Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Plant Cell ; 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38801743

RESUMO

Transcription of antisense long noncoding RNAs (lncRNAs) occurs pervasively across eukaryotic genomes. Only a few antisense lncRNAs have been characterized and shown to control biological processes, albeit with idiosyncratic regulatory mechanisms. Thus, we largely lack knowledge about the general role of antisense transcription in eukaryotic organisms. Here, we characterized genes with antisense transcription initiating close to the Poly(A) signal (PAS genes) in Arabidopsis (Arabidopsis thaliana). We compared plant native elongation transcript sequencing (plaNET-seq) with RNA sequencing (RNA-seq) during short-term cold exposure and detected massive differences between the response in active transcription and steady-state levels of PAS gene-derived mRNAs. The cold-induced expression of transcription factors B-BOX DOMAIN PROTEIN28 (BBX28) and C2H2-TYPE ZINC FINGER FAMILY PROTEIN5 (ZAT5) was detected by plaNET-seq, while their steady-state level was only slightly altered due to high mRNA turnover. Knockdown of BBX28 and ZAT5 or of their respective antisense transcripts severely compromised plant freezing tolerance. Decreased antisense transcript expression levels resulted in a reduced cold response of BBX28 and ZAT5, revealing a positive regulatory role of both antisense transcripts. This study expands the known repertoire of noncoding transcripts. It highlights that native transcription approaches can complement steady state RNA techniques to identify biologically relevant players in stress responses.

2.
Nat Commun ; 15(1): 4540, 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38811542

RESUMO

Stomata govern the gaseous exchange between the leaf and the external atmosphere, and their function is essential for photosynthesis and the global carbon and oxygen cycles. Rhythmic stomata movements in daily dark/light cycles prevent water loss at night and allow CO2 uptake during the day. How the actors involved are transcriptionally regulated and how this might contribute to rhythmicity is largely unknown. Here, we show that morning stomata opening depends on the previous night period. The transcription factors PHYTOCHROME-INTERACTING FACTORS (PIFs) accumulate at the end of the night and directly induce the guard cell-specific K+ channel KAT1. Remarkably, PIFs and KAT1 are required for blue light-induced stomata opening. Together, our data establish a molecular framework for daily rhythmic stomatal movements under well-watered conditions, whereby PIFs are required for accumulation of KAT1 at night, which upon activation by blue light in the morning leads to the K+ intake driving stomata opening.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Regulação da Expressão Gênica de Plantas , Luz , Estômatos de Plantas , Estômatos de Plantas/fisiologia , Estômatos de Plantas/efeitos da radiação , Estômatos de Plantas/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Arabidopsis/genética , Arabidopsis/fisiologia , Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Ritmo Circadiano/fisiologia , Canais de Potássio Corretores do Fluxo de Internalização/metabolismo , Canais de Potássio Corretores do Fluxo de Internalização/genética , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética
3.
Nucleic Acids Res ; 51(20): 10992-11009, 2023 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-37791849

RESUMO

A wide range of nuclear proteins are involved in the spatio-temporal organization of the genome through diverse biological processes such as gene transcription and DNA replication. Upon stimulation by testosterone and translocation to the nucleus, multiple androgen receptors (ARs) accumulate in microscopically discernable foci which are irregularly distributed in the nucleus. Here, we investigated the formation and physical nature of these foci, by combining novel fluorescent labeling techniques to visualize a defined chromatin locus of AR-regulated genes-PTPRN2 or BANP-simultaneously with either AR foci or individual AR molecules. Quantitative colocalization analysis showed evidence of AR foci formation induced by R1881 at both PTPRN2 and BANP loci. Furthermore, single-particle tracking (SPT) revealed three distinct subdiffusive fractional Brownian motion (fBm) states: immobilized ARs were observed near the labeled genes likely as a consequence of DNA-binding, while the intermediate confined state showed a similar spatial behavior but with larger displacements, suggesting compartmentalization by liquid-liquid phase separation (LLPS), while freely mobile ARs were diffusing in the nuclear environment. All together, we show for the first time in living cells the presence of AR-regulated genes in AR foci.


