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1.
Toxicol Lett ; 317: 110-119, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31618666

RESUMO

Trichloroethylene (TCE), a commonly used industrial solvent and degreasing agent, is known to cause trichloroethylene hypersensitivity syndrome (THS) with multi-system damage, including skin, liver and kidney. Clinical evidence have shown that the kidney injury occurs in THS and our previous studies suggested that the terminal complement complex C5b-9 deposited in impaired renal tubules induced by TCE with unclear mechanisms. In the present study, we questioned whether activation of the complement system with renal deposition of C5b-9 contributes to TCE-induced kidney injury in THS. We established a BALB/c mouse model of TCE sensitization with or without pretreatment of exogenous CD59, a C5b-9 inhibitory protein. H&E staining, PAS staining, and biochemical detection of urinary proteins were performed to assess renal function. Deposition of C5b-9 and expression of CD59 were evaluated by immunohistochemistry. Sub-lytic effects of C5b-9 in tubular epithelial cells were assessed by lactate dehydrogenase (LDH) cytotoxicity assay. Expression of endocytosis receptors megalin and cubilin on proximal tubules were assessed by immunofluorescence and qRT-PCR. We found that TCE sensitization induced structural and functional changes of renal tubules in mice, associated with the deposition of sub-lytic C5b-9 on proximal tubular epithelial cells. TCE sensitization decreased proximal tubule uptake of filtered proteins and renal expression of megalin and cubilin, phenotypes that were attenuated by pretreatment with exogenous CD59. Overall, our findings reveal a novel mechanism underlying sub-lytic C5b-9 acting on megalin and cubilin, contributes to the renal tubules damage by TCE exposure.


Assuntos
Complexo de Ataque à Membrana do Sistema Complemento/metabolismo , Endocitose , Hipersensibilidade/metabolismo , Nefropatias/metabolismo , Túbulos Renais Proximais/metabolismo , Proteína-2 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Receptores de Superfície Celular/metabolismo , Tricloroetileno , Animais , Células Cultivadas , Ativação do Complemento , Complexo de Ataque à Membrana do Sistema Complemento/imunologia , Modelos Animais de Doenças , Feminino , Hipersensibilidade/imunologia , Hipersensibilidade/patologia , Nefropatias/induzido quimicamente , Nefropatias/imunologia , Nefropatias/patologia , Túbulos Renais Proximais/imunologia , Túbulos Renais Proximais/patologia , Camundongos Endogâmicos BALB C , Transporte Proteico
3.
Nat Cell Biol ; 21(10): 1219-1233, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31576058

RESUMO

Protein trafficking requires coat complexes that couple recognition of sorting motifs in transmembrane cargoes with biogenesis of transport carriers. The mechanisms of cargo transport through the endosomal network are poorly understood. Here, we identify a sorting motif for endosomal recycling of cargoes, including the cation-independent mannose-6-phosphate receptor and semaphorin 4C, by the membrane tubulating BAR domain-containing sorting nexins SNX5 and SNX6. Crystal structures establish that this motif folds into a ß-hairpin, which binds a site in the SNX5/SNX6 phox homology domains. Over sixty cargoes share this motif and require SNX5/SNX6 for their recycling. These include cargoes involved in neuronal migration and a Drosophila snx6 mutant displays defects in axonal guidance. These studies identify a sorting motif and provide molecular insight into an evolutionary conserved coat complex, the 'Endosomal SNX-BAR sorting complex for promoting exit 1' (ESCPE-1), which couples sorting motif recognition to the BAR-domain-mediated biogenesis of cargo-enriched tubulo-vesicular transport carriers.


