Regulation of Apterous activity inDrosophilawing development

Development ◽  
2001 ◽  
Vol 128 (22) ◽  
pp. 4615-4622 ◽  
Author(s):  
Ulrich Weihe ◽  
Marco Milán ◽  
Stephen M. Cohen
Keyword(s):  
Complex Formation ◽  
Wing Development ◽  
Homeodomain Protein ◽  
Activity Levels ◽  
Present Evidence ◽  
Drosophila Wing ◽  
Lim Domains ◽  
Regulation Of Activity ◽  
Lim Homeodomain

Apterous is a LIM-homeodomain protein that confers dorsal compartment identity in Drosophila wing development. Apterous activity requires formation of a complex with a co-factor, Chip/dLDB. Apterous activity is regulated during wing development by dLMO, which competes with Apterous for complex formation. Here, we present evidence that complex formation between Apterous, Chip and DNA stabilizes Apterous protein in vivo. We also report that a difference in the ability of Chip to bind the LIM domains of Apterous and dLMO contributes to regulation of activity levels in vivo.

scholarly journals Crystallization and diffraction of an Isl1–Ldb1 complex

2012 ◽  
Vol 68 (11) ◽  
pp. 1398-1401 ◽  
Author(s):  
Morgan S. Gadd ◽  
David A. Jacques ◽  
J. Mitchell Guss ◽  
Jacqueline M. Matthews
Keyword(s):  
Unit Cell ◽  
Homeodomain Protein ◽  
Unit Cell Parameters ◽  
Space Group ◽  
Cell Parameters ◽  
Lim Domains ◽  
Intramolecular Complex ◽  
Orthorhombic Crystals ◽  
Peptide Region ◽  
Lim Homeodomain

A stable intramolecular complex comprising the LIM domains of the LIM-homeodomain protein Isl1 tethered to a peptide region of Ldb1 has been engineered, purified and crystallized. The orthorhombic crystals belonged to space groupP2221, with unit-cell parametersa= 57.2,b= 56.7,c= 179.8 Å, and diffracted to 3.10 Å resolution.

scholarly journals Functional analysis of the nuclear LIM domain interactor NLI.

1997 ◽  
Vol 17 (10) ◽  
pp. 5688-5698 ◽  
Author(s):  
L W Jurata ◽  
G N Gill
Keyword(s):  
Transcriptional Activation ◽  
Negative Regulator ◽  
Homeodomain Protein ◽  
Lim Domain ◽  
Transcriptional Responses ◽  
Amino Terminal ◽  
High Affinity ◽  
Lim Domains ◽  
Lim Homeodomain

LIM homeodomain and LIM-only (LMO) transcription factors contain two tandemly arranged Zn2+-binding LIM domains capable of mediating protein-protein interactions. These factors have restricted patterns of expression, are found in invertebrates as well as vertebrates, and are required for cell type specification in a variety of developing tissues. A recently identified, widely expressed protein, NLI, binds with high affinity to the LIM domains of LIM homeodomain and LMO proteins in vitro and in vivo. In this study, a 38-amino-acid fragment of NLI was found to be sufficient for the association of NLI with nuclear LIM domains. In addition, NLI was shown to form high affinity homodimers through the amino-terminal 200 amino acids, but dimerization of NLI was not required for association with the LIM homeodomain protein Lmxl. Chemical cross-linking analysis revealed higher-order complexes containing multiple NLI molecules bound to Lmx1, indicating that dimerization of NLI does not interfere with LIM domain interactions. Additionally, NLI formed complexes with Lmx1 on the rat insulin I promoter and inhibited the LIM domain-dependent synergistic transcriptional activation by Lmx1 and the basic helix-loop-helix protein E47 from the rat insulin I minienhancer. These studies indicate that NLI contains at least two functionally independent domains and may serve as a negative regulator of synergistic transcriptional responses which require direct interaction via LIM domains. Thus, NLI may regulate the transcriptional activity of LIM homeodomain proteins by determining specific partner interactions.

