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1.
Mol Biol (Mosk) ; 53(4): 638-647, 2019.
Artigo em Russo | MEDLINE | ID: mdl-31397437

RESUMO

The ubiquitin-proteasome system (UPS) performs proteolysis of most intracellular proteins. The key components of the UPS are the proteasomes, multi-subunit protein complexes, playing an important role in cellular adaptation to various types of stress. We analyzed the dynamics of the proteasome activity, the content of proteasome subunits, and the expression levels of genes encoding catalytic subunits of proteasomes in the human histiocytic lymphoma U937 cell line immediately, 2, 4, 6, 9, 24, and 48 h after a heat shock (HS). The initial decrease (up to 62%) in the proteasome activity in cellular lysates was revealed, then 10 h after HS the activity began to recover. The amount of proteasomal α-subunits in the cells decreased 2 h after HS, and was restored to 24-48 h after HS. Fluctuations in the levels of mRNAs encoding proteasome catalytic subunits with the maximum expression 2 h after HS and a gradual decrease to 48 h after HS were observed. The average estimated number of mRNA copies per cell ranged from 10 for weakly to 150 for highly expressed proteasome genes. Thus, the recovery efficiency of UPS functionality after HS, which reflects the important role of proteasomes in maintaining cell homeostasis, was evaluated.


Assuntos
Resposta ao Choque Térmico , Complexo de Endopeptidases do Proteassoma/química , Complexo de Endopeptidases do Proteassoma/metabolismo , Subunidades Proteicas/metabolismo , Humanos , Complexo de Endopeptidases do Proteassoma/genética , Subunidades Proteicas/genética , Proteólise , Células U937 , Ubiquitina/metabolismo
2.
BMC Bioinformatics ; 20(Suppl 5): 182, 2019 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-31272390

RESUMO

BACKGROUND: Human immunology studies often rely on the isolation and quantification of cell populations from an input sample based on flow cytometry and related techniques. Such techniques classify cells into populations based on the detection of a pattern of markers. The description of the cell populations targeted in such experiments typically have two complementary components: the description of the cell type targeted (e.g. 'T cells'), and the description of the marker pattern utilized (e.g. CD14-, CD3+). RESULTS: We here describe our attempts to use ontologies to cross-compare cell types and marker patterns (also referred to as gating definitions). We used a large set of such gating definitions and corresponding cell types submitted by different investigators into ImmPort, a central database for immunology studies, to examine the ability to parse gating definitions using terms from the Protein Ontology (PRO) and cell type descriptions, using the Cell Ontology (CL). We then used logical axioms from CL to detect discrepancies between the two. CONCLUSIONS: We suggest adoption of our proposed format for describing gating and cell type definitions to make comparisons easier. We also suggest a number of new terms to describe gating definitions in flow cytometry that are not based on molecular markers captured in PRO, but on forward- and side-scatter of light during data acquisition, which is more appropriate to capture in the Ontology for Biomedical Investigations (OBI). Finally, our approach results in suggestions on what logical axioms and new cell types could be considered for addition to the Cell Ontology.


Assuntos
Ontologias Biológicas , Bases de Dados Factuais , Humanos , Sistema Imunitário/metabolismo , Subunidades Proteicas/metabolismo , Proteínas/metabolismo
3.
Genes Dev ; 33(15-16): 1031-1047, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31196865

RESUMO

Aneuploidy, a condition characterized by chromosome gains and losses, causes reduced fitness and numerous cellular stresses, including increased protein aggregation. Here, we identify protein complex stoichiometry imbalances as a major cause of protein aggregation in aneuploid cells. Subunits of protein complexes encoded on excess chromosomes aggregate in aneuploid cells, which is suppressed when expression of other subunits is coordinately altered. We further show that excess subunits are either degraded or aggregate and that protein aggregation is nearly as effective as protein degradation at lowering levels of excess proteins. Our study explains why proteotoxic stress is a universal feature of the aneuploid state and reveals protein aggregation as a form of dosage compensation to cope with disproportionate expression of protein complex subunits.


Assuntos
Aneuploidia , Citosol/metabolismo , Compensação de Dosagem (Genética)/fisiologia , Agregados Proteicos/genética , Humanos , Complexos Multiproteicos/química , Complexos Multiproteicos/metabolismo , Agregação Patológica de Proteínas , Subunidades Proteicas/metabolismo , Proteólise , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
4.
Biochemistry (Mosc) ; 84(4): 407-415, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31228932