Assuntos
Endossomos/metabolismo , Proteínas de Membrana/metabolismo , Nexinas de Classificação/química , Nexinas de Classificação/metabolismo , Motivos de Aminoácidos/genética , Animais , Drosophila melanogaster , Células HEK293 , Células HeLa , Humanos , Domínios Proteicos/genética , Transporte Proteico/fisiologia , Receptor IGF Tipo 2/química , Receptor IGF Tipo 2/metabolismo , Semaforinas/genética , Semaforinas/metabolismo , Nexinas de Classificação/genética
4.
J Chem Theory Comput ; 15(11): 6433-6443, 2019 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-31639304

RESUMO

Proteins involved in peptide uptake and transport belong to the proton-coupled oligopeptide transporter (POT) family. Crystal structures of POT family members reveal a common fold consisting of two domains of six transmembrane α helices that come together to form a "V" shaped transporter with a central substrate binding site. Proton-coupled oligopeptide transporters operate through an alternate access mechanism, where the membrane transporter undergoes global conformational changes, alternating between inward-facing (IF), outward-facing (OF), and occluded (OC) states. Conformational transitions are promoted by proton and ligand binding; however, due to the absence of crystallographic models of the outward-open state, the role of H+ and ligands is still not fully understood. To provide a comprehensive picture of the POT conformational equilibrium, conventional and enhanced sampling molecular dynamics simulations of PepTst in the presence or absence of ligand and protonation were performed. Free-energy profiles of the conformational variability of PepTst were obtained from microseconds of adaptive biasing force (ABF) simulations. Our results reveal that both proton and ligand significantly change the conformational free-energy landscape. In the absence of ligand and protonation, only transitions involving IF and OC states are allowed. After protonation of the residue Glu300, the wider free-energy well for Glu300 protonated PepTst indicates a greater conformational variability relative to the apo system, and OF conformations became accessible. For the Glu300 protonated Holo-PepTst, the presence of a second free-energy minimum suggests that OF conformations are not only accessible, but also stable. The differences in the free-energy profiles demonstrate that transitions toward outward-facing conformation occur only after protonation, which is likely the first step in the mechanism of peptide transport. Our extensive ABF simulations provide a fully atomic description of all states of the transport process, offering a model for the alternating access mechanism and how protonation and ligand control the conformational changes.


Assuntos
Simulação de Dinâmica Molecular , Oligopeptídeos/metabolismo , Citoplasma/química , Citoplasma/metabolismo , Ligantes , Oligopeptídeos/química , Conformação Proteica , Transporte Proteico , Prótons , Termodinâmica
5.
Nihon Yakurigaku Zasshi ; 154(4): 186-191, 2019.
Artigo em Japonês | MEDLINE | ID: mdl-31597897

RESUMO

Primary cilia, which protrude from the surfaces of most human cells, function as cellular antennae that receive extracellular signals. To serve as antennae, primary cilia contain unique proteins, such as G-protein-coupled receptors and ion channels. Defects in the assembly and functions of primary cilia cause hereditary disorders with a wide range of symptoms, including cystic kidney and retinal degeneration. The assembly and maintenance of cilia depend on protein trafficking mediated by the intraflagellar transport (IFT) machinery, which contains three protein complexes (IFT-A, IFT-B, and BBSome) and two motor proteins (kinesin-2 and dynein-2 complex) and is composed of more than 40 subunits in total. We recently revealed the interaction between the kinesin-2 and IFT-B complexes and overall architecture of the dynein-2 complex by taking advantage of the visible immunoprecipitation (VIP) assay. In addition, we clarified the roles of dynein-2 subunits using gene knockout cell lines established using the CRISPR/Cas9 system. This review focuses on recent advances in the architectures and functions of two motor proteins underlying the IFT machinery.


Assuntos
Cílios/fisiologia , Dineínas/fisiologia , Flagelos/fisiologia , Cinesina/fisiologia , Linhagem Celular , Técnicas de Inativação de Genes , Humanos , Imunoprecipitação , Transporte Proteico
6.
Cell Physiol Biochem ; 53(4): 687-700, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31577078

