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1.
Nat Commun ; 12(1): 841, 2021 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-33547291

RESUMO

A new life begins with the unification of the maternal and paternal chromosomes upon fertilization. The parental chromosomes first become enclosed in two separate pronuclei near the surface of the fertilized egg. The mechanisms that then move the pronuclei inwards for their unification are only poorly understood in mammals. Here, we report two mechanisms that act in concert to unite the parental genomes in fertilized mouse eggs. The male pronucleus assembles within the fertilization cone and is rapidly moved inwards by the flattening cone. Rab11a recruits the actin nucleation factors Spire and Formin-2 into the fertilization cone, where they locally nucleate actin and further accelerate the pronucleus inwards. In parallel, a dynamic network of microtubules assembles that slowly moves the male and female pronuclei towards the cell centre in a dynein-dependent manner. Both mechanisms are partially redundant and act in concert to unite the parental pronuclei in the zygote's centre.


Assuntos
Núcleo Celular/metabolismo , Fertilização/genética , Forminas/genética , Proteínas dos Microfilamentos/genética , Proteínas do Tecido Nervoso/genética , Zigoto/metabolismo , Proteínas rab de Ligação ao GTP/genética , Actinas/genética , Actinas/metabolismo , Animais , Núcleo Celular/ultraestrutura , Feminino , Forminas/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Genes Reporter , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Proteínas dos Microfilamentos/metabolismo , Microtúbulos/metabolismo , Microtúbulos/ultraestrutura , Movimento , Proteínas do Tecido Nervoso/metabolismo , Oócitos/metabolismo , Oócitos/ultraestrutura , Espermatozoides/metabolismo , Espermatozoides/ultraestrutura , Zigoto/ultraestrutura , Proteínas rab de Ligação ao GTP/metabolismo
2.
Nat Commun ; 12(1): 836, 2021 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-33547321

RESUMO

Dynamic regulation of intestinal cell differentiation is crucial for both homeostasis and the response to injury or inflammation. Sprouty2, an intracellular signaling regulator, controls pathways including PI3K and MAPKs that are implicated in differentiation and are dysregulated in inflammatory bowel disease. Here, we ask whether Sprouty2 controls secretory cell differentiation and the response to colitis. We report that colonic epithelial Sprouty2 deletion leads to expanded tuft and goblet cell populations. Sprouty2 loss induces PI3K/Akt signaling, leading to GSK3ß inhibition and epithelial interleukin (IL)-33 expression. In vivo, this results in increased stromal IL-13+ cells. IL-13 in turn induces tuft and goblet cell expansion in vitro and in vivo. Sprouty2 is downregulated by acute inflammation; this appears to be a protective response, as VillinCre;Sprouty2F/F mice are resistant to DSS colitis. In contrast, Sprouty2 is elevated in chronic colitis and in colons of inflammatory bowel disease patients, suggesting that this protective epithelial-stromal signaling mechanism is lost in disease.


Assuntos
Colite/genética , Glicogênio Sintase Quinase 3 beta/genética , Homeostase/genética , Interleucina-33/genética , Proteínas de Membrana/genética , Proteínas Serina-Treonina Quinases/genética , Animais , Contagem de Células , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Criança , Colite/induzido quimicamente , Colite/metabolismo , Colite/patologia , Colo/efeitos dos fármacos , Colo/metabolismo , Colo/patologia , Feminino , Regulação da Expressão Gênica , Glicogênio Sintase Quinase 3 beta/metabolismo , Células Caliciformes/efeitos dos fármacos , Células Caliciformes/metabolismo , Células Caliciformes/patologia , Células HT29 , Homeostase/efeitos dos fármacos , Humanos , Interleucina-33/metabolismo , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Masculino , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Dodecilsulfato de Sódio/administração & dosagem
3.
Gene ; 775: 145428, 2021 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-33460763

RESUMO

BACKGROUND: Myocardial infarction (MI) and underlining atherosclerosis are the main causes of death worldwide. Phosphatase and actin regulator 1 (PHACTR1) variants have been associated with early onset MI, coronary artery disease and carotid dissection. PHACTR1 mRNA expression has been detected in tissues and cells related to atherosclerosis. Nonetheless, the true effect of PHACTR1 on vascular diseases is still unknown. Our aim was to examine the association of PHACTR1 intronic variants, rs9349379, rs2026458 and rs2876300, with MI and multi-vessel disease (MVD) and to assess their effect on PHACTR1 and EDN1 mRNA expression in PBMCs of patients six months after MI. METHODS: The study enrolled 537 patients with the first MI and 310 controls. Gene expression was assessed in 74 patients six months after MI and 37 healthy controls. Rs9349379, rs2026458, rs2876300 and relative mRNA expressions were detected by TaqMan® technology. RESULTS: The significant association between PHACTR1 variants and MI was not found, either individually or in haplotype. A higher frequency of rs2876300G-allele in MVD was rendered not significant after Bonferroni correction. PHACTR1 mRNA was significantly increased in PBMCs of patients six months after MI compared to controls (p = 0.02). Patients that carry ACG haplotype have increased PHACTR1 mRNA expression in PBMCs (p = 0.04). There was no effect of PHACTR1 variants on EDN1 mRNA expression. CONCLUSION: Our findings suggest that PHACTR1 intronic variants may have a role in severity and progression of coronary atherosclerosis. Future research is needed to clarify the mechanism underlying the role of PHACTR1 in coronary atherosclerosis and MI.


