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1.
PLoS Genet ; 16(8): e1008976, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32866141

RESUMO

Neural circuitry for mating and reproduction resides within the terminal segments of central nervous system (CNS) which express Hox paralogous group 9-13 (in vertebrates) or Abdominal-B (Abd-B) in Drosophila. Terminal neuroblasts (NBs) in A8-A10 segments of Drosophila larval CNS are subdivided into two groups based on expression of transcription factor Doublesex (Dsx). While the sex specific fate of Dsx-positive NBs is well investigated, the fate of Dsx-negative NBs is not known so far. Our studies with Dsx-negative NBs suggests that these cells, like their abdominal counterparts (in A3-A7 segments) use Hox, Grainyhead (Grh) and Notch to undergo cell death during larval development. This cell death also happens by transcriptionally activating RHG family of apoptotic genes through a common apoptotic enhancer in early to mid L3 stages. However, unlike abdominal NBs (in A3-A7 segments) which use increasing levels of resident Hox factor Abdominal-A (Abd-A) as an apoptosis trigger, Dsx-negative NBs (in A8-A10 segments) keep the levels of resident Hox factor Abd-B constant. These cells instead utilize increasing levels of the temporal transcription factor Grh and a rise in Notch activity to gain apoptotic competence. Biochemical and in vivo analysis suggest that Abdominal-A and Grh binding motifs in the common apoptotic enhancer also function as Abdominal-B and Grh binding motifs and maintains the enhancer activity in A8-A10 NBs. Finally, the deletion of this enhancer by the CRISPR-Cas9 method blocks the apoptosis of Dsx-negative NBs. These results highlight the fact that Hox dependent NB apoptosis in abdominal and terminal regions utilizes common molecular players (Hox, Grh and Notch), but seems to have evolved different molecular strategies to pattern CNS.


Assuntos
Apoptose/genética , Proteínas de Ligação a DNA/genética , Proteínas de Drosophila/genética , Receptores Notch/genética , Fatores de Transcrição/genética , Abdome/crescimento & desenvolvimento , Animais , Sistema Nervoso Central/crescimento & desenvolvimento , Drosophila melanogaster/genética , Drosophila melanogaster/crescimento & desenvolvimento , Feminino , Regulação da Expressão Gênica no Desenvolvimento/genética , Larva/genética , Larva/crescimento & desenvolvimento , Masculino , Células-Tronco Neurais/metabolismo , Sequências Reguladoras de Ácido Nucleico/genética
2.
Nat Commun ; 11(1): 4673, 2020 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-32938917

RESUMO

RAS-MAPK signaling mediates processes critical to normal development including cell proliferation, survival, and differentiation. Germline mutation of RAS-MAPK genes lead to the Noonan-spectrum of syndromes. Here, we present a patient affected by a 6p-interstitial microdeletion with unknown underlying molecular etiology. Examination of 6p-interstitial microdeletion cases reveals shared clinical features consistent with Noonan-spectrum disorders including short stature, facial dysmorphia and cardiovascular abnormalities. We find the RAS-responsive element binding protein-1 (RREB1) is the common deleted gene in multiple 6p-interstitial microdeletion cases. Rreb1 hemizygous mice display orbital hypertelorism and cardiac hypertrophy phenocopying the human syndrome. Rreb1 haploinsufficiency leads to sensitization of MAPK signaling. Rreb1 recruits Sin3a and Kdm1a to control H3K4 methylation at MAPK pathway gene promoters. Haploinsufficiency of SIN3A and mutations in KDM1A cause syndromes similar to RREB1 haploinsufficiency suggesting genetic perturbation of the RREB1-SIN3A-KDM1A complex represents a new category of RASopathy-like syndromes arising through epigenetic reprogramming of MAPK pathway genes.


Assuntos
Proteínas de Ligação a DNA/genética , Haploinsuficiência , Sistema de Sinalização das MAP Quinases/genética , Síndrome de Noonan/etiologia , Fatores de Transcrição/genética , Proteínas ras/metabolismo , Anormalidades Múltiplas/genética , Animais , Deleção Cromossômica , Cromossomos Humanos Par 6 , Proteínas de Ligação a DNA/metabolismo , Epigênese Genética , Feminino , Fatores de Crescimento de Fibroblastos/genética , Fatores de Crescimento de Fibroblastos/metabolismo , Histona Desmetilases/genética , Histona Desmetilases/metabolismo , Histonas/metabolismo , Humanos , Masculino , Metilação , Camundongos Endogâmicos C57BL , Camundongos Knockout , Complexo Correpressor Histona Desacetilase e Sin3/genética , Complexo Correpressor Histona Desacetilase e Sin3/metabolismo , Fatores de Transcrição/metabolismo , Proteínas ras/genética
3.
Nat Commun ; 11(1): 4666, 2020 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-32938943