RESUMO

Proton-translocating FOF1-ATP synthase (F-type ATPase, F-ATPase or FOF1) performs ATP synthesis/hydrolysis coupled to proton transport across the membrane in mitochondria, chloroplasts, and most eubacteria. The ATPase activity of the enzyme is suppressed in the absence of protonmotive force by several regulatory mechanisms. The most conserved of these mechanisms is noncompetitive inhibition of ATP hydrolysis by the MgADP complex (ADP-inhibition) which has been found in all the enzymes studied. When MgADP binds without phosphate in the catalytic site, the enzyme enters an inactive state, and MgADP gets locked in the catalytic site and does not exchange with the medium. The degree of ADP-inhibition varies in FOF1 enzymes from different organisms. In the Escherichia coli enzyme, ADP-inhibition is relatively weak and, in contrast to other organisms, is enhanced rather than suppressed by phosphate. In this study, we used site-directed mutagenesis to investigate the role of amino acid residues ß139, ß158, ß189, and ß319 of E. coli FOF1-ATP synthase in the mechanism of ADP-inhibition and its modulation by the protonmotive force. The amino acid residues in these positions differ in the enzymes from beta- and gammaproteobacteria (including E. coli) and FOF1-ATP synthases from other eubacteria, mitochondria, and chloroplasts. The ßN158L substitution produced no effect on the enzyme activity, while substitutions ßF139Y, ßF189L, and ßV319T only slightly affected ATP (1 mM) hydrolysis. However, in a mixture of ATP and ADP, the activity of the mutants was less suppressed than that of the wild-type enzyme. In addition, mutations ßF189L and ßV319T weakened the ATPase activity inhibition by phosphate in the presence of ADP. We suggest that residues ß139, ß189, and ß319 are involved in the mechanism of ADP-inhibition and its modulation by phosphate.


Assuntos
Difosfato de Adenosina/metabolismo , Proteínas de Escherichia coli/metabolismo , Escherichia coli/enzimologia , ATPases Translocadoras de Prótons/metabolismo , Difosfato de Adenosina/química , Trifosfato de Adenosina/metabolismo , Sequência de Aminoácidos , Domínio Catalítico , Proteínas de Escherichia coli/antagonistas & inibidores , Proteínas de Escherichia coli/genética , Cinética , Mutagênese Sítio-Dirigida , Subunidades Proteicas/química , Subunidades Proteicas/metabolismo , Força Próton-Motriz , ATPases Translocadoras de Prótons/antagonistas & inibidores , ATPases Translocadoras de Prótons/genética , Alinhamento de Sequência
5.
Nat Commun ; 10(1): 2393, 2019 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-31160557

RESUMO

Bacterial ClpB and yeast Hsp104 are homologous Hsp100 protein disaggregases that serve critical functions in proteostasis by solubilizing protein aggregates. Two AAA+ nucleotide binding domains (NBDs) power polypeptide translocation through a central channel comprised of a hexameric spiral of protomers that contact substrate via conserved pore-loop interactions. Here we report cryo-EM structures of a hyperactive ClpB variant bound to the model substrate, casein in the presence of slowly hydrolysable ATPγS, which reveal the translocation mechanism. Distinct substrate-gripping interactions are identified for NBD1 and NBD2 pore loops. A trimer of N-terminal domains define a channel entrance that binds the polypeptide substrate adjacent to the topmost NBD1 contact. NBD conformations at the seam interface reveal how ATP hydrolysis-driven substrate disengagement and re-binding are precisely tuned to drive a directional, stepwise translocation cycle.


Assuntos
Trifosfato de Adenosina/análogos & derivados , Caseínas/metabolismo , Endopeptidase Clp/ultraestrutura , Proteínas de Escherichia coli/ultraestrutura , Escherichia coli/metabolismo , Proteínas de Choque Térmico/ultraestrutura , Transporte Proteico , Domínio AAA , Trifosfato de Adenosina/metabolismo , Microscopia Crioeletrônica , Endopeptidase Clp/metabolismo , Proteínas de Escherichia coli/metabolismo , Proteínas de Choque Térmico/metabolismo , Hidrólise , Modelos Moleculares , Peptídeos/metabolismo , Agregados Proteicos , Subunidades Proteicas/metabolismo
6.
Int J Mol Sci ; 20(9)2019 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-31035668