Assuntos
Proteínas dos Microfilamentos/genética , Infarto do Miocárdio/genética , Polimorfismo de Nucleotídeo Único , Regulação para Cima , Adulto , Idade de Início , Idoso , Estudos de Casos e Controles , Endotelina-1/genética , Feminino , Estudos de Associação Genética , Humanos , Íntrons , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença
4.
Development ; 147(23)2020 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-33310787

RESUMO

Planar cell polarity (PCP) is essential for tissue morphogenesis and homeostasis; however, the mechanisms that orchestrate the cell shape and packing dynamics required to establish PCP are poorly understood. Here, we identified a major role for the globular (G)-actin-binding protein thymosin-ß4 (TMSB4X) in PCP establishment and cell adhesion in the developing epidermis. Depletion of Tmsb4x in mouse embryos hindered eyelid closure and hair-follicle angling owing to PCP defects. Tmsb4x depletion did not preclude epidermal cell adhesion in vivo or in vitro; however, it resulted in abnormal structural organization and stability of adherens junction (AJ) due to defects in filamentous (F)-actin and G-actin distribution. In cultured keratinocytes, TMSB4X depletion increased the perijunctional G/F-actin ratio and decreased G-actin incorporation into junctional actin networks, but it did not change the overall actin expression level or cellular F-actin content. A pharmacological treatment that increased the G/F-actin ratio and decreased actin polymerization mimicked the effects of Tmsb4x depletion on both AJs and PCP. Our results provide insights into the regulation of the actin pool and its involvement in AJ function and PCP establishment.


Assuntos
Polaridade Celular/genética , Desenvolvimento Embrionário/genética , Morfogênese/genética , Timosina/genética , Citoesqueleto de Actina/genética , Actinas/genética , Junções Aderentes/genética , Animais , Adesão Celular/genética , Forma Celular/genética , Células Epidérmicas/metabolismo , Epiderme/crescimento & desenvolvimento , Homeostase/genética , Queratinócitos/metabolismo , Camundongos , Proteínas dos Microfilamentos/genética
5.
PLoS Genet ; 16(12): e1009266, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33370279

RESUMO

Malaria continues to impose a significant health burden in the continent of Africa with 213 million cases in 2018 alone, representing 93% of cases worldwide. Because of high transmission of malaria within the continent, the selection pressures to develop drug resistance in African parasites are distinct compared to the rest of the world. In light of the spread of resistance to artemisinin conferred by the C580Y mutation in the PfKelch13 propeller domain in Southeast Asia, and its independent emergence in South America, it is important to study genetic determinants of resistance in the African context using African parasites. Through in vitro evolution of Senegalese parasites, we had previously generated the artemisinin-resistant parasites Pikine_R and Thiès_R and established pfcoronin mutations to be sufficient to confer artemisinin resistance in the standard ring-stage survival assay (RSA). In the current study, we used genetic analysis of revertants to demonstrate pfcoronin to be the major driver of elevated RSA in the artemisinin-resistant parasites Pikine_R and Thiès_R evolved in vitro. We interrogated the role of a second gene PF3D7_1433800, which also had mutations in both the Pikine_R and Thiès_R selected lines, but found no evidence of a contribution to reduced susceptibility in the RSA survival assay. Nevertheless, our genetic analysis demonstrates that parasite genetic background is important in the level of pfcoronin mediated RSA survival, and therefore we cannot rule out a role for PF3D7_1433800 in other genetic backgrounds. Finally, we tested the potential synergy between the mutations of pfcoronin and pfkelch13 through the generation of single and double mutants in the Pikine genetic background and found that the contribution of pfcoronin to reduced susceptibility is masked by the presence of pfkelch13. This phenomenon was also observed in the 3D7 background, suggesting that pfcoronin may mediate its effects via the same pathway as pfkelch13. Investigating the biology of proteins containing the beta-propeller domain could further elucidate the different pathways that the parasite could use to attain resistance.


