Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.065
Filtrar
1.
Medicine (Baltimore) ; 99(33): e21632, 2020 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-32872024

RESUMO

INTRODUCTION: The oligophrenin-1 (OPHN1) gene, localized on the X chromosome, is a Rho-GTPase activating protein that is related to syndromic X-linked intellectual disability (XLID). XLID, characterized by brain anomalies, namely cerebellar hypoplasia, specific facial features, and intellectual disability, is produced by different mutations in the OPHN1 gene. PATIENT CONCERNS: In this report, we present the clinical and molecular findings of a family affected by a mild XLID due to a deletion in the OPHN1 gene, exon 21, Xq12 region using Multiplex Ligation-dependent Probe Amplification (MLPA) analysis. The clinical features present in the family are a mild developmental delay, behavioral disturbances, facial dysmorphism, pes planus, nystagmus, strabismus, epilepsy, and occipital arachnoid cyst. INTERVENTIONS: The MLPA analysis was performed for investigation of the copy number variations within the X chromosome for the family. DIAGNOSIS AND OUTCOME: The MLPA analysis detected a deletion in the OPHN1 gene, exon 21 for the proband, and a heterozygous deletion for the probands mother. The deletion of the Xq12 region of maternal origin, including the exon 21 of the OPHN1 gene, confirmed for the probands nephew. LESSONS: Our findings emphasize the utility of the MLPA analysis to identify deletions in the OPHN1 gene responsible for syndromic XLID. Therefore, we suggest that MLPA analysis should be performed as an alternative diagnostic test for all patients with a mild intellectual disability associated or not with behavioral disturbances, facial dysmorphism, and brain anomalies.


Assuntos
Proteínas do Citoesqueleto/genética , Proteínas Ativadoras de GTPase/genética , Deficiência Intelectual/genética , Proteínas Nucleares/genética , Adolescente , Éxons , Deleção de Genes , Humanos , Masculino
2.
Nat Commun ; 11(1): 3464, 2020 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-32651375

RESUMO

DOCK (dedicator of cytokinesis) proteins are multidomain guanine nucleotide exchange factors (GEFs) for RHO GTPases that regulate intracellular actin dynamics. DOCK proteins share catalytic (DOCKDHR2) and membrane-associated (DOCKDHR1) domains. The structurally-related DOCK1 and DOCK2 GEFs are specific for RAC, and require ELMO (engulfment and cell motility) proteins for function. The N-terminal RAS-binding domain (RBD) of ELMO (ELMORBD) interacts with RHOG to modulate DOCK1/2 activity. Here, we determine the cryo-EM structures of DOCK2-ELMO1 alone, and as a ternary complex with RAC1, together with the crystal structure of a RHOG-ELMO2RBD complex. The binary DOCK2-ELMO1 complex adopts a closed, auto-inhibited conformation. Relief of auto-inhibition to an active, open state, due to a conformational change of the ELMO1 subunit, exposes binding sites for RAC1 on DOCK2DHR2, and RHOG and BAI GPCRs on ELMO1. Our structure explains how up-stream effectors, including DOCK2 and ELMO1 phosphorylation, destabilise the auto-inhibited state to promote an active GEF.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Ativadoras de GTPase/metabolismo , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Calorimetria , Proteínas Ativadoras de GTPase/genética , Fatores de Troca do Nucleotídeo Guanina/genética , Células HEK293 , Células HeLa , Humanos , Immunoblotting , Cinética , Microscopia Eletrônica , Fosforilação , Proteínas rac1 de Ligação ao GTP/genética , Proteínas rac1 de Ligação ao GTP/metabolismo , Proteínas rho de Ligação ao GTP/genética , Proteínas rho de Ligação ao GTP/metabolismo
3.
Science ; 369(6503): 546-550, 2020 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-32554627

RESUMO

The neocortex has expanded during mammalian evolution. Overexpression studies in developing mouse and ferret neocortex have implicated the human-specific gene ARHGAP11B in neocortical expansion, but the relevance for primate evolution has been unclear. Here, we provide functional evidence that ARHGAP11B causes expansion of the primate neocortex. ARHGAP11B expressed in fetal neocortex of the common marmoset under control of the gene's own (human) promoter increased the numbers of basal radial glia progenitors in the marmoset outer subventricular zone, increased the numbers of upper-layer neurons, enlarged the neocortex, and induced its folding. Thus, the human-specific ARHGAP11B drives changes in development in the nonhuman primate marmoset that reflect the changes in evolution that characterize human neocortical development.