RESUMO

Adhesion is a crucial characteristic of epithelial cells to form barriers to pathogens and toxic substances from the environment. Epithelial cells attach to each other using intercellular junctions on the lateral membrane, including tight and adherent junctions, as well as the Na+,K+-ATPase. Our group has shown that non-adherent chinese hamster ovary (CHO) cells transfected with the canine ß1 subunit become adhesive, and those homotypic interactions amongst ß1 subunits of the Na+,K+-ATPase occur between neighboring epithelial cells. Ouabain, a cardiotonic steroid, binds to the α subunit of the Na+,K+-ATPase, inhibits the pump activity and induces the detachment of epithelial cells when used at concentrations above 300 nM. At nanomolar non-inhibiting concentrations, ouabain affects the adhesive properties of epithelial cells by inducing the expression of cell adhesion molecules through the activation of signaling pathways associated with the α subunit. In this study, we investigated whether the adhesion between ß1 subunits was also affected by ouabain. We used CHO fibroblasts stably expressing the ß1 subunit of the Na+,K+-ATPase (CHO ß1), and studied the effect of ouabain on cell adhesion. Aggregation assays showed that ouabain increased the adhesion between CHO ß1 cells. Immunofluorescence and biotinylation assays showed that ouabain (50 nM) increases the expression of the ß1 subunit of the Na+,K+-ATPase at the cell membrane. We also examined the effect of ouabain on the activation of signaling pathways in CHO ß1 cells, and their subsequent effect on cell adhesion. We found that cSrc is activated by ouabain and, therefore, that it likely regulates the adhesive properties of CHO ß1 cells. Collectively, our findings suggest that the ß1 subunit adhesion is modulated by the expression levels of the Na+,K+-ATPase at the plasma membrane, which is regulated by ouabain.


Assuntos
Adesão Celular/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Ouabaína/farmacologia , Subunidades Proteicas/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Animais , Células CHO , Membrana Celular/metabolismo , Cricetulus , Expressão Gênica , Ligação Proteica , Subunidades Proteicas/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Sódio/metabolismo , ATPase Trocadora de Sódio-Potássio/química , ATPase Trocadora de Sódio-Potássio/genética , Quinases da Família src/metabolismo
7.
Mar Drugs ; 17(5)2019 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-31035425

RESUMO

Nicotinic acetylcholine receptors (nAChRs) are associated with various cancers, but the relation between nAChRs and cervical cancer remains unclear. Therefore, this study investigated the differential expression of nAChR subunits in human cervical cancer cell lines (SiHa, HeLa, and CaSki) and in normal ectocervical cell lines (Ect1/E6E7) at mRNA and protein levels. Two specific nAChR subtype blockers, αO-conotoxin GeXIVA and α-conotoxin TxID, were then selected to treat different human cervical cancer cell lines with specific nAChR subtype overexpression. The results showed that α3, α9, α10, and ß4 nAChR subunits were overexpressed in SiHa cells compared with that in normal cells. α9 and α10 nAChR subunits were overexpressed in CaSki cells. α*-conotoxins that targeted either α9α10 or α3ß4 nAChR were able to significantly inhibit cervical cancer cell proliferation. These findings may provide a basis for new targets for cervical cancer targeted therapy.


Assuntos
Caramujo Conus , Antagonistas Nicotínicos/farmacologia , Receptores Nicotínicos/metabolismo , Neoplasias do Colo do Útero/tratamento farmacológico , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Conotoxinas/farmacologia , Conotoxinas/uso terapêutico , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Antagonistas Nicotínicos/uso terapêutico , Subunidades Proteicas/antagonistas & inibidores , Subunidades Proteicas/metabolismo , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/patologia
8.
Acta Crystallogr F Struct Biol Commun ; 75(Pt 5): 359-367, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31045565

RESUMO

As of 2017, tuberculosis had infected 1.7 billion people (23% of the population of the world) and caused ten million deaths. Mycobacterium tuberculosis (Mtb) is quickly evolving, and new strains are classified as multidrug resistant. Thus, the identification of novel druggable targets is essential to combat the proliferation of these drug-resistant strains. Filamenting temperature-sensitive mutant Z (FtsZ) is a key protein involved in cytokinesis, an important process for Mtb proliferation and viability. FtsZ is required for bacterial cell division because it polymerizes into a structure called the Z-ring, which recruits accessory division proteins to the septum. Here, the crystal structure of the MtbFtsZ protein has been determined to 3.46 Šresolution and is described as a dimer of trimers, with an inter-subunit interface between protomers AB and DE. In this work, a novel conformation of MtbFtsZ is revealed involving the T9 loop and the nucleotide-binding pocket of protomers BC and EF.


Assuntos
Proteínas de Bactérias/química , Proteínas do Citoesqueleto/química , Mycobacterium tuberculosis/química , Subunidades Proteicas/química , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Sítios de Ligação , Divisão Celular , Clonagem Molecular , Cristalografia por Raios X , Proteínas do Citoesqueleto/genética , Proteínas do Citoesqueleto/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Cinética , Modelos Moleculares , Mutação , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Multimerização Proteica , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Homologia Estrutural de Proteína , Temperatura Ambiente
9.
Molecules ; 24(8)2019 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-31018491

RESUMO

This study aimed to investigate the antioxidant activity and release behavior of anthocyanin (ANC) loaded within FA-g-MD wall (ANC-FA-g-MD microcapsule) in vitro. The microencapsulation of ANC was prepared by spray drying and displayed a biphasic release profile. The combination of ANC and FA-g-MD (0.0625-1 mg/mL) showed a higher antioxidant activity than that of both individuals. A possible intermolecular interaction between ANC and FA-g-MD was studied by UV-vis spectra. Intracellular reactive oxygen species (ROS), 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) test, and protein expression of quinone oxidoreductase 1(NQO1), glutathione reductase (GSR) and γ-glutamate cysteine ligase catalytic subunit (γ-GCLC) were measured through human colon cancer cells (HT-29). After a 24-hour incubation of the HT-29, the combinations (0-60 µg/mL) exhibited a high potential to diminish the ROS level. And the distinct upregulated expressions of GCLC and NQO1 of HT-29 were detected after treatment with combinations compared to those of single ones. These results suggested that the ANC-FA-g-MD microcapsules exerts enhanced antioxidant effect with capability of the modulation of GCLC and NQO1.