RESUMO

Intercalated discs (ICD), specific cell-to-cell contacts that connect adjacent cardiomyocytes, ensure mechanical and electrochemical coupling during contraction of the heart. Mutations in genes encoding ICD components are linked to cardiovascular diseases. Here, we show that loss of Xinß, a newly-identified component of ICDs, results in cardiomyocyte proliferation defects and cardiomyopathy. We uncovered a role for Xinß in signaling via the Hippo-YAP pathway by recruiting NF2 to the ICD to modulate cardiac function. In Xinß mutant hearts levels of phosphorylated NF2 are substantially reduced, suggesting an impairment of Hippo-YAP signaling. Cardiac-specific overexpression of YAP rescues cardiac defects in Xinß knock-out mice-indicating a functional and genetic interaction between Xinß and YAP. Our study reveals a molecular mechanism by which cardiac-expressed intercalated disc protein Xinß modulates Hippo-YAP signaling to control heart development and cardiac function in a tissue specific manner. Consequently, this pathway may represent a therapeutic target for the treatment of cardiovascular diseases.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas do Citoesqueleto/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas com Domínio LIM/metabolismo , Miócitos Cardíacos/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Cardiomiopatia Dilatada/genética , Comunicação Celular , Proteínas de Ciclo Celular/genética , Proliferação de Células , Proteínas do Citoesqueleto/genética , Proteínas de Ligação a DNA/genética , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Ventrículos do Coração/crescimento & desenvolvimento , Proteínas com Domínio LIM/genética , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mutação , Miócitos Cardíacos/citologia , Miócitos Cardíacos/patologia , Neurofibromina 2/genética , Neurofibromina 2/metabolismo , Proteínas Nucleares/genética , Transdução de Sinais
4.
Nat Commun ; 11(1): 4471, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32901010

RESUMO

A human cell contains hundreds to thousands of mitochondrial DNA (mtDNA) packaged into nucleoids. Currently, the segregation and allocation of nucleoids are thought to be passively determined by mitochondrial fusion and division. Here we provide evidence, using live-cell super-resolution imaging, that nucleoids can be actively transported via KIF5B-driven mitochondrial dynamic tubulation (MDT) activities that predominantly occur at the ER-mitochondria contact sites (EMCS). We further demonstrate that a mitochondrial inner membrane protein complex MICOS links nucleoids to Miro1, a KIF5B receptor on mitochondria, at the EMCS. We show that such active transportation is a mechanism essential for the proper distribution of nucleoids in the peripheral zone of the cell. Together, our work identifies an active transportation mechanism of nucleoids, with EMCS serving as a key platform for the interplay of nucleoids, MICOS, Miro1, and KIF5B to coordinate nucleoids segregation and transportation.


Assuntos
DNA Mitocondrial/metabolismo , Retículo Endoplasmático/metabolismo , Mitocôndrias/metabolismo , Dinâmica Mitocondrial/fisiologia , Animais , Transporte Biológico Ativo , Células COS , Células Cultivadas , Chlorocebus aethiops , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Células HEK293 , Humanos , Cinesina/metabolismo , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Camundongos , Membranas Mitocondriais/metabolismo , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Modelos Biológicos , Ratos , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transfecção , Proteínas rho de Ligação ao GTP/metabolismo
5.
Nat Commun ; 11(1): 4642, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32934200

RESUMO

Epigenetic regulation plays an important role in governing stem cell fate and tumorigenesis. Lost expression of a key DNA demethylation enzyme TET2 is associated with human cancers and has been linked to stem cell traits in vitro; however, whether and how TET2 regulates mammary stem cell fate and mammary tumorigenesis in vivo remains to be determined. Here, using our recently established mammary specific Tet2 deletion mouse model, the data reveals that TET2 plays a pivotal role in mammary gland development and luminal lineage commitment. We show that TET2 and FOXP1 form a chromatin complex that mediates demethylation of ESR1, GATA3, and FOXA1, three key genes that are known to coordinately orchestrate mammary luminal lineage specification and endocrine response, and also are often silenced by DNA methylation in aggressive breast cancers. Furthermore, Tet2 deletion-PyMT breast cancer mouse model exhibits enhanced mammary tumor development with deficient ERα expression that confers tamoxifen resistance in vivo. As a result, this study elucidates a role for TET2 in governing luminal cell differentiation and endocrine response that underlies breast cancer resistance to anti-estrogen treatments.


