial proline homeostasis and cellular redox balance. Yeast cells lacking either Put6 or Put7 exhibit a pronounced defect in proline utilization, which can be corrected by the heterologous expression of human MCUR1. Our work uncovers an unexpected role of MCUR1 homologs in mitochondrial proline metabolism.


Assuntos
Proteínas de Membrana/metabolismo , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Prolina/metabolismo , Saccharomyces cerevisiae/metabolismo , Canais de Cálcio , Regulação Fúngica da Expressão Gênica , Genes Fúngicos/genética , Homeostase , Humanos , Proteínas de Membrana/genética , Redes e Vias Metabólicas/genética , Membranas Mitocondriais/metabolismo , Proteínas Mitocondriais/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento , Transcriptoma
7.
Maturitas ; 140: 64-71, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32972637

RESUMO

OBJECTIVES: Progesterone receptor membrane component-1 (PGRMC1) in breast cancer tissue has been suggested to predict a worse prognosis. The aim of this study was to assess for the first time whether PGRMC1 expressed in cancer tissue is associated with PGRMC1 blood concentrations and whether both are correlated with clinical tumour characteristics known to predict a worse outcome. METHODS: In total, 201 patients with invasive breast cancer and 65 with benign breast disease (control group) were recruited. PGRMC1 blood concentrations were measured by a recently developed ELISA, PGRMC1 in breast cancer tissue was assessed by immunohistochemistry, and the correlation between the two was calculated. Receiver-operating characteristic (ROC) curve analysis was used to assess area under the curve (AUC). Furthermore, PGRMC1 was correlated with tumour characteristics such as tumour diameter, tumour grade and metastatic status, and with known blood tumour markers. RESULTS: AUC for the breast cancer group was 0.713, which was significantly higher than in the control group (p < 0.01). Blood PGRMC1 concentrations had a strong (positive) correlation with tissue PGRMC1 expression (p < 0.01) but were not associated with serum tumour markers CEA, CA125, CA153 and TPS. Tissue PGRMC1, ER and cancer stage were positively associated with blood PGRMC1 (p < 0.05). CONCLUSIONS: As PGRMC1 expression levels in cancer tissue were significantly correlated with PGRMC1 in blood, and because concentrations in blood were also positively associated with breast tumour characteristics known to predict a worse prognosis, PGRMC1 may be valuable as a new tumour marker and may be superior to known tumour markers such as CEA, CA125, CA153 and TPS.


Assuntos
Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama , Proteínas de Membrana/sangue , Proteínas de Membrana/metabolismo , Receptores de Progesterona/sangue , Receptores de Progesterona/metabolismo , Adulto , Idoso , Neoplasias da Mama/sangue , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Adulto Jovem
8.
Am J Physiol Lung Cell Mol Physiol ; 319(4): L670-L674, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32878480

RESUMO

The severity of coronavirus disease 2019 (COVID-19) is linked to an increasing number of risk factors, including exogenous (environmental) stimuli such as air pollution, nicotine, and cigarette smoke. These three factors increase the expression of angiotensin I converting enzyme 2 (ACE2), a key receptor involved in the entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-the etiological agent of COVID-19-into respiratory tract epithelial cells. Patients with severe COVID-19 are managed with oxygen support, as are at-risk individuals with chronic lung disease. To date, no study has examined whether an increased fraction of inspired oxygen (FiO2) may affect the expression of SARS-CoV-2 entry receptors and co-receptors, including ACE2 and the transmembrane serine proteases TMPRSS1, TMPRSS2, and TMPRSS11D. To address this, steady-state mRNA levels for genes encoding these SARS-CoV-2 receptors were assessed in the lungs of mouse pups chronically exposed to elevated FiO2, and in the lungs of preterm-born human infants chronically managed with an elevated FiO2. These two scenarios served as models of chronic elevated FiO2 exposure. Additionally, SARS-CoV-2 receptor expression was assessed in primary human nasal, tracheal, esophageal, bronchial, and alveolar epithelial cells, as well as primary mouse alveolar type II cells exposed to elevated oxygen concentrations. While gene expression of ACE2 was unaffected, gene and protein expression of TMPRSS11D was consistently upregulated by exposure to an elevated FiO2. These data highlight the need for further studies that examine the relative contribution of the various viral co-receptors on the infection cycle, and point to oxygen supplementation as a potential risk factor for COVID-19.