Assuntos
Proteínas Ativadoras de GTPase/metabolismo , Neocórtex/embriologia , Animais , Animais Geneticamente Modificados , Callithrix , Feto , Proteínas Ativadoras de GTPase/genética , Humanos , Ventrículos Laterais/embriologia , Ventrículos Laterais/metabolismo , Neocórtex/anatomia & histologia , Neocórtex/metabolismo , Células-Tronco Neurais/metabolismo , Neuroglia/metabolismo , Neurônios/metabolismo , Tamanho do Órgão , Regiões Promotoras Genéticas
4.
Proc Natl Acad Sci U S A ; 117(27): 15852-15861, 2020 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-32576693

RESUMO

In humans, a subset of placental cytotrophoblasts (CTBs) invades the uterus and its vasculature, anchoring the pregnancy and ensuring adequate blood flow to the fetus. Appropriate depth is critical. Shallow invasion increases the risk of pregnancy complications, e.g., severe preeclampsia. Overly deep invasion, the hallmark of placenta accreta spectrum (PAS), increases the risk of preterm delivery, hemorrhage, and death. Previously a rare condition, the incidence of PAS has increased to 1:731 pregnancies, likely due to the rise in uterine surgeries (e.g., Cesarean sections). CTBs track along scars deep into the myometrium and beyond. Here we compared the global gene expression patterns of CTBs from PAS cases to gestational age-matched control cells that invaded to the normal depth from preterm birth (PTB) deliveries. The messenger RNA (mRNA) encoding the guanine nucleotide exchange factor, DOCK4, mutations of which promote cancer cell invasion and angiogenesis, was the most highly up-regulated molecule in PAS samples. Overexpression of DOCK4 increased CTB invasiveness, consistent with the PAS phenotype. Also, this analysis identified other genes with significantly altered expression in this disorder, potential biomarkers. These data suggest that CTBs from PAS cases up-regulate a cancer-like proinvasion mechanism, suggesting molecular as well as phenotypic similarities in the two pathologies.


Assuntos
Proteínas Ativadoras de GTPase/genética , Proteínas Ativadoras de GTPase/metabolismo , Regulação da Expressão Gênica , Placenta Acreta/metabolismo , Trofoblastos/metabolismo , Regulação para Cima , Feminino , Humanos , Miométrio , Placenta/patologia , Placenta Acreta/genética , Placenta Acreta/patologia , Pré-Eclâmpsia , Gravidez , Transcriptoma , Útero/patologia
5.
Am J Physiol Cell Physiol ; 319(2): C404-C418, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32520609

RESUMO

The ADP-ribosylation factor (ARF) superfamily of regulatory GTPases, including both the ARF and ARF-like (ARL) proteins, control a multitude of cellular functions, including aspects of vesicular traffic, lipid metabolism, mitochondrial architecture, the assembly and dynamics of the microtubule and actin cytoskeletons, and other pathways in cell biology. Considering their general utility, it is perhaps not surprising that increasingly ARF/ARLs have been found in connection to primary cilia. Here, we critically evaluate the current knowledge of the roles four ARF/ARLs (ARF4, ARL3, ARL6, ARL13B) play in cilia and highlight key missing information that would help move our understanding forward. Importantly, these GTPases are themselves regulated by guanine nucleotide exchange factors (GEFs) that activate them and by GTPase-activating proteins (GAPs) that act as both effectors and terminators of signaling. We believe that the identification of the GEFs and GAPs and better models of the actions of these GTPases and their regulators will provide a much deeper understanding and appreciation of the mechanisms that underly ciliary functions and the causes of a number of human ciliopathies.


Assuntos
Fatores de Ribosilação do ADP/genética , Cílios/genética , Ciliopatias/genética , GTP Fosfo-Hidrolases/genética , Fatores de Ribosilação do ADP/classificação , Cílios/metabolismo , Ciliopatias/patologia , Citoesqueleto/genética , GTP Fosfo-Hidrolases/classificação , Proteínas Ativadoras de GTPase/genética , Fatores de Troca do Nucleotídeo Guanina/genética , Humanos , Microtúbulos/genética , Transdução de Sinais/genética
6.
Life Sci ; 255: 117857, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32470446

RESUMO

AIMS: To explore the pro-metastatic role of exosomes derived from highly invasive pancreatic cancer cell and the associated aberrant expression of exosomal microRNAs (miRNAs). MAIN METHODS: Weakly invasive PC-1 cells were treated with exosomes of highly invasive PC-1.0 cells to determine the pro-metastatic effect of PC-1.0 derived exosomes. The exosomal miRNA profile was further investigated using high-throughput sequencing. The level of miR-125b-5p in highly and weakly invasive pancreatic cancer cells was further determined. Pancreatic cancer cells transfected with miR-125b-5p mimic and inhibitor were used to explore the effect of miR-125b-5p on migration, invasion and epithelial-to-mesenchymal transition (EMT). Treatment with PC-1.0 derived exosome and Western blot assay were performed to validate STARD13 as a target of exosomal miR-125b-5p in pancreatic cancer. KEY FINDINGS: PC-1.0 derived exosomes promoted the migration and invasion of weakly invasive PC-1 cells. miRNA sequencing revealed 62 miRNAs upregulated in PC-1.0 derived exosomes. miR-125b-5p most significantly promoted migration and invasion and was associated with metastasis in pancreatic cancer. Further, miR-125b-5p was upregulated in highly invasive pancreatic cancer cells and increased migration, invasion, and EMT. Moreover, its upregulation was associated with activation of MEK2/ERK2 signaling. The tumor suppressor STARD13 was directly targeted by miR-125b-5p in pancreatic cancer, which was associated with good prognosis and was suppressed by exosomes derived from highly invasive cancer cells. SIGNIFICANCE: This study explored the pro-metastatic role of exosomes derived from highly invasive pancreatic cancer cells and the associated aberrant expression of exosomal miRNAs, which may help to elucidate the metastatic mechanism of pancreatic cancer.