RESUMO

BACKGROUND/AIMS: Apelin and its G protein-coupled receptor APJ (gene symbol Aplnr) are strongly expressed in magnocellular vasopressinergic neurons suggesting that the apelin/APJ system plays a key role at the central level in regulating salt and water balance by counteracting the antiduretic action of vasopressin (AVP). Likewise, recent studies revealed that apelin exerts opposite effects to those of vasopressin induced on water reabsorption via a direct action on the kidney collecting duct. However, the underlying mechanisms of the peripheral action of apelin are not clearly understood. Here, we thus investigated the role of the apelin/APJ system in the regulation of water balance in the kidney, and more specifically its involvement in modulating the function of aquaporin-2 (AQP2) in the collecting duct. METHODS: Mouse cortical collecting duct cells (mpkCCD) were incubated in the presence of dDAVP and treated with or without apelin-13. Changes in AQP2 expression and localization were determined by immunoblotting and confocal immunofluorescence staining. RESULTS: Herein, we showed that the APJ was present in mpkCCD cells. Treatment of mpkCCD with apelin-13 reduced the cAMP production and antagonized the AVP-induced increase in AQP2 mRNA and protein expressions. Immunofluorescent experiments also revealed that the AVP-induced apical cell surface expression of AQP2, and notably its phosphorylated isoform AQP2-pS269, was considerably reduced following apelin-13 application to mpkCCD cells. CONCLUSION: Our data reinforce the aquaretic role of the apelin/APJ system in the fine regulation of body fluid homeostasis at the kidney level and its physiological opposite action to the antiduretic activity of AVP.


Assuntos
Aquaporina 2/metabolismo , Desamino Arginina Vasopressina/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Transporte Proteico/efeitos dos fármacos , Animais , Receptores de Apelina/metabolismo , Aquaporina 2/genética , Linhagem Celular , AMP Cíclico/metabolismo , Células HEK293 , Humanos , Túbulos Renais Coletores/citologia , Túbulos Renais Coletores/metabolismo , Camundongos , Fosforilação/efeitos dos fármacos
7.
J Biol Regul Homeost Agents ; 33(5): 1327-1335, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31487982

RESUMO

The glucose transporter 4 (GLUT4) translocation is a vital link of insulin-induced glucose uptake in adipose tissue and skeletal muscle. It is an important topic in anti-diabetic research to explore novel agents to facilitate the role of insulin. The aim of this study was to verify the hypothesis that neuropeptide galanin may enhance insulin-induced GLUT4 translocation to increase glucose uptake in adipose tissue of type 2 diabetic models. Insulin and/or galanin were injected respectively or cooperatively into type 2 diabetic rats once a day for fifteen days. The results showed that administration of galanin significantly enhanced insulin-induced GLUT4 and vesicle-associated membrane protein 2 (VAMP2) translocation, Akt phosphorylation and glucose uptake, but not GLUT4 mRNA and protein expression levels in adipose cells. The beneficial roles of galanin on insulin-induced events may be blocked by MK-2206, an Akt inhibitor, indicating that the Akt phosphorylation is essential for promoting impact of galanin on the insulin-induced events. These results suggest that galanin may benefit insulin-induced GLUT4 and VAMP2 translocation, and subsequent glucose uptake via the activated Akt-VAMP2-GLUT4 pathway in adipose cells. These findings deepen our understanding of the anti-diabetic effect of galanin and its mechanism.


Assuntos
Adipócitos/metabolismo , Diabetes Mellitus Experimental/tratamento farmacológico , Galanina/farmacologia , Transportador de Glucose Tipo 4/metabolismo , Insulina/farmacologia , Animais , Diabetes Mellitus Experimental/metabolismo , Glucose/metabolismo , Transporte Proteico , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Proteína 2 Associada à Membrana da Vesícula/metabolismo
8.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 41(4): 443-451, 2019 Aug 30.
Artigo em Chinês | MEDLINE | ID: mdl-31484604

