gro

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..are enhanced by loss-of-function mutations in the Notch pathway elements, Notch, Delta, mastermind, deltex and groucho, but are suppressed by a duplication of Delta or mutations in Hairless, a negative regulator of the pathway...

..Previous studies have shown that two of the repressors, Hairy and Dorsal, recruit a common co-repressor protein, Groucho. Here we present evidence that three different repressors, Knirps, Krüppel and Snail, recruit a different co-..

..In contrast, the two long-range repressors, Hairy and Dorsal, recruit a different corepressor protein, Groucho. Hairy also was shown to interact with dCtBP, thereby raising the possibility that Groucho and dCtBP are ..

..Notch activity affects the implementation of differentiation, proliferation, and apoptotic programs, providing a general developmental tool to influence organ formation and morphogenesis...

..Our results show that the highly divergent REF-1 proteins are nonetheless HES-like bHLH effectors of Notch signaling...

..This unusual promoter organization may be necessary for brk to respond to the Dpp gradient in a precise and robust fashion...

..Irrespective of whether E(spl) are recruited via direct DNA binding or interaction with proneural proteins, the co-repressor Groucho is always needed for target gene repression.

Transcriptional corepressors of the Groucho/transducin-like Enhancer of split (Gro/TLE) family are involved in a variety of cell differentiation mechanisms in both invertebrates and vertebrates...

..Here we show that, in vitro, H directly binds two corepressor proteins, Groucho (Gro) and dCtBP...

..that Brk harbours a functional and transferable repression domain, through which it recruits the corepressors Groucho and CtBP...

..Deletion analysis indicates that this region mediates transcriptional repression and binding to Groucho, a co-repressor known to be required for Dorsal-mediated repression...

..We show that most of these homeodomain proteins possess a conserved eh1 motif that mediates the recruitment of Gro/TLE corepressors...

The Drosophila Groucho (Gro) protein is the defining member of a family of metazoan corepressors that have roles in many aspects of development, including segmentation, dorsal/ventral pattern formation, Notch signaling, and Wnt/Wg ..

..Finally, we present our initial studies of the structure, expression and regulation of the newest member of the Brd gene family, Ocho, which is located in the recently identified Bearded Complex...

The Drosophila gene groucho (gro) encodes a transcriptional corepressor that has critical roles in many development processes...

..In summary, this evolutionary study improves the knowledge on functionally significant domains of the Hairless protein, and may be helpful for the future identification of homologues in other animals, especially in vertebrates...

The Drosophila Groucho (Gro) protein is a corepressor required by a number of DNA-binding transcriptional repressors...

..This study provides a mechanistic basis for the dual function of Runx proteins that is likely to be conserved in mammalian systems...

Drosophila Groucho (Gro) is a member of a family of metazoan corepressors with widespread roles in development...

..Several long-range repressors interact with Groucho, a conserved corepressor that is homologous to mammalian TLE proteins...

..We have previously shown that the EGFR RTK pathway causes phosphorylation and downregulation of Groucho, a global co-repressor that is widely used by many developmentally important repressors for silencing their ..

The Groucho (Gro)/transducin-like enhancer of split family of transcriptional corepressors are implicated in many signalling pathways that are important in development and disease, including those mediated by Notch, Wnt and Hedgehog...

..chromatin profiling, we identified a protein-protein interaction between the Drosophila Myc oncogene and the Groucho corepressor that regulates a subset of direct dMyc targets...

The Groucho/Tle family of corepressor proteins has important roles in development and in adult tissue in both Protostomes and Deuterostomes. In Drosophila, a single member of this family has been identified...

The Groucho (Gro)/TLE/Grg family of corepressors operates in many signaling pathways (including Notch and Wnt)...

..been suggested to stem from the differential recruitment of the CtBP corepressor to short-range repressors and Groucho to long-range repressors...

..The question arose how these complexes evolved with regard to gene number in the evolution of insects concentrating on Diptera and the Hymenoptera Apis mellifera...

..in conjunction with a partner, Hairless, which contains binding motifs for two global corepressors, CtBP and Groucho (Gro)...

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..Finally, we define crucial roles for the adaptor protein Hairless and the co-repressors Groucho and CtBP in conferring repressive activity on Su(H) in the SOP...

b>Groucho function is essential for Drosophila development, acting as a corepressor for specific transcription factors that are downstream targets of various signaling pathways...

..The global corepressor Groucho (Gro) and its transducin-like Enhancer-of-split (TLE) mammalian homologs mediate repression by a myriad of ..

..the absence of Armadillo, dTcf acts as a transcriptional repressor of Wingless-responsive genes, and we show that Groucho acts as a corepressor in this process...

..Another gene in the 96F region, namely groucho, is also required for this process...

..Transcriptional activation mediated by Suppressor of Hairless and transcriptional repression mediated by Enhancer of split could provide greater diversity in the response of individual genes to Notch activity...

..This motif was previously shown to be necessary for interactions with Groucho, a genetically defined corepressor for Drosophila Hairy-related proteins...

