Interplay between apicobasal cell polarity modules and the cytoskeleton is critical for differentiation and integrity of epithelia. However, this coordination is poorly understood at the level of gene regulation by transcription factors. Here, we establish the Drosophila activating transcription factor 3 (atf3) as a cell polarity response gene acting downstream of the membrane-associated Scribble polarity complex. Loss of the tumor suppressors Scribble or Dlg1 induces atf3 expression via aPKC but independent of Jun-N-terminal kinase (JNK) signaling. Strikingly, removal of Atf3 from Dlg1 deficient cells restores polarized cytoarchitecture, levels and distribution of endosomal trafficking machinery, and differentiation. Conversely, excess Atf3 alters microtubule network, vesicular trafficking and the partition of polarity proteins along the apicobasal axis. Genomic and genetic approaches implicate Atf3 as a regulator of cytoskeleton organization and function, and identify Lamin C as one of its bona fide target genes. By affecting structural features and cell morphology, Atf3 functions in a manner distinct from other transcription factors operating downstream of disrupted cell polarity.

• MeSH
• buněčná diferenciace MeSH
• chromatinová imunoprecipitace MeSH
• Drosophila melanogaster cytologie   genetika   MeSH
• endozomy metabolismus   MeSH
• geneticky modifikovaná zvířata MeSH
• imaginální disky cytologie   fyziologie   MeSH
• lamin typ A genetika   metabolismus   MeSH
• larva MeSH
• MAP kinasový signální systém MeSH
• membránové proteiny MeSH
• nádorové supresorové proteiny genetika   metabolismus   MeSH
• nukleotidové motivy fyziologie   MeSH
• oči růst a vývoj   MeSH
• polarita buněk fyziologie   MeSH
• proteinkinasa C metabolismus   MeSH
• proteiny Drosophily genetika   metabolismus   MeSH
• transkripční faktor ATF3 genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• dlg1 protein, Drosophila MeSH Prohlížeč
• lamin C MeSH Prohlížeč
• lamin typ A MeSH
• membránové proteiny MeSH
• nádorové supresorové proteiny MeSH
• proteinkinasa C MeSH
• proteiny Drosophily MeSH
• Scrib protein, Drosophila MeSH Prohlížeč
• transkripční faktor ATF3 MeSH

Juvenile hormones (JHs) play a major role in controlling development and reproduction in insects and other arthropods. Synthetic JH-mimicking compounds such as methoprene are employed as potent insecticides against significant agricultural, household and disease vector pests. However, a receptor mediating effects of JH and its insecticidal mimics has long been the subject of controversy. The bHLH-PAS protein Methoprene-tolerant (Met), along with its Drosophila melanogaster paralog germ cell-expressed (Gce), has emerged as a prime JH receptor candidate, but critical evidence that this protein must bind JH to fulfill its role in normal insect development has been missing. Here, we show that Gce binds a native D. melanogaster JH, its precursor methyl farnesoate, and some synthetic JH mimics. Conditional on this ligand binding, Gce mediates JH-dependent gene expression and the hormone's vital role during development of the fly. Any one of three different single amino acid mutations in the ligand-binding pocket that prevent binding of JH to the protein block these functions. Only transgenic Gce capable of binding JH can restore sensitivity to JH mimics in D. melanogaster Met-null mutants and rescue viability in flies lacking both Gce and Met that would otherwise die at pupation. Similarly, the absence of Gce and Met can be compensated by expression of wild-type but not mutated transgenic D. melanogaster Met protein. This genetic evidence definitively establishes Gce/Met in a JH receptor role, thus resolving a long-standing question in arthropod biology.