RESUMO

Objective To analyze the differences in biological functions between bone marrow(BM)-derived CD106 +mesenchymal stem cells(MSCs)and the CD106 - subgroup. Methods The MSCs from normal BM were isolated and expanded.The subgroups of CD106 + and CD106 -MSCs were sorted.The cell proliferation and adhesion functions,chemotactic activities,adipogenic and osteogenic potentials,senescence,and senescence protein 21(p21)were detected.The capacity of translocation into nucleus of nuclear factor-kappa B(NF-κB)when stimulated by tumor necrosis factor(TNF-α)was measured. Results The proliferative ability was higher in CD106 +MSCs than that in CD106 -MSCs.In 48 hours,the value of optical density(OD)was significantly higher in CD106 +MSCs than that in CD106 - subgroup(1.004±0.028 vs. 0.659±0.023,t=3.946,P=0.0225).In 72 hours,this phenomenon was even more pronounced(2.574±0.089 vs. 1.590±0.074,t=11.240,P=0.0000).The adhesive capacity of CD106 +MSCs was significantly stronger than that of CD106 - subgroup(0.648±0.018 vs. 0.418±0.023,t=7.869,P=0.0002).Besides,the metastasis ability of CD106 +MSCs were significantly stronger than that of CD106 - subgroup(114.500±4.481 vs.71.000±4.435,t=6.900,P=0.0005).The CD106 +MSCs had signifcnatly lower proportions of senescent cells.The expression of aging protein p21 in CD106 +MSCs was significantly lower than that in CD106 -MSCs [(17.560±1.421)% vs.(45.800±2.569)%,t=9.618,P=0.0000].Furthermore,there were no visible pigmenting cells after ß-galactosidase staining in CD106 +MSCs subgroup.However,in CD106 -MSCs,some colored green cells were detected.The rate of NF-κB translocation into nucleus after stimulated by TNF-α was significantly higher in CD106 +MSCs than CD106 - MSCs [(37.780±3.268)% vs.(7.30±1.25)%,t=8.713,P=0.0001]. Conclusion Bone marrow-derived CD106 +MSCs possess more powerful biological functions than CD106 -MSCs.


Assuntos
Células da Medula Óssea/citologia , Células-Tronco Mesenquimais/citologia , Molécula 1 de Adesão de Célula Vascular/metabolismo , Adesão Celular , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Humanos , NF-kappa B/metabolismo , Transporte Proteico , Fator de Necrose Tumoral alfa/farmacologia
9.
Zhejiang Da Xue Xue Bao Yi Xue Ban ; 48(3): 318-325, 2019 May 25.
Artigo em Chinês | MEDLINE | ID: mdl-31496165

RESUMO

Proteins are the physical basis of life and perform all kinds of life activities. Proteins have different orientations and function in different tissues. The same protein, located in different subcellular regions, can perform different and even opposite functions. Both functional and structural proteins are capable of undergoing re-localization which can directly or indirectly participate in signal transduction. Due to abnormal transduction of signals during carcinogenesis, the proteins originally expressed in the cytoplasm are translocated into the nucleus and lead to functional changes in the tumor tissue. The changes of protein localization are affected by many factors, including the interaction between proteins, expression level of proteins and the cleaved intracellular domain of transmembrane protein.


Assuntos
Núcleo Celular , Citoplasma , Proteínas de Membrana , Carcinogênese/patologia , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Proteínas de Membrana/metabolismo , Domínios Proteicos , Transporte Proteico/fisiologia , Transdução de Sinais
10.
Sheng Wu Gong Cheng Xue Bao ; 35(8): 1537-1545, 2019 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-31441625

RESUMO

Exosomes have many advantages as natural drug delivery carriers, but their application is limited by the inefficient loading of intracellular drugs (such as proteins and nucleic acids). In this study, mCherry, a red fluorescent protein, was used as the endogenous cargo target. Through gene modification of donor cells and fusion expression of membrane localization elements (PB, CAAX, Palm and CD63), mCherry was specifically sorted into exosomes through biogenesis. Results show that CD63 had the highest sorting efficiency, followed by Palm. PB and CAAX led enrichment of mCherry on the plasma membrane, but not in exosomes. The approach provides an alternative to facilitate packaging of cargo by exosomes and thus to increase the efficient delivery of endogenous protein drugs.


Assuntos
Exossomos , Portadores de Fármacos , Sistemas de Liberação de Medicamentos , Células HEK293 , Humanos , Transporte Proteico
11.
Gene ; 719: 144074, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31446094

RESUMO

Kinesin-14 motor es-kifc1 is highly expressed in the male reproductive system of the Chinese mitten crab Eriocheir sinensis (E. sinensis). In addition to acrosomal formation, es-KIFC1 also tightly surrounds the nucleus and its specific mechanism remains unknown. During spermatogenesis, sperm nucleus dents into a cup-shaped structure with several radial arms and completed the nuclear decondensation. In this study, the spatial expression pattern of es-KIFC1 indicates a potential function in nuclear formation with the nuclear localization sequence (NLS) on N-terminal domain which is crucial for the translocation of es-KIFC1 into the nucleus. The Motor domain is associated with microtubule modulation and the Golgi vesicles positioning. Furthermore, the expression level of es-KIFC1 is not only related to the seasonal variation of crustacean development, but also associates with mature sperm storage. The double strand RNA (dsRNA) mediated RNA interference manifests that the cup-shaped sperm nucleus is remarkably malformed and even separates the chromatin throughout the nuclei at the last stage of spermiogenesis. Besides, the sperm nucleus almost disperses its structure and separates the chromatin into several segments throughout the nucleus showing an asymmetrical performance without cytoskeleton. In summary, these results indicate the importance of es-KIFC1 in microtubule positioning and the maintenance of the mature sperm nuclei.