Assuntos
Diferenciação Celular , Proteínas de Ligação a DNA/metabolismo , Estradiol/metabolismo , Estrogênios/metabolismo , Glândulas Mamárias Animais/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Animais , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/fisiopatologia , Linhagem da Célula , Metilação de DNA , Proteínas de Ligação a DNA/genética , Sistema Endócrino/metabolismo , Epigênese Genética , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Feminino , Humanos , Glândulas Mamárias Animais/fisiopatologia , Camundongos , Camundongos Knockout , Proteínas Proto-Oncogênicas/genética
6.
Nat Commun ; 11(1): 4718, 2020 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-32948777

RESUMO

Disturbances in glucose homeostasis and low-grade chronic inflammation culminate into metabolic syndrome that increase the risk for the development of type 2 diabetes mellitus (T2DM). The recently discovered group 2 innate lymphoid cells (ILC2s) are capable of secreting copious amounts of type 2 cytokines to modulate metabolic homeostasis in adipose tissue. In this study, we have established that expression of Death Receptor 3 (DR3), a member of the TNF superfamily, on visceral adipose tissue (VAT)-derived murine and peripheral blood human ILC2s is inducible by IL-33. We demonstrate that DR3 engages the canonical and/or non-canonical NF-κB pathways, and thus stimulates naïve and co-stimulates IL-33-activated ILC2s. Importantly, DR3 engagement on ILC2s significantly ameliorates glucose tolerance, protects against insulin-resistance onset and remarkably reverses already established insulin-resistance. Taken together, these results convey the potent role of DR3 as an ILC2 regulator and introduce DR3 agonistic treatment as a novel therapeutic avenue for treating T2DM.


Assuntos
Tecido Adiposo/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Linfócitos/metabolismo , Membro 25 de Receptores de Fatores de Necrose Tumoral/metabolismo , Adipócitos/metabolismo , Adolescente , Adulto , Idoso , Animais , Citocinas/metabolismo , Proteínas de Ligação a DNA/genética , Feminino , Glucose/metabolismo , Homeostase , Humanos , Imunidade Inata , Resistência à Insulina , Interleucina-33/metabolismo , Gordura Intra-Abdominal/metabolismo , Masculino , Síndrome Metabólica/complicações , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Membro 25 de Receptores de Fatores de Necrose Tumoral/uso terapêutico , Adulto Jovem
7.
Anticancer Res ; 40(10): 5883-5893, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32988919

RESUMO

BACKGROUND/AIM: Somatic mutations were investigated in 21 patients with postmenopausal estrogen receptor (ER)-positive and human epidermal growth factor receptor-2 (HER-2)-positive (ER+HER2+) breast cancer (BC) treated with neoadjuvant letrozole and lapatinib, to identify their distinct molecular landscape. PATIENTS AND METHODS: We used tissue samples of 21 patients from phase II Neo ALL-IN cohort, and somatic alterations were examined using targeted exome sequencing performed in Foundation Medicine, Inc. (FMI). RESULTS: TP53 (61.9%) and PIK3CA (57.1%) were the two most frequently mutated genes that were inter-correlated (p=0.026). They were associated with unfavorable clinical outcomes, particularly when accompanying PIK3CA mutations at exon 9 in helical domains. Meanwhile, MLL2 alteration was negatively associated with mutations of TP53 or PIK3CA, and it tended to be present in patients with low KI-67 levels and no initial nodal involvement. Moreover, patients with MLL2 mutations numerically showed more favorable overall response rates (ORR) (80% vs. 56.2%) and better 5-year event-free survival (EFS) rates (100% vs. 87.5%) compared to the wild-type. CONCLUSION: Mutations in TP53 and PIK3CA hotspot at exon 9 may be potential negative predictors of ER+HER2+ BC treated with neoadjuvant letrozole and lapatinib, while MLL2 inactivating mutation might confer therapeutic benefit in these patients.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Classe I de Fosfatidilinositol 3-Quinases/genética , Proteínas de Ligação a DNA/genética , Proteínas de Neoplasias/genética , Proteína Supressora de Tumor p53/genética , Idoso , Biomarcadores Tumorais/genética , Mama/efeitos dos fármacos , Mama/patologia , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Receptor alfa de Estrogênio/genética , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Lapatinib/administração & dosagem , Letrozol/administração & dosagem , Pessoa de Meia-Idade , Mutação/genética , Intervalo Livre de Progressão , Receptor ErbB-2/genética
8.
Nat Commun ; 11(1): 4313, 2020 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-32855402

RESUMO

It has been suggested that beige fat thermogenesis is tightly controlled by epigenetic regulators that sense environmental cues such as temperature. Here, we report that subcutaneous adipose expression of the DNA demethylase TET1 is suppressed by cold and other stimulators of beige adipocyte thermogenesis. TET1 acts as an autonomous repressor of key thermogenic genes, including Ucp1 and Ppargc1a, in beige adipocytes. Adipose-selective Tet1 knockout mice generated by using Fabp4-Cre improves cold tolerance and increases energy expenditure and protects against diet-induced obesity and insulin resistance. Moreover, the suppressive role of TET1 in the thermogenic gene regulation of beige adipocytes is largely DNA demethylase-independent. Rather, TET1 coordinates with HDAC1 to mediate the epigenetic changes to suppress thermogenic gene transcription. Taken together, TET1 is a potent beige-selective epigenetic breaker of the thermogenic gene program. Our findings may lead to a therapeutic strategy to increase energy expenditure in obesity and related metabolic disorders.