• MeSH
• buněčné linie MeSH
• Drosophila melanogaster embryologie   genetika   MeSH
• geneticky modifikovaná zvířata MeSH
• juvenilní hormony metabolismus   MeSH
• nenasycené mastné kyseliny metabolismus   MeSH
• proteiny Drosophily genetika   MeSH
• signální transdukce genetika   MeSH
• transkripční faktory bHLH genetika   MeSH
• transkripční faktory genetika   MeSH
• vazba proteinů fyziologie   MeSH
• vývojová regulace genové exprese genetika   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• gce protein, Drosophila MeSH Prohlížeč
• juvenilní hormony MeSH
• MET protein, Drosophila MeSH Prohlížeč
• methyl farnesoate MeSH Prohlížeč
• nenasycené mastné kyseliny MeSH
• proteiny Drosophily MeSH
• TAI protein, Drosophila MeSH Prohlížeč
• transkripční faktory bHLH MeSH
• transkripční faktory MeSH

The steroid hormone ecdysone coordinates insect growth and development, directing the major postembryonic transition of forms, metamorphosis. The steroid-deficient ecdysoneless1 (ecd1) strain of Drosophila melanogaster has long served to assess the impact of ecdysone on gene regulation, morphogenesis, or reproduction. However, ecd also exerts cell-autonomous effects independently of the hormone, and mammalian Ecd homologs have been implicated in cell cycle regulation and cancer. Why the Drosophila ecd1 mutants lack ecdysone has not been resolved. Here, we show that in Drosophila cells, Ecd directly interacts with core components of the U5 snRNP spliceosomal complex, including the conserved Prp8 protein. In accord with a function in pre-mRNA splicing, Ecd and Prp8 are cell-autonomously required for survival of proliferating cells within the larval imaginal discs. In the steroidogenic prothoracic gland, loss of Ecd or Prp8 prevents splicing of a large intron from CYP307A2/spookier (spok) pre-mRNA, thus eliminating this essential ecdysone-biosynthetic enzyme and blocking the entry to metamorphosis. Human Ecd (hEcd) can substitute for its missing fly ortholog. When expressed in the Ecd-deficient prothoracic gland, hEcd re-establishes spok pre-mRNA splicing and protein expression, restoring ecdysone synthesis and normal development. Our work identifies Ecd as a novel pre-mRNA splicing factor whose function has been conserved in its human counterpart. Whether the role of mammalian Ecd in cancer involves pre-mRNA splicing remains to be discovered.

• MeSH
• buněčný cyklus genetika   MeSH
• Drosophila melanogaster genetika   MeSH
• ekdyson genetika   MeSH
• kultivované buňky MeSH
• larva genetika   MeSH
• mutace genetika   MeSH
• prekurzory RNA genetika   MeSH
• proteiny Drosophily genetika   MeSH
• ribonukleoproteiny malé jaderné genetika   MeSH
• sestřih RNA genetika   MeSH
• spliceozomy genetika   MeSH
• steroidy metabolismus   MeSH
• vývojová regulace genové exprese genetika   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• ecd protein, Drosophila MeSH Prohlížeč
• ekdyson MeSH
• prekurzory RNA MeSH
• proteiny Drosophily MeSH
• ribonukleoproteiny malé jaderné MeSH
• steroidy MeSH

Epithelial sheet spreading and fusion underlie important developmental processes. Well-characterized examples of such epithelial morphogenetic events have been provided by studies in Drosophila, and include embryonic dorsal closure, formation of the adult thorax and wound healing. All of these processes require the basic region-leucine zipper (bZIP) transcription factors Jun and Fos. Much less is known about morphogenesis of the fly abdomen, which involves replacement of larval epidermal cells (LECs) with adult histoblasts that divide, migrate and finally fuse to form the adult epidermis during metamorphosis. Here, we implicate Drosophila Activating transcription factor 3 (Atf3), the single ortholog of human ATF3 and JDP2 bZIP proteins, in abdominal morphogenesis. During the process of the epithelial cell replacement, transcription of the atf3 gene declines. When this downregulation is experimentally prevented, the affected LECs accumulate cell-adhesion proteins and their extrusion and replacement with histoblasts are blocked. The abnormally adhering LECs consequently obstruct the closure of the adult abdominal epithelium. This closure defect can be either mimicked and further enhanced by knockdown of the small GTPase Rho1 or, conversely, alleviated by stimulating ecdysone steroid hormone signaling. Both Rho and ecdysone pathways have been previously identified as effectors of the LEC replacement. To elicit the gain-of-function effect, Atf3 specifically requires its binding partner Jun. Our data thus identify Atf3 as a new functional partner of Drosophila Jun during development.