Assuntos
Exossomos/genética , Proteínas Ativadoras de GTPase/genética , MicroRNAs/genética , Neoplasias Pancreáticas/patologia , Proteínas Supressoras de Tumor/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Transição Epitelial-Mesenquimal/genética , Humanos , Invasividade Neoplásica/genética , Metástase Neoplásica/genética , Neoplasias Pancreáticas/genética , Fenótipo , Regulação para Cima
7.
PLoS One ; 15(5): e0226057, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32413024

RESUMO

Estrogen receptor ß (ERß) was first identified in the rodent prostate and is abundantly expressed in human and rodent prostate epithelium, stroma, immune cells and endothelium of the blood vessels. In the prostates of mice with inactivated ERß, mutant phenotypes include epithelial hyperplasia and increased expression of androgen receptor (AR)-regulated genes, most of which are also upregulated in prostate cancer (PCa). ERß is expressed in both basal and luminal cells in the prostate while AR is expressed in luminal but not in the basal cell layer which harbors the prostate stem cells. To investigate the mechanisms of action of ERß and its potential cross-talk with AR, we used RNA-seq to study the effects of estradiol or the synthetic ligand, LY3201, in AR-positive LNCaP PCa cells which had been engineered to express ERß. Transcriptomic analysis indicated relatively few changes in gene expression with ERß overexpression, but robust responses following ligand treatments. There is significant overlap of responsive genes between the two ligands, estradiol and LY3201 as well as ligand-specific alterations. Gene set analysis of down-regulated genes identified an enrichment of androgen-responsive genes, such as FKBP5, CAMKK2, and TBC1D4. Consistently, AR transcript, protein levels, and transcriptional activity were down-regulated following ERß activation. In agreement with this, we find that the phosphorylation of the CAMKK2 target, AMPK, was repressed by ligand-activated ERß. These findings suggest that ERß-mediated signaling pathways are involved in the negative regulation of AR expression and activity, thus supporting a tumor suppressive role for ERß in PCa.


Assuntos
Receptor beta de Estrogênio/metabolismo , Neoplasias da Próstata/metabolismo , Receptores Androgênicos/metabolismo , Benzopiranos/farmacologia , Quinase da Proteína Quinase Dependente de Cálcio-Calmodulina/genética , Quinase da Proteína Quinase Dependente de Cálcio-Calmodulina/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Estradiol/farmacologia , Receptor beta de Estrogênio/agonistas , Proteínas Ativadoras de GTPase/genética , Proteínas Ativadoras de GTPase/metabolismo , Humanos , Masculino , Receptores Androgênicos/genética , Transdução de Sinais , Proteínas de Ligação a Tacrolimo/genética , Proteínas de Ligação a Tacrolimo/metabolismo
8.
DNA Cell Biol ; 39(9): 1545-1557, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32456571

RESUMO

ADP-ribosylation factor (Arf) GTPase-activating protein (GAP) with coiled-coil, ankyrin repeat and PH domains 1 (ACAP1) is an Arf6 GAP that regulates membrane trafficking and is critical for the migratory potential of cells. However, the roles of ACAP1 have not been fully explored and its association with clinicopathological features in ovarian cancer is still unknown. In this study, we systematically analyzed multiple databases, including TISIDB, Tumor Immune Estimation Resource (TIMER2.0), Gene Expression Omnibus (GEO), CORTECON, Kaplan-Meier Plotter and LinkedOmics platforms to reveal the clinical significance and function of ACAP1 in ovarian cancer. We found that the expression of ACAP1 was upregulated in ovarian cancer and high ACAP1 expression predicted poor prognosis. Our data demonstrated that the expression and methylation status of ACAP1 were strongly correlated with immune infiltration levels, immunomodulators, and chemokines. Gene set enrichment analysis (GSEA) analysis also showed that the mechanism of ACAP1 in regulating ovarian cancer was related to a variety of immune-related pathways. In addition, we also revealed that the expression of ACAP1 was altered during cell differentiation and associated with cancer cell stemness markers. Our study highlights the clinical significance of ACAP1 in ovarian cancer and provides insight into the novel function of ACAP1 in regulation of tumor immune microenvironment and cancer cell stemness.