Assuntos
Infecções por Coronavirus/patologia , Proteínas de Membrana/metabolismo , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/patologia , Mucosa Respiratória/metabolismo , Serina Endopeptidases/metabolismo , Serina Proteases/metabolismo , Células Epiteliais Alveolares/metabolismo , Animais , Betacoronavirus , Células Cultivadas , Feminino , Humanos , Masculino , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Oxigênio/administração & dosagem , Oxigênio/análise , Pandemias , Receptores Virais/metabolismo , Fatores de Risco , Serina Endopeptidases/genética , Serina Proteases/genética , Índice de Gravidade de Doença
9.
PLoS One ; 15(9): e0237743, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32911484

RESUMO

The cGAS/STING pathway initiates an innate immune response when DNA is detected in the cytosol. DNA bound cGAS synthesizes cyclic dinucleotides which bind and activate the adaptor STING, leading to downstream secretion of Type I interferons and other pro-inflammatory NFκB pathway cytokines. In the mouse, the STING driven innate immune response is central to immune based clearance of various tumors and this has triggered a significant effort focused on the discovery of human STING agonists for the treatment of cancer. This report uses an in vitro kinase assay to show that G10, a previously identified STING pathway activator is actually a weak but direct STING agonist and identifies other more potent leads.


Assuntos
Proteínas de Membrana/metabolismo , Animais , Retículo Endoplasmático/metabolismo , Células HEK293 , Humanos , Fator Regulador 3 de Interferon/metabolismo , Proteínas de Membrana/química , Camundongos , Fosforilação , Domínios Proteicos , Estabilidade Proteica , Transdução de Sinais , Células THP-1
10.
Nat Commun ; 11(1): 4545, 2020 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-32917858

RESUMO

TGF-ß1, ß2 and ß3 bind a common receptor to exert vastly diverse effects in cancer, supporting either tumor progression by favoring metastases and inhibiting anti-tumor immunity, or tumor suppression by inhibiting malignant cell proliferation. Global TGF-ß inhibition thus bears the risk of undesired tumor-promoting effects. We show that selective blockade of TGF-ß1 production by Tregs with antibodies against GARP:TGF-ß1 complexes induces regressions of mouse tumors otherwise resistant to anti-PD-1 immunotherapy. Effects of combined GARP:TGF-ß1/PD-1 blockade are immune-mediated, do not require FcγR-dependent functions and increase effector functions of anti-tumor CD8+ T cells without augmenting immune cell infiltration or depleting Tregs within tumors. We find GARP-expressing Tregs and evidence that they produce TGF-ß1 in one third of human melanoma metastases. Our results suggest that anti-GARP:TGF-ß1 mAbs, by selectively blocking a single TGF-ß isoform emanating from a restricted cellular source exerting tumor-promoting activity, may overcome resistance to PD-1/PD-L1 blockade in patients with cancer.


Assuntos
Antineoplásicos Imunológicos/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Proteínas de Membrana/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Fator de Crescimento Transformador beta1/antagonistas & inibidores , Animais , Antineoplásicos Imunológicos/uso terapêutico , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/imunologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Linhagem Celular Tumoral/transplante , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Resistencia a Medicamentos Antineoplásicos/imunologia , Células HEK293 , Humanos , Proteínas de Membrana/metabolismo , Camundongos , Neoplasias/imunologia , Neoplasias/patologia , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/imunologia , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Fator de Crescimento Transformador beta1/metabolismo
11.
DNA Cell Biol ; 39(10): 1895-1906, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32882141

RESUMO

Acute aortic dissection (AD) is one of the most severe and highly mortality vascular disease. Its actual prevalence may be seriously underestimated. We studied different expression genes to understand gene profile change between acute AD and nondiseased individuals, and then discover potential biomarkers and therapeutic targets of acute AD. In our study, acute AD differentially expressed mRNAs and miRNAs were identified through bioinformatics analysis on Gene Expression Omnibus data sets GSE52093, GSE98770, and GSE92427. Then, comprehensive target prediction and network analysis methods were used to evaluate protein-protein interaction networks and to identify Gene Ontology terms for differentially expressed mRNAs. Differentially expressed mRNAs-miRNAs involved in acute AD were assessed as well. Finally, the quantitative real-time PCR and in vitro experiment was used to validate the results. We found Integral Membrane Protein 2C (ITM2C) was low expressed and miR-107-5p was highly expressed in acute AD tissues. Meanwhile, overexpression miR-107-5p promoted the cell proliferation and inhibited the cell apoptosis in RASMC cells. miR-107-5p inhibited the progression of acute AD through targeted ITM2C.