Assuntos
Antocianinas/farmacologia , Cápsulas/síntese química , Ácidos Cumáricos/química , Portadores de Fármacos , Depuradores de Radicais Livres/farmacologia , Peróxido de Hidrogênio/antagonistas & inibidores , Polissacarídeos/química , Antocianinas/química , Sobrevivência Celular/efeitos dos fármacos , Composição de Medicamentos/métodos , Ativação Enzimática/efeitos dos fármacos , Depuradores de Radicais Livres/química , Regulação da Expressão Gênica , Glutamato-Cisteína Ligase/genética , Glutamato-Cisteína Ligase/metabolismo , Glutationa Redutase/genética , Glutationa Redutase/metabolismo , Células HT29 , Humanos , Peróxido de Hidrogênio/farmacologia , NAD(P)H Desidrogenase (Quinona)/genética , NAD(P)H Desidrogenase (Quinona)/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Subunidades Proteicas/agonistas , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo
10.
Int J Mol Sci ; 20(8)2019 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-31013569

RESUMO

Congenital FXIII deficiency is a rare bleeding disorder in which mutations are detected in F13A1 and F13B genes that express the two subunits of coagulation FXIII, the catalytic FXIII-A, and protective FXIII-B. Mutations in FXIII-B subunit are considerably rarer compared to FXIII-A. Three mutations in the F13B gene have been reported on its structural disulfide bonds. In the present study, we investigate the structural and functional importance of all 20 structural disulfide bonds in FXIII-B subunit. All disulfide bonds were ablated by individually mutating one of its contributory cysteine's, and these variants were transiently expressed in HEK293t cell lines. The expression products were studied for stability, secretion, the effect on oligomeric state, and on FXIII-A activation. The structural flexibility of these disulfide bonds was studied using classical MD simulation performed on a FXIII-B subunit monomer model. All 20 FXIII-B were found to be important for the secretion and stability of the protein since ablation of any of these led to a secretion deficit. However, the degree of effect that the disruption of disulfide bond had on the protein differed between individual disulfide bonds reflecting a functional hierarchy/diversity within these disulfide bonds.


Assuntos
Coagulação Sanguínea , Dissulfetos/química , Fator XIII/química , Subunidades Proteicas/química , Transtornos da Coagulação Sanguínea/sangue , Retículo Endoplasmático/metabolismo , Fator XIII/metabolismo , Humanos , Modelos Moleculares , Conformação Proteica , Multimerização Proteica , Subunidades Proteicas/metabolismo , Relação Estrutura-Atividade
11.
Biomed Res Int ; 2019: 9630793, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30941374

RESUMO

Background: A recombinant BCG strain expressing the genetically detoxified S1 subunit of pertussis toxin 9K/129G (rBCG-S1PT), previously constructed by our research group, demonstrated the ability to develop high protection in mouse models of pertussis challenge which correlated with the induction of a Th1 immune response pattern. The Th1 immune response induced by rBCG-S1PT treatment was also confirmed in the murine orthotopic bladder cancer model, in which the intravesical instillation of rBCG-S1PT resulted in an improved antitumor effect. Based on these observations, we hypothesize that the reengineering of the S1PT expression in BCG could increase the efficiency of the protective Th1 immune response in order to develop a new alternative of immunotherapy in bladder cancer treatment. Objectives: To construct rBCG strains expressing S1PT from extrachromosomal (rBCG-S1PT) and integrative vectors (rBCG-Sli), or their combination, generating the bivalent strain (rBCG-S1+S1i), and to evaluate the respective immunogenicity of rBCG strains in mice. Methods: Mycobacterial plasmids were constructed by cloning the s1pt gene under integrative and extrachromosomal vectors and used to transform BCG, individually or in combination. Antigen expression and localization were confirmed by Western blot. Mice were immunized with wild-type BCG or the rBCG strains, and cytokines quantification and flow cytometry analysis were performed in splenocytes culture stimulated with mycobacterial-specific proteins. Findings: S1PT expression was confirmed in all rBCG strains. The extrachromosomal vector directs S1PT to the cell wall-associated fraction, while the integrative vector directs its expression mainly to the intracellular fraction. Higher levels of IFN-γ were observed in the splenocytes culture from the group immunized with rBCG-S1i in comparison to BCG or rBCG-S1PT. rBCG-S1+S1i showed higher levels of CD4+ IFN-γ + and double-positive CD4+ IFN-γ + TNF-α + T cells. Conclusions: rBCG-S1+S1i was able to express the two forms of S1PT and elicited higher induction of polyfunctional CD4+ T cells, indicating enhanced immunogenicity and suggesting its use as immunotherapy for bladder cancer.