Assuntos
Biomarcadores Tumorais/genética , Proteínas Ativadoras de GTPase/genética , Neoplasias Ovarianas/genética , Biomarcadores Tumorais/metabolismo , Diferenciação Celular , Quimiocinas/genética , Quimiocinas/metabolismo , Metilação de DNA , Feminino , Proteínas Ativadoras de GTPase/metabolismo , Humanos , Linfócitos do Interstício Tumoral/metabolismo , Células-Tronco Neoplásicas/metabolismo , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , Análise de Sobrevida , Microambiente Tumoral , Regulação para Cima
9.
Am J Respir Crit Care Med ; 202(2): 259-274, 2020 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-32255672

RESUMO

Rationale: Obesity-related asthma disproportionately affects minority children and is associated with nonatopic T-helper type 1 (Th1) cell polarized inflammation that correlates with pulmonary function deficits. Its underlying mechanisms are poorly understood.Objectives: To use functional genomics to identify cellular mechanisms associated with nonatopic inflammation in obese minority children with asthma.Methods: CD4+ (cluster of differentiation 4-positive) Th cells from 59 obese Hispanic and African American children with asthma and 61 normal-weight Hispanic and African American children with asthma underwent quantification of the transcriptome and DNA methylome and genotyping. Expression and methylation quantitative trait loci revealed the contribution of genetic variation to transcription and DNA methylation. Adjusting for Th-cell subtype proportions discriminated loci where transcription or methylation differences were driven by differences in subtype proportions from loci that were independently associated with obesity-related asthma.Measurements and Main Results: Obese children with asthma had more memory and fewer naive Th cells than normal-weight children with asthma. Differentially expressed and methylated genes and methylation quantitative trait loci in obese children with asthma, independent of Th-cell subtype proportions, were enriched in Rho-GTPase pathways. Inhibition of CDC42 (cell division cycle 42), one of the Rho-GTPases associated with Th-cell differentiation, was associated with downregulation of the IFNγ, but not the IL-4, gene. Differential expression of the RPS27L (40S ribosomal protein S27-like) gene, part of the p53/mammalian target of rapamycin pathway, was due to nonrandom distribution of expression quantitative trait loci variants between groups. Differentially expressed and/or methylated genes, including RPS27L, were associated with pulmonary function deficits in obese children with asthma.Conclusions: We found enrichment of Rho-GTPase pathways in obese asthmatic Th cells, identifying them as a novel therapeutic target for obesity-related asthma, a disease that is suboptimally responsive to current therapies.


Assuntos
Afro-Americanos/genética , Asma/genética , Proteínas Ativadoras de GTPase/genética , Genômica , Hispano-Americanos/genética , Obesidade Pediátrica/genética , Fenótipo , Adolescente , Asma/fisiopatologia , Criança , Pré-Escolar , Feminino , Proteínas Ativadoras de GTPase/metabolismo , Voluntários Saudáveis , Humanos , Lactente , Masculino
10.
Hum Cell ; 33(3): 437-443, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32274657

RESUMO

StarD13 is a tumor suppressor and a GTPase activating protein (GAP) for Rho GTPases. Thus, StarD13 regulates cell survival pathways and induces apoptosis in a p53-dependent and independent manners. In tumors, StarD13 is either downregulated or completely inhibited, depending on the tumor type. As such, and through the dysregulation of Rho GTPases, this affects adhesion dynamics, actin dynamics, and leads to an increase or a decrease in tumor metastasis depending on the tumor grade and type. Being a key regulatory protein, StarD13 is a potential promising candidate for therapeutic approaches. This paper reviews the key characteristics of this protein and its role in tumor malignancies.


Assuntos
Proteínas Ativadoras de GTPase/genética , Terapia de Alvo Molecular , Neoplasias/tratamento farmacológico , Neoplasias/genética , Proteínas Supressoras de Tumor/genética , Sequência de Aminoácidos , Regulação para Baixo , Proteínas Ativadoras de GTPase/química , Proteínas Ativadoras de GTPase/metabolismo , Genes Supressores de Tumor , Humanos , Neoplasias/patologia , Proteína Supressora de Tumor p53 , Proteínas Supressoras de Tumor/química , Proteínas Supressoras de Tumor/metabolismo , Proteínas rho de Ligação ao GTP
11.
Nat Commun ; 11(1): 1913, 2020 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-32312989

RESUMO

The TAGAP gene locus has been linked to several infectious diseases or autoimmune diseases, including candidemia and multiple sclerosis. While previous studies have described a role of TAGAP in T cells, much less is known about its function in other cell types. Here we report that TAGAP is required for Dectin-induced anti-fungal signaling and proinflammatory cytokine production in myeloid cells. Following stimulation with Dectin ligands, TAGAP is phosphorylated by EPHB2 at tyrosine 310, which bridges proximal Dectin-induced EPHB2 activity to downstream CARD9-mediated signaling pathways. During Candida albicans infection, mice lacking TAGAP mount defective immune responses, impaired Th17 cell differentiation, and higher fungal burden. Similarly, in experimental autoimmune encephalomyelitis model of multiple sclerosis, TAGAP deficient mice develop significantly attenuated disease. In summary, we report that TAGAP plays an important role in linking Dectin-induced signaling to the promotion of effective T helper cell immune responses, during both anti-fungal host defense and autoimmunity.