The distribution of PS integrins, laminin A and F-actin during key stages in Drosophila wing development

Development ◽  
1993 ◽  
Vol 117 (2) ◽  
pp. 509-523 ◽  
Author(s):  
D. Fristrom ◽  
M. Wilcox ◽  
J. Fristrom
Keyword(s):  
Wing Disc ◽  
Wing Development ◽  
Filamentous Actin ◽  
Pupal Development ◽  
Drosophila Wing ◽  
Junction Formation ◽  
Hair Morphogenesis ◽  
Cytoplasmic Processes ◽  
Intercellular Connections

We first summarize wing development during metamorphosis of Drosophila and identify four critical steps in the conversion of a folded single layered wing disc to a flat bilayered wing. Each step occurs twice, once during the 12 hour prepupal period and again during the 84 hour pupal period. (1) Apposition in which basal surfaces of dorsal and ventral epithelia come close together. (2) Adhesion in which basal junctions form between the apposed basal surfaces. (3) Expansion in which wing area increases as a result of cells flattening. (4) Separation in which dorsal and ventral epithelia are separated by a bulky extracellular matrix but remain connected by slender cytoplasmic processes containing the microtubules and microfilaments of the transalar cytoskeleton. Disc ultrastructure is correlated with the distribution of the beta chain of integrin, laminin A, and filamentous actin for each key stage of pupal development. Integrin and laminin exhibit a mutually exclusive distribution from the adhesion stage onwards. Integrin is present on the basal surface of intervein cells but not on vein cells whereas laminin A is absent from the basal surfaces of intervein cells but is present on vein cells. We conclude that laminin is not a ligand for integrin in this context. During apposition and adhesion stages integrin is broadly distributed over the basal and lateral surfaces of intervein cells but subsequently becomes localized to small basal foci. These foci correspond to basal contact zones between transalar processes. The distribution of filamentous actin is dynamic, changing from an apical distribution during hair morphogenesis to a basal distribution as the transalar cytoskeleton develops. Basal adherens-type junctions are first evident during the adhesion stage and become closely associated with the transalar cytoskeleton during the separation stage. Thus, basal junction formation occurs in two discrete steps; intercellular connections are established first and junction/cytoskeletal connections are formed about 20 hours later. These observations provide a basis for future investigations of integrin mediated adhesion in vivo.

scholarly journals Arf6 is necessary for senseless expression in response to Wingless signalling during Drosophila wing development

Biology Open ◽  
2021 ◽  
Author(s):  
Julien Marcetteau ◽  
Tamàs Matusek ◽  
Frédéric Luton ◽  
Pascal P. Thérond
Keyword(s):  
Signal Transduction ◽  
Developmental Model ◽  
Wing Development ◽  
Wing Margin ◽  
Drosophila Wing ◽  
Gtp Binding ◽  
Wide Range ◽  
High Level

Wnt signalling is a core pathway involved in a wide range of developmental processes throughout the metazoa. In vitro studies have suggested that the small GTP binding protein Arf6 regulates upstream steps of Wnt transduction, by promoting the phosphorylation of the Wnt co-receptor, LRP6, and the release of β-catenin from the adherens junctions. To assess the relevance of these previous findings in vivo, we analysed the consequence of the absence of Arf6 activity on Drosophila wing patterning, a developmental model of Wnt/Wingless signalling. We observed a dominant loss of wing margin bristles and Senseless expression in Arf6 mutant flies, phenotypes characteristic of a defect in high level Wingless signalling. In contrast to previous findings, we show that Arf6 is required downstream of Armadillo/β-catenin stabilisation in Wingless signal transduction. Our data suggest that Arf6 modulates the activity of a downstream nuclear regulator of Pangolin activity in order to control the induction of high level Wingless signalling. Our findings represent a novel regulatory role for Arf6 in Wingless signalling.

scholarly journals In vivo relevance of intercellular calcium signaling in Drosophila wing development

2017 ◽  
Author(s):  
Qinfeng Wu ◽  
Pavel A. Brodskiy ◽  
Francisco Huizar ◽  
Jamison J. Jangula ◽  
Cody Narciso ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Wing Disc ◽  
Chemical Stimulus ◽  
Wing Development ◽  
Dependent Manner ◽  
Drosophila Wing ◽  
Wing Discs ◽  
Vein Patterning ◽  
Dose Dependent

AbstractRecently, organ-scale intercellular Ca2+ transients (ICTs) were reported in the Drosophila wing disc. However, the functional in vivo significance of ICTs remains largely unknown. Here we demonstrate the in vivo relevance of intercellular Ca2+ signaling and its impact on wing development. We report that Ca2+ signaling in vivo decreases as wing discs mature. Ca2+ signaling ex vivo responds to fly extract in a dose-dependent manner. This suggests ICTs occur in vivo due to chemical stimulus that varies in concentration during development. RNAi mediated inhibition of genes required for ICTs results in defects in the size, shape, and vein patterning of adult wings. It also leads to reduction or elimination of in vivo Ca2+ transients. Further, perturbations to the extracellular matrix along the basal side of the wing disc stimulates intercellular Ca2+ waves. This is the first identified chemically defined, non-wounding stimulus of ICTs. Together, these results point toward specific in vivo functions of intercellular Ca2+ signaling to mediate mechanical stress dissipation and ensure robust patterning during development.

scholarly journals Transcriptional synergy between LIM-homeodomain proteins and basic helix-loop-helix proteins: the LIM2 domain determines specificity.