Assuntos
Adipócitos Bege/metabolismo , Proteínas de Ligação a DNA/metabolismo , Epigênese Genética , Obesidade/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Termogênese/genética , Animais , Calorimetria Indireta , Linhagem Celular , Temperatura Baixa/efeitos adversos , Proteínas de Ligação a DNA/genética , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Metabolismo Energético/genética , Regulação da Expressão Gênica/fisiologia , Células HEK293 , Humanos , Resistência à Insulina/genética , Masculino , Camundongos , Camundongos Knockout , Obesidade/etiologia , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Proteínas Proto-Oncogênicas/genética , RNA-Seq , Gordura Subcutânea/citologia , Gordura Subcutânea/metabolismo , Proteína Desacopladora 1/metabolismo
9.
Plant Mol Biol ; 104(3): 235-248, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32757127

RESUMO

KEY MESSAGE: Two PaGL1-like genes were identified in London plane and functional in Arabidopsis, moreover, may play an important role in the regulation of trichome development in London plane. Trichome development is governed by a complex regulatory network. In Arabidopsis, subgroup 15 of the R2R3 MYB transcription factor family, which includes GLABRA1 (GL1), is involved in trichome development. In this study, we isolated and characterized two PaGL1-like genes from London plane (Platanus acerifolia). Sequence alignment and phylogenetic analysis indicated that these PaGL1-like genes are homologous to AtGL1. Quantitative real-time PCR (qRT-PCR) analysis showed that PaGL1-like1 was expressed in all of the tested organs taken from adult London plane trees, including trichomes, petioles after trichome removal, stems after trichome removal, and leaves after trichome removal, and also in the roots, cotyledons, hypocotyls and true leaves of seedlings. By contrast, the PaGL1-like2 was expressed only in the trichomes and leaves after trichome removal from adult trees, and in the cotyledons and true leaves of seedlings. Overexpression of PaGL1-like genes caused trichome abortion when transferred into wild type Arabidopsis and promoted trichome formation in the gl1 mutant. The expression profiles of some trichome-related genes were changed in transgenic Arabidopsis lines, and yeast two-hybrid analysis indicated that PaGL1-like proteins can directly interact with trichome-related bHLH proteins from both P. acerifolia and Arabidopsis. These results suggest that PaGL1-like genes are functional in Arabidopsis and may play an important role in the regulation of trichome development in London plane.


Assuntos
Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Traqueófitas/genética , Tricomas/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Regulação da Expressão Gênica de Plantas , Proteínas de Homeodomínio/genética , Filogenia , Folhas de Planta/genética , Plantas Geneticamente Modificadas , Alinhamento de Sequência , Traqueófitas/metabolismo , Fatores de Transcrição/genética , Transcriptoma , Tricomas/crescimento & desenvolvimento
10.
PLoS One ; 15(8): e0236896, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32745119

RESUMO

Single-stranded DNA binding protein 2 (SSBP2) is ubiquitously expressed, with several studies reporting it to be a tumor suppressor. We investigated SSBP2 expression and its clinicopathological significance in gastric cancer. SSBP2 expression was examined by immunohistochemistry in 539 gastric cancer sections. The cases were divided into three subtypes, namely, Epstein-Barr virus-associated (EBV), microsatellite unstable, and others (microsatellite stable and EBV negative), based on the molecular classification of The Cancer Genome Atlas (TCGA). Cases were also divided into two subgroups according to the amplification status of human epidermal growth factor receptor 2 (HER2). Most cases showed SSBP2 positivity, and only 24 (4.5%) cases displayed negative nuclear expression. Loss of nuclear expression correlated significantly with high pT category (P = 0.001), nodal metastasis (P = 0.002), and stage of progression (P = 0.005), with no correlation between molecular characteristics and SSBP2 expression. All HER2 amplification cases displayed positive SSBP2 expression. Negative SSBP2 cases showed significantly shorter recurrence-free survival (RFS) compared to positive SSBP2 cases (P = 0.008). Loss of nuclear expression of SSBP2 was significantly associated with shorter RFS in the microsatellite stable and EBV negative groups (P = 0.002), as well as the HER2 negative group (P = 0.007). However, there were no statistically significant differences in multivariate analyses. Loss of nuclear expression of SSBP2 was a poor prognostic factor, associated with stage of progression and recurrence, and showed no significant difference in molecular characteristics, including TCGA subtype and HER2 status.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Receptor ErbB-2/genética , Neoplasias Gástricas , Adenocarcinoma/patologia , Idoso , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Núcleo Celular/metabolismo , Proteínas de Ligação a DNA/genética , Feminino , Expressão Gênica , Herpesvirus Humano 4/isolamento & purificação , Humanos , Imuno-Histoquímica , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Prognóstico , Receptor ErbB-2/metabolismo , Neoplasias Gástricas/classificação , Neoplasias Gástricas/patologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
11.
PLoS One ; 15(8): e0236823, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32745143