Assuntos
Antifúngicos/imunologia , Candidíase/imunologia , Diferenciação Celular , Proteínas Ativadoras de GTPase/química , Proteínas Ativadoras de GTPase/metabolismo , Receptor EphB2/metabolismo , Transdução de Sinais/efeitos dos fármacos , Células Th17/metabolismo , Animais , Antifúngicos/farmacologia , Proteínas Adaptadoras de Sinalização CARD/metabolismo , Citocinas/metabolismo , Modelos Animais de Doenças , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/microbiologia , Feminino , Proteínas Ativadoras de GTPase/genética , Humanos , Lectinas Tipo C/metabolismo , Masculino , Camundongos Knockout , Esclerose Múltipla/complicações , Esclerose Múltipla/imunologia , Fosforilação , Receptor EphB2/imunologia , Receptores Imunológicos , Receptores de Reconhecimento de Padrão/metabolismo , Células Th17/imunologia
12.
Proc Natl Acad Sci U S A ; 117(18): 9876-9883, 2020 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-32303654

RESUMO

A massive intronic hexanucleotide repeat (GGGGCC) expansion in C9ORF72 is a genetic origin of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Recently, C9ORF72, together with SMCR8 and WDR41, has been shown to regulate autophagy and function as Rab GEF. However, the precise function of C9ORF72 remains unclear. Here, we report the cryogenic electron microscopy (cryo-EM) structure of the human C9ORF72-SMCR8-WDR41 complex at a resolution of 3.2 Å. The structure reveals the dimeric assembly of a heterotrimer of C9ORF72-SMCR8-WDR41. Notably, the C-terminal tail of C9ORF72 and the DENN domain of SMCR8 play critical roles in the dimerization of the two protomers of the C9ORF72-SMCR8-WDR41 complex. In the protomer, C9ORF72 and WDR41 are joined by SMCR8 without direct interaction. WDR41 binds to the DENN domain of SMCR8 by the C-terminal helix. Interestingly, the prominent structural feature of C9ORF72-SMCR8 resembles that of the FLNC-FNIP2 complex, the GTPase activating protein (GAP) of RagC/D. Structural comparison and sequence alignment revealed that Arg147 of SMCR8 is conserved and corresponds to the arginine finger of FLCN, and biochemical analysis indicated that the Arg147 of SMCR8 is critical to the stimulatory effect of the C9ORF72-SMCR8 complex on Rab8a and Rab11a. Our study not only illustrates the basis of C9ORF72-SMCR8-WDR41 complex assembly but also reveals the GAP activity of the C9ORF72-SMCR8 complex.


Assuntos
Proteínas Relacionadas à Autofagia/ultraestrutura , Proteína C9orf72/ultraestrutura , Proteínas de Transporte/ultraestrutura , Complexos Multiproteicos/ultraestrutura , Sequência de Aminoácidos/genética , Esclerose Amiotrófica Lateral/genética , Arginina/genética , Autofagia/genética , Proteínas Relacionadas à Autofagia/genética , Proteína C9orf72/genética , Proteínas de Transporte/genética , Microscopia Crioeletrônica , Filaminas/genética , Filaminas/ultraestrutura , Demência Frontotemporal/genética , Proteínas Ativadoras de GTPase/genética , Proteínas Ativadoras de GTPase/ultraestrutura , Predisposição Genética para Doença , Humanos , Complexos Multiproteicos/genética , Alinhamento de Sequência , Proteínas rab de Ligação ao GTP/genética
13.
Nat Cell Biol ; 22(4): 498-511, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32203420

RESUMO

Rho GTPases are central regulators of the cytoskeleton and, in humans, are controlled by 145 multidomain guanine nucleotide exchange factors (RhoGEFs) and GTPase-activating proteins (RhoGAPs). How Rho signalling patterns are established in dynamic cell spaces to control cellular morphogenesis is unclear. Through a family-wide characterization of substrate specificities, interactomes and localization, we reveal at the systems level how RhoGEFs and RhoGAPs contextualize and spatiotemporally control Rho signalling. These proteins are widely autoinhibited to allow local regulation, form complexes to jointly coordinate their networks and provide positional information for signalling. RhoGAPs are more promiscuous than RhoGEFs to confine Rho activity gradients. Our resource enabled us to uncover a multi-RhoGEF complex downstream of G-protein-coupled receptors controlling CDC42-RHOA crosstalk. Moreover, we show that integrin adhesions spatially segregate GEFs and GAPs to shape RAC1 activity zones in response to mechanical cues. This mechanism controls the protrusion and contraction dynamics fundamental to cell motility. Our systems analysis of Rho regulators is key to revealing emergent organization principles of Rho signalling.