Assuntos
Resistência a Medicamentos , Patrimônio Genético , Proteínas dos Microfilamentos/genética , Mutação , Plasmodium falciparum/genética , Proteínas de Protozoários/genética , Antimaláricos/farmacologia , Artemisininas/farmacologia , Repetição Kelch , Proteínas dos Microfilamentos/química , Plasmodium falciparum/efeitos dos fármacos , Proteínas de Protozoários/química
6.
Nat Commun ; 11(1): 5476, 2020 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-33127887

RESUMO

The formation of vascular tubes is driven by extensive changes in endothelial cell (EC) shape. Here, we have identified a role of the actin-binding protein, Marcksl1, in modulating the mechanical properties of EC cortex to regulate cell shape and vessel structure during angiogenesis. Increasing and depleting Marcksl1 expression level in vivo results in an increase and decrease, respectively, in EC size and the diameter of microvessels. Furthermore, endothelial overexpression of Marcksl1 induces ectopic blebbing on both apical and basal membranes, during and after lumen formation, that is suppressed by reduced blood flow. High resolution imaging reveals that Marcksl1 promotes the formation of linear actin bundles and decreases actin density at the EC cortex. Our findings demonstrate that a balanced network of linear and branched actin at the EC cortex is essential in conferring cortical integrity to resist the deforming forces of blood flow to regulate vessel structure.


Assuntos
Vasos Sanguíneos/anatomia & histologia , Vasos Sanguíneos/fisiologia , Proteínas de Ligação a Calmodulina/metabolismo , Células Endoteliais/metabolismo , Hemodinâmica/fisiologia , Proteínas dos Microfilamentos/metabolismo , Actinas/metabolismo , Actomiosina/metabolismo , Animais , Animais Geneticamente Modificados , Vasos Sanguíneos/citologia , Proteínas de Ligação a Calmodulina/genética , Células Endoteliais/citologia , Regulação da Expressão Gênica no Desenvolvimento , Proteínas dos Microfilamentos/genética , Modelos Animais , Transcriptoma , Peixe-Zebra/embriologia
7.
Nat Commun ; 11(1): 5315, 2020 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-33082334

RESUMO

Melanoma is a highly aggressive tumour that can metastasize very early in disease progression. Notably, melanoma can disseminate using amoeboid invasive strategies. We show here that high Myosin II activity, high levels of ki-67 and high tumour-initiating abilities are characteristic of invasive amoeboid melanoma cells. Mechanistically, we find that WNT11-FZD7-DAAM1 activates Rho-ROCK1/2-Myosin II and plays a crucial role in regulating tumour-initiating potential, local invasion and distant metastasis formation. Importantly, amoeboid melanoma cells express both proliferative and invasive gene signatures. As such, invasive fronts of human and mouse melanomas are enriched in amoeboid cells that are also ki-67 positive. This pattern is further enhanced in metastatic lesions. We propose eradication of amoeboid melanoma cells after surgical removal as a therapeutic strategy.


Assuntos
Receptores Frizzled/metabolismo , Melanoma/metabolismo , Proteínas dos Microfilamentos/metabolismo , Proteínas Wnt/metabolismo , Proteínas rho de Ligação ao GTP/metabolismo , Animais , Transformação Celular Neoplásica , Feminino , Receptores Frizzled/genética , Humanos , Masculino , Melanoma/genética , Melanoma/patologia , Camundongos , Camundongos SCID , Proteínas dos Microfilamentos/genética , Miosina Tipo II/genética , Miosina Tipo II/metabolismo , Invasividade Neoplásica , Transdução de Sinais , Proteínas Wnt/genética , Proteínas rho de Ligação ao GTP/genética , Quinases Associadas a rho/genética , Quinases Associadas a rho/metabolismo
8.
Maturitas ; 141: 9-19, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33036707

RESUMO

Ovarian deficiency, including premature ovarian insufficiency (POI) and diminished ovarian reserve (DOR), represents one of the main causes of female infertility. POI is a genetically heterogeneous condition but current understanding of its genetic basis is far from complete, with the cause remaining unknown in the majority of patients. The genes that regulate DOR have been reported but the genetic basis of DOR has not been explored in depth. Both conditions are likely to lie along a continuum of degrees of decrease in ovarian reserve. We performed genomic analysis via whole exome sequencing (WES) followed by in silico analyses and functional experiments to investigate the genetic cause of ovarian deficiency in ten affected women. We achieved diagnoses for three of them, including the identification of novel variants in STAG3, GDF9, and FANCM. We identified potentially causative FSHR variants in another patient. This is the second report of biallelic GDF9 and FANCM variants, and, combined with functional support, validates these genes as bone fide autosomal recessive "POI genes". We also identified new candidate genes, NRIP1, XPO1, and MACF1. These genes have been linked to ovarian function in mouse, pig, and zebrafish respectively, but never in humans. In the case of NRIP1, we provide functional support for the deleterious nature of the variant via SUMOylation and luciferase/ß-galactosidase reporter assays. Our study provides multiple insights into the genetic basis of POI/DOR. We have further elucidated the involvement of GDF9, FANCM, STAG3 and FSHR in POI pathogenesis, and propose new candidate genes, NRIP1, XPO1, and MACF1, which should be the focus of future studies.