RESUMO

Stem rot, a devastating fungal disease of peanut, is caused by Sclerotium rolfsii. RNA-sequencing approaches have been used to unravel the mechanisms of resistance to stem rot in peanut over the course of fungal infection in resistant (NRCG-CS85) and susceptible (TG37A) genotypes under control conditions and during the course of infection. Out of about 290 million reads, nearly 251 million (92.22%) high-quality reads were obtained and aligned to the Arachis duranensis and Arachis ipaensis genomes with the average mapping of 78.91% and 78.61%, respectively. In total, about 48.6% of genes were commonly regulated, while approximately 21.8% and 29.6% of uniquely regulated genes from A. duranensis and A. ipaensis genomes, respectively, were identified. Several annotated transcripts, such as receptor-like kinases, jasmonic acid pathway enzymes, and transcription factors (TFs), including WRKY, Zinc finger protein, and C2-H2 zinc finger, showed higher expression in resistant genotypes upon infection. These transcripts have a known role in channelizing the downstream of pathogen perception. The higher expression of WRKY transcripts might have induced the systemic acquired resistance (SAR) by the activation of the jasmonic acid defense signaling pathway. Furthermore, a set of 30 transcripts involved in the defense mechanisms were validated with quantitative real-time PCR. This study suggested PAMP-triggered immunity as a probable mechanism of resistance, while the jasmonic acid signaling pathway was identified as a possible defense mechanism in peanut. The information generated is of immense importance in developing more effective ways to combat the stem rot disease in peanut.


Assuntos
Agaricales/patogenicidade , Arachis/genética , Doenças das Plantas , Imunidade Vegetal/genética , Arachis/microbiologia , Ciclopentanos/metabolismo , Proteínas de Ligação a DNA/genética , Genes de Plantas , Genótipo , Oxilipinas/metabolismo , Fosfotransferases (Aceptor do Grupo Fosfato)/genética , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Reguladores de Crescimento de Planta/genética , Proteínas de Plantas/genética , RNA-Seq , Transdução de Sinais/genética , Fatores de Transcrição/genética
12.
Nat Commun ; 11(1): 3796, 2020 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-32732900

RESUMO

The ter region of the bacterial chromosome, where replication terminates, is the last to be segregated before cell division in Escherichia coli. Delayed segregation is controlled by the MatP protein, which binds to specific sites (matS) within ter, and interacts with other proteins such as ZapB. Here, we investigate the role of MatP by combining short-time mobility analyses of the ter locus with biochemical approaches. We find that ter mobility is similar to that of a non ter locus, except when sister ter loci are paired after replication. This effect depends on MatP, the persistence of catenanes, and ZapB. We characterise MatP/DNA complexes and conclude that MatP binds DNA as a tetramer, but bridging matS sites in a DNA-rich environment remains infrequent. We propose that tetramerisation of MatP links matS sites with ZapB and/or with non-specific DNA to promote optimal pairing of sister ter regions until cell division.


Assuntos
Proteínas de Ciclo Celular/genética , Proteínas Cromossômicas não Histona/genética , Cromossomos Bacterianos/genética , Proteínas de Escherichia coli/genética , Escherichia coli/genética , Divisão Celular/genética , Proteínas Cromossômicas não Histona/metabolismo , Replicação do DNA/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo
13.
Nat Commun ; 11(1): 3839, 2020 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-32737294

RESUMO

Chromatin regulates spatiotemporal gene expression during neurodevelopment, but it also mediates DNA damage repair essential to proliferating neural progenitor cells (NPCs). Here, we uncover molecularly dissociable roles for nucleosome remodeler Ino80 in chromatin-mediated transcriptional regulation and genome maintenance in corticogenesis. We find that conditional Ino80 deletion from cortical NPCs impairs DNA double-strand break (DSB) repair, triggering p53-dependent apoptosis and microcephaly. Using an in vivo DSB repair pathway assay, we find that Ino80 is selectively required for homologous recombination (HR) DNA repair, which is mechanistically distinct from Ino80 function in YY1-associated transcription. Unexpectedly, sensitivity to loss of Ino80-mediated HR is dependent on NPC division mode: Ino80 deletion leads to unrepaired DNA breaks and apoptosis in symmetric NPC-NPC divisions, but not in asymmetric neurogenic divisions. This division mode dependence is phenocopied following conditional deletion of HR gene Brca2. Thus, distinct modes of NPC division have divergent requirements for Ino80-dependent HR DNA repair.