Assuntos
Citoesqueleto/genética , Proteínas Ativadoras de GTPase/genética , Integrinas/genética , Mecanotransdução Celular/genética , Fatores de Troca de Nucleotídeo Guanina Rho/genética , Proteínas rac1 de Ligação ao GTP/genética , Animais , Células COS , Adesão Celular , Linhagem Celular , Movimento Celular , Chlorocebus aethiops , Biologia Computacional , Citoesqueleto/metabolismo , Citoesqueleto/ultraestrutura , Cães , Fibroblastos/metabolismo , Fibroblastos/ultraestrutura , Proteínas Ativadoras de GTPase/classificação , Proteínas Ativadoras de GTPase/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Células HEK293 , Células HeLa , Humanos , Integrinas/metabolismo , Células Madin Darby de Rim Canino , Camundongos , Pan troglodytes , Domínios Proteicos , Ratos , Fatores de Troca de Nucleotídeo Guanina Rho/classificação , Fatores de Troca de Nucleotídeo Guanina Rho/metabolismo , Proteínas rac1 de Ligação ao GTP/metabolismo
14.
Mol Genet Genomics ; 295(3): 751-763, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32146541

RESUMO

It is thought that despite highly variable phenotypic expression, 70-80% of all epileptic cases are caused by one or more genetic mutations. Next generation sequencing technologies, such as whole exome sequencing (WES), can be used in a diagnostic or research setting to identify genetic mutations which may have significant prognostic implications for patients and their families. In this study, 398 genes associated with epilepsy or recurrent seizures were stratified into tiers based on genotype-phenotype concordance, tissue gene expression, frequency of affected individuals with mutations and evidence from functional and family studies. WES was completed on 14 DNA samples (2 with known mutations in SCN1A and 12 with no known mutations) from individuals diagnosed with epilepsy using an Ion AmpliSeq approach. WES confirmed positive SCN1A mutations in two samples. In n = 5/12 samples (S-3 to -14) we identified potentially causative mutations across five different genes. S-5 was identified to have a novel missense mutation in CCM2; S-6 a novel frameshift mutation identified in ADGRV1; S-10 had a previously reported pathogenic mutation in PCDH19, whilst a novel missense mutation in PCDH19 was shown in S-12; and S-13 identified to have separate missense mutations in KCNA2 and NPRL3. The application of WES followed by a targeted variant prioritization approach allowed for the discovery of potentially causative mutations in our cohort of previously undiagnosed epilepsy patients.


Assuntos
Biomarcadores/análise , Epilepsia/diagnóstico , Epilepsia/genética , Exoma/genética , Mutação , Sequenciamento Completo do Exoma/métodos , Adolescente , Adulto , Caderinas/genética , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Proteínas Ativadoras de GTPase/genética , Testes Genéticos/métodos , Humanos , Lactente , Canal de Potássio Kv1.2/genética , Masculino , Prognóstico
15.
Nat Commun ; 11(1): 1465, 2020 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-32193374

RESUMO

Genetic variation in the FAM13A (Family with Sequence Similarity 13 Member A) locus has been associated with several glycemic and metabolic traits in genome-wide association studies (GWAS). Here, we demonstrate that in humans, FAM13A alleles are associated with increased FAM13A expression in subcutaneous adipose tissue (SAT) and an insulin resistance-related phenotype (e.g. higher waist-to-hip ratio and fasting insulin levels, but lower body fat). In human adipocyte models, knockdown of FAM13A in preadipocytes accelerates adipocyte differentiation. In mice, Fam13a knockout (KO) have a lower visceral to subcutaneous fat (VAT/SAT) ratio after high-fat diet challenge, in comparison to their wild-type counterparts. Subcutaneous adipocytes in KO mice show a size distribution shift toward an increased number of smaller adipocytes, along with an improved adipogenic potential. Our results indicate that GWAS-associated variants within the FAM13A locus alter adipose FAM13A expression, which in turn, regulates adipocyte differentiation and contribute to changes in body fat distribution.


Assuntos
Adipócitos/metabolismo , Distribuição da Gordura Corporal , Proteínas Ativadoras de GTPase/genética , Adipogenia/genética , Animais , Diferenciação Celular/genética , Proteínas Ativadoras de GTPase/metabolismo , Técnicas de Silenciamento de Genes , Loci Gênicos , Estudo de Associação Genômica Ampla , Células HEK293 , Humanos , Resistência à Insulina/genética , Gordura Intra-Abdominal/metabolismo , Masculino , Metabolômica , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fenótipo , Polimorfismo de Nucleotídeo Único/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Gordura Subcutânea/metabolismo
16.
J Vet Med Sci ; 82(4): 483-487, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32147621

RESUMO

DEP domain-containing 1B (DEPDC1B) is involved in the regulation of cell de-adhesion and actin cytoskeleton activity during the G2/M transition of the cell cycle, and its overexpression has been proven to be associated with cancer progression in several human cancers. Canine DEPDC1B was identified as a gene that was overexpressed in canine lymphoma tissues in our previous study. However, in dogs, the protein expression of DEPDC1B remains to be determined due to the lack of a specific monoclonal antibody. Here, we developed rat monoclonal antibodies against canine DEPDC1B and characterized their applicability for immunodetection assays. Our findings demonstrated that these antibodies are functional and can be important tools to investigate the precise role of DEPDC1B in canine tumors.