Assuntos
Aneurisma Dissecante/genética , MicroRNAs/genética , Aneurisma Dissecante/metabolismo , Aneurisma Dissecante/patologia , Animais , Apoptose , Biomarcadores/metabolismo , Proliferação de Células , Células Cultivadas , Redes Reguladoras de Genes , Humanos , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , MicroRNAs/metabolismo , Miócitos de Músculo Liso/metabolismo , Mapas de Interação de Proteínas , Ratos , Transcriptoma
12.
Mol Cell ; 80(1): 72-86.e7, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32910895

RESUMO

Membrane protein biogenesis faces the challenge of chaperoning hydrophobic transmembrane helices for faithful membrane insertion. The guided entry of tail-anchored proteins (GET) pathway targets and inserts tail-anchored (TA) proteins into the endoplasmic reticulum (ER) membrane with an insertase (yeast Get1/Get2 or mammalian WRB/CAML) that captures the TA from a cytoplasmic chaperone (Get3 or TRC40, respectively). Here, we present cryo-electron microscopy reconstructions, native mass spectrometry, and structure-based mutagenesis of human WRB/CAML/TRC40 and yeast Get1/Get2/Get3 complexes. Get3 binding to the membrane insertase supports heterotetramer formation, and phosphatidylinositol binding at the heterotetramer interface stabilizes the insertase for efficient TA insertion in vivo. We identify a Get2/CAML cytoplasmic helix that forms a "gating" interaction with Get3/TRC40 important for TA insertion. Structural homology with YidC and the ER membrane protein complex (EMC) implicates an evolutionarily conserved insertion mechanism for divergent substrates utilizing a hydrophilic groove. Thus, we provide a detailed structural and mechanistic framework to understand TA membrane insertion.


Assuntos
Proteínas de Membrana/biossíntese , Proteínas de Membrana/química , Complexos Multiproteicos/metabolismo , Linhagem Celular , Sequência Conservada , Evolução Molecular , Humanos , Proteínas de Membrana/metabolismo , Modelos Moleculares , Fosfatidilinositóis/metabolismo , Ligação Proteica , Multimerização Proteica , Estabilidade Proteica , Estrutura Secundária de Proteína , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo
13.
Nat Commun ; 11(1): 4765, 2020 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-32958780

RESUMO

Fatty acids (FAs) are essential nutrients, but how they are transported into cells remains unclear. Here, we show that FAs trigger caveolae-dependent CD36 internalization, which in turn delivers FAs into adipocytes. During the process, binding of FAs to CD36 activates its downstream kinase LYN, which phosphorylates DHHC5, the palmitoyl acyltransferase of CD36, at Tyr91 and inactivates it. CD36 then gets depalmitoylated by APT1 and recruits another tyrosine kinase SYK to phosphorylate JNK and VAVs to initiate endocytic uptake of FAs. Blocking CD36 internalization by inhibiting APT1, LYN or SYK abolishes CD36-dependent FA uptake. Restricting CD36 at either palmitoylated or depalmitoylated state eliminates its FA uptake activity, indicating an essential role of dynamic palmitoylation of CD36. Furthermore, blocking endocytosis by targeting LYN or SYK inhibits CD36-dependent lipid droplet growth in adipocytes and high-fat-diet induced weight gain in mice. Our study has uncovered a dynamic palmitoylation-regulated endocytic pathway to take up FAs.


Assuntos
Antígenos CD36/metabolismo , Endocitose/fisiologia , Ácidos Graxos/metabolismo , Lipoilação , Células 3T3-L1 , Aciltransferases/metabolismo , Adipócitos/metabolismo , Animais , Antígenos CD36/deficiência , Antígenos CD36/genética , Cavéolas/metabolismo , Células Cultivadas , Dieta Hiperlipídica/efeitos adversos , Humanos , Gotículas Lipídicas/metabolismo , Masculino , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mutação , Obesidade/tratamento farmacológico , Fosforilação , Transdução de Sinais , Quinase Syk/antagonistas & inibidores , Quinase Syk/metabolismo , Ganho de Peso/efeitos dos fármacos , Quinases da Família src/antagonistas & inibidores , Quinases da Família src/metabolismo
14.
Nat Commun ; 11(1): 4589, 2020 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-32917887

RESUMO

Mandibuloacral dysplasia syndromes are mainly due to recessive LMNA or ZMPSTE24 mutations, with cardinal nuclear morphological abnormalities and dysfunction. We report five homozygous null mutations in MTX2, encoding Metaxin-2 (MTX2), an outer mitochondrial membrane protein, in patients presenting with a severe laminopathy-like mandibuloacral dysplasia characterized by growth retardation, bone resorption, arterial calcification, renal glomerulosclerosis and severe hypertension. Loss of MTX2 in patients' primary fibroblasts leads to loss of Metaxin-1 (MTX1) and mitochondrial dysfunction, including network fragmentation and oxidative phosphorylation impairment. Furthermore, patients' fibroblasts are resistant to induced apoptosis, leading to increased cell senescence and mitophagy and reduced proliferation. Interestingly, secondary nuclear morphological defects are observed in both MTX2-mutant fibroblasts and mtx-2-depleted C. elegans. We thus report the identification of a severe premature aging syndrome revealing an unsuspected link between mitochondrial composition and function and nuclear morphology, establishing a pathophysiological link with premature aging laminopathies and likely explaining common clinical features.


Assuntos
Acro-Osteólise/metabolismo , Predisposição Genética para Doença/genética , Lipodistrofia/metabolismo , Mandíbula/anormalidades , Proteínas de Membrana/metabolismo , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Acro-Osteólise/diagnóstico por imagem , Acro-Osteólise/genética , Acro-Osteólise/patologia , Senilidade Prematura/genética , Senilidade Prematura/metabolismo , Animais , Apoptose , Caenorhabditis elegans , Proliferação de Células , Criança , Regulação para Baixo , Feminino , Fibroblastos/metabolismo , Fibroblastos/patologia , Regulação da Expressão Gênica , Genótipo , Homozigoto , Humanos , Lipodistrofia/diagnóstico por imagem , Lipodistrofia/genética , Lipodistrofia/patologia , Masculino , Mandíbula/diagnóstico por imagem , Proteínas de Membrana/genética , Metaloendopeptidases , Proteínas de Transporte da Membrana Mitocondrial/genética , Proteínas Mitocondriais/genética , Mutação , Fenótipo , Pele , Sequenciamento Completo do Genoma
15.
PLoS One ; 15(8): e0237514, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32790781

RESUMO

Golgi phosphoprotein 3 (GOLPH3) is a peripheral membrane protein localized at the trans-Golgi network that is also distributed in a large cytosolic pool. GOLPH3 has been involved in several post-Golgi protein trafficking events, but its precise function at the molecular level is not well understood. GOLPH3 is also considered the first oncoprotein of the Golgi apparatus, with important roles in several types of cancer. Yet, it is unknown how GOLPH3 is regulated to achieve its contribution in the mechanisms that lead to tumorigenesis. Binding of GOLPH3 to Golgi membranes depends on its interaction to phosphatidylinositol-4-phosphate. However, an early finding showed that GTP promotes the binding of GOLPH3 to Golgi membranes and vesicles. Nevertheless, it remains largely unknown whether this response is consequence of the function of GTP-dependent regulatory factors, such as proteins of the RAB family of small GTPases. Interestingly, in Drosophila melanogaster the ortholog of GOLPH3 interacts with- and behaves as effector of the ortholog of RAB1. However, there is no experimental evidence implicating GOLPH3 as a possible RAB1 effector in mammalian cells. Here, we show that human GOLPH3 interacted directly with either RAB1A or RAB1B, the two isoforms of RAB1 in humans. The interaction was nucleotide dependent and it was favored with GTP-locked active state variants of these GTPases, indicating that human GOLPH3 is a bona fide effector of RAB1A and RAB1B. Moreover, the expression in cultured cells of the GTP-locked variants resulted in less distribution of GOLPH3 in the Golgi apparatus, suggesting an intriguing model of GOLPH3 regulation.