Assuntos
Núcleo Celular , Receptores Androgênicos , Animais , Núcleo Celular/genética , Núcleo Celular/metabolismo , Proteínas Nucleares/metabolismo , Receptores Androgênicos/metabolismo , Humanos , Camundongos , Linhagem Celular Tumoral
4.
Hum Mol Genet ; 32(9): 1497-1510, 2023 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-36579832

RESUMO

TBR1 is a neuron-specific transcription factor involved in brain development and implicated in a neurodevelopmental disorder (NDD) combining features of autism spectrum disorder (ASD), intellectual disability (ID) and speech delay. TBR1 has been previously shown to interact with a small number of transcription factors and co-factors also involved in NDDs (including CASK, FOXP1/2/4 and BCL11A), suggesting that the wider TBR1 interactome may have a significant bearing on normal and abnormal brain development. Here, we have identified approximately 250 putative TBR1-interaction partners by affinity purification coupled to mass spectrometry. As well as known TBR1-interactors such as CASK, the identified partners include transcription factors and chromatin modifiers, along with ASD- and ID-related proteins. Five interaction candidates were independently validated using bioluminescence resonance energy transfer assays. We went on to test the interaction of these candidates with TBR1 protein variants implicated in cases of NDD. The assays uncovered disturbed interactions for NDD-associated variants and identified two distinct protein-binding domains of TBR1 that have essential roles in protein-protein interaction.


Assuntos
Transtornos do Neurodesenvolvimento , Proteínas com Domínio T , Humanos , Transtorno do Espectro Autista/genética , Transtorno do Espectro Autista/metabolismo , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Deficiência Intelectual/genética , Deficiência Intelectual/metabolismo , Transtornos do Neurodesenvolvimento/genética , Transtornos do Neurodesenvolvimento/metabolismo , Ligação Proteica/genética , Ligação Proteica/fisiologia , Proteínas/genética , Proteínas/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Proteínas com Domínio T/genética , Proteínas com Domínio T/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
6.
Nat Commun ; 10(1): 2669, 2019 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-31209209

RESUMO

The Mediator complex regulates transcription by connecting enhancers to promoters. High Mediator binding density defines super enhancers, which regulate cell-identity genes and oncogenes. Protein interactions of Mediator may explain its role in these processes but have not been identified comprehensively. Here, we purify Mediator from neural stem cells (NSCs) and identify 75 protein-protein interaction partners. We identify super enhancers in NSCs and show that Mediator-interacting chromatin modifiers colocalize with Mediator at enhancers and super enhancers. Transcription factor families with high affinity for Mediator dominate enhancers and super enhancers and can explain genome-wide Mediator localization. We identify E-box transcription factor Tcf4 as a key regulator of NSCs. Tcf4 interacts with Mediator, colocalizes with Mediator at super enhancers and regulates neurogenic transcription factor genes with super enhancers and broad H3K4me3 domains. Our data suggest that high binding-affinity for Mediator is an important organizing feature in the transcriptional network that determines NSC identity.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Redes Reguladoras de Genes/fisiologia , Complexo Mediador/metabolismo , Células-Tronco Neurais/fisiologia , Neurogênese/genética , Fator de Transcrição 4/metabolismo , Linhagem Celular , Elementos Facilitadores Genéticos/genética , Histonas/metabolismo , Humanos , Histona Desmetilases com o Domínio Jumonji/metabolismo , Oxirredutases N-Desmetilantes/metabolismo , Regiões Promotoras Genéticas/genética , Mapeamento de Interação de Proteínas , Mapas de Interação de Proteínas/genética , Proteína-Arginina N-Metiltransferases/metabolismo , Transcrição Gênica/fisiologia
8.
Hum Mol Genet ; 27(7): 1212-1227, 2018 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-29365100