Assuntos
Anticorpos Monoclonais/imunologia , Proteínas Ativadoras de GTPase/imunologia , Animais , Western Blotting/veterinária , Linhagem Celular Tumoral , Doenças do Cão/imunologia , Cães/imunologia , Feminino , Proteínas Ativadoras de GTPase/genética , Imuno-Histoquímica/métodos , Imuno-Histoquímica/veterinária , Imunoprecipitação/métodos , Imunoprecipitação/veterinária , Linfoma de Células T/veterinária , Células Madin Darby de Rim Canino , Camundongos , Ratos Sprague-Dawley , Proteínas Recombinantes/imunologia
17.
Biomed Res Int ; 2020: 7573689, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32149133

RESUMO

Background: Lung cancer is the most common cancer and the most common cause of cancer-related death worldwide. However, the molecular mechanism of its development is unclear. It is imperative to identify more novel biomarkers. Methods: Two datasets (GSE70880 and GSE113852) were downloaded from the Gene Expression Omnibus (GEO) database and used to identify the differentially expressed genes (DEGs) between lung cancer tissues and normal tissues. Then, we constructed a competing endogenous RNA (ceRNA) network and a protein-protein interaction (PPI) network and performed gene ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and survival analyses to identify potential biomarkers that are related to the diagnosis and prognosis of lung cancer. Results: A total of 41 lncRNAs and 805 mRNAs were differentially expressed in lung cancer. The ceRNA network contained four lncRNAs (CLDN10-AS1, SFTA1P, SRGAP3-AS2, and ADAMTS9-AS2), 21 miRNAs, and 48 mRNAs. Functional analyses revealed that the genes in the ceRNA network were mainly enriched in cell migration, transmembrane receptor, and protein kinase activity. mRNAs DLGAP5, E2F7, MCM7, RACGAP1, and RRM2 had the highest connectivity in the PPI network. Immunohistochemistry (IHC) demonstrated that mRNAs DLGAP5, MCM7, RACGAP1, and RRM2 were upregulated in lung adenocarcinoma (LUAD). Survival analyses showed that lncRNAs CLDN10-AS1, SFTA1P, and ADAMTS9-AS2 were associated with the prognosis of LUAD. Conclusion: lncRNAs CLDN10-AS1, SFTA1P, and ADAMTS9-AS2 might be the biomarkers of LUAD. For the first time, we confirmed the important role of lncRNA CLDN10-AS1 in LUAD.


Assuntos
Adenocarcinoma de Pulmão/genética , Biomarcadores Tumorais/genética , Neoplasias Pulmonares/genética , RNA Longo não Codificante/genética , RNA Longo não Codificante/isolamento & purificação , Adenocarcinoma de Pulmão/diagnóstico , Adenocarcinoma de Pulmão/patologia , Bases de Dados Factuais , Proteínas Ativadoras de GTPase/genética , Regulação Neoplásica da Expressão Gênica , Ontologia Genética , Redes Reguladoras de Genes , Humanos , Pulmão/metabolismo , Pulmão/patologia , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/patologia , Componente 7 do Complexo de Manutenção de Minicromossomo/genética , Proteínas de Neoplasias/genética , Prognóstico , Mapas de Interação de Proteínas , RNA Mensageiro/genética , Ribonucleosídeo Difosfato Redutase , Análise de Sobrevida , Transcriptoma
18.
Arch Virol ; 165(4): 799-807, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32100137

RESUMO

We previously found that infection with human parainfluenza virus type 2 (hPIV-2), a member of the genus Orthorubulavirus, family Paramyxoviridae, causes filamentous actin (F-actin) formation to promote viral growth. In the present study, we investigated whether similar regulation of F-actin formation is observed in infections with other rubulaviruses, such as parainfluenza virus type 5 (PIV-5) and simian virus 41 (SV41). Infection with these viruses caused F-actin formation and RhoA activation, which promoted viral growth. These results indicate that RhoA-induced F-actin formation is important for efficient growth of these rubulaviruses. Only SV41 and hPIV-2 V and P proteins bound to Graf1, while the V and P proteins of PIV-5, mumps virus, and hPIV-4 did not bind to Graf1. In contrast, the V proteins of these rubulaviruses bound to both inactive RhoA and profilin 2. These results suggest that there are common and unique mechanisms involved in regulation of F-actin formation by members of the genus Orthorubulavirus.