Assuntos
Carioferinas/genética , Proteínas dos Microfilamentos/genética , Proteína 1 de Interação com Receptor Nuclear/genética , Reserva Ovariana/genética , Insuficiência Ovariana Primária/genética , Receptores Citoplasmáticos e Nucleares/genética , Adolescente , Proteínas de Ciclo Celular/genética , DNA Helicases/genética , Feminino , Genômica , Fator 9 de Diferenciação de Crescimento/genética , Humanos , Infertilidade Feminina , Menopausa Precoce/genética , Doenças Ovarianas , Sequenciamento Completo do Exoma , Adulto Jovem
9.
Nat Commun ; 11(1): 4432, 2020 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-32887874

RESUMO

Spontaneous coronary artery dissection (SCAD) is a non-atherosclerotic cause of myocardial infarction (MI), typically in young women. We undertook a genome-wide association study of SCAD (Ncases = 270/Ncontrols = 5,263) and identified and replicated an association of rs12740679 at chromosome 1q21.2 (Pdiscovery+replication = 2.19 × 10-12, OR = 1.8) influencing ADAMTSL4 expression. Meta-analysis of discovery and replication samples identified associations with P < 5 × 10-8 at chromosome 6p24.1 in PHACTR1, chromosome 12q13.3 in LRP1, and in females-only, at chromosome 21q22.11 near LINC00310. A polygenic risk score for SCAD was associated with (1) higher risk of SCAD in individuals with fibromuscular dysplasia (P = 0.021, OR = 1.82 [95% CI: 1.09-3.02]) and (2) lower risk of atherosclerotic coronary artery disease and MI in the UK Biobank (P = 1.28 × 10-17, HR = 0.91 [95% CI :0.89-0.93], for MI) and Million Veteran Program (P = 9.33 × 10-36, OR = 0.95 [95% CI: 0.94-0.96], for CAD; P = 3.35 × 10-6, OR = 0.96 [95% CI: 0.95-0.98] for MI). Here we report that SCAD-related MI and atherosclerotic MI exist at opposite ends of a genetic risk spectrum, inciting MI with disparate underlying vascular biology.


Assuntos
Anomalias dos Vasos Coronários/genética , Genes Neoplásicos , Infarto do Miocárdio/genética , Doenças Vasculares/congênito , Proteínas ADAMTS/genética , Doenças das Artérias Carótidas/complicações , Doenças das Artérias Carótidas/genética , Cromossomos/genética , Estudos de Coortes , Doença da Artéria Coronariana/genética , Feminino , Displasia Fibromuscular/complicações , Displasia Fibromuscular/genética , Estudo de Associação Genômica Ampla , Humanos , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade/genética , Masculino , Metanálise como Assunto , Proteínas dos Microfilamentos/genética , Fatores de Risco , Doenças Vasculares/genética
10.
Nat Commun ; 11(1): 4818, 2020 09 23.
Artigo em Inglês | MEDLINE | ID: mdl-32968060

RESUMO

Migrating cells move across diverse assemblies of extracellular matrix (ECM) that can be separated by micron-scale gaps. For membranes to protrude and reattach across a gap, actin filaments, which are relatively weak as single filaments, must polymerize outward from adhesion sites to push membranes towards distant sites of new adhesion. Here, using micropatterned ECMs, we identify T-Plastin, one of the most ancient actin bundling proteins, as an actin stabilizer that promotes membrane protrusions and enables bridging of ECM gaps. We show that T-Plastin widens and lengthens protrusions and is specifically enriched in active protrusions where F-actin is devoid of non-muscle myosin II activity. Together, our study uncovers critical roles of the actin bundler T-Plastin to promote protrusions and migration when adhesion is spatially-gapped.


Assuntos
Movimento Celular/fisiologia , Extensões da Superfície Celular/metabolismo , Glicoproteínas de Membrana/metabolismo , Proteínas dos Microfilamentos/metabolismo , Citoesqueleto de Actina/metabolismo , Actinas/metabolismo , Sistemas CRISPR-Cas , Adesão Celular , Linhagem Celular , Citoesqueleto/metabolismo , Matriz Extracelular/metabolismo , Técnicas de Inativação de Genes , Humanos , Cinética , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/ultraestrutura , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/ultraestrutura , Miosinas/metabolismo , Pseudópodes/metabolismo , Receptor EphB2
11.
PLoS Comput Biol ; 16(9): e1007815, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32925900

RESUMO

Protein-protein interactions are involved in a wide range of cellular processes. These interactions often involve intrinsically disordered proteins (IDPs) and protein binding domains. However, the details of IDP binding pathways are hard to characterize using experimental approaches, which can rarely capture intermediate states present at low populations. SH3 domains are common protein interaction domains that typically bind proline-rich disordered segments and are involved in cell signaling, regulation, and assembly. We hypothesized, given the flexibility of SH3 binding peptides, that their binding pathways include multiple steps important for function. Molecular dynamics simulations were used to characterize the steps of binding between the yeast Abp1p SH3 domain (AbpSH3) and a proline-rich IDP, ArkA. Before binding, the N-terminal segment 1 of ArkA is pre-structured and adopts a polyproline II helix, while segment 2 of ArkA (C-terminal) adopts a 310 helix, but is far less structured than segment 1. As segment 2 interacts with AbpSH3, it becomes more structured, but retains flexibility even in the fully engaged state. Binding simulations reveal that ArkA enters a flexible encounter complex before forming the fully engaged bound complex. In the encounter complex, transient nonspecific hydrophobic and long-range electrostatic contacts form between ArkA and the binding surface of SH3. The encounter complex ensemble includes conformations with segment 1 in both the forward and reverse orientation, suggesting that segment 2 may play a role in stabilizing the correct binding orientation. While the encounter complex forms quickly, the slow step of binding is the transition from the disordered encounter ensemble to the fully engaged state. In this transition, ArkA makes specific contacts with AbpSH3 and buries more hydrophobic surface. Simulating the binding between ApbSH3 and ArkA provides insight into the role of encounter complex intermediates and nonnative hydrophobic interactions for other SH3 domains and IDPs in general.