Assuntos
Proteínas de Artrópodes/genética , Braquiúros/fisiologia , Núcleo Celular/metabolismo , Cinesina/genética , Espermatogênese/genética , Animais , Proteínas de Artrópodes/metabolismo , Núcleo Celular/ultraestrutura , Citoesqueleto/metabolismo , Cinesina/metabolismo , Masculino , Microtúbulos/metabolismo , Transporte Proteico , RNA de Cadeia Dupla/genética , Espermatozoides/ultraestrutura
12.
Cell Physiol Biochem ; 53(2): 400-412, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31403270

RESUMO

BACKGROUND/AIMS: Mutations in ABCA4 cause Stargardt macular degeneration, which invariably ends in legal blindness. We studied two common mutants, A1038V (in NBD1) and G1961E (in NBD2), with the purpose of exploring how they interact with the cell's quality control mechanism. The study was designed to determine how these mutants can be rescued. METHODS: We expressed wt and mutant ABCA4 in HEK293 cells and studied the effect of the mutations on trafficking and processing and the ability of correctors to rescue them. We used a combination of western blotting, confocal microscopy and surface biotinylation coupled with pulldown of plasma membrane proteins. RESULTS: G1961E is sensitive to inhibitors of the aggresome, tubacin and the lysosome, bafilomycin A. Both mutants cause a reduction in heat shock protein, Hsp27. Incubation of HEK293 cells expressing the mutants with VX-809, an FDA approved drug for the treatment of cystic fibrosis, increased the levels of A1038V and G1961E by 2- to 3-fold. Importantly, VX-809 increased the levels of both mutants at the plasma membrane suggesting that trafficking had been restored. Transfecting additional Hsp27 to the cells also increased the steady state levels of both mutants. However, in combination with VX-809 the addition of Hsp27 caused a dramatic increase in the protein expression particularly in the G1961 mutant which increased approximately 5-fold. CONCLUSION: Our results provide a new mechanism for the rescue of ABCA4 trafficking mutants based on the restoration of Hsp27. Our results provide a pathway for the treatment of Stargardt disease.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Aminopiridinas/farmacologia , Benzodioxóis/farmacologia , Transportadores de Cassetes de Ligação de ATP/genética , Aminopiridinas/uso terapêutico , Anilidas/farmacologia , Benzodioxóis/uso terapêutico , Membrana Celular/metabolismo , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Células HEK293 , Proteínas de Choque Térmico HSP27/metabolismo , Humanos , Ácidos Hidroxâmicos/farmacologia , Leupeptinas/farmacologia , Lisossomos/metabolismo , Degeneração Macular/congênito , Degeneração Macular/tratamento farmacológico , Degeneração Macular/metabolismo , Degeneração Macular/patologia , Mutação , Transporte Proteico/efeitos dos fármacos
13.
Microbiol Res ; 227: 126293, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31421715

RESUMO

T. gondii is a major opportunistic pathogen chronically infecting nearly one third of the world's population. Due to the high infection and mortality rates in immunocompromised patients and newborns, the extent or magnitude of T. gondii pathogenesis is determined mainly by host-pathogen interactions. T. gondii utilizes specialized secretory proteins to modify host cellular factors and facilitate invasion and replication. This review provides update on the recent progress in this field of research with particular emphasis on the T. gondii secretory proteins and their role in invasion and pathogenesis.