RESUMO

FOXP transcription factors play important roles in neurodevelopment, but little is known about how their transcriptional activity is regulated. FOXP proteins cooperatively regulate gene expression by forming homo- and hetero-dimers with each other. Physical associations with other transcription factors might also modulate the functions of FOXP proteins. However, few FOXP-interacting transcription factors have been identified so far. Therefore, we sought to discover additional transcription factors that interact with the brain-expressed FOXP proteins, FOXP1, FOXP2 and FOXP4, through affinity-purifications of protein complexes followed by mass spectrometry. We identified seven novel FOXP-interacting transcription factors (NR2F1, NR2F2, SATB1, SATB2, SOX5, YY1 and ZMYM2), five of which have well-estabslished roles in cortical development. Accordingly, we found that these transcription factors are co-expressed with FoxP2 in the deep layers of the cerebral cortex and also in the Purkinje cells of the cerebellum, suggesting that they may cooperate with the FoxPs to regulate neural gene expression in vivo. Moreover, we demonstrated that etiological mutations of FOXP1 and FOXP2, known to cause neurodevelopmental disorders, severely disrupted the interactions with FOXP-interacting transcription factors. Additionally, we pinpointed specific regions within FOXP2 sequence involved in mediating these interactions. Thus, by expanding the FOXP interactome we have uncovered part of a broader neural transcription factor network involved in cortical development, providing novel molecular insights into the transcriptional architecture underlying brain development and neurodevelopmental disorders.


Assuntos
Fatores de Transcrição Forkhead , Regulação da Expressão Gênica , Transtornos do Neurodesenvolvimento , Células de Purkinje/metabolismo , Proteínas Repressoras , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Células HEK293 , Humanos , Transtornos do Neurodesenvolvimento/genética , Transtornos do Neurodesenvolvimento/metabolismo , Transtornos do Neurodesenvolvimento/patologia , Células de Purkinje/patologia , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
9.
Toxicol Sci ; 139(2): 407-20, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24595818

RESUMO

3,4-Methylenedioxymethamphetamine (MDMA; "ecstasy") is a potentially neurotoxic recreational drug of abuse. Though the mechanisms involved are still not completely understood, formation of reactive metabolites and mitochondrial dysfunction contribute to MDMA-related neurotoxicity. Neuronal mitochondrial trafficking, and their targeting to synapses, is essential for proper neuronal function and survival, rendering neurons particularly vulnerable to mitochondrial dysfunction. Indeed, MDMA-associated disruption of Ca(2+) homeostasis and ATP depletion have been described in neurons, thus suggesting possible MDMA interference on mitochondrial dynamics. In this study, we performed real-time functional experiments of mitochondrial trafficking to explore the role of in situ mitochondrial dysfunction in MDMA's neurotoxic actions. We show that the mixture of MDMA and six of its major in vivo metabolites, each compound at 10µM, impaired mitochondrial trafficking and increased the fragmentation of axonal mitochondria in cultured hippocampal neurons. Furthermore, the overexpression of mitofusin 2 (Mfn2) or dynamin-related protein 1 (Drp1) K38A constructs almost completely rescued the trafficking deficits caused by this mixture. Finally, in hippocampal neurons overexpressing a Mfn2 mutant, Mfn2 R94Q, with impaired fusion and transport properties, it was confirmed that a dysregulation of mitochondrial fission/fusion events greatly contributed to the reported trafficking phenotype. In conclusion, our study demonstrated, for the first time, that the mixture of MDMA and its metabolites, at concentrations relevant to the in vivo scenario, impaired mitochondrial trafficking and increased mitochondrial fragmentation in hippocampal neurons, thus providing a new insight in the context of "ecstasy"-induced neuronal injury.


Assuntos
Transporte Axonal/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Dinâmica Mitocondrial/efeitos dos fármacos , N-Metil-3,4-Metilenodioxianfetamina/metabolismo , N-Metil-3,4-Metilenodioxianfetamina/toxicidade , Neurônios/efeitos dos fármacos , Trifosfato de Adenosina/metabolismo , Animais , Cálcio/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , GTP Fosfo-Hidrolases/metabolismo , Hipocampo/metabolismo , Camundongos , Neurônios/metabolismo , Síndromes Neurotóxicas/etiologia , Síndromes Neurotóxicas/metabolismo , Ratos
10.
Arch Toxicol ; 88(8): 1561-72, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24522274

RESUMO

Identification of the mechanisms by which drugs of abuse cause neuronal dysfunction is essential for understanding the biological bases of their acute and long-lasting effects in the brain. Here, we performed real-time functional experiments of axonal transport of mitochondria to explore the role of in situ mitochondrial dysfunction in 3,4-methylenedioxymethamphetamine (MDMA; "ecstasy")-related brain actions. We showed that MDMA dramatically reduced mitochondrial trafficking in hippocampal neurons in a Tau-dependent manner, in which glycogen synthase kinase 3ß activity was implicated. Furthermore, we found that these trafficking abnormalities were rescued by over-expression of Mitofusin2 and dynamin-related protein 1, but not of Miro1. Given the relevance of mitochondrial targeting for neuronal function and neurotransmission, our data underscore a novel mechanism of action of MDMA that may contribute to our understanding of how this drug of abuse alters neuronal functioning.


Assuntos
Dinaminas/metabolismo , GTP Fosfo-Hidrolases/metabolismo , Mitocôndrias/efeitos dos fármacos , Dinâmica Mitocondrial/efeitos dos fármacos , N-Metil-3,4-Metilenodioxianfetamina/toxicidade , Neurônios/efeitos dos fármacos , Proteínas tau/metabolismo , Animais , Transporte Axonal/efeitos dos fármacos , Cálcio/metabolismo , Células Cultivadas , Hipocampo/citologia , Hipocampo/efeitos dos fármacos , Hipocampo/embriologia , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Neurônios/metabolismo , Fosforilação
11.
PLoS One ; 8(7): e67773, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23844091

RESUMO

The regulation of mitochondrial dynamics is vital in complex cell types, such as neurons, that transport and localize mitochondria in high energy-demanding cell domains. The Armcx3 gene encodes a mitochondrial-targeted protein (Alex3) that contains several arm-like domains. In a previous study we showed that Alex3 protein regulates mitochondrial aggregation and trafficking. Here we studied the contribution of Wnt proteins to the mitochondrial aggregation and dynamics regulated by Alex3. Overexpression of Alex3 in HEK293 cells caused a marked aggregation of mitochondria, which was attenuated by treatment with several Wnts. We also found that this decrease was caused by Alex3 degradation induced by Wnts. While the Wnt canonical pathway did not alter the pattern of mitochondrial aggregation induced by Alex3, we observed that the Wnt/PKC non-canonical pathway regulated both mitochondrial aggregation and Alex3 protein levels, thereby rendering a mitochondrial phenotype and distribution similar to control patterns. Our data suggest that the Wnt pathway regulates mitochondrial distribution and dynamics through Alex3 protein degradation.


Assuntos
Proteínas do Domínio Armadillo/metabolismo , Mitocôndrias/metabolismo , Dinâmica Mitocondrial/genética , Proteínas Mitocondriais/metabolismo , Proteína Quinase C/metabolismo , Proteínas Wnt/metabolismo , Via de Sinalização Wnt , Motivos de Aminoácidos , Proteínas do Domínio Armadillo/genética , Regulação da Expressão Gênica , Genes Reporter , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Células HEK293 , Humanos , Mitocôndrias/genética , Proteínas Mitocondriais/genética , Dados de Sequência Molecular , Naftalenos/farmacologia , Proteína Quinase C/genética , Inibidores de Proteínas Quinases/farmacologia , Estabilidade Proteica , Estrutura Terciária de Proteína , Proteólise , Proteínas Wnt/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...