Assuntos
Proteínas Intrinsicamente Desordenadas , Proteínas dos Microfilamentos , Proteínas de Saccharomyces cerevisiae , Domínios de Homologia de src , Proteínas Intrinsicamente Desordenadas/química , Proteínas Intrinsicamente Desordenadas/genética , Proteínas Intrinsicamente Desordenadas/metabolismo , Proteínas dos Microfilamentos/química , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Simulação de Dinâmica Molecular , Ligação Proteica , Conformação Proteica , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Domínios de Homologia de src/genética , Domínios de Homologia de src/fisiologia
12.
PLoS Pathog ; 16(9): e1008879, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32997728

RESUMO

The Human T-cell leukemia virus type 1 (HTLV-1) orf I-encoded accessory protein p8 is cleaved from its precursor p12, and both proteins contribute to viral persistence. p8 induces cellular protrusions, which are thought to facilitate transfer of p8 to target cells and virus transmission. Host factors interacting with p8 and mediating p8 transfer are unknown. Here, we report that vasodilator-stimulated phosphoprotein (VASP), which promotes actin filament elongation, is a novel interaction partner of p8 and important for p8 and HTLV-1 Gag cell-to-cell transfer. VASP contains an Ena/VASP homology 1 (EVH1) domain that targets the protein to focal adhesions. Bioinformatics identified a short stretch in p8 (amino acids (aa) 24-45) which may mediate interactions with the EVH1 domain of VASP. Co-immunoprecipitations confirmed interactions of VASP:p8 in 293T, Jurkat and HTLV-1-infected MT-2 cells. Co-precipitation of VASP:p8 could be significantly blocked by peptides mimicking aa 26-37 of p8. Mutational studies revealed that the EVH1-domain of VASP is necessary, but not sufficient for the interaction with p8. Further, deletion of the VASP G- and F-actin binding domains significantly diminished co-precipitation of p8. Imaging identified areas of partial co-localization of VASP with p8 at the plasma membrane and in protrusive structures, which was confirmed by proximity ligation assays. Co-culture experiments revealed that p8 is transferred between Jurkat T-cells via VASP-containing conduits. Imaging and flow cytometry revealed that repression of both endogenous and overexpressed VASP by RNA interference or by CRISPR/Cas9 reduced p8 transfer to the cell surface and to target Jurkat T-cells. Stable repression of VASP by RNA interference in chronically infected MT-2 cells impaired both p8 and HTLV-1 Gag transfer to target Jurkat T-cells, while virus release was unaffected. Thus, we identified VASP as a novel interaction partner of p8, which is important for transfer of HTLV-1 p8 and Gag to target T-cells.


Assuntos
Moléculas de Adesão Celular , Adesões Focais , Produtos do Gene gag , Vírus Linfotrópico T Tipo 1 Humano , Proteínas dos Microfilamentos , Fosfoproteínas , Linfócitos T , Moléculas de Adesão Celular/química , Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/metabolismo , Adesões Focais/química , Adesões Focais/genética , Adesões Focais/metabolismo , Adesões Focais/virologia , Produtos do Gene gag/química , Produtos do Gene gag/genética , Produtos do Gene gag/metabolismo , Vírus Linfotrópico T Tipo 1 Humano/química , Vírus Linfotrópico T Tipo 1 Humano/genética , Vírus Linfotrópico T Tipo 1 Humano/metabolismo , Humanos , Células Jurkat , Proteínas dos Microfilamentos/química , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Fosfoproteínas/química , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Domínios Proteicos , Linfócitos T/química , Linfócitos T/metabolismo , Linfócitos T/virologia
13.
Medicine (Baltimore) ; 99(37): e22092, 2020 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-32925750