Assuntos
ATPases Associadas a Diversas Atividades Celulares/genética , Proteína BRCA2/genética , Cromatina/química , Proteínas de Ligação a DNA/genética , Células-Tronco Neurais/metabolismo , Neurogênese/genética , Reparo de DNA por Recombinação , ATPases Associadas a Diversas Atividades Celulares/deficiência , Animais , Apoptose/genética , Proteína BRCA2/deficiência , Divisão Celular , Cromatina/metabolismo , Montagem e Desmontagem da Cromatina , DNA/genética , DNA/metabolismo , Quebras de DNA de Cadeia Dupla , Proteínas de Ligação a DNA/deficiência , Embrião de Mamíferos , Regulação da Expressão Gênica no Desenvolvimento , Camundongos , Camundongos Transgênicos , Neocórtex/citologia , Neocórtex/crescimento & desenvolvimento , Neocórtex/metabolismo , Células-Tronco Neurais/citologia , Transdução de Sinais , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Fator de Transcrição YY1/genética , Fator de Transcrição YY1/metabolismo
14.
PLoS Genet ; 16(8): e1008953, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32776944

RESUMO

Apoptosis of cochlear hair cells is a key step towards age-related hearing loss. Although numerous genes have been implicated in the genetic causes of late-onset, progressive hearing loss, few show direct links to the proapoptotic process. By genome-wide linkage analysis and whole exome sequencing, we identified a heterozygous p.L183V variant in THOC1 as the probable cause of the late-onset, progressive, non-syndromic hearing loss in a large family with autosomal dominant inheritance. Thoc1, a member of the conserved multisubunit THO/TREX ribonucleoprotein complex, is highly expressed in mouse and zebrafish hair cells. The thoc1 knockout (thoc1 mutant) zebrafish generated by gRNA-Cas9 system lacks the C-startle response, indicative of the hearing dysfunction. Both Thoc1 mutant and knockdown zebrafish have greatly reduced hair cell numbers, while the latter can be rescued by embryonic microinjection of human wild-type THOC1 mRNA but to significantly lesser degree by the c.547C>G mutant mRNA. The Thoc1 deficiency resulted in marked apoptosis in zebrafish hair cells. Consistently, transcriptome sequencing of the mutants showed significantly increased gene expression in the p53-associated signaling pathway. Depletion of p53 or applying the p53 inhibitor Pifithrin-α significantly rescued the hair cell loss in the Thoc1 knockdown zebrafish. Our results suggested that THOC1 deficiency lead to late-onset, progressive hearing loss through p53-mediated hair cell apoptosis. This is to our knowledge the first human disease associated with THOC1 mutations and may shed light on the molecular mechanism underlying the age-related hearing loss.


Assuntos
Proteínas de Ligação a DNA/genética , Surdez/genética , Células Ciliadas Auditivas Internas/metabolismo , Proteínas de Ligação a RNA/genética , Proteína Supressora de Tumor p53/genética , Animais , Apoptose/genética , Benzotiazóis/farmacologia , Proteína 9 Associada à CRISPR/genética , Proteínas de Ligação a DNA/deficiência , Surdez/patologia , Modelos Animais de Doenças , Regulação da Expressão Gênica/efeitos dos fármacos , Técnicas de Inativação de Genes , Células Ciliadas Auditivas/metabolismo , Células Ciliadas Auditivas/patologia , Células Ciliadas Auditivas Internas/patologia , Humanos , Camundongos , Mutação , RNA Guia/genética , Transdução de Sinais/efeitos dos fármacos , Tolueno/análogos & derivados , Tolueno/farmacologia , Proteína Supressora de Tumor p53/antagonistas & inibidores , Sequenciamento Completo do Exoma , Peixe-Zebra/genética
15.
PLoS Genet ; 16(8): e1008989, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32810129