Assuntos
Vacina BCG/imunologia , Linfócitos T CD4-Positivos/imunologia , Imunidade Celular , Mycobacterium bovis/fisiologia , Toxina Pertussis/metabolismo , Subunidades Proteicas/metabolismo , Vacinas Sintéticas/imunologia , Animais , Citocinas/biossíntese , Citocinas/metabolismo , Feminino , Imunização , Mediadores da Inflamação/metabolismo , Camundongos Endogâmicos BALB C , Fenótipo , Plasmídeos/metabolismo , Baço/citologia
12.
Nat Commun ; 10(1): 1740, 2019 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-30988355

RESUMO

Cells dedicate significant energy to build proteins often organized in multiprotein assemblies with tightly regulated stoichiometries. As genes encoding subunits assembling in a multisubunit complex are dispersed in the genome of eukaryotes, it is unclear how these protein complexes assemble. Here, we show that mammalian nuclear transcription complexes (TFIID, TREX-2 and SAGA) composed of a large number of subunits, but lacking precise architectural details are built co-translationally. We demonstrate that dimerization domains and their positions in the interacting subunits determine the co-translational assembly pathway (simultaneous or sequential). The lack of co-translational interaction can lead to degradation of the partner protein. Thus, protein synthesis and complex assembly are linked in building mammalian multisubunit complexes, suggesting that co-translational assembly is a general principle in mammalian cells to avoid non-specific interactions and protein aggregation. These findings will also advance structural biology by defining endogenous co-translational building blocks in the architecture of multisubunit complexes.


Assuntos
Multimerização Proteica , Subunidades Proteicas/metabolismo , Exodesoxirribonucleases/química , Exodesoxirribonucleases/metabolismo , Células HeLa , Humanos , Fosfoproteínas/química , Fosfoproteínas/metabolismo , Domínios Proteicos , Dobramento de Proteína , Subunidades Proteicas/química , Fatores Associados à Proteína de Ligação a TATA/química , Fatores Associados à Proteína de Ligação a TATA/metabolismo , Fator de Transcrição TFIID/química , Fator de Transcrição TFIID/metabolismo
13.
Viruses ; 11(3)2019 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-30841485

RESUMO

Herpesvirus infection is an orderly, regulated process. Among these viruses, the encapsidation of viral DNA is a noteworthy link; the entire process requires a powered motor that binds to viral DNA and carries it into the preformed capsid. Studies have shown that this power motor is a complex composed of a large subunit, a small subunit, and a third subunit, which are collectively known as terminase. The terminase large subunit is highly conserved in herpesvirus. It mainly includes two domains: the C-terminal nuclease domain, which cuts the viral concatemeric DNA into a monomeric genome, and the N-terminal ATPase domain, which hydrolyzes ATP to provide energy for the genome cutting and transfer activities. Because this process is not present in eukaryotic cells, it provides a reliable theoretical basis for the development of safe and effective anti-herpesvirus drugs. This article reviews the genetic characteristics, protein structure, and function of the herpesvirus terminase large subunit, as well as the antiviral drugs that target the terminase large subunit. We hope to provide a theoretical basis for the prevention and treatment of herpesvirus.


Assuntos
Endodesoxirribonucleases/metabolismo , Infecções por Herpesviridae/tratamento farmacológico , Herpesviridae/efeitos dos fármacos , Herpesviridae/enzimologia , Subunidades Proteicas/metabolismo , Proteínas Virais/metabolismo , Empacotamento do DNA , DNA Viral , Desenvolvimento de Medicamentos , Endodesoxirribonucleases/genética , Modelos Moleculares , Domínios Proteicos , Subunidades Proteicas/genética , Proteínas Virais/genética , Montagem de Vírus
14.
Int J Mol Med ; 43(5): 2177-2186, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30896858