• MeSH
• Drosophila růst a vývoj   metabolismus   MeSH
• epitelové buňky cytologie   metabolismus   MeSH
• imunoprecipitace MeSH
• konfokální mikroskopie MeSH
• proteiny Drosophily genetika   metabolismus   MeSH
• protoonkogenní proteiny c-jun genetika   metabolismus   MeSH
• retardační test MeSH
• transkripční faktor ATF3 genetika   metabolismus   MeSH
• vazba proteinů MeSH
• vývojová regulace genové exprese genetika   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• proteiny Drosophily MeSH
• protoonkogenní proteiny c-jun MeSH
• transkripční faktor ATF3 MeSH

Basic leucine zipper proteins Jun and Fos form the dimeric transcription factor AP-1, essential for cell differentiation and immune and antioxidant defenses. AP-1 activity is controlled, in part, by the redox state of critical cysteine residues within the basic regions of Jun and Fos. Mutation of these cysteines contributes to oncogenic potential of Jun and Fos. How cells maintain the redox-dependent AP-1 activity at favorable levels is not known. We show that the conserved coactivator MBF1 is a positive modulator of AP-1. Via a direct interaction with the basic region of Drosophila Jun (D-Jun), MBF1 prevents an oxidative modification (S-cystenyl cystenylation) of the critical cysteine and stimulates AP-1 binding to DNA. Cytoplasmic MBF1 translocates to the nucleus together with a transfected D-Jun protein, suggesting that MBF1 protects nascent D-Jun also in Drosophila cells. mbf1-null mutants live shorter than mbf1+ controls in the presence of hydrogen peroxide (H2O2). An AP-1-dependent epithelial closure becomes sensitive to H2O2 in flies lacking MBF1. We conclude that by preserving the redox-sensitive AP-1 activity, MBF1 provides an advantage during oxidative stress.

• MeSH
• cystein chemie   MeSH
• Drosophila genetika   metabolismus   MeSH
• molekulární sekvence - údaje MeSH
• mutace MeSH
• oxidace-redukce MeSH
• oxidační stres MeSH
• proteiny Drosophily chemie   genetika   metabolismus   MeSH
• protoonkogenní proteiny c-fos chemie   genetika   metabolismus   MeSH
• protoonkogenní proteiny c-jun chemie   genetika   metabolismus   MeSH
• rekombinantní proteiny chemie   genetika   metabolismus   MeSH
• sekvence aminokyselin MeSH
• trans-aktivátory chemie   genetika   metabolismus   MeSH
• transkripční faktor AP-1 chemie   genetika   metabolismus   MeSH
• vazebná místa MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cystein MeSH
• MBF1 protein, Drosophila MeSH Prohlížeč
• proteiny Drosophily MeSH
• protoonkogenní proteiny c-fos MeSH
• protoonkogenní proteiny c-jun MeSH
• rekombinantní proteiny MeSH
• trans-aktivátory MeSH
• transkripční faktor AP-1 MeSH

The transcription factor Broad-Complex (BR-C) is required for differentiation of adult structures as well as for the programmed death of obsolete larval organs during metamorphosis of the fruit fly Drosophila melanogaster. Whether BR-C has a similar role in other holometabolous insects could not be proven without a loss-of-function genetic test, performed in a non-drosophilid species. Here we use a recombinant Sindbis virus as a tool to silence BR-C expression in the silkmoth Bombyx mori. The virus expressing a BR-C antisense RNA fragment reduced endogenous BR-C mRNA levels in infected tissues (adult wing and leg primordia) via RNA interference (RNAi). The RNAi knock-down of BR-C resulted in the failure of animals to complete the larval-pupal transition or in later morphogenetic defects, including differentiation of adult compound eyes, legs, and wings from their larval progenitors. BR-C RNAi also perturbed the programmed cell death of larval silk glands. These developmental defects correspond to loss-of-function phenotypes of BR-C Drosophila mutants in both the morphogenetic and degenerative aspects, suggesting that the critical role of BR-C in metamorphosis is evolutionarily conserved. We also demonstrate that the Sindbis virus is a useful vehicle for silencing of developmental genes in new insect models.