RESUMO

Drosophila Myc (dMyc), as a broad-spectrum transcription factor, can regulate the expression of a large number of genes to control diverse cellular processes, such as cell cycle progression, cell growth, proliferation and apoptosis. However, it remains largely unknown about whether dMyc can be involved in Drosophila innate immune response. Here, we have identified dMyc to be a negative regulator of Drosophila Imd pathway via the loss- and gain-of-function screening. We demonstrate that dMyc inhibits Drosophila Imd immune response via directly activating miR-277 transcription, which further inhibit the expression of imd and Tab2-Ra/b. Importantly, dMyc can improve the survival of flies upon infection, suggesting inhibiting Drosophila Imd pathway by dMyc is vital to restore immune homeostasis that is essential for survival. Taken together, our study not only reports a new dMyc-miR-277-imd/Tab2 axis involved in the negative regulation of Drosophila Imd pathway, and provides a new insight into the complex regulatory mechanism of Drosophila innate immune homeostasis maintenance.


Assuntos
Proteínas de Ligação a DNA/genética , Proteínas de Drosophila/genética , Imunidade Inata/genética , MicroRNAs/genética , Fatores de Transcrição/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Divisão Celular/genética , Proteínas de Ligação a DNA/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Homeostase/genética , Humanos , Transdução de Sinais/genética , Fatores de Transcrição/metabolismo , Transcrição Genética/genética
16.
PLoS Genet ; 16(8): e1008896, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32853200

RESUMO

Identifying regions of positive selection in genomic data remains a challenge in population genetics. Most current approaches rely on comparing values of summary statistics calculated in windows. We present an approach termed SURFDAWave, which translates measures of genetic diversity calculated in genomic windows to functional data. By transforming our discrete data points to be outputs of continuous functions defined over genomic space, we are able to learn the features of these functions that signify selection. This enables us to confidently identify complex modes of natural selection, including adaptive introgression. We are also able to predict important selection parameters that are responsible for shaping the inferred selection events. By applying our model to human population-genomic data, we recapitulate previously identified regions of selective sweeps, such as OCA2 in Europeans, and predict that its beneficial mutation reached a frequency of 0.02 before it swept 1,802 generations ago, a time when humans were relatively new to Europe. In addition, we identify BNC2 in Europeans as a target of adaptive introgression, and predict that it harbors a beneficial mutation that arose in an archaic human population that split from modern humans within the hypothesized modern human-Neanderthal divergence range.


Assuntos
Grupo com Ancestrais do Continente Europeu/genética , Modelos Genéticos , Taxa de Mutação , Animais , Proteínas de Ligação a DNA/genética , Variação Genética , Humanos , Proteínas de Membrana Transportadoras , Homem de Neandertal/genética , Seleção Genética , Software
17.
Gene ; 760: 145020, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32755656

RESUMO

Conserved sequences across species have always provided valuable insights to improve our understanding on the human genome's entity and the interplay among different loci. Lymphoma/leukemia related factor (LRF) is encoded by ZBTB7A gene and belongs to an evolutionarily conserved family of transcription factors, implicated in vital cellular functions. The present data, demonstrating the wide-spread and the high overlap of the LRF/ZBTB7A recognition sites with genomic segments identified as CpG islands in the human genome, suggest that its binding capacity strongly depends on a specific sequence-encoded feature within CpGs. We have previously shown that de-methylation of the CpG island 326 lying in the ZBTB7A gene promoter is associated with impaired pharmacological induction of fetal hemoglobin in ß-type hemoglobinopathies patients. Within this context we aimed to investigate the extent of the LRF/ZBTB7A conservation among primates and mouse genome, focusing our interest also on the CpG island flanking the gene's promoter region, in an effort to further establish its epigenetic regulatory role in human hematopoiesis and pharmacological involvement in hematopoietic disorders. Comparative analysis of the human ZBTB7A nucleotide and amino acid sequences and orthologous sequences among non-human primates and mouse, exhibited high conservation scores. Pathway analysis, clearly indicated that LRF/ZBTB7A influences conserved cellular processes. These data in conjunction with the high levels of expression foremost in hematopoietic tissues, highlighted LRF/ZBTB7A as an essential factor operating indisputably during hematopoiesis.


Assuntos
Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Doenças Hematológicas/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Animais , Sítios de Ligação/genética , Diferenciação Celular/genética , Linhagem Celular Tumoral , Sequência Conservada/genética , Ilhas de CpG/genética , Bases de Dados Genéticas , Hemoglobina Fetal/genética , Hematopoese/genética , Humanos , Camundongos , Primatas/genética , Regiões Promotoras Genéticas/genética
18.
Mol Cell ; 79(6): 902-916.e6, 2020 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-32768407

RESUMO

A long-standing conundrum is how mitotic chromosomes can compact, as required for clean separation to daughter cells, while maintaining close parallel alignment of sister chromatids. Pursuit of this question, by high resolution 3D fluorescence imaging of living and fixed mammalian cells, has led to three discoveries. First, we show that the structural axes of separated sister chromatids are linked by evenly spaced "mini-axis" bridges. Second, when chromosomes first emerge as discrete units, at prophase, they are organized as co-oriented sister linear loop arrays emanating from a conjoined axis. We show that this same basic organization persists throughout mitosis, without helical coiling. Third, from prophase onward, chromosomes are deformed into sequential arrays of half-helical segments of alternating handedness (perversions), accompanied by correlated kinks. These arrays fluctuate dynamically over <15 s timescales. Together these discoveries redefine the foundation for thinking about the evolution of mitotic chromosomes as they prepare for anaphase segregation.