1997 ◽  
Vol 17 (7) ◽  
pp. 3488-3496 ◽  
Author(s):  
J D Johnson ◽  
W Zhang ◽  
A Rudnick ◽  
W J Rutter ◽  
M S German
Keyword(s):  
Bhlh Protein ◽  
Homeodomain Protein ◽  
Cell Type ◽  
Homeodomain Proteins ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
Lim Domains ◽  
Insulin Promoter ◽  
Physical Interactions ◽  
Lim Homeodomain

LIM-homeodomain proteins direct cellular differentiation by activating transcription of cell-type-specific genes, but this activation requires cooperation with other nuclear factors. The LIM-homeodomain protein Lmx1 cooperates with the basic helix-loop-helix (bHLH) protein E47/Pan-1 to activate the insulin promoter in transfected fibroblasts. In this study, we show that two proteins originally called Lmx1 are the closely related products of two distinct vertebrate genes, Lmx1.1 and Lmx1.2. We have used yeast genetic systems to delineate the functional domains of the Lmx1 proteins and to characterize the physical interactions between Lmx1 proteins and E47/Pan-1 that produce synergistic transcriptional activation. The LIM domains of the Lmx1 proteins, and particularly the second LIM domain, mediate both specific physical interactions and transcriptional synergy with E47/Pan-1. The LIM domains of the LIM-homeodomain protein Isl-1, which cannot mediate transcriptional synergy with E47/Pan-1, do not interact with E47/Pan-1. In vitro studies demonstrate that the Lmx1.1 LIM2 domain interacts specifically with the bHLH domain of E47/Pan-1. These studies provide the basis for a model of the assembly of LIM-homeodomain-containing complexes on DNA elements that direct cell-type-restricted transcription in differentiated tissues.

scholarly journals Ocular and Cerebellar Defects in Zebrafish Induced by Overexpression of the LIM Domains of the Islet-3 LIM/Homeodomain Protein

Neuron ◽  
1997 ◽  
Vol 18 (3) ◽  
pp. 369-382 ◽  
Author(s):  
Yutaka Kikuchi ◽  
Hiroshi Segawa ◽  
Mika Tokumoto ◽  
Tatsuya Tsubokawa ◽  
Yoshiki Hotta ◽  
...  
Keyword(s):  
Homeodomain Protein ◽  
Lim Domains ◽  
Lim Homeodomain

scholarly journals Chip is an essential cofactor for apterous in the regulation of axon guidance in Drosophila

Development ◽  
2000 ◽  
Vol 127 (9) ◽  
pp. 1823-1831 ◽  
Author(s):  
D.J. van Meyel ◽  
D.D. O'Keefe ◽  
S. Thor ◽  
L.W. Jurata ◽  
G.N. Gill ◽  
...  
Keyword(s):  
Axon Guidance ◽  
Functional Unit ◽  
Loss Of Function ◽  
Homeodomain Proteins ◽  
Interaction Domain ◽  
Drosophila Wing ◽  
Embryonic Nervous System ◽  
Tetrameric Complex ◽  
Lim Homeodomain

LIM-homeodomain transcription factors are expressed in subsets of neurons and are required for correct axon guidance and neurotransmitter identity. The LIM-homeodomain family member Apterous requires the LIM-binding protein Chip to execute patterned outgrowth of the Drosophila wing. To determine whether Chip is a general cofactor for diverse LIM-homeodomain functions in vivo, we studied its role in the embryonic nervous system. Loss-of-function Chip mutations cause defects in neurotransmitter production that mimic apterous and islet mutants. Chip is also required cell-autonomously by Apterous-expressing neurons for proper axon guidance, and requires both a homodimerization domain and a LIM interaction domain to function appropriately. Using a Chip/Apterous chimeric molecule lacking domains normally required for their interaction, we reconstituted the complex and rescued the axon guidance defects of apterous mutants, of Chip mutants and of embryos doubly mutant for both apterous and Chip. Our results indicate that Chip participates in a range of developmental programs controlled by LIM-homeodomain proteins and that a tetrameric complex comprising two Apterous molecules bridged by a Chip homodimer is the functional unit through which Apterous acts during neuronal differentiation.

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