..Here we show that mutation of either the bHLH-encoding genes of the Enhancer of split complex (E(spl)-C) or groucho, like Notch or Delta mutants, cause an overproduction of sensory organ precursors at the expense of epidermis...

..distinct functions, vital and neurogenic, reside within the complex defined by lethal mutations in the l(3) gro gene and by the typical neurogenic phenotype of deletions, respectively...

b>Groucho is a transcriptional repressor implicated in Notch signaling and involved in neural development and segmentation in Drosophila...

..eh1) is highly conserved throughout several classes of homeoproteins and interacts specifically with the Groucho corepressor...

..Another lesion is a deletion in the coding region that leads to a shorter protein which, in addition, differs in its carboxy-terminal end from the wild-type protein by the presence of nine amino acids...

..We find that the groucho (gro) protein binds specifically to hairy and also to hairy-related bHLH proteins encoded by deadpan and the ..

..Immunocytochemical localization of the E(spl) m9/10 protein has revealed that it is a ubiquitously distributed nuclear component in embryonic, larval and imaginal tissues...

..We demonstrate that expression of the transcripts relates to the developing central nervous system. These data suggest a mechanism of interaction between the gene products of Notch and Enhancer of split...

..an evolutionarily conserved protein-protein interaction between Runt domain proteins and the corepressor Groucho. The interaction, however, is independent of the Runt domain and can be mapped to a 5-amino-acid sequence, VWRPY, ..

..repression of specific transcriptional activators, such as Scute, through the bHLH and Orange domains and repression of other activators via interaction of the C-terminal WRPW motif with corepressors, such as the Groucho protein.

..indicates that this transcription unit includes functions associated with both the dominant E(spl)D mutation and the recessive visible allele groucho, and is necessary for the correct differentiation of the embryonic nervous system.

..The Slp1 protein contains a protein motif (EH1) which mediates binding to the transcriptional corepressor Groucho (Gro). We show that this domain is required for Slp1-mediated repression in vivo.

..Selective expression of certain neuronal-type selector genes further specifies the type of neuron(s) that a neural precursor will produce...

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..Repression by Dorsal requires the corepressor Groucho (Gro) and is mediated by silencers termed ventral repression regions (VRRs)...

..most mammalian RD proteins terminate in a common pentapeptide, VWRPY, which serves to recruit the corepressor Groucho (Gro)...

..The N-terminal domain of Vnd contains a putative eh1 repression domain that binds Groucho in vitro. Mutations in this domain diminish Groucho binding and also attenuate repression in vivo...

The Drosophila protein Groucho is involved in embryonic segmentation and neural development, and is implicated in the Notch signal transduction pathway...

..CtBPs play important roles during development and oncogenesis. In this review, their unusual properties, the mechanisms of transcriptional repression, regulation, and their biological functions are discussed...

..The potent modulatory effect of Neur on Dl activity makes Neur a candidate for establishing signaling asymmetries within cellular equivalence groups...

The Drosophila Groucho (Gro) protein was the founding member of the family of transcriptional co-repressor proteins that now includes the transducin-like enhancer of split (TLE) and Grorelated gene (Grg) proteins in vertebrates...

..of Armadillo but is sensitive both to the relative levels of activating Armadillo/Pangolin and repressing Groucho/Pangolin complexes present and to the responsiveness of the promoter to Wingless...

..Taken together these results suggest that the complexities of development are best appreciated when spatial and temporal information is incorporated when describing gene regulatory networks...

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Drosophila Groucho, like its vertebrate Transducin-like Enhancer-of-split homologues, is a corepressor that silences gene expression in numerous developmental settings...

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..These findings are consistent with the idea that sumoylation stimulates Vg function during wing morphogenesis...

..Recent studies suggest that a growing set of coactivators and corepressors mediate communication between diverse upstream regulatory proteins and the core RNA polymerase II transcription complex...

..CtBP binds to Wnt-regulated enhancers in a TCF-independent manner and represses target genes in parallel with TCF. Our data indicate dual roles for CtBP as a gene-specific activator and repressor of Wnt target gene transcription...

..This general function in cell fate specification has been conserved from Drosophila to vertebrates and has implications for human disease pathogenesis...

..Therefore, E(spl) formally behaves as a gene switching between neural and epidermal pathways...

..These results indicate that fusion cells undergo dynamic changes in gene expression as they switch from migratory to fusion modes and that dysfusion regulates a discrete, but important, set of these genes...

..In both flies and in human cells, SoxN repression is potentiated by adding ectopic Tcf, suggesting that SoxN interacts with the repressor form of Tcf to influence Wg/Wnt target gene transcription...

..In conclusion, E(spl) proteins have partially redundant functions, yet they have evolved distinct preferences in implementing different cell fate decisions, which closely match their individual normal expression patterns...

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..Furthermore, we could show that the dominant enhancement of spl is caused by truncation of the E(SPL)D protein in combination with deletion of a putative regulatory element...

..In this review, we discuss the significance of this phenomenon in the case of the basic Helix-Loop-Helix (bHLH) proteins that are involved at different steps of the development of the peripheral nervous system (PNS) of Drosophila...