RESUMO

The epidemiological, animal and cell effects of plant metabolites suggest versatile health benefits of flavonoids. However, whether flavonoids affect the deleterious biological activity of oxygenated cholesterol molecules remains to be elucidated. The present study investigated the effects of 4'­O­methylalpinumisoflavone (mAI) isolated from Maclura tricuspidata (Cudrania tricuspidata) on the 27­hydroxycholesterol (27OHChol)­induced activation of monocytes/macrophages using human THP­1 cells. mAI dose­dependently impaired the expression of C­C motif chemokine ligand (CCL)2 chemokine and the migration of monocytic cells enhanced by 27OHChol. mAI downregulated the surface and cellular levels of CD14 and inhibited the release of soluble CD14. This isoflavone significantly weakened the lipopolysaccharide responses that were enhanced in the presence of 27OHChol, and inhibited the transcription and secretion of the active gene product of matrix metalloproteinase­9. mAI also suppressed the expression of C­C motif chemokine receptor 5 ligands, including CL3 and CCL4, and M1­phenotype markers induced by 27OHChol. Furthermore, mAI impaired phosphorylation of the nuclear factor­κB p65 subunit without affecting the phosphorylation of Akt. These results indicate that mAI inhibits the activation of monocytes/macrophages to the immunostimulatory phenotype in a milieu rich in 27OHChol, suggesting potential benefits of the flavonoid for the treatment of diseases in which the pathogenesis is linked to 27OHChol­induced inflammatory responses.


Assuntos
Hidroxicolesteróis/farmacologia , Isoflavonas/farmacologia , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Biomarcadores/metabolismo , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Quimiocina CCL2/metabolismo , Regulação para Baixo/efeitos dos fármacos , Humanos , Células Jurkat , Ligantes , Receptores de Lipopolissacarídeos/metabolismo , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Modelos Biológicos , Monócitos/citologia , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Fenótipo , Fosforilação/efeitos dos fármacos , Subunidades Proteicas/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores CCR5/metabolismo , Células THP-1 , Fator de Transcrição RelA/metabolismo
15.
EBioMedicine ; 41: 333-344, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30827928

RESUMO

BACKGROUND: Innate lymphoid cells (ILCs) are a newly discovered family of immune cells that have similar cytokine-secreting profiles as T helper cell subsets. Although ILCs are critical for host defense against infections and tissue homeostasis, their roles in tumor development are not well established. METHODS: We studied the function of ILC3 cells in the liver for the development of hepatocellular carcinoma (HCC) in murine HCC models using flow cytometry, adoptive transfer, and in vitro functional assays. FINDINGS: We found that ILC3 lacking the natural cytotoxicity-triggering receptor (NCR-ILC3) promoted the development of HCC in response to interleukin 23 (IL-23). IL-23 serum level is elevated in HCC patients and its high expression is associated with poor clinical outcomes. We found that IL-23 could promote tumor development in murine HCC tumor models. IL-23 promoted the expansion of NCR-ILC3 and its differentiation from group 1 ILCs (ILC1s). Furthermore, NCR-ILC3 initiated IL-17 production upon IL-23 stimulation and directly inhibited CD8+ T cell immunity by promoting lymphocyte apoptosis and limiting their proliferation. INTERPRETATION: Together, our findings suggest that NCR-ILC3 initiates the IL-17-rich immunosuppressive tumor microenvironment and promotes the development of HCC, thus may serve as a promising target for future cancer immunotherapy. FUND: This work was supported by grants from National Natural Science Foundation of China (81471586, 81571556), the Priority Academic Program Development of Jiangsu Higher Education Institutions, the collaborative Innovation Center of Hematology, start-up grant from National University of Singapore, the Cancer Prevention and Research Institute of Texas CPRIT (RR180017), and the National Cancer Institute's Cancer Center Support (Core) Grant CA016672 (to The University of Texas MD Anderson Cancer Center).


Assuntos
Carcinoma Hepatocelular/patologia , Interleucina-17/metabolismo , Interleucina-23/metabolismo , Neoplasias Hepáticas/patologia , Animais , Apoptose , Carcinoma Hepatocelular/imunologia , Carcinoma Hepatocelular/metabolismo , Diferenciação Celular , Linhagem Celular Tumoral , Técnicas de Cocultura , Modelos Animais de Doenças , Imunidade Inata , Interleucina-12/metabolismo , Interleucina-17/análise , Interleucina-23/análise , Interleucina-23/genética , Neoplasias Hepáticas/imunologia , Neoplasias Hepáticas/metabolismo , Linfócitos/citologia , Linfócitos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Subunidades Proteicas/deficiência , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo , Transplante Homólogo
16.
Nat Commun ; 10(1): 1288, 2019 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-30894545

RESUMO

The TFIIH subunit XPB is involved in combined Xeroderma Pigmentosum and Cockayne syndrome (XP-B/CS). Our analyses reveal that XPB interacts functionally with KAT2A, a histone acetyltransferase (HAT) that belongs to the hSAGA and hATAC complexes. XPB interacts with KAT2A-containing complexes on chromatin and an XP-B/CS mutation specifically elicits KAT2A-mediated large-scale chromatin decondensation. In XP-B/CS cells, the abnormal recruitment of TFIIH and KAT2A to chromatin causes inappropriate acetylation of histone H3K9, leading to aberrant formation of transcription initiation complexes on the promoters of several hundred genes and their subsequent overexpression. Significantly, this cascade of events is similarly sensitive to KAT2A HAT inhibition or to the rescue with wild-type XPB. In agreement, the XP-B/CS mutation increases KAT2A HAT activity in vitro. Our results unveil a tight connection between TFIIH and KAT2A that controls higher-order chromatin structure and gene expression and provide new insights into transcriptional misregulation in a cancer-prone DNA repair-deficient disorder.


Assuntos
Cromatina/química , Síndrome de Cockayne/genética , Histona Acetiltransferases/genética , Histonas/metabolismo , Subunidades Proteicas/genética , Fator de Transcrição TFIIH/genética , Xeroderma Pigmentoso/genética , Acetilação , Proteína 9 Associada à CRISPR/genética , Proteína 9 Associada à CRISPR/metabolismo , Sistemas CRISPR-Cas , Linhagem Celular Tumoral , Cromatina/metabolismo , Síndrome de Cockayne/metabolismo , Síndrome de Cockayne/patologia , Fibroblastos/citologia , Fibroblastos/metabolismo , Edição de Genes , Regulação da Expressão Gênica , Histona Acetiltransferases/antagonistas & inibidores , Histona Acetiltransferases/metabolismo , Histonas/genética , Humanos , Modelos Biológicos , Osteoblastos/citologia , Osteoblastos/metabolismo , Cultura Primária de Células , Subunidades Proteicas/metabolismo , RNA Guia/genética , RNA Guia/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Transdução de Sinais , Fator de Transcrição TFIIH/metabolismo , Iniciação da Transcrição Genética , Xeroderma Pigmentoso/metabolismo , Xeroderma Pigmentoso/patologia
17.
Int J Mol Sci ; 20(4)2019 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-30813492

RESUMO

AGPase catalyzes a key rate-limiting step that converts ATP and Glc-1-p into ADP-glucose and diphosphate in maize starch biosynthesis. Previous studies suggest that AGPase is modulated by redox, thermal and allosteric regulation. However, the phosphorylation of AGPase is unclear in the kernel starch biosynthesis process. Phos-tagTM technology is a novel method using phos-tagTM agarose beads for separation, purification, and detection of phosphorylated proteins. Here we identified phos-tagTM agarose binding proteins from maize endosperm. Results showed a total of 1733 proteins identified from 10,678 distinct peptides. Interestingly, a total of 21 unique peptides for AGPase sub-unit Brittle-2 (Bt2) were identified. Bt2 was demonstrated by immunoblot when enriched maize endosperm protein with phos-tagTM agarose was in different pollination stages. In contrast, Bt2 would lose binding to phos-tagTM when samples were treated with alkaline phosphatase (ALP). Furthermore, Bt2 could be detected by Pro-Q diamond staining specifically for phosphorylated protein. We further identified the phosphorylation sites of Bt2 at Ser10, Thr451, and Thr462 by iTRAQ. In addition, dephosphorylation of Bt2 decreased the activity of AGPase in the native gel assay through ALP treatment. Taking together, these results strongly suggest that the phosphorylation of AGPase may be a new model to regulate AGPase activity in the starch biosynthesis process.


Assuntos
Endosperma/metabolismo , Glucose-1-Fosfato Adenililtransferase/metabolismo , Proteínas de Plantas/metabolismo , Subunidades Proteicas/metabolismo , Proteômica/métodos , Amido/biossíntese , Zea mays/metabolismo , Sequência de Aminoácidos , Anticorpos/metabolismo , Modelos Biológicos , Fosforilação , Proteínas de Plantas/química , Sefarose
18.
Proc Jpn Acad Ser B Phys Biol Sci ; 95(3): 111-135, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30853698

RESUMO

The voltage sensor domain (VSD) has long been studied as a unique domain intrinsic to voltage-gated ion channels (VGICs). Within VGICs, the VSD is tightly coupled to the pore-gate domain (PGD) in diverse ways suitable for its specific function in each physiological context, including action potential generation, muscle contraction and relaxation, hormone and neurotransmitter secretion, and cardiac pacemaking. However, some VSD-containing proteins lack a PGD. Voltage-sensing phosphatase contains a cytoplasmic phosphoinositide phosphatase with similarity to phosphatase and tensin homolog (PTEN). Hv1, a voltage-gated proton channel, also lacks a PGD. Within Hv1, the VSD operates as a voltage sensor, gate, and pore for both proton sensing and permeation. Hv1 has a C-terminal coiled coil that mediates dimerization for cooperative gating. Recent progress in the structural biology of VGICs and VSD proteins provides insights into the principles of VSD coupling conserved among these proteins as well as the hierarchy of protein organization for voltage-evoked cell signaling.


Assuntos
Canais Iônicos/metabolismo , Monoéster Fosfórico Hidrolases/metabolismo , Membrana Celular/metabolismo , Humanos , Ativação do Canal Iônico , Modelos Moleculares , Ligação Proteica , Conformação Proteica , Multimerização Proteica , Subunidades Proteicas/metabolismo , Transdução de Sinais
19.
Cell Mol Biol (Noisy-le-grand) ; 65(2): 63-68, 2019 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-30860473

RESUMO

Caffeine is one of the most extensively consumed stimulants in the world and has been suggested to induce wakefulness by antagonizing the function of the adenosine A2A receptor. Therefore, we investigated the effects of chronic caffeine consumption on learning and memory in the REM sleep-deprived rats.Male Wistar rats (n = 50), were randomly assigned into 5 groups: Control (C), Caffeine (Cf), Pedestal Control (PC), Sleep Deprivation (SD), Sleep Deprivation and Caffeine (SD + Cf). Sleep deprivation procedure was applied as the flower-pot technique. SD and SD + Cf groups were deprived for 18 hours in a day for 21 days. Caffeine was administered daily in drinking water (0.3 g/L) for 5 weeks. For evaluated learning and memory function, Morris Water Maze Test (MWM) was used. Fluidigm Access Array was used for Grin2a, Grin2b, BDNF, cdk5/cdk5r1, CaMKIIa genes expression in the hippocampus. Distance moved and escape latency were decreased through trial days (p<0.05). However, there is no significant difference between groups for time spent in targeted quadrant during probe test for memory performance. Grin2a up-regulation was found in Cf and SD+Cf (p<0.05), and cdk5r1 increased in Cf and PC control (p<0.05). Also, BDNF up-regulation was found in PC group. Grin2b, Cdk5, CaMKIIa expression levels were not changed significantly. We showed chronic caffeine altered some of the hippocampal genes without changing learning and memory in REM sleep deprived rats. Chronic consumption of caffeine caused up-regulation in Grin2a that subunit of NMDA receptor. We supposed that chronic caffeine consumption maintained arousal without affecting learning and memory performance.


Assuntos
Nível de Alerta/efeitos dos fármacos , Cafeína/farmacologia , Cognição/efeitos dos fármacos , Regulação da Expressão Gênica , N-Metilaspartato/genética , Subunidades Proteicas/genética , Privação do Sono/genética , Privação do Sono/fisiopatologia , Animais , Doença Crônica , Regulação da Expressão Gênica/efeitos dos fármacos , Aprendizagem em Labirinto , Memória/efeitos dos fármacos , N-Metilaspartato/metabolismo , Subunidades Proteicas/metabolismo , Ratos Wistar , Aprendizagem Espacial/efeitos dos fármacos
20.
Int J Mol Sci ; 20(5)2019 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-30813527

RESUMO

Integrins are transmembrane cell receptors involved in two crucial mechanisms for successful fertilization, namely, mammalian intracellular signaling and cell adhesion. Integrins α6ß4, α3ß1 and α6ß1 are three major laminin receptors expressed on the surface of mammalian cells including gametes, and the presence of individual integrin subunits α3, α6, ß1 and ß4 has been previously detected in mammalian sperm. However, to date, proof of the existence of individual heterodimer pairs in sperm and their detailed localization is missing. The major conclusion of this study is evidence that the ß4 integrin subunit is expressed in mouse sperm and that it pairs with subunit α6; additionally, there is a detailed identification of integrin heterodimer pairs across individual membranes in an intact mouse sperm head. We also demonstrate the existence of ß4 integrin mRNAs in round spermatids and spermatogonia by q-RT-PCR, which was further supported by sequencing the PCR products. Using super-resolution microscopy accompanied by colocalization analysis, we located integrin subunits as follows: α6/ß4-inner apical acrosomal membrane and equatorial segment; α3, α6/ß1, ß4-plasma membrane overlaying the apical acrosome; and α3/ß1-outer acrosomal membrane. The existence of α6ß4, α3ß1 and α6ß1 heterodimers was further confirmed by proximity ligation assay (PLA). In conclusion, we delivered detailed characterization of α3, α6, ß1 and ß4 integrin subunits, showing their presence in distinct compartments of the intact mouse sperm head. Moreover, we identified sperm-specific localization for heterodimers α6ß4, α3ß1 and α6ß1, and their membrane compartmentalization and the presented data show a complexity of membranes overlaying specialized microdomain structures in the sperm head. Their different protein compositions of these individual membrane rafts may play a specialized role, based on their involvement in sperm-epithelium and sperm-egg interaction.


Assuntos
Compartimento Celular , Integrinas/metabolismo , Multimerização Proteica , Espermatozoides/metabolismo , Animais , Integrinas/química , Masculino , Camundongos Endogâmicos C57BL , Modelos Biológicos , Domínios Proteicos , Subunidades Proteicas/metabolismo
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