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1.
Adv Exp Med Biol ; 1167: 105-112, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31520351

RESUMO

Human P53 (HsP53) is the most frequently mutated gene associated with cancers. Despite heightened research interest over the last four decades, a clear picture of how wild type HsP53 functions as the guardian against malignant transformation remains elusive. Studying the ortholog of P53 in the genetic model organism Drosophila melanogaster (DmP53) has revealed many interesting insights. This chapter focuses on recent findings that have shed light on how DmP53 -mediated apoptosis plays an important role in maintaining genome integrity, and how the immediate output of activated DmP53 is determined by the epigenetic landscape of individual cells.


Assuntos
Apoptose , Proteínas de Drosophila/genética , Drosophila melanogaster , Proteína Supressora de Tumor p53/genética , Animais , Epigênese Genética , Instabilidade Genômica , Humanos
2.
Adv Exp Med Biol ; 1167: 129-155, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31520353

RESUMO

Multiple large-scale epidemiological studies have identified obesity as an important risk factor for a variety of human cancers, particularly cancers of the uterus, gallbladder, kidney, liver, colon, and ovary, but there is much uncertainty regarding how obesity increases the cancer risks. Given that obesity has been consistently identified as a major risk factor for uterine tumors, the most common malignancies of the female reproductive system, we use uterine tumors as a pathological context to survey the relevant literature and propose a novel hypothesis: chronic downregulation of the cyclin-dependent kinase 8 (CDK8) module, composed of CDK8 (or its paralog CDK19), Cyclin C, MED12 (or MED12L), and MED13 (or MED13L), by elevated insulin or insulin-like growth factor signaling in obese women may increase the chances to dysregulate the activities of transcription factors regulated by the CDK8 module, thereby increasing the risk of uterine tumors. Although we focus on endometrial cancer and uterine leiomyomas (or fibroids), two major forms of uterine tumors, our model may offer additional insights into how obesity increases the risk of other types of cancers and diseases. To illustrate the power of model organisms for studying human diseases, here we place more emphasis on the findings obtained from Drosophila melanogaster.


Assuntos
Drosophila melanogaster , Obesidade/complicações , Neoplasias Uterinas/patologia , Animais , Quinase 8 Dependente de Ciclina/genética , Modelos Animais de Doenças , Proteínas de Drosophila/genética , Feminino , Humanos , Complexo Mediador/genética , Fatores de Risco
3.
Dokl Biochem Biophys ; 486(1): 187-191, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31367818

RESUMO

Using transgenic Drosophila model systems, we showed that four binding sites for the architectural protein dCTCF per se cannot form an effective insulator that blocks enhancers and protects against the Polycomb-dependent repression. These results suggest that, in the known Drosophila insulators, the dCTCF protein functions in cooperation with other architectural proteins.


Assuntos
Fator de Ligação a CCCTC/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Animais , Animais Geneticamente Modificados
4.
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
5.
Genes Dev ; 33(17-18): 1208-1220, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31416967

RESUMO

The PIWI-interacting RNA (piRNA) pathway is a conserved small RNA-based immune system that protects animal germ cell genomes from the harmful effects of transposon mobilization. In Drosophila ovaries, most piRNAs originate from dual-strand clusters, which generate piRNAs from both genomic strands. Dual-strand clusters use noncanonical transcription mechanisms. Although transcribed by RNA polymerase II, cluster transcripts lack splicing signatures and poly(A) tails. mRNA processing is important for general mRNA export mediated by nuclear export factor 1 (Nxf1). Although UAP56, a component of the transcription and export complex, has been implicated in piRNA precursor export, it remains unknown how dual-strand cluster transcripts are specifically targeted for piRNA biogenesis by export from the nucleus to cytoplasmic processing centers. Here we report that dual-strand cluster transcript export requires CG13741/Bootlegger and the Drosophila nuclear export factor family protein Nxf3. Bootlegger is specifically recruited to piRNA clusters and in turn brings Nxf3. We found that Nxf3 specifically binds to piRNA precursors and is essential for their export to piRNA biogenesis sites, a process that is critical for germline transposon silencing. Our data shed light on how dual-strand clusters compensate for a lack of canonical features of mature mRNAs to be specifically exported via Nxf3, ensuring proper piRNA production.