RESUMO

Pancreatic cancer (PaCa) is one of the most fatal cancers in the world. Although great efforts have made to explore the mechanisms of PaCa oncogenesis, the prognosis of PaCa patients is still unsatisfactory. Thus, it is imperative to further understand the potential carcinogenesis of PaCa and reliable prognostic models.The gene expression profile and clinical information of GSE21501 were downloaded from the Gene Expression Omnibus (GEO) database. Weighted gene co-expression network analysis (WGCNA) was applied to explore the potent genes associated with the overall survival (OS) events of PaCa patients. Cox regression model was applied to selecting prognostic genes and establish prognostic model. The prognostic values of six-gene signature were validated in TCGA-PAAD cohort.According to the WGCNA analysis, a total of 19 modules were identified and 115 hub genes in the mostly associated module were reserved for next analysis. According to the univariate and multivariate Cox regression analysis, we established a six-gene signature (FTSJ3, STAT1, STX2, CDX2, RASSF4, MACF1) which could effectively evaluate the overall survival (OS) of PaCa patients. In validated patients' cohorts, the six-gene signature exhibited excellent prognostic value in TCGA-PAAD cohort as well.We developed a six-gene signature to exactly predict OS of PaCa patients and provide a novel personalized strategy for evaluating prognosis. The findings may be contributed to medical customization and therapeutic decision in clinical practice.


Assuntos
Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/mortalidade , Fator de Transcrição CDX2/genética , Perfilação da Expressão Gênica , Humanos , Metiltransferases/genética , Proteínas dos Microfilamentos/genética , Modelos Estatísticos , Neoplasias Pancreáticas/patologia , Valor Preditivo dos Testes , Prognóstico , Modelos de Riscos Proporcionais , Fator de Transcrição STAT1/genética , Sintaxina 1/genética , Proteínas Supressoras de Tumor/genética
14.
Plast Reconstr Surg ; 146(2): 165e-176e, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32740585

RESUMO

BACKGROUND: Trigger finger, or stenosing tenosynovitis, is one of the most common conditions affecting the hand, yet its pathophysiology remains poorly understood, and genetic association studies of trigger finger are lacking. The purpose of this study was to identify single-nucleotide polymorphisms associated with trigger finger through a genomewide approach. METHODS: The authors performed a case-control genomewide association study in the Partners HealthCare Biobank. Single-nucleotide polymorphism- and gene-based association analyses were carried out after quality control, imputation, and filtering. RESULTS: Among 942 trigger finger cases and 24,472 controls, the authors tested 7,846,471 single-nucleotide polymorphisms for association with trigger finger. In the single-nucleotide polymorphism-based analysis, a single locus on chromosome 13 corresponding to KLHL1 met the genomewide significance threshold (lead single-nucleotide polymorphism rs59988404; OR, 1.74; 95 percent CI, 1.47 to 2.07; p = 1.99 × 10). After mapping, gene-based analysis demonstrated a significant association with POLE2 (p = 7.53 × 10) on chromosome 14. Among trigger finger cases, rs59988404 genotype was significantly associated with the total number of trigger finger procedures performed (p = 0.026). CONCLUSIONS: In the first reported genomewide association study of trigger finger, the authors report significant associations of KLHL1 and POLE2 with risk of trigger finger. The authors' results may help to elucidate the pathophysiology of trigger finger and facilitate an individualized, precision-medicine treatment approach. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.


Assuntos
DNA Polimerase II/genética , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Proteínas dos Microfilamentos/genética , Dedo em Gatilho/genética , Adulto , Estudos de Casos e Controles , Humanos , Polimorfismo de Nucleotídeo Único , Medicina de Precisão , Fatores de Risco , Dedo em Gatilho/terapia
15.
Proc Natl Acad Sci U S A ; 117(36): 22462-22472, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32839311

RESUMO

Huntingtin-interacting protein family members are evolutionarily conserved from yeast to humans, and they are known to be key factors in clathrin-mediated endocytosis. Here we identified the Caenorhabditis elegans protein huntingtin-interacting protein-related 1 (HIPR-1) as a host factor essential for Orsay virus infection of C. elegans Ablation of HIPR-1 resulted in a greater than 10,000-fold reduction in viral RNA, which could be rescued by ectopic expression of HIPR-1. Viral RNA replication from an endogenous transgene replicon system was not affected by lack of HIPR-1, suggesting that HIPR-1 plays a role during an early, prereplication virus life-cycle stage. Ectopic expression of HIPR-1 mutants demonstrated that neither the clathrin light chain-binding domain nor the clathrin heavy chain-binding motif were needed for virus infection, whereas the inositol phospholipid-binding and F-actin-binding domains were essential. In human cell culture, deletion of the human HIP orthologs HIP1 and HIP1R led to decreased infection by Coxsackie B3 virus. Finally, ectopic expression of a chimeric HIPR-1 harboring the human HIP1 ANTH (AP180 N-terminal homology) domain rescued Orsay infection in C. elegans, demonstrating conservation of its function through evolution. Collectively, these findings further our knowledge of cellular factors impacting viral infection in C. elegans and humans.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Ligação a DNA/metabolismo , Interações Hospedeiro-Patógeno , Proteínas dos Microfilamentos/metabolismo , Células A549 , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/fisiologia , Animais , Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/virologia , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/fisiologia , Sequência Conservada/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/fisiologia , Enterovirus Humano B/patogenicidade , Enterovirus Humano B/fisiologia , Feminino , Técnicas de Silenciamento de Genes , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/fisiologia , Humanos , Masculino , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/fisiologia , Nodaviridae/patogenicidade , Nodaviridae/fisiologia , Domínios Proteicos/genética , Replicação Viral
16.
Nat Commun ; 11(1): 4187, 2020 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-32826901