Assuntos
Transporte Proteico/fisiologia , Proteínas de Protozoários/metabolismo , Toxoplasma/fisiologia , Toxoplasma/patogenicidade , Animais , Interações Hospedeiro-Parasita , Humanos , Estágios do Ciclo de Vida , Toxoplasmose/parasitologia
14.
Food Chem ; 299: 125051, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31284245

RESUMO

This study aims to exploit the molecular and cellular mechanisms concerning the functionality of dietary polyphenols (catechin, procyanidin B3, procyanidin C2, epigallocatechin and epigallocatechin gallate) in a nutritional context to prevent Celiac Disease (CD). In that sense, the interaction between the main CD bioactive peptide (32-mer peptide) and some polyphenols was fully characterized at the intestinal level under near physiological conditions by means of different spectroscopic techniques and dynamic simulations. Accordingly, it is proposed that the primarily polyphenol-binding sites on the 32-mer peptide correspond to leucine, tyrosine and phenylalanine containing domains being this interaction entropy-driven. Although procyanidin B3 and trimer C2 had a similar low-affinity constant at 310 K, both procyanidins were able to reduce the 32-mer peptide apical-to-basolateral translocation in in vitro simulated intestinal epithelial barrier thus prospecting the occurrence of additional and still unexplored regulatory mechanisms by which dietary polyphenols might modulate the transepithelial transport of CD bioactive peptides.


Assuntos
Alimentos , Glutens/química , Fragmentos de Peptídeos/química , Polifenóis/química , Análise Espectral , Glutens/metabolismo , Mucosa Intestinal/metabolismo , Fragmentos de Peptídeos/metabolismo , Ligação Proteica , Transporte Proteico
15.
Artigo em Inglês | MEDLINE | ID: mdl-31255699

RESUMO

Organic anion transporters (OATs) are membrane proteins within the Solute carrier family 22 (SLC22). They play important roles in cellular uptake of various organic compounds, and due to their expression in barrier tissues of major excretory and non-excretory organs are considered as crucial elements in absorption and distribution of a wide range of endobiotic and xenobiotic compounds. Based on our previous work and initial insights on SLC22 members in zebrafish (Danio rerio), in this study we aimed at in vitro characterization of Oat1 and Oat3 transporters and understanding of their interaction with potential physiological substrates. We first performed synteny analysis to describe in more detail orthological relationship of zebrafish oat1 and oat3 genes. We then developed stable cell lines overexpressing Oat1 and Oat3, and identified Lucifer yellow as Oat1 model fluorescent substrate (Km = 11.4 µM) and 6-carboxyfluorescein as Oat3 model substrate (Km = 5.8 µM). Initial identification performed using the developed assays revealed Kreb's cycle intermediates, bilirubin, bile salts and steroid hormones as the most potent of Oat1 and Oat3 interactors, with IC50 values in micromolar range. Finally, we showed that bilirubin, deoxycholic acid, α-ketoglutarate, pregnenolone, estrone-3-sulfate and corticosterone are in vitro substrates of zebrafish Oat1, and bilirubin and deoxycholic acid are Oat3 substrates. In conclusion, using the approach described, structural and functional similarities of both transporters to human and mammalian orthologs are revealed, their broad ligand selectivity confirmed, potent interactors among endobiotic compounds identified, and first indications of their potential physiological role(s) in zebrafish obtained.


Assuntos
Proteína 1 Transportadora de Ânions Orgânicos/metabolismo , Transportadores de Ânions Orgânicos Sódio-Independentes/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/metabolismo , Animais , Avaliação Pré-Clínica de Medicamentos , Proteína 1 Transportadora de Ânions Orgânicos/antagonistas & inibidores , Transportadores de Ânions Orgânicos Sódio-Independentes/antagonistas & inibidores , Ligação Proteica , Transporte Proteico , Proteínas de Peixe-Zebra/antagonistas & inibidores
16.
Bioengineered ; 10(1): 282-291, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31311401