Assuntos
Proteínas de Ciclo Celular/genética , Cromossomos/genética , Proteínas de Ligação a DNA/genética , Mitose/genética , Adenosina Trifosfatases/genética , Anáfase/genética , Animais , Proteínas de Ciclo Celular/isolamento & purificação , Cromátides/genética , Proteínas Cromossômicas não Histona , DNA Topoisomerases Tipo II/genética , Proteínas de Ligação a DNA/isolamento & purificação , Imageamento Tridimensional , Mamíferos , Metáfase/genética , Prófase/genética
19.
Nat Commun ; 11(1): 3998, 2020 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-32778730

RESUMO

Allergic asthma is a leading chronic disease associated with airway hyperreactivity (AHR). Type-2 innate lymphoid cells (ILC2s) are a potent source of T-helper 2 (Th2) cytokines that promote AHR and lung inflammation. As the programmed cell death protein-1 (PD-1) inhibitory axis regulates a variety of immune responses, here we investigate PD-1 function in pulmonary ILC2s during IL-33-induced airway inflammation. PD-1 limits the viability of ILC2s and downregulates their effector functions. Additionally, PD-1 deficiency shifts ILC2 metabolism toward glycolysis, glutaminolysis and methionine catabolism. PD-1 thus acts as a metabolic checkpoint in ILC2s, affecting cellular activation and proliferation. As the blockade of PD-1 exacerbates AHR, we also develop a human PD-1 agonist and show that it can ameliorate AHR and suppresses lung inflammation in a humanized mouse model. Together, these results highlight the importance of PD-1 agonistic treatment in allergic asthma and underscore its therapeutic potential.


Assuntos
Asma/imunologia , Asma/metabolismo , Imunidade Inata/imunologia , Linfócitos/metabolismo , Receptor de Morte Celular Programada 1/metabolismo , Animais , Citocinas/metabolismo , Proteínas de Ligação a DNA/genética , Modelos Animais de Doenças , Humanos , Inflamação/imunologia , Subunidade gama Comum de Receptores de Interleucina/genética , Interleucina-33/metabolismo , Pulmão/imunologia , Pulmão/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Receptor de Morte Celular Programada 1/genética , Células Th2/metabolismo , Transcriptoma
20.
Nat Commun ; 11(1): 4076, 2020 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-32796851

RESUMO

Group 3 innate lymphoid cells (ILC3) are an important regulator for immunity, inflammation and tissue homeostasis in the intestine, but how ILC3 activation is regulated remains elusive. Here we identify a new circular RNA (circRNA) circKcnt2 that is induced in ILC3s during intestinal inflammation. Deletion of circKcnt2 causes gut ILC3 activation and severe colitis in mice. Mechanistically, circKcnt2, as a nuclear circRNA, recruits the nucleosome remodeling deacetylase (NuRD) complex onto Batf promoter to inhibit Batf expression; this in turn suppresses Il17 expression and thereby ILC3 inactivation to promote innate colitis resolution. Furthermore, Mbd3-/-Rag1-/- and circKcnt2-/-Rag1-/- mice develop severe innate colitis following dextran sodium sulfate (DSS) treatments, while simultaneous deletion of Batf promotes colitis resolution. In summary, our data support a function of the circRNA circKcnt2 in regulating ILC3 inactivation and resolution of innate colitis.


Assuntos
Colite/imunologia , Colite/metabolismo , Linfócitos/metabolismo , Canais de Potássio Ativados por Sódio/metabolismo , RNA Circular/metabolismo , Animais , Colite/patologia , Proteínas de Ligação a DNA/genética , Modelos Animais de Doenças , Feminino , Proteínas de Homeodomínio/genética , Homeostase , Humanos , Imunidade Inata , Inflamação/imunologia , Inflamação/patologia , Intestinos/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos ICR , Camundongos Knockout , Canais de Potássio Ativados por Sódio/genética , RNA Circular/genética , RNA não Traduzido/genética , RNA não Traduzido/metabolismo , Fatores de Transcrição/genética
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