RESUMO

EHBP1 is an adaptor protein that regulates vesicular trafficking by recruiting Rab8 family members and Eps15-homology domain-containing proteins 1/2 (EHD1/2). It also links endosomes to the actin cytoskeleton. However, the underlying molecular mechanism of activation of EHBP1 actin-binding activity is unclear. Here, we show that both termini of EHBP1 have membrane targeting potential. EHBP1 associates with PI(3)P, PI(5)P, and phosphatidylserine via its N-terminal C2 domain. We show that in the absence of Rab8 family members, the C-terminal bivalent Mical/EHBP Rab binding (bMERB) domain forms an intramolecular complex with its central calponin homology (CH) domain and auto-inhibits actin binding. Rab8 binding to the bMERB domain relieves this inhibition. We have analyzed the CH:bMERB auto-inhibited complex and the active bMERB:Rab8 complex biochemically and structurally. Together with structure-based mutational studies, this explains how binding of Rab8 frees the CH domain and allows it to interact with the actin cytoskeleton, leading to membrane tubulation.


Assuntos
Proteínas de Transporte/química , Proteínas de Transporte/metabolismo , Proteínas dos Microfilamentos/química , Proteínas dos Microfilamentos/metabolismo , Proteínas rab de Ligação ao GTP/química , Proteínas rab de Ligação ao GTP/metabolismo , Citoesqueleto de Actina/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/química , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas de Transporte/genética , Proteínas dos Microfilamentos/genética , Modelos Moleculares , Fosfatos de Fosfatidilinositol/metabolismo , Ligação Proteica , Conformação Proteica , Domínios Proteicos , Domínios e Motivos de Interação entre Proteínas , Transporte Proteico/fisiologia , Alinhamento de Sequência , Proteínas de Transporte Vesicular , Proteínas rab de Ligação ao GTP/genética
17.
Proc Natl Acad Sci U S A ; 117(32): 19388-19398, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32727906

RESUMO

CD8+ T cells play pivotal roles in eradicating pathogens and tumor cells. T cell receptor (TCR) signaling is vital for the optimal activation of CD8+ T cells. Upon TCR engagement, the transmembrane adapter protein LAT (linker for activation of T cells) recruits other key signaling molecules and forms the "LAT signalosome" for downstream signal transduction. However, little is known about which functional partners could restrain the formation of the LAT signalosome and inhibit CD8+ cytotoxic T lymphocyte (CTL)-mediated cytotoxicity. Here we have demonstrated that LRCH1 (leucine-rich repeats and calponin homology domain containing 1) directly binds LAT, reduces LAT phosphorylation and interaction with GRB2, and also promotes the endocytosis of LAT. Lrch1 -/- mice display better protection against influenza virus and Listeria infection, with enhanced CD8+ T cell proliferation and cytotoxicity. Adoptive transfer of Lrch1 -/- CD8+ CTLs leads to increased B16-MO5 tumor clearance in vivo. Furthermore, knockout of LRCH1 in human chimeric antigen receptor (CAR) T cells that recognize the liver tumor-associated antigen glypican-3 could improve CAR T cell migration and proliferation in vitro. These findings suggest LRCH1 as a potential translational target to improve T cell immunotherapy against infection and tumors.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Linfócitos T CD8-Positivos/imunologia , Proteínas de Membrana/metabolismo , Proteínas dos Microfilamentos/deficiência , Transdução de Sinais , Animais , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/transplante , Movimento Celular , Células Cultivadas , Citotoxicidade Imunológica , Endocitose , Proteína Adaptadora GRB2/metabolismo , Humanos , Imunoterapia Adotiva , Infecções/imunologia , Infecções/microbiologia , Infecções/virologia , Interferon gama/metabolismo , Neoplasias Pulmonares/terapia , Ativação Linfocitária , Camundongos , Camundongos Knockout , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Fosforilação , Ligação Proteica , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores de Antígenos Quiméricos/metabolismo
18.
Nat Commun ; 11(1): 3457, 2020 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-32651364

RESUMO

Glioblastoma is a deadly cancer, with no effective therapies. Better understanding and identification of selective targets are urgently needed. We found that advillin (AVIL) is overexpressed in all the glioblastomas we tested including glioblastoma stem/initiating cells, but hardly detectable in non-neoplastic astrocytes, neural stem cells or normal brain. Glioma patients with increased AVIL expression have a worse prognosis. Silencing AVIL nearly eradicated glioblastoma cells in culture, and dramatically inhibited in vivo xenografts in mice, but had no effect on normal control cells. Conversely, overexpressing AVIL promoted cell proliferation and migration, enabled fibroblasts to escape contact inhibition, and transformed immortalized astrocytes, supporting AVIL being a bona fide oncogene. We provide evidence that the tumorigenic effect of AVIL is partly mediated by FOXM1, which regulates LIN28B, whose expression also correlates with clinical prognosis. AVIL regulates the cytoskeleton through modulating F-actin, while mutants disrupting F-actin binding are defective in its tumorigenic capabilities.