• MeSH
• biologická proměna MeSH
• bourec růst a vývoj   MeSH
• Cercopithecus aethiops MeSH
• Culicidae MeSH
• DNA primery MeSH
• Drosophila melanogaster růst a vývoj   MeSH
• křečci praví MeSH
• kukla MeSH
• larva MeSH
• malá interferující RNA farmakologie   fyziologie   MeSH
• molekulární sekvence - údaje MeSH
• oči růst a vývoj   MeSH
• proteiny Drosophily metabolismus   MeSH
• RNA virová fyziologie   MeSH
• sekvence nukleotidů MeSH
• transkripční faktory metabolismus   MeSH
• Vero buňky MeSH
• virus Sindbis genetika   MeSH
• zvířata MeSH
• Check Tag
• křečci praví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, P.H.S. MeSH
• Názvy látek
• Br protein, Drosophila MeSH Prohlížeč
• DNA primery MeSH
• malá interferující RNA MeSH
• proteiny Drosophily MeSH
• RNA virová MeSH
• transkripční faktory MeSH

Germline transformation with new transposon vectors now enables causal tests of gene function via ectopic protein expression or RNA interference in non-drosophilid insects. The problem remains of how to drive the transgene expression in vivo. We employed germline transformation using the piggyBac 3xP3-EGFP vector to test whether the Drosophila heat shock hsp70 promoter will be active in the live silkworm. We modified the original vector by cloning the coding sequence for Bombyx nuclear receptor Ftz-F1 between the hsp70 promoter and the terminator. Three independent transgenic lines expressing the Pax-6-driven EGFP marker in larval and adult photoreceptors were obtained with efficiencies of up to 1.7% of fertile G0 adults that gave GFP-positive progeny. Chromosomal integration of the transposon was confirmed with inverse PCR. Heat induction of the transgenic BmFtz-F1 was proven at both the mRNA and protein levels. RT-PCR data showed that the Drosophila heat shock promoter was functional in all three transgenic lines. Although basal activity was apparent at 25 degrees C, 1 h at 42 degrees C induced BmFtz-F1 mRNA at different stages of development and in diverse tissues. The relative levels of induction differed among the transgenic lines. Northern blot hybridization detected transgenic BmFtz-F1 only after heat shock and low levels of the mRNA were still present 6 h after the heat treatment. Immunostaining of epidermis using anti-BmFtz-F1 antibody showed a clear increase of nuclear signal 90 min after a heat shock.

• MeSH
• aktivace transkripce * MeSH
• bourec genetika   MeSH
• DNA vazebné proteiny biosyntéza   chemie   genetika   MeSH
• hmyzí proteiny MeSH
• homeodoménové proteiny MeSH
• klonování DNA MeSH
• messenger RNA genetika   metabolismus   MeSH
• molekulární sekvence - údaje MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• proteiny tepelného šoku HSP70 genetika   MeSH
• receptory cytoplazmatické a nukleární MeSH
• sekvence aminokyselin MeSH
• steroidogenní faktor 1 MeSH
• transformace genetická MeSH
• transgeny genetika   MeSH
• transkripční faktory fushi tarazu MeSH
• transkripční faktory biosyntéza   chemie   genetika   MeSH
• vysoká teplota * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, P.H.S. MeSH
• Názvy látek
• DNA vazebné proteiny MeSH
• hmyzí proteiny MeSH
• homeodoménové proteiny MeSH
• messenger RNA MeSH
• nuclear hormone receptor FTZ-F1, Bombyx mori MeSH Prohlížeč
• proteiny tepelného šoku HSP70 MeSH
• receptory cytoplazmatické a nukleární MeSH
• steroidogenní faktor 1 MeSH
• transkripční faktory fushi tarazu MeSH
• transkripční faktory MeSH