..A recent study identified novel Hox molecular partners, whose properties set a conceptual framework to understand how Hox proteins use and integrate contextual information...

..Pokkuri-mediated repression represents one such regulatory mechanism. The positive and negative signaling pathways operating in the fate determination of other photoreceptor cells are also discussed...

..These results indicate that Sir2 in higher organisms plays an essential role in both euchromatic repression and heterochromatic silencing...

..of the embryo, but under certain conditions, such as when it is associated with the non-DNA-binding co-repressor Groucho (Gro), it is converted into a repressor...

..This banding pattern suggests gene-specific regulatory functions for dMBD-like and the Drosophila Mi-2 complex...

A gene family of the Groucho, TLE, ESG and AES proteins has been characterized from Drosophila, nematode, Xenopus, mouse, rat and human, and their structural relationships have been analyzed...

..Although no overlap has been found among the molecules used by flies and worms to achieve sex determination, striking similarities have been found in the genetic strategies used by these two species to differentiate their sexes...

..The basis for the genetic antimorphism of NM1 seems to reside in the titration of Notch wild-type products into NM1/N+ nonfunctional dimers and/or the titration of Delta products into nonfunctional ligand-receptor complexes...

..During Drosophila eye development, Notch plays an additional role in promoting neural fate independently of Su(H) and E(spl)-C, and this finding suggests an alternative mechanism of Notch signal transduction...

..By comparing findings from Caenorhabditis elegans, Drosophila and vertebrate model systems, it is apparent that both evolutionarily conserved and non-conserved mechanisms are used...

..The APC/beta-catenin pathway is highly regulated and includes players such as GSK3-beta, CBP, Groucho, Axin, Conductin, and TCF...

The Groucho corepressor mediates negative transcriptional regulation in association with various DNA-binding proteins in diverse developmental contexts...

..In this paper, we show that the Groucho (Gro) corepressor acts in this process to confine terminal gap gene expression to the embryonic termini...

..Each of the regulatory networks could themselves serve as the subject of a detailed review and that is beyond the scope of this discussion. Here we will focus on the interplay between the regulatory networks in patterning the tissue...

..While lineage identity genes allow the various lineages to acquire specific identities, neuronal precursor genes presumably regulate functional and developmental characteristics common to all neuronal precursor cells...

..Signalling by the Torso pathway relieves repression mediated by the Capicua and Groucho repressors, allowing the restricted expression of the zygotic terminal gap genes tailless and huckebein...

..Recent studies have revealed that regulatory interactions at several steps in the pathway can modify its outcome, helping to explain how the same pathway can, in different contexts, have very different characteristics and consequences...

..Together, our results suggest that for embryonic patterning the activator as well as repressor forms of Pan play important roles, while for wing development Pan operates primarily in the activator mode...

..In addition to mutations in several unknown loci, we recovered multiple alleles of groucho (gro) and Hairless (H)...

..Thus, our proposed studies should illuminate how a viral oncoprotein, adenovirus EtA, modulates oncogenesis novel pathways that involve cellular proteins CtBP and CtIP. ..

..Our proposed studies will harness the knowledge gained from the study of the viral oncoprotein E1A to unravel potential new mechanisms governing oncogenesis and suggest strategies to inhibit the process in humans. ..

..The proposed studies should illuminate the mechanisms by which E1B-19K and related BCL-2 family proteins control cellular life and death cycles. ..

..These studies hope to provide tools and strategies to interfere with Bcl-2 activity in neoplastic diseases. ..

..Our proposed studies will harness the knowledge gained from the study of the viral oncoprotein E1A to unravel potential new mechanisms governing oncogenesis and suggest strategies to inhibit the process in humans. ..

..The knowledge gained would be valuable in modulating the activity of BAX in cancer and in degenerative diseases. ..

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..Our results may also provide the experimental support to suggest that BNIP3 may be a new prognostic marker for human cancer. ..

..Since 175R T antigen is also localized on the nuclear envelope, we will investigate whether this protein could play a role in the nucleocytoplasmic transport of RNA via enhanced nucleoside triphophatase activity...

..The role of the chimeric receptor in calcium mobilization and ligand-dependent internalization will be determined. The proposed studies should facilitate understanding of the biochemical mechanism of 19K-mediated transformation...

..Students also participate in a school-wide research day held each Spring. Future goals include further expansion of funded slots and development of additional strategies for recruitment of veterinary students into research careers. ..

..Dorsalinteracting protein that plays a key role in regulating dorsal/ventral pattern formation is the corepressor Groucho. This factor, which functions as a homotetramer, may mediate an interaction between Dorsal and histone ..

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..One Dorsal-interacting protein that is essential for Dorsal-mediated repression is the corepressor Groucho. The first specific aim of this proposal is to illuminate the mechanism of Dorsal-mediated activation by ..

..The conjugation of this protein to Smt3 appears to control its localization to discrete nuclear foci termed PML bodies. Recent experiments suggest that Drosophila nuclei may contain similar Smt3-dependent foci. ..

..The anticipated results will have relevant applicability to stem cell and germline biology and lead to a better understanding of human reproduction. ..