Assuntos
Glioblastoma/metabolismo , Glioblastoma/patologia , Proteínas dos Microfilamentos/metabolismo , Animais , Western Blotting , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Movimento Celular/fisiologia , Proliferação de Células/genética , Proliferação de Células/fisiologia , Citoesqueleto/metabolismo , Imunofluorescência , Glioblastoma/genética , Humanos , Imuno-Histoquímica , Técnicas In Vitro , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Proteínas dos Microfilamentos/genética , Microscopia Confocal , Reação em Cadeia da Polimerase em Tempo Real
19.
Circ Heart Fail ; 13(7): e006935, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32635769

RESUMO

BACKGROUND: NEXN (nexilin) is a protein of the junctional membrane complex required for development of cardiac T-tubules. Global and cardiomyocyte-specific loss of Nexn in mice leads to a rapidly progressive dilated cardiomyopathy and premature death. Therefore, little is known as to the role of NEXN in adult cardiomyocytes. Transverse-axial tubular system remodeling are well-known features in heart failure. Although NEXN is required during development for T-tubule formation, its role, if any, in mature T-tubules remains to be addressed. METHODS: Nexn inducible adult cardiomyocyte-specific KO mice were generated. Comprehensive morphological and functional analyses were performed. Heart samples (n>3) were analyzed by molecular, biochemical, and electron microscopy analyses. Isolated single adult cardiomyocytes were analyzed by confocal microscopy, and myocyte shortening/re-lengthening and Ca2+ transient studies were conducted. RESULTS: Inducible cardiomyocyte-specific loss of Nexn in adult mice resulted in a dilated cardiomyopathy with reduced cardiac function (13% reduction in percentage fractional shortening; P<0.05). In vivo and in vitro analyses of adult mouse heart samples revealed that NEXN was essential for optimal contraction and calcium handling and was required for maintenance of T-tubule network organization (transverse tubular component in Nexn inducible adult cardiomyocyte-specific KO mice reduced by 40% with respect to controls, P<0.05). CONCLUSIONS: Results here reported reveal NEXN to be a pivotal component of adult junctional membrane complexes required for maintenance of transverse-axial tubular architecture. These results demonstrate that NEXN plays an essential role in the adult cardiomyocyte and give further understanding of pathological mechanisms responsible for cardiomyopathy in patients carrying mutations in the NEXN gene.


Assuntos
Cardiomiopatia Dilatada/fisiopatologia , Proteínas dos Microfilamentos/fisiologia , Microtúbulos/fisiologia , Miócitos Cardíacos/fisiologia , Disfunção Ventricular Esquerda/fisiopatologia , Fatores Etários , Animais , Cálcio/metabolismo , Cardiomiopatia Dilatada/genética , Cardiomiopatia Dilatada/metabolismo , Modelos Animais de Doenças , Camundongos , Camundongos Knockout , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Microtúbulos/metabolismo , Miócitos Cardíacos/metabolismo , Disfunção Ventricular Esquerda/genética , Disfunção Ventricular Esquerda/metabolismo
20.
Mol Cell Biol ; 40(17)2020 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-32601107

RESUMO

Fodrin and its erythroid cell-specific isoform spectrin are actin-associated fibrous proteins that play crucial roles in the maintenance of structural integrity in mammalian cells, which is necessary for proper cell function. Normal cell morphology is altered in diseases such as various cancers and certain neuronal disorders. Fodrin and spectrin are two-chain (αß) molecules that are encoded by paralogous genes and share many features but also demonstrate certain differences. Fodrin (in humans, typically a heterodimer of the products of the SPTAN1 and SPTBN1 genes) is expressed in nearly all cell types and is especially abundant in neuronal tissues, whereas spectrin (in humans, a heterodimer of the products of the SPTA1 and SPTB1 genes) is expressed almost exclusively in erythrocytes. To fulfill a role in such a variety of different cell types, it was anticipated that fodrin would need to be a more versatile scaffold than spectrin. Indeed, as summarized here, domains unique to fodrin and its regulation by Ca2+, calmodulin, and a variety of posttranslational modifications (PTMs) endow fodrin with additional specific functions. However, how fodrin structural variations and misregulated PTMs may contribute to the etiology of various cancers and neurodegenerative diseases needs to be further investigated.


Assuntos
Proteínas de Transporte/química , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Proteínas dos Microfilamentos/química , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Actinas/metabolismo , Animais , Cálcio/metabolismo , Calmodulina/metabolismo , Células Eritroides/metabolismo , Humanos , Neurônios/metabolismo , Espectrina/metabolismo , Espectrina/fisiologia , Relação Estrutura-Atividade
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