Assuntos
Actinas/metabolismo , Vírus da Parainfluenza 2 Humana/metabolismo , Vírus da Parainfluenza 5/metabolismo , Infecções por Rubulavirus/metabolismo , Rubulavirus/metabolismo , Actinas/química , Actinas/genética , Animais , Linhagem Celular , Proteínas Ativadoras de GTPase/genética , Proteínas Ativadoras de GTPase/metabolismo , Interações Hospedeiro-Patógeno , Humanos , Vírus da Parainfluenza 2 Humana/genética , Vírus da Parainfluenza 2 Humana/crescimento & desenvolvimento , Vírus da Parainfluenza 5/genética , Vírus da Parainfluenza 5/crescimento & desenvolvimento , Ligação Proteica , Rubulavirus/genética , Rubulavirus/crescimento & desenvolvimento , Infecções por Rubulavirus/genética , Infecções por Rubulavirus/virologia , Proteínas Virais/genética , Proteínas Virais/metabolismo , Proteína rhoA de Ligação ao GTP/genética , Proteína rhoA de Ligação ao GTP/metabolismo
19.
PLoS Genet ; 16(1): e1008587, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-32004315

RESUMO

Perturbation of synapse development underlies many inherited neurodevelopmental disorders including intellectual disability (ID). Diverse mutations on the human TBC1D24 gene are strongly associated with epilepsy and ID. However, the physiological function of TBC1D24 in the brain is not well understood, and there is a lack of genetic mouse model that mimics TBC1D24 loss-of-function for the study of animal behaviors. Here we report that TBC1D24 is present at the postsynaptic sites of excitatory synapses, where it is required for the maintenance of dendritic spines through inhibition of the small GTPase ARF6. Mice subjected to viral-mediated knockdown of TBC1D24 in the adult hippocampus display dendritic spine loss, deficits in contextual fear memory, as well as abnormal behaviors including hyperactivity and increased anxiety. Interestingly, we show that the protein stability of TBC1D24 is diminished by the disease-associated missense mutation that leads to F251L amino acid substitution. We further generate the F251L knock-in mice, and the homozygous mutants show increased neuronal excitability, spontaneous seizure and pre-mature death. Moreover, the heterozygous F251L knock-in mice survive into adulthood but display dendritic spine defects and impaired memory. Our findings therefore uncover a previously uncharacterized postsynaptic function of TBC1D24, and suggest that impaired dendritic spine maintenance contributes to the pathophysiology of individuals harboring TBC1D24 gene mutations. The F251L knock-in mice represent a useful animal model for investigation of the mechanistic link between TBC1D24 loss-of-function and neurodevelopmental disorders.


Assuntos
Epilepsia/genética , Potenciais Pós-Sinápticos Excitadores , Proteínas Ativadoras de GTPase/genética , Deficiência Intelectual/genética , Animais , Células Cultivadas , Hipocampo/metabolismo , Hipocampo/patologia , Hipocampo/fisiologia , Memória , Camundongos , Camundongos Endogâmicos C57BL , Mutação de Sentido Incorreto , Neurônios/metabolismo , Neurônios/patologia , Neurônios/fisiologia
20.
Clin Sci (Lond) ; 134(4): 419-434, 2020 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-32065214

RESUMO

Cancer-derived exosomal miRNAs play an important role in the development of metastasis, but the effects and underlying mechanisms remain unclear. In the present study, we investigated the miRNA expression profiles of 5 paired serum exosomal samples from metastatic colorectal cancer (mCRC) and non-mCRC patients via RNA sequencing. After we evaluated the differentially expressed miRNAs in 80 CRC patients, miR-106b-3p was selected as a metastasis-associated miRNA of CRC. We showed that the expression level of serum exosomal miR-106b-3p was significantly higher in CRC patients with metastasis than those without metastasis. Additionally, high serum exosomal miR-106b-3p expression in patients was correlated with a poor prognosis. Coculture of low-metastatic CRC cells with high-metastatic CRC cell-derived exosomes promoted cell migration, invasion, and epithelial-to-mesenchymal transition (EMT), which was caused by the transport and transduction of miR-106b-3p in vitro. Moreover, exosomal miR-106b-3p promoted lung metastasis of CRC cells in vivo. In addition, we demonstrated that miR-106b-3p regulated metastasis by targeting deleted in liver cancer-1 (DLC-1). A negative correlation was also identified between miR-106b-3p and DLC-1 expression in human CRC tumour tissues and in mouse lung metastatic lesions. Collectively, our study indicated that metastasis-associated miR-106b-3p from serum exosomes could be used as a potential prognostic biomarker and therapeutic target for CRC patients.


Assuntos
Neoplasias Colorretais/genética , Exossomos/genética , Proteínas Ativadoras de GTPase/genética , MicroRNAs/metabolismo , Proteínas Supressoras de Tumor/genética , Animais , Sequência de Bases , Linhagem Celular Tumoral , Neoplasias Colorretais/sangue , Progressão da Doença , Regulação para Baixo , Transição Epitelial-Mesenquimal/genética , Proteínas Ativadoras de GTPase/metabolismo , Regulação Neoplásica da Expressão Gênica , Células HEK293 , Humanos , Neoplasias Pulmonares/secundário , Camundongos Endogâmicos BALB C , Camundongos Nus , MicroRNAs/sangue , MicroRNAs/genética , Invasividade Neoplásica , Metástase Neoplásica , Prognóstico , Reprodutibilidade dos Testes , Proteínas Supressoras de Tumor/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA