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1.
Pestic Biochem Physiol ; 159: 136-143, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31400775

RESUMO

Cytochrome P450s are part of a super-gene family that has undergone gene duplication, divergence, over-expression and, in some cases, loss of function. One such case is the 91-R and 91-C strains of common origin, in Drosophila melanogaster, whereby 91-R (DDT resistant strain) overexpresses Cyp4p1 and Cyp4p2 and both genes are lost in 91-C (DDT susceptible strain). In this study, we used a comparative approach to demonstrate that transcription of Cyp4p1 and Cyp4p2 were constitutively up-regulated in the Drosophila melanogaster strain 91-R as compared to another DDT susceptible strain Canton-S which does not have a loss of function of these genes. Furthermore, significantly increased expression of Cyp4p1 and Cyp4p2 was induced in 91-R in response to sublethal DDT exposure, however, such induction did not occur in the DDT treated Canton-S. Additionally, fixed nucleotide variation within putative transcription factor binding sites of Cyp4p1 and Cyp4p2 promoters were observed between 91-R and Canton-S, however, their impact on transcription remains to be determined. Two GAL4/UAS transgenic strains with integrated heat shock-inducible Cyp4p1- or Cyp4p2-RNAi constructs within wild-type genetic backgrounds were developed. Following heat shock induction of Cyp4p1 and Cyp4p2 knockdown, these transgenic lines showed increased DDT mortality as compared to their corresponding non-heat shock controls. These results provide a functional link of Cyp4p1 and Cyp4p2 in conferring tolerance to DDT exposure.


Assuntos
DDT/farmacologia , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/efeitos dos fármacos , Drosophila melanogaster/metabolismo , Inseticidas/farmacologia , Animais , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Proteínas de Drosophila/genética , Resistência a Inseticidas/genética
3.
Nat Commun ; 10(1): 2951, 2019 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-31273212

RESUMO

Epithelial-mesenchymal transition (EMT) is an essential process both in physiological and pathological contexts. Intriguingly, EMT is often associated with tissue invagination during development; however, the impact of EMT on tissue remodeling remain unexplored. Here, we show that at the initiation of the EMT process, cells produce an apico-basal force, orthogonal to the surface of the epithelium, that constitutes an important driving force for tissue invagination in Drosophila. When EMT is ectopically induced, cells starting their delamination generate an orthogonal force and induce ectopic folding. Similarly, during mesoderm invagination, cells undergoing EMT generate an apico-basal force through the formation of apico-basal structures of myosin II. Using both laser microdissection and in silico physical modelling, we show that mesoderm invagination does not proceed if apico-basal forces are impaired, indicating that they constitute driving forces in the folding process. Altogether, these data reveal the mechanical impact of EMT on morphogenesis.


Assuntos
Drosophila melanogaster/embriologia , Transição Epitelial-Mesenquimal , Epitélio/embriologia , Morfogênese , Animais , Polaridade Celular , Simulação por Computador , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/citologia , Drosophila melanogaster/metabolismo , Embrião não Mamífero/citologia , Embrião não Mamífero/metabolismo , Epitélio/metabolismo , Mesoderma/citologia , Mesoderma/embriologia , Mesoderma/metabolismo , Modelos Moleculares , Miosina Tipo II/metabolismo
5.
Genome Biol ; 20(1): 115, 2019 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-31159833

RESUMO

BACKGROUND: Hox transcription factors specify segmental diversity along the anterior-posterior body axis in metazoans. While the different Hox family members show clear functional specificity in vivo, they all show similar binding specificity in vitro and a satisfactory understanding of in vivo Hox target selectivity is still lacking. RESULTS: Using transient transfection in Kc167 cells, we systematically analyze the binding of all eight Drosophila Hox proteins. We find that Hox proteins show considerable binding selectivity in vivo even in the absence of canonical Hox cofactors Extradenticle and Homothorax. Hox binding selectivity is strongly associated with chromatin accessibility, being highest in less accessible chromatin. Individual Hox proteins exhibit different propensities to bind less accessible chromatin, and high binding selectivity is associated with high-affinity binding regions, leading to a model where Hox proteins derive binding selectivity through affinity-based competition with nucleosomes. Extradenticle/Homothorax cofactors generally facilitate Hox binding, promoting binding to regions in less accessible chromatin but with little effect on the overall selectivity of Hox targeting. These cofactors collaborate with Hox proteins in opening chromatin, in contrast to the pioneer factor, Glial cells missing, which facilitates Hox binding by independently generating accessible chromatin regions. CONCLUSIONS: These studies indicate that chromatin accessibility plays a key role in Hox selectivity. We propose that relative chromatin accessibility provides a basis for subtle differences in binding specificity and affinity to generate significantly different sets of in vivo genomic targets for different Hox proteins.


Assuntos
Montagem e Desmontagem da Cromatina , Cromatina/metabolismo , Proteínas de Homeodomínio/metabolismo , Motivos de Aminoácidos , Animais , Linhagem Celular , Drosophila , Proteínas de Drosophila/metabolismo , Fatores de Transcrição/metabolismo
6.
Dokl Biochem Biophys ; 485(1): 138-140, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31201635

RESUMO

To study the mechanisms of transcriptional regulation, a convenient experimental approach is to use the artificial chimeric constructs carrying the regulatory elements of interest. In the present work, we describe the creation and characterization of a novel genetic construct that makes it possible to study the transcriptional regulation of the early-late gene of the ecdysone cascade. Using the data of genome-wide experiments, we have isolated the main regulatory region of the hr4 gene, which was successfully used to create a chimeric reporter construct expressing a fluorescent protein upon the treatment with the ecdysone hormone. This reporter system can be used to study the mechanisms of the ecdysone response, both in cell culture and in tissues, at various stages of the Drosophila development.


Assuntos
Proteínas de Drosophila , Ecdisona/metabolismo , Genes Reporter , Receptores Citoplasmáticos e Nucleares , Transcrição Genética , Animais , Linhagem Celular , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster , Estudo de Associação Genômica Ampla , Receptores Citoplasmáticos e Nucleares/genética , Receptores Citoplasmáticos e Nucleares/metabolismo
7.
Nat Commun ; 10(1): 2593, 2019 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-31197139

RESUMO

Prion-like domains (PLDs), defined by their low sequence complexity and intrinsic disorder, are present in hundreds of human proteins. Although gain-of-function mutations in the PLDs of neuronal RNA-binding proteins have been linked to neurodegenerative disease progression, the physiological role of PLDs and their range of molecular functions are still largely unknown. Here, we show that the PLD of Drosophila Imp, a conserved component of neuronal ribonucleoprotein (RNP) granules, is essential for the developmentally-controlled localization of Imp RNP granules to axons and regulates in vivo axonal remodeling. Furthermore, we demonstrate that Imp PLD restricts, rather than promotes, granule assembly, revealing a novel modulatory function for PLDs in RNP granule homeostasis. Swapping the position of Imp PLD compromises RNP granule dynamic assembly but not transport, suggesting that these two functions are uncoupled. Together, our study uncovers a physiological function for PLDs in the spatio-temporal control of neuronal RNP assemblies.


Assuntos
Transporte Axonal/fisiologia , Grânulos Citoplasmáticos/metabolismo , Proteínas de Drosophila/metabolismo , Domínios Proteicos/fisiologia , Proteínas de Ligação a RNA/metabolismo , Ribonucleoproteínas/metabolismo , Animais , Animais Geneticamente Modificados , Axônios/metabolismo , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Linhagem Celular , Proteínas de Drosophila/química , Proteínas de Drosophila/genética , Drosophila melanogaster , Feminino , Microscopia de Fluorescência , Modelos Animais , Príons/química , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/genética
8.
Nat Commun ; 10(1): 2714, 2019 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-31221956

RESUMO

The dopamine transporter is a member of the neurotransmitter:sodium symporters (NSSs), which are responsible for termination of neurotransmission through Na+-driven reuptake of neurotransmitter from the extracellular space. Experimental evidence elucidating the coordinated conformational rearrangements related to the transport mechanism has so far been limited. Here we probe the global Na+- and dopamine-induced conformational dynamics of the wild-type Drosophila melanogaster dopamine transporter using hydrogen-deuterium exchange mass spectrometry. We identify Na+- and dopamine-induced changes in specific regions of the transporter, suggesting their involvement in protein conformational transitions. Furthermore, we detect ligand-dependent slow cooperative fluctuations of helical stretches in several domains of the transporter, which could be a molecular mechanism that assists in the transporter function. Our results provide a framework for understanding the molecular mechanism underlying the function of NSSs by revealing detailed insight into the state-dependent conformational changes associated with the alternating access model of the dopamine transporter.


Assuntos
Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Dopamina/metabolismo , Proteínas de Drosophila/metabolismo , Simulação de Dinâmica Molecular , Sódio/metabolismo , Proteínas da Membrana Plasmática de Transporte de Dopamina/química , Proteínas da Membrana Plasmática de Transporte de Dopamina/isolamento & purificação , Proteínas de Drosophila/química , Proteínas de Drosophila/isolamento & purificação , Células HEK293 , Humanos , Ligantes , Espectrometria de Massas , Conformação Proteica em alfa-Hélice/fisiologia , Domínios Proteicos/fisiologia , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo
9.
J Insect Sci ; 19(3)2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31115476

RESUMO

Alkaline ceramidase (Dacer) in Drosophila melanogaster was demonstrated to be resistant to paraquat-induced oxidative stress. However, the underlying mechanism for this resistance remained unclear. Here, we showed that sphingosine feeding triggered the accumulation of hydrogen peroxide (H2O2). Dacer-deficient D. melanogaster (Dacer mutant) has higher catalase (CAT) activity and CAT transcription level, leading to higher resistance to oxidative stress induced by paraquat. By performing a quantitative proteomic analysis, we identified 79 differentially expressed proteins in comparing Dacer mutant to wild type. Three oxidoreductases, including two cytochrome P450 (CG3050, CG9438) and an oxoglutarate/iron-dependent dioxygenase (CG17807), were most significantly upregulated in Dacer mutant. We presumed that altered antioxidative activity in Dacer mutant might be responsible for increased oxidative stress resistance. Our work provides a novel insight into the oxidative antistress response in D. melanogaster.


Assuntos
Ceramidase Alcalina/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/enzimologia , Estresse Oxidativo , Esfingosina/administração & dosagem , Ceramidase Alcalina/efeitos dos fármacos , Ceramidase Alcalina/genética , Animais , Catalase/metabolismo , Proteínas de Drosophila/efeitos dos fármacos , Proteínas de Drosophila/genética , Drosophila melanogaster/efeitos dos fármacos , Drosophila melanogaster/genética , Peróxido de Hidrogênio/metabolismo , Paraquat , Proteoma
10.
Nat Commun ; 10(1): 2219, 2019 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-31101825

RESUMO

A long-standing question in the field of embryogenesis is how the zygotic genome is precisely activated by maternal factors, allowing normal early embryonic development. We have previously shown that N6-methyladenine (6mA) DNA modification is highly dynamic in early Drosophila embryos and forms an epigenetic mark. However, little is known about how 6mA-formed epigenetic information is decoded. Here we report that the Fox-family protein Jumu binds 6mA-marked DNA and acts as a maternal factor to regulate the maternal-to-zygotic transition. We find that zelda encoding the pioneer factor Zelda is marked by 6mA. Our genetic assays suggest that Jumu controls the proper zygotic genome activation (ZGA) in early embryos, at least in part, by regulating zelda expression. Thus, our findings not only support that the 6mA-formed epigenetic marks can be read by specific transcription factors, but also uncover a mechanism by which the Jumu regulates ZGA partially through Zelda in early embryos.


Assuntos
DNA/metabolismo , Proteínas de Drosophila/metabolismo , Desenvolvimento Embrionário/fisiologia , Fatores de Transcrição/metabolismo , Zigoto/metabolismo , Adenina/análogos & derivados , Adenina/metabolismo , Animais , Animais Geneticamente Modificados , Proteínas de Drosophila/genética , Drosophila melanogaster/fisiologia , Embrião não Mamífero , Epigênese Genética/fisiologia , Feminino , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Técnicas de Silenciamento de Genes , Genoma de Inseto , Masculino , Fatores de Transcrição/genética
11.
BMC Evol Biol ; 19(1): 99, 2019 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-31068148

RESUMO

BACKGROUND: RNA interference (RNAi) related pathways provide defense against viruses and transposable elements, and have been implicated in the suppression of meiotic drive elements. Genes in these pathways often exhibit high levels of adaptive substitution, and over longer timescales show gene duplication and loss-most likely as a consequence of their role in mediating conflict with these parasites. This is particularly striking for Argonaute 2 (Ago2), which is ancestrally the key effector of antiviral RNAi in insects, but has repeatedly formed new testis-specific duplicates in the recent history of the obscura species-group of Drosophila. RESULTS: Here we take advantage of publicly available genomic and transcriptomic data to identify six further RNAi-pathway genes that have duplicated in this clade of Drosophila, and examine their evolutionary history. As seen for Ago2, we observe high levels of adaptive amino-acid substitution and changes in sex-biased expression in many of the paralogs. However, our phylogenetic analysis suggests that co-duplications of the RNAi machinery were not synchronous, and our expression analysis fails to identify consistent male-specific expression. CONCLUSIONS: These results confirm that RNAi genes, including genes of the antiviral and piRNA pathways, have undergone multiple independent duplications and that their history has been particularly labile within the obscura group. However, they also suggest that the selective pressures driving these changes have not been consistent, implying that more than one selective agent may be responsible.


Assuntos
Adaptação Fisiológica/genética , Drosophila/genética , Duplicação Gênica , Genes de Insetos , Interferência de RNA , Substituição de Aminoácidos/genética , Animais , Teorema de Bayes , Proteínas CLOCK/genética , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Evolução Molecular , Regulação da Expressão Gênica , Masculino , Filogenia
12.
Nat Commun ; 10(1): 2159, 2019 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-31089141

RESUMO

Accurate DNA replication is tightly regulated in eukaryotes to ensure genome stability during cell division and is performed by the multi-protein replisome. At the core an AAA+ hetero-hexameric complex, Mcm2-7, together with GINS and Cdc45 form the active replicative helicase Cdc45/Mcm2-7/GINS (CMG). It is not clear how this replicative ring helicase translocates on, and unwinds, DNA. We measure real-time dynamics of purified recombinant Drosophila melanogaster CMG unwinding DNA with single-molecule magnetic tweezers. Our data demonstrates that CMG exhibits a biased random walk, not the expected unidirectional motion. Through building a kinetic model we find CMG may enter up to three paused states rather than unwinding, and should these be prevented, in vivo fork rates would be recovered in vitro. We propose a mechanism in which CMG couples ATP hydrolysis to unwinding by acting as a lazy Brownian ratchet, thus providing quantitative understanding of the central process in eukaryotic DNA replication.


Assuntos
DNA Helicases/metabolismo , Replicação do DNA , Proteínas de Drosophila/metabolismo , Modelos Moleculares , DNA Helicases/isolamento & purificação , Proteínas de Drosophila/isolamento & purificação , Fenômenos Magnéticos , Pinças Ópticas , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Imagem Individual de Molécula/métodos
13.
Nat Commun ; 10(1): 2133, 2019 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-31086177

RESUMO

Polycomb (PcG) and Trithorax (TrxG) group proteins give stable epigenetic memory of silent and active gene expression states, but also allow poised states in pluripotent cells. Here we systematically address the relationship between poised, active and silent chromatin, by integrating 73 publications on PcG/TrxG biochemistry into a mathematical model comprising 144 nucleosome modification states and 8 enzymatic reactions. Our model predicts that poised chromatin is bistable and not bivalent. Bivalent chromatin, containing opposing active and silent modifications, is present as an unstable background population in all system states, and different subtypes co-occur with active and silent chromatin. In contrast, bistability, in which the system switches frequently between stable active and silent states, occurs under a wide range of conditions at the transition between monostable active and silent system states. By proposing that bistability and not bivalency is associated with poised chromatin, this work has implications for understanding the molecular nature of pluripotency.


Assuntos
Cromatina/metabolismo , Epigênese Genética/fisiologia , Modelos Biológicos , Proteínas do Grupo Polycomb/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Proteínas de Drosophila/metabolismo , Enzimas/metabolismo , Código das Histonas/fisiologia , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Proteína de Leucina Linfoide-Mieloide/metabolismo , Nucleossomos/metabolismo
14.
Genes Cells ; 24(7): 464-472, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31095815

RESUMO

Dendrites of neurons receive and process synaptic or sensory inputs. The Drosophila class IV dendritic arborization (da) neuron is an established model system to explore molecular mechanisms of dendrite morphogenesis. The total number of dendritic branch terminals is one of the frequently employed parameters to characterize dendritic arborization complexity of class IV neurons. This parameter gives a useful phenotypic readout of arborization during neurogenesis, and it is typically determined by laborious manual analyses of numerous images. Ideally, an automated analysis would greatly reduce the workload; however, it is challenging to automatically discriminate dendritic branch terminals from signals of surrounding tissues in whole-mount live larvae. Here, we describe our newly developed software, called DeTerm, which automatically recognizes and quantifies dendrite branch terminals via an artificial neural network. Once we input an image file of a neuronal dendritic arbor and its region of interest information, DeTerm is capable of labeling terminals of larval class IV neurons with high precision, and it also provides positional data of individual terminals. We further show that DeTerm is applicable to other types of neurons, including mouse cerebellar Purkinje cells. DeTerm is freely available on the web and was successfully tested on Mac, Windows and Linux.


Assuntos
Cerebelo/fisiologia , Dendritos/fisiologia , Redes Neurais (Computação) , Neurogênese , Neurônios/fisiologia , Células de Purkinje/fisiologia , Software , Animais , Cerebelo/citologia , Drosophila , Proteínas de Drosophila/metabolismo , Larva , Camundongos , Neurônios/citologia , Células de Purkinje/citologia
15.
Genes Cells ; 24(7): 496-510, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31124270

RESUMO

In the Drosophila brain, neurons form genetically specified synaptic connections with defined neuronal targets. It is proposed that each central nervous system neuron expresses specific cell surface proteins, which act as identification tags. Through an RNAi screen of cell surface molecules in the Drosophila visual system, we found that the cell adhesion molecule Klingon (Klg) plays an important role in repressing the ectopic formation of extended axons, preventing the formation of excessive synapses. Cell-specific manipulation of klg showed that Klg is required in both photoreceptors and the glia, suggesting that the balanced homophilic interaction between photoreceptor axons and the glia is required for normal synapse formation. Previous studies suggested that Klg binds to cDIP and our genetic analyses indicate that cDIP is required in glia for ectopic synaptic repression. These data suggest that Klg play a critical role together with cDIP in refining synaptic specificity and preventing unnecessary connections in the brain.


Assuntos
Moléculas de Adesão Celular/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/fisiologia , Proteínas do Olho/metabolismo , Neuroglia/fisiologia , Células Fotorreceptoras de Invertebrados/fisiologia , Sinapses/fisiologia , Vias Visuais , Animais , Animais Geneticamente Modificados/genética , Animais Geneticamente Modificados/fisiologia , Axônios/fisiologia , Moléculas de Adesão Celular/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Proteínas do Olho/genética , Feminino
16.
Mol Cells ; 42(4): 301-312, 2019 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-31091556

RESUMO

Post-transcriptional regulation underlies the circadian control of gene expression and animal behaviors. However, the role of mRNA surveillance via the nonsense-mediated mRNA decay (NMD) pathway in circadian rhythms remains elusive. Here, we report that Drosophila NMD pathway acts in a subset of circadian pacemaker neurons to maintain robust 24 h rhythms of free-running locomotor activity. RNA interference-mediated depletion of key NMD factors in timeless-expressing clock cells decreased the amplitude of circadian locomotor behaviors. Transgenic manipulation of the NMD pathway in clock neurons expressing a neuropeptide PIGMENT-DISPERSING FACTOR (PDF) was sufficient to dampen or lengthen free-running locomotor rhythms. Confocal imaging of a transgenic NMD reporter revealed that arrhythmic Clock mutants exhibited stronger NMD activity in PDF-expressing neurons than wild-type. We further found that hypomorphic mutations in Suppressor with morphogenetic effect on genitalia 5 (Smg5 ) or Smg6 impaired circadian behaviors. These NMD mutants normally developed PDF-expressing clock neurons and displayed daily oscillations in the transcript levels of core clock genes. By contrast, the loss of Smg5 or Smg6 function affected the relative transcript levels of cAMP response element-binding protein B (CrebB ) in an isoform-specific manner. Moreover, the overexpression of a transcriptional repressor form of CrebB rescued free-running locomotor rhythms in Smg5-depleted flies. These data demonstrate that CrebB is a rate-limiting substrate of the genetic NMD pathway important for the behavioral output of circadian clocks in Drosophila.


Assuntos
Relógios Circadianos , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila/genética , Mutação , Degradação do RNAm Mediada por Códon sem Sentido , Transativadores/metabolismo , Animais , Animais Geneticamente Modificados , Proteínas CLOCK/genética , Drosophila/metabolismo , Proteínas de Drosophila/genética , Endorribonucleases/genética , Endorribonucleases/metabolismo , Neurônios/metabolismo , Neuropeptídeos/genética , Neuropeptídeos/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Processamento Pós-Transcricional do RNA , Transdução de Sinais
17.
Int J Mol Sci ; 20(9)2019 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-31060255

RESUMO

GSK3 (glycogen synthase kinase 3) is a conserved protein kinase governing numerous regulatory pathways. In Drosophila melanogaster, GSK3 is encoded by shaggy (sgg), which forms 17 annotated transcripts corresponding to 10 protein isoforms. Our goal was to demonstrate how differential sgg transcription affects lifespan, which GSK3 isoforms are important for the nervous system, and which changes in the nervous system accompany accelerated aging. Overexpression of three sgg transcripts affected the lifespan in a stage- and tissue-specific way: sgg-RA and sgg-RO affected the lifespan only when overexpressed in muscles and in embryos, respectively; the essential sgg-RB transcript affected lifespan when overexpressed in all tissues tested. In the nervous system, only sgg-RB overexpression affected lifespan, causing accelerated aging in a neuron-specific way, with the strongest effects in dopaminergic neurons and the weakest effects in GABAergic neurons. Pan-neuronal sgg-RB overexpression violated the properties of the nervous system, including the integrity of neuron bodies; the number, distribution, and structure of mitochondria; cytoskeletal characteristics; and synaptic activity. Such changes observed in young individuals indicated premature aging of their nervous system, which paralleled a decline in survival. Our findings demonstrated the key role of GSK3 in ensuring the link between the pathology of neurons and lifespan.


Assuntos
Proteínas de Drosophila/genética , Drosophila/genética , Regulação da Expressão Gênica , Quinase 3 da Glicogênio Sintase/genética , Estágios do Ciclo de Vida/genética , Longevidade/genética , Animais , Drosophila/crescimento & desenvolvimento , Drosophila/metabolismo , Proteínas de Drosophila/metabolismo , Feminino , Quinase 3 da Glicogênio Sintase/metabolismo , Masculino , Mitocôndrias/genética , Mitocôndrias/metabolismo , Mitocôndrias/ultraestrutura , Neurônios/metabolismo , Neurônios/ultraestrutura , Especificidade de Órgãos/genética , Fenótipo
18.
Genetics ; 212(1): 13-24, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31053615

RESUMO

Transcription by RNA polymerase II initiates at the core promoter, which is sometimes referred to as the "gateway to transcription." Here, we describe the properties of the RNA polymerase II core promoter in Drosophila The core promoter is at a strategic position in the expression of genes, as it is the site of convergence of the signals that lead to transcriptional activation. Importantly, core promoters are diverse in terms of their structure and function. They are composed of various combinations of sequence motifs such as the TATA box, initiator (Inr), and downstream core promoter element (DPE). Different types of core promoters are transcribed via distinct mechanisms. Moreover, some transcriptional enhancers exhibit specificity for particular types of core promoters. These findings indicate that the core promoter is a central component of the transcriptional apparatus that regulates gene expression.


Assuntos
Drosophila/genética , Regiões Promotoras Genéticas , RNA Polimerase II/metabolismo , Transcrição Genética , Animais , Drosophila/enzimologia , Proteínas de Drosophila/metabolismo , Ativação Transcricional
19.
Nat Commun ; 10(1): 2193, 2019 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-31097705

RESUMO

Filamentous actin (F-actin) networks facilitate key processes like cell shape control, division, polarization and motility. The dynamic coordination of F-actin networks and its impact on cellular activities are poorly understood. We report an antagonistic relationship between endosomal F-actin assembly and cortical actin bundle integrity during Drosophila airway maturation. Double mutants lacking receptor tyrosine phosphatases (PTP) Ptp10D and Ptp4E, clear luminal proteins and disassemble apical actin bundles prematurely. These defects are counterbalanced by reduction of endosomal trafficking and by mutations affecting the tyrosine kinase Btk29A, and the actin nucleation factor WASH. Btk29A forms protein complexes with Ptp10D and WASH, and Btk29A phosphorylates WASH. This phosphorylation activates endosomal WASH function in flies and mice. In contrast, a phospho-mimetic WASH variant induces endosomal actin accumulation, premature luminal endocytosis and cortical F-actin disassembly. We conclude that PTPs and Btk29A regulate WASH activity to balance the endosomal and cortical F-actin networks during epithelial tube maturation.


Assuntos
Proteínas de Drosophila/metabolismo , Endossomos/metabolismo , Morfogênese/fisiologia , Proteínas Tirosina Quinases/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Actinas/metabolismo , Animais , Animais Geneticamente Modificados , Linhagem Celular , Proteínas de Drosophila/genética , Drosophila melanogaster , Embrião não Mamífero/diagnóstico por imagem , Epitélio/diagnóstico por imagem , Epitélio/crescimento & desenvolvimento , Fibroblastos , Microscopia Intravital , Camundongos , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Microscopia Confocal , Fosforilação/fisiologia , Proteínas Tirosina Fosfatases/genética , Proteínas Tirosina Fosfatases/metabolismo , Proteínas Tirosina Quinases/genética , Proteínas Tirosina Fosfatases Classe 4 Semelhantes a Receptores/genética , Proteínas Tirosina Fosfatases Classe 4 Semelhantes a Receptores/metabolismo , Sistema Respiratório/diagnóstico por imagem , Sistema Respiratório/crescimento & desenvolvimento , Proteínas de Transporte Vesicular/genética
20.
Nat Commun ; 10(1): 1986, 2019 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-31064979

RESUMO

Natural D-serine (D-Ser) has been detected in animals more than two decades ago, but little is known about the physiological functions of D-Ser. Here we reveal sleep regulation by endogenous D-Ser. Sleep was decreased in mutants defective in D-Ser synthesis or its receptor the N-methyl-D-aspartic receptor 1 (NMDAR1), but increased in mutants defective in D-Ser degradation. D-Ser but not L-Ser rescued the phenotype of mutants lacking serine racemase (SR), the key enzyme for D-Ser synthesis. Pharmacological and triple gene knockout experiments indicate that D-Ser functions upstream of NMDAR1. Expression of SR was detected in both the nervous system and the intestines. Strikingly, reintroduction of SR into specific intestinal epithelial cells rescued the sleep phenotype of sr mutants. Our results have established a novel physiological function for endogenous D-Ser and a surprising role for intestinal cells.


Assuntos
Proteínas de Drosophila/metabolismo , Racemases e Epimerases/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Serina/metabolismo , Sono/fisiologia , Animais , Animais Geneticamente Modificados , Comportamento Animal/fisiologia , Drosophila/fisiologia , Proteínas de Drosophila/genética , Células Epiteliais/metabolismo , Feminino , Técnicas de Inativação de Genes , Mucosa Intestinal/citologia , Mucosa Intestinal/metabolismo , Masculino , Modelos Animais , Racemases e Epimerases/genética , Receptores de N-Metil-D-Aspartato/genética , Estereoisomerismo
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