Assuntos
Complexo de Golgi/metabolismo , Proteínas de Membrana/metabolismo , Proteínas rab1 de Ligação ao GTP/metabolismo , Células HeLa , Humanos , Proteínas de Membrana/genética , Transporte Proteico , Proteínas rab1 de Ligação ao GTP/genética , Rede trans-Golgi
16.
Virology ; 548: 82-92, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32838949

RESUMO

Japanese encephalitis virus (JEV) is an infectious pathogen spreading in a wide range of vertebrate species. Pigs are amplifying hosts of JEV and thought to be maintained in nature predominantly by avian-mosquito cycles. In the innate immune system, interferon-inducible transmembrane protein (IFITM) is a small transmembrane protein family and has been identified as the first line of defense against a broad range of RNA virus invasion. In this paper, we found that swine IFITM (sIFITM) could restrict the replication of both JEV vaccine strain and wild strain NJ-2008. The cysteine S-palmitoylation modification of sIFITM plays important roles in their anti-JEV effects and intracellular distributions. Our findings show the anti-JEV activities of swine interferon-inducible transmembrane proteins and broaden the antiviral spectrum of IFITM protein family. The preliminary exploration of S-palmitoylation modification of sIFITM may contribute to understanding of the antiviral molecular mechanism of sIFITM.


Assuntos
Vírus da Encefalite Japonesa (Espécie)/fisiologia , Encefalite Japonesa/virologia , Proteínas de Membrana/imunologia , Animais , Vírus da Encefalite Japonesa (Espécie)/genética , Lipoilação , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Família Multigênica , Suínos , Replicação Viral
17.
Nat Commun ; 11(1): 4012, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32782388

RESUMO

Transmembrane B cell lymphoma 2-associated X protein inhibitor motif-containing (TMBIM) 6, a Ca2+ channel-like protein, is highly up-regulated in several cancer types. Here, we show that TMBIM6 is closely associated with survival in patients with cervical, breast, lung, and prostate cancer. TMBIM6 deletion or knockdown suppresses primary tumor growth. Further, mTORC2 activation is up-regulated by TMBIM6 and stimulates glycolysis, protein synthesis, and the expression of lipid synthesis genes and glycosylated proteins. Moreover, ER-leaky Ca2+ from TMBIM6, a unique characteristic, is shown to affect mTORC2 assembly and its association with ribosomes. In addition, we identify that the BIA compound, a potentialTMBIM6 antagonist, prevents TMBIM6 binding to mTORC2, decreases mTORC2 activity, and also regulates TMBIM6-leaky Ca2+, further suppressing tumor formation and progression in cancer xenograft models. This previously unknown signaling cascade in which mTORC2 activity is enhanced via the interaction with TMBIM6 provides potential therapeutic targets for various malignancies.


Assuntos
Proteínas Reguladoras de Apoptose/antagonistas & inibidores , Indenos/farmacologia , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo , Proteínas de Membrana/antagonistas & inibidores , Neoplasias/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Cálcio/metabolismo , Linhagem Celular Tumoral , Transformação Celular Neoplásica/efeitos dos fármacos , Retículo Endoplasmático/metabolismo , Humanos , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Neoplasias/genética , Neoplasias/patologia , Ligação Proteica , Ribossomos/metabolismo , Transdução de Sinais , Análise de Sobrevida , Ensaios Antitumorais Modelo de Xenoenxerto , Peixe-Zebra
18.
Nat Commun ; 11(1): 4259, 2020 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-32848156

RESUMO

The plasma membrane is the interface through which cells interact with their environment. Membrane proteins are embedded in the lipid bilayer of the plasma membrane and their function in this context is often linked to their specific location and dynamics within the membrane. However, few methods are available to manipulate membrane protein location at the single-molecule level. Here, we use fluorescent magnetic nanoparticles (FMNPs) to track membrane molecules and to control their movement. FMNPs allow single-particle tracking (SPT) at 10 nm and 5 ms spatiotemporal resolution, and using a magnetic needle, we pull membrane components laterally with femtonewton-range forces. In this way, we drag membrane proteins over the surface of living cells. Doing so, we detect barriers which we could localize to the submembrane actin cytoskeleton by super-resolution microscopy. We present here a versatile approach to probe membrane processes in live cells via the magnetic control of membrane protein motion.