RESUMO

Transforming growth factor (TGF)-ß1 plays a crucial role in the epithelial-to-mesenchymal transition (EMT) in many cancer types and in thyroid cancers. Epigallocatechin-3-gallate (EGCG), the most important ingredient in the green tea, has been reported to possess antioxidant and anticancer activities. However, the cellular and molecular mechanisms explaining its action have not been completely understood. In this study, we found that EGCG significantly suppresses EMT, invasion and migration in anaplastic thyroid carcinoma (ATC) 8505C cells in vitro by regulating the TGF-ß/Smad signaling pathways. EGCG significantly inhibited TGF-ß1-induced expression of EMT markers (E-cadherin reduction and vimentin induction) in 8505C cells in vitro. Treatment with EGCG completely blocked the phosphorylation of Smad2/3, translocation of Smad4. Taken together, these results suggest that EGCG suppresses EMT and invasion and migration by blocking TGFß/Smad signaling pathways.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Catequina/análogos & derivados , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica , Transdução de Sinais/efeitos dos fármacos , Células Epiteliais da Tireoide/efeitos dos fármacos , Fator de Crescimento Transformador beta1/antagonistas & inibidores , Antígenos CD/genética , Antígenos CD/metabolismo , Caderinas/antagonistas & inibidores , Caderinas/genética , Caderinas/metabolismo , Catequina/farmacologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Transição Epitelial-Mesenquimal/genética , Humanos , Fosforilação/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Proteína Smad2/genética , Proteína Smad2/metabolismo , Proteína Smad3/genética , Proteína Smad3/metabolismo , Proteína Smad4/genética , Proteína Smad4/metabolismo , Células Epiteliais da Tireoide/metabolismo , Células Epiteliais da Tireoide/patologia , Fator de Crescimento Transformador beta1/farmacologia , Vimentina/agonistas , Vimentina/genética , Vimentina/metabolismo
17.
Nat Commun ; 10(1): 2902, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31263173

RESUMO

Exogenous metabolites from microbial and dietary origins have profound effects on host metabolism. Here, we report that a sub-population of lipid droplets (LDs), which are conserved organelles for fat storage, is defined by metabolite-modulated targeting of the C. elegans seipin ortholog, SEIP-1. Loss of SEIP-1 function reduces the size of a subset of LDs while over-expression of SEIP-1 has the opposite effect. Ultrastructural analysis reveals SEIP-1 enrichment in an endoplasmic reticulum (ER) subdomain, which co-purifies with LDs. Analyses of C. elegans and bacterial genetic mutants indicate a requirement of polyunsaturated fatty acids (PUFAs) and microbial cyclopropane fatty acids (CFAs) for SEIP-1 enrichment, as confirmed by dietary supplementation experiments. In mammalian cells, heterologously expressed SEIP-1 engages nascent lipid droplets and promotes their subsequent expansion in a conserved manner. Our results suggest that microbial and polyunsaturated fatty acids serve unexpected roles in regulating cellular fat storage by promoting LD diversity.


Assuntos
Caenorhabditis elegans/metabolismo , Retículo Endoplasmático/metabolismo , Ácidos Graxos/metabolismo , Gotículas Lipídicas/metabolismo , Animais , Caenorhabditis elegans/química , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Linhagem Celular , Retículo Endoplasmático/química , Retículo Endoplasmático/genética , Subunidades gama da Proteína de Ligação ao GTP/genética , Subunidades gama da Proteína de Ligação ao GTP/metabolismo , Humanos , Transporte Proteico
18.
Yi Chuan ; 41(6): 451-468, 2019 Jun 20.
Artigo em Chinês | MEDLINE | ID: mdl-31257195

RESUMO

Endocytic transport is imperative for the exchange of information between cells and the external environment. Specifically, the process of endocytic transport comprises precise regulation of uptake and sorting of extracellular macromolecules, phospholipids, and membrane proteins. In the endocytic transport system, the recycling pathways are responsible for delivering membrane proteins and phospholipids back to the plasma membrane. Thus, endocytic recycling plays critical roles in various biological processes, including nutrient absorption, cell polarity establishment, cell migration, cell division, synaptic plasticity, immune response, and growth factor receptor regulation. There are two essential types of recycling pathways in eukaryotic cells, recycling of clathrin-dependent endocytic cargos (CDE recycling) and recycling of clathrin-independent endocytic cargos (CIE recycling). The transferrin receptor TfR and the low-density lipoprotein receptor LDLR, which have essential physiological roles in vivo, are representative membrane proteins of the CDE recycling transport. In recent years, various membrane proteins governed by CIE recycling transport have been identified, including IL2 receptor α-subunit, major histocompatibility complex MHC Class I, and glucose transporter GLUT4. Therefore, the investigation of the regulatory mechanisms of CIE recycling has drawn notable attention in the field. Moreover, CIE recycling research presents fundamental significance in cell biology, which also provides scientific evidence and potential therapeutic clues for the diagnosis and treatment strategies of diseases such as type 2 diabetes and cancer. Compared with the CDE recycling, the study on CIE recycling started later, and there is much to be learned of its regulatory mechanisms. To this end, this review summarizes the features of endocytic recycling pathways, focuses on the molecular basis of CIE recycling regulation and elaborates on the latest progress and newly developed research model systems in the field of CIE recycling.