Assuntos
Transporte Ativo do Núcleo Celular/genética , Proteínas de Drosophila/metabolismo , Drosophila/metabolismo , Precursores de RNA/metabolismo , RNA Interferente Pequeno/metabolismo , Animais , Elementos de DNA Transponíveis/genética , Drosophila/genética , Proteínas de Drosophila/genética
7.
J Phys Chem Lett ; 10(15): 4362-4367, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31306018

RESUMO

Dynein adaptors such as Bicaudal D2 (BicD2) recognize cargo for dynein-dependent transport, and cargo-bound adaptors are required to activate dynein for processive transport, but the mechanism of action is unknown. Here we report the X-ray structure of the cargo-binding domain of human BicD2 and investigate the structural dynamics of the coiled-coil. Our molecular dynamics simulations support the fact that BicD2 can switch from a homotypic coiled-coil registry, in which both helices of the homodimer are aligned, to an asymmetric registry, where a portion of one helix is vertically shifted, as both states are similarly stable and defined by distinct conformations of F743. The F743I variant increases dynein recruitment in the Drosophila homologue, whereas the human R747C variant causes spinal muscular atrophy. We report spontaneous registry shifts for both variants, which may be the cause for BicD2 hyperactivation and disease. We propose that a registry shift upon cargo binding may activate autoinhibited BicD2 for dynein recruitment.


Assuntos
Dineínas/química , Proteínas Associadas aos Microtúbulos/química , Animais , Proteínas de Drosophila/química , Proteínas de Drosophila/genética , Humanos , Simulação de Dinâmica Molecular , Atrofia Muscular Espinal/genética , Mutação , Fenilalanina/química , Ligação Proteica , Conformação Proteica em alfa-Hélice , Domínios Proteicos
8.
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
9.
Mol Biol (Mosk) ; 53(3): 476-484, 2019.
Artigo em Russo | MEDLINE | ID: mdl-31184613

RESUMO

It is known that long (200-300 nucleotides and longer) non-protein-coding RNAs (ncRNAs) tissue-specifically expressed from the regulatory regions of developmental genes can regulate the transcription of the mRNA of these genes. In this study, an attempt is made to identify differentially expressed ncRNAs in the extended promoter region of the fork head (fkh) gene of the fruit fly Drosophila melanogaster. We investigated four preparations of the total RNA: from embryos, from adult flies (separately from females and males), and from the S2 cell line of cultured Drosophila cells. In the total RNA preparations from embryos and adult flies, the levels of fkh expression differed substantially, whereas in S2 cells its expression is not detected at all (shown in this work). We perform classical Northern blot analysis of gel-separated RNAs hybridized to a series of radioactively labeled DNA fragments corresponding to the adjacent and partially overlapping regions of the promoter region of the fkh gene. Several previously unknown differentially expressed ncRNAs are detected, including those in the regions overlapping with the previously detected regulatory elements (TRE1 and salivary gland enhancer sgE) and the transcription start site of the fkh gene. The collected data complement and clarify the results of the previously conducted RNA-seq experiments, in particular, in terms of the length of the detected RNAs. These results may serve as a foundation for further studies of the mechanisms of tissue-specific regulation of the fkh gene expression.


Assuntos
Northern Blotting , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Fatores de Transcrição Forkhead/genética , Regulação da Expressão Gênica no Desenvolvimento , Regiões Promotoras Genéticas/genética , RNA Longo não Codificante/análise , RNA Longo não Codificante/genética , Animais , Linhagem Celular , Drosophila melanogaster/embriologia , Drosophila melanogaster/crescimento & desenvolvimento , Elementos Facilitadores Genéticos/genética , Feminino , Masculino , Especificidade de Órgãos
10.
Nat Cell Biol ; 21(6): 710-720, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31160709

RESUMO

The capacity of stem cells to self-renew or differentiate has been attributed to distinct metabolic states. A genetic screen targeting regulators of mitochondrial dynamics revealed that mitochondrial fusion is required for the maintenance of male germline stem cells (GSCs) in Drosophila melanogaster. Depletion of Mitofusin (dMfn) or Opa1 led to dysfunctional mitochondria, activation of Target of rapamycin (TOR) and a marked accumulation of lipid droplets. Enhancement of lipid utilization by the mitochondria attenuated TOR activation and rescued the loss of GSCs that was caused by inhibition of mitochondrial fusion. Moreover, constitutive activation of the TOR-pathway target and lipogenesis factor Sterol regulatory element binding protein (SREBP) also resulted in GSC loss, whereas inhibition of SREBP rescued GSC loss triggered by depletion of dMfn. Our findings highlight a critical role for mitochondrial fusion and lipid homeostasis in GSC maintenance, providing insight into the potential impact of mitochondrial and metabolic diseases on the function of stem and/or germ cells.


Assuntos
Proteínas de Drosophila/genética , Proteínas de Membrana/genética , Dinâmica Mitocondrial/genética , Células-Tronco/metabolismo , Proteínas de Ligação a Elemento Regulador de Esterol/genética , Animais , Diferenciação Celular/genética , Drosophila melanogaster/genética , Drosophila melanogaster/crescimento & desenvolvimento , Drosophila melanogaster/metabolismo , Homeostase , Metabolismo dos Lipídeos/genética , Masculino , Mitocôndrias/genética , Receptores Proteína Tirosina Quinases/genética , Transdução de Sinais/genética , Nicho de Células-Tronco/genética , Células-Tronco/citologia , Testículo/crescimento & desenvolvimento , Testículo/metabolismo
11.
Nat Commun ; 10(1): 2365, 2019 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-31147540

RESUMO

Sensory perception modulates health and aging across taxa. Understanding the nature of relevant cues and the mechanisms underlying their action may lead to novel interventions that improve the length and quality of life. We found that in the vinegar fly, Drosophila melanogaster, exposure to dead conspecifics in the environment induced cues that were aversive to other flies, modulated physiology, and impaired longevity. The effects of exposure to dead conspecifics on aversiveness and lifespan required visual and olfactory function in the exposed flies. Furthermore, the sight of dead flies was sufficient to produce aversive cues and to induce changes in the head metabolome. Genetic and pharmacologic attenuation of serotonergic signaling eliminated the effects of exposure on aversiveness and lifespan. Our results indicate that Drosophila have an ability to perceive dead conspecifics in their environment and suggest conserved mechanistic links between neural state, health, and aging; the roots of which might be unearthed using invertebrate model systems.


Assuntos
Sinais (Psicologia) , Morte , Longevidade , Percepção Olfatória , Serotonina/metabolismo , Percepção Visual , Animais , Dióxido de Carbono/metabolismo , Drosophila , Proteínas de Drosophila/genética , Drosophila melanogaster , Drosophila simulans , Metaboloma , Fosfolipase C beta/genética , Receptores Odorantes/genética , Transdução de Sinais , Triglicerídeos/metabolismo
12.
BMC Bioinformatics ; 20(1): 327, 2019 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-31195954

RESUMO

BACKGROUND: The gap gene system controls the early cascade of the segmentation pathway in Drosophila melanogaster as well as other insects. Owing to its tractability and key role in embryo patterning, this system has been the focus for both computational modelers and experimentalists. The gap gene expression dynamics can be considered strictly as a one-dimensional process and modeled as a system of reaction-diffusion equations. While substantial progress has been made in modeling this phenomenon, there still remains a deficit of approaches to evaluate competing hypotheses. Most of the model development has happened in isolation and there has been little attempt to compare candidate models. RESULTS: The Bayesian framework offers a means of doing formal model evaluation. Here, we demonstrate how this framework can be used to compare different models of gene expression. We focus on the Papatsenko-Levine formalism, which exploits a fractional occupancy based approach to incorporate activation of the gap genes by the maternal genes and cross-regulation by the gap genes themselves. The Bayesian approach provides insight about relationship between system parameters. In the regulatory pathway of segmentation, the parameters for number of binding sites and binding affinity have a negative correlation. The model selection analysis supports a stronger binding affinity for Bicoid compared to other regulatory edges, as shown by a larger posterior mean. The procedure doesn't show support for activation of Kruppel by Bicoid. CONCLUSIONS: We provide an efficient solver for the general representation of the Papatsenko-Levine model. We also demonstrate the utility of Bayes factor for evaluating candidate models for spatial pattering models. In addition, by using the parallel tempering sampler, the convergence of Markov chains can be remarkably improved and robust estimates of Bayes factors obtained.


Assuntos
Drosophila melanogaster/genética , Redes Reguladoras de Genes , Animais , Teorema de Bayes , Proteínas de Drosophila/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Funções Verossimilhança , Cadeias de Markov , Modelos Genéticos , Método de Monte Carlo
13.
Immunogenetics ; 71(7): 501-510, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31147740

RESUMO

The common fruit fly Drosophila melanogaster is a powerful model for studying signaling pathway regulation. Conserved signaling pathways underlying physiological processes signify evolutionary relationship between organisms and the nature of the mechanisms they control. This study explores the cross-talk between the well-characterized nuclear factor kappa B (NF-κB) innate immune signaling pathways and transforming growth factor beta (TGF-ß) signaling pathway in response to parasitic nematode infection in Drosophila. To understand the link between signaling pathways, we followed on our previous studies by performing a transcript-level analysis of different TGF-ß signaling components following infection of immune-compromised Drosophila adult flies with the nematode parasites Heterorhabditis gerrardi and H. bacteriophora. Our findings demonstrate the requirement of NF-κB transcription factors for activation of TGF-ß signaling pathway in Drosophila in the context of parasitic nematode infection. We observe significant decrease in transcript level of glass bottom boat (gbb) and screw (scw), components of the bone morphogenic protein (BMP) branch, as well as Activinß (actß) which is a component of the Activin branch of the TGF-ß signaling pathway. These results are observed only in H. gerrardi nematode-infected flies compared to uninfected control. Also, this significant decrease in transcript level is found only for extracellular ligands. Future research examining the mechanisms regulating the interaction of these signaling pathways could provide further insight into Drosophila anti-nematode immune function against infection with potent parasitic nematodes.


Assuntos
Drosophila melanogaster/parasitologia , NF-kappa B/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Animais , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/imunologia , Perfilação da Expressão Gênica , Interações Hospedeiro-Parasita/genética , Interações Hospedeiro-Parasita/imunologia , NF-kappa B/genética , NF-kappa B/imunologia , Nematoides/microbiologia , Nematoides/patogenicidade , Transdução de Sinais , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/imunologia
14.
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
15.
Nat Commun ; 10(1): 2654, 2019 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-31201326

RESUMO

Animal locomotion requires spatiotemporally coordinated contraction of muscles throughout the body. Here, we investigate how contractions of antagonistic groups of muscles are intersegmentally coordinated during bidirectional crawling of Drosophila larvae. We identify two pairs of higher-order premotor excitatory interneurons present in each abdominal neuromere that intersegmentally provide feedback to the adjacent neuromere during motor propagation. The two feedback neuron pairs are differentially active during either forward or backward locomotion but commonly target a group of premotor interneurons that together provide excitatory inputs to transverse muscles and inhibitory inputs to the antagonistic longitudinal muscles. Inhibition of either feedback neuron pair compromises contraction of transverse muscles in a direction-specific manner. Our results suggest that the intersegmental feedback neurons coordinate contraction of synergistic muscles by acting as delay circuits representing the phase lag between segments. The identified circuit architecture also shows how bidirectional motor networks could be economically embedded in the nervous system.


Assuntos
Retroalimentação Fisiológica , Locomoção/fisiologia , Rede Nervosa/fisiologia , Animais , Animais Geneticamente Modificados , Proteínas de Drosophila/genética , Drosophila melanogaster/fisiologia , Interneurônios/fisiologia , Larva/fisiologia , Microscopia Eletrônica , Modelos Animais , Contração Muscular/fisiologia , Músculos/inervação , Músculos/fisiologia , Optogenética
16.
Behav Processes ; 164: 133-142, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31051219

RESUMO

Starting in late 1980's, Bill Timberlake and associates conducted a series of experiments on anticipatory contrast which showed that rats' feeding decisions were regulated by the nutritive value of currently ingested and anticipated food. The effects of nutrient sensing on feeding regulation have been studied intensively in rodents, and recently, in the fruit fly Drosophila melanogaster. In this study, we developed a new behavioral test to study rapid feeding decisions of tethered flies within 6-8 s of ingestion. Using a two-phase experimental design, we presented individual flies one of four serial combinations of a non-nutritive sugar, arabinose, or a nutritive sugar, sucrose. Feeding decisions of wildtype (Canton-S) flies are altered both by immediate effects of nutrient sensing and 1-hour delayed effects of nutrient-feeding, and the two effects act additively to yield a signature pattern of behavioral contrast based on nutritive contrast. Feeding phenotype of flies that carry a mutation of the dSLC5A11 (cupcake) gene varied with the mutant allele and genetic background. Fasted dSLC5A11 mutants showed an overeating phenotype and a defect in short-term feeding regulation irrespective of the nutritive value of sugar. Flies that carried the dSLC5A111 allele showed differential feeding for arabinose and sucrose. However, dSLC5A112 allele yielded a conspicuous deficit in delayed effects of nutrient ingestion, but only when it was expressed on a Canton-S background. Our results suggest that dSLC5A11 might function to integrate external stimulus properties and internal state for feeding regulation and action selection.


Assuntos
Tomada de Decisões , Proteínas de Drosophila/genética , Proteínas de Drosophila/fisiologia , Drosophila melanogaster/fisiologia , Comportamento Alimentar/fisiologia , Nutrientes/fisiologia , Proteínas de Transporte de Sódio-Glucose/genética , Proteínas de Transporte de Sódio-Glucose/fisiologia , Alelos , Animais , Arabinose , Drosophila melanogaster/genética , Mutação , Valor Nutritivo , Percepção/fisiologia , Fenótipo , Ratos , Sacarose , Fatores de Tempo
17.
Genes Dev ; 33(13-14): 844-856, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31123065

RESUMO

The Piwi-interacting RNA (piRNA) pathway is a small RNA-based immune system that silences mobile genetic elements in animal germlines. piRNA biogenesis requires a specialized machinery that converts long single-stranded precursors into small RNAs of ∼25-nucleotides in length. This process involves factors that operate in two different subcellular compartments: the nuage/Yb body and mitochondria. How these two sites communicate to achieve accurate substrate selection and efficient processing remains unclear. Here, we investigate a previously uncharacterized piRNA biogenesis factor, Daedalus (Daed), that is located on the outer mitochondrial membrane. Daed is essential for Zucchini-mediated piRNA production and the correct localization of the indispensable piRNA biogenesis factor Armitage (Armi). We found that Gasz and Daed interact with each other and likely provide a mitochondrial "anchoring platform" to ensure that Armi is held in place, proximal to Zucchini, during piRNA processing. Our data suggest that Armi initially identifies piRNA precursors in nuage/Yb bodies in a manner that depends on Piwi and then moves to mitochondria to present precursors to the mitochondrial biogenesis machinery. These results represent a significant step in understanding a critical aspect of transposon silencing; namely, how RNAs are chosen to instruct the piRNA machinery in the nature of its silencing targets.


Assuntos
Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Mitocôndrias/metabolismo , RNA Helicases/metabolismo , RNA Interferente Pequeno/biossíntese , Animais , Linhagem Celular , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Técnicas de Silenciamento de Genes , Ligação Proteica , Transporte Proteico , RNA Interferente Pequeno/metabolismo
18.
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
19.
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
20.
Chemosphere ; 231: 450-456, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31146137

RESUMO

The translation control tumor protein (TCTP) is a kind of conservative, common and important molecule, several functions (such as regulating cell cycle, apoptosis and calcium binding) have been reported. However, few academic researches for role of TCTP in insecticides stress were made so far. In this research, Drosophila kc cells treated with different doses of deltamethrin at different times, indicated that the expression of TCTP reached the highest level when the cells were treated with 20 ppm of deltamethrin at 24 h. The results showed that TCTP expression is associated with deltamethrin stress. To investigate the functional relationship between this gene and deltamethrin resistance, RNA interference (RNAi) and cell transfection were utilized. TCTP knockdown significantly reduced the level of resistance of RNAi-treated cells, and the overexpressions of TCTP in Drosophila kc cells conferred a degree of protection against deltamethrin. Flow cytometry data showed increased apoptosis rate of RNAi-treated cells and decreased apoptosis following cell transfection. These results represent the first evidence that TCTP plays an important role in the regulation of deltamethrin resistance. Therefore, this study could help us to elucidate the environmental toxicity of deltamethrin and new target genes associated with resistance.


Assuntos
Inseticidas/toxicidade , Nitrilos/toxicidade , Piretrinas/toxicidade , Testes de Toxicidade , Animais , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Drosophila , Proteínas de Drosophila/genética , Resistência a Inseticidas/efeitos dos fármacos , Inseticidas/metabolismo , Neoplasias/genética , Interferência de RNA
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