Assuntos
Nanopartículas de Magnetita , Proteínas de Membrana/metabolismo , Citoesqueleto de Actina/metabolismo , Animais , Linhagem Celular , Chlorocebus aethiops , Proteínas de Fluorescência Verde/metabolismo , Campos Magnéticos , Lipídeos de Membrana/metabolismo , Microscopia de Fluorescência , Nanotecnologia , Imagem Individual de Molécula/métodos
19.
Gene ; 761: 145043, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32777530

RESUMO

Tonoplast Intrinsic Proteins (TIPs) constitute a significant class of the aquaporins. The TIPs control water trade among cytosolic and vacuolar compartments and can also transport glycerol, ammonia, urea, hydrogen peroxide, metals/metalloids, and so forth. Additionally, TIPs are engaged with different abiotic stress responses and developmental processes like leaf expansion, root elongation and seed germination. In this study, ten TIP genes in the rice genome were identified from Oryza sativa ssp indica. Among these, representative groups of TIP genes were cloned and sequenced whilst some TIP sequences showed stop codons in the coding region. The secondary structure analysis represented six conserved transmembrane helices along with the inter-helical regions having conserved motifs. The representative three-dimensional tetrameric design of protein sequence of TIP1;1 displayed key features like NPA motifs, aromatic/arginine (ar/R) selectivity filters, and Froger's residues. The vacuolar localization, transmembrane topological properties, and conserved motif analysis of the cloned genes altogether supported their identity as TIPs. An unrooted phylogenetic tree delineated the relatedness of TIPs from Oryza with different species and bunched them into five clades. The promoter analysis uncovered key regulons associated with administering abiotic stress responses. Gene expression studies showed thatTIPsare differentially regulated under salt and drought stress at various time points in shoots and roots of rice. Also, the pattern of expression was found to be significantly variable in five different rice tissues. The heat-map based tissue and stress- specific expression analysis supported the experimental findings. In conclusion, the identification and transcript-level expression studies of TIPs significantly contribute towards the comprehension of their utilitarian significance in the abiotic stress response.


Assuntos
Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Oryza/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Aquaporinas/genética , Aquaporinas/metabolismo , Clonagem Molecular/métodos , Secas , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica de Plantas/genética , Genes de Plantas/genética , Oryza/metabolismo , Filogenia , Folhas de Planta/metabolismo , Cloreto de Sódio/metabolismo , Estresse Fisiológico/genética , Vacúolos/genética , Água/metabolismo
20.
Protein Sci ; 29(10): 2038-2042, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32822073

RESUMO

The Envelope protein (E) is one of the four structural proteins encoded by the genome of SARS-CoV and SARS-CoV-2 Coronaviruses. It is an integral membrane protein, highly expressed in the host cell, which is known to have an important role in Coronaviruses maturation, assembly and virulence. The E protein presents a PDZ-binding motif at its C-terminus. One of the key interactors of the E protein in the intracellular environment is the PDZ containing protein PALS1. This interaction is known to play a key role in the SARS-CoV pathology and suspected to affect the integrity of the lung epithelia. In this paper we measured and compared the affinity of peptides mimicking the E protein from SARS-CoV and SARS-CoV-2 for the PDZ domain of PALS1, through equilibrium and kinetic binding experiments. Our results support the hypothesis that the increased virulence of SARS-CoV-2 compared to SARS-CoV may rely on the increased affinity of its Envelope protein for PALS1.


Assuntos
Betacoronavirus/metabolismo , Infecções por Coronavirus/metabolismo , Proteínas de Membrana/metabolismo , Núcleosídeo-Fosfato Quinase/metabolismo , Pneumonia Viral/metabolismo , Vírus da SARS/metabolismo , Síndrome Respiratória Aguda Grave/metabolismo , Proteínas do Envelope Viral/metabolismo , Sequência de Aminoácidos , Betacoronavirus/química , Sítios de Ligação , Infecções por Coronavirus/virologia , Humanos , Proteínas de Membrana/química , Modelos Moleculares , Núcleosídeo-Fosfato Quinase/química , Domínios PDZ , Pandemias , Peptídeos/química , Peptídeos/metabolismo , Pneumonia Viral/virologia , Ligação Proteica , Vírus da SARS/química , Síndrome Respiratória Aguda Grave/virologia , Proteínas do Envelope Viral/química
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