Assuntos
Endocitose , Proteínas de Membrana/fisiologia , Transporte Proteico , Clatrina , Diabetes Mellitus Tipo 2 , Endossomos , Humanos
19.
Cell Mol Life Sci ; 76(21): 4245-4273, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31317204

RESUMO

Molecular self-organziation, also regarded as pattern formation, is crucial for the correct distribution of cellular content. The processes leading to spatiotemporal patterns often involve a multitude of molecules interacting in complex networks, so that only very few cellular pattern-forming systems can be regarded as well understood. Due to its compositional simplicity, the Escherichia coli MinCDE system has, thus, become a paradigm for protein pattern formation. This biological reaction diffusion system spatiotemporally positions the division machinery in E. coli and is closely related to ParA-type ATPases involved in most aspects of spatiotemporal organization in bacteria. The ATPase MinD and the ATPase-activating protein MinE self-organize on the membrane as a reaction matrix. In vivo, these two proteins typically oscillate from pole-to-pole, while in vitro they can form a variety of distinct patterns. MinC is a passenger protein supposedly operating as a downstream cue of the system, coupling it to the division machinery. The MinCDE system has helped to extract not only the principles underlying intracellular patterns, but also how they are shaped by cellular boundaries. Moreover, it serves as a model to investigate how patterns can confer information through specific and non-specific interactions with other molecules. Here, we review how the three Min proteins self-organize to form patterns, their response to geometric boundaries, and how these patterns can in turn induce patterns of other molecules, focusing primarily on experimental approaches and developments.


Assuntos
Adenosina Trifosfatases/fisiologia , Proteínas de Ciclo Celular/fisiologia , Divisão Celular/fisiologia , Proteínas de Escherichia coli/fisiologia , Proteínas de Membrana/fisiologia , Transporte Proteico/fisiologia , Adenosina Trifosfatases/metabolismo , Proteínas de Ciclo Celular/metabolismo , Membrana Celular/metabolismo , Citoplasma/metabolismo , Proteínas do Citoesqueleto/metabolismo , Escherichia coli/citologia , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Proteínas de Membrana/metabolismo , Multimerização Proteica/fisiologia , Transporte Proteico/genética
20.
Cell Mol Life Sci ; 76(21): 4233-4243, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31270581

RESUMO

Circular RNAs (circRNAs) are single-stranded and covalently closed back-splicing products of pre-mRNAs. They can be derived from exons, introns, or exons with intron retained between exons of transcripts, as well as antisense transcripts. CircRNAs have been reported to function as microRNA sponges, regulate gene transcription mediated by RNA polymerase II, and modulate the splicing or stability of mRNA. However, emerging studies demonstrate that they affect the behavior of proteins via direct interactions with them. Here, we summarize that by binding directly with proteins; circRNAs can facilitate their nuclear or cytoplasmic localizations, regulate their functions or stability, promote or inhibit the interactions between them, or influence the interactions between them and DNA. Furthermore, these circRNA-binding proteins contain transcription factors, RNA processing proteins, proteases, and some other RNA-binding proteins. As a consequence, circRNAs are involved in the regulation of multiple physiological or pathological processes, including tumorigenesis, atherosclerosis, wound repair, cardiac senescence, myocardial ischemia/reperfusion injury, and so forth. Nonetheless, it is worthwhile to further explore more types of proteins that interact with circRNAs, which would be helpful in revealing other unknown biological functions of circRNAs that guide the variation in behavior of cellular proteins.


Assuntos
Proteínas/metabolismo , RNA/fisiologia , Animais , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica/fisiologia , Humanos , Ligação Proteica , Estabilidade Proteica , Transporte Proteico/genética , RNA/metabolismo , Proteínas de Ligação a RNA/metabolismo
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