scholarly journals Studying interactions between the Mod(mdg4)-67.2 protein and other isoforms of the Mod(mdg4) in the embryonic cells of Drosophila melanogaster

2019 ◽  
Vol 486 (2) ◽  
pp. 247-254
Author(s):  
M. V. Kostyuchenko ◽  
L. S. Melnikova ◽  
P. G. Georgiev ◽  
A. K. Golovnin
Keyword(s):  
Drosophila Melanogaster ◽  
Protein Complexes ◽  
Specific Interaction ◽  
Embryonic Cells ◽  
Btb Domains

It was found that in the embryonic cells of D. melanogaster, the isoforms of the Mod(mdg4) protein is able to interact with each other through the BTB domains. However, this non-specific interaction is destroyed when protein complexes recruiting to chromatin sites.

scholarly journals The rosy locus in Drosophila melanogaster: xanthine dehydrogenase and eye pigments.

Genetics ◽  
1991 ◽  
Vol 129 (4) ◽  
pp. 1099-1109 ◽  
Author(s):  
A G Reaume ◽  
D A Knecht ◽  
A Chovnick
Keyword(s):  
Drosophila Melanogaster ◽  
Structural Integrity ◽  
Present Report ◽  
Specific Interaction ◽  
Pigment Granule ◽  
Ultrastructural Localization ◽  
Xanthine Dehydrogenase ◽  
Pigment Formation ◽  
Antibody Staining ◽  
Pigment Granules

Abstract The rosy gene in Drosophila melanogaster codes for the enzyme xanthine dehydrogenase (XDH). Mutants that have no enzyme activity are characterized by a brownish eye color phenotype reflecting a deficiency in the red eye pigment. Xanthine dehydrogenase is not synthesized in the eye, but rather is transported there. The present report describes the ultrastructural localization of XDH in the Drosophila eye. Three lines of evidence are presented demonstrating that XDH is sequestered within specific vacuoles, the type II pigment granules. Histochemical and antibody staining of frozen sections, as well as thin layer chromatography studies of several adult genotypes serve to examine some of the factors and genic interactions that may be involved in transport of XDH, and in eye pigment formation. While a specific function for XDH in the synthesis of the red, pteridine eye pigments remains unknown, these studies present evidence that: (1) the incorporation of XDH into the pigment granules requires specific interaction between a normal XDH molecule and one or more transport proteins; (2) the structural integrity of the pigment granule itself is dependent upon the presence of a normal balance of eye pigments, a notion advanced earlier.

scholarly journals Multiple interactions are involved in a highly specific association of the Mod(mdg4)-67.2 isoform with the Su(Hw) sites in Drosophila

Open Biology ◽  
2017 ◽  
Vol 7 (10) ◽  
pp. 170150 ◽  
Author(s):  
Larisa Melnikova ◽  
Margarita Kostyuchenko ◽  
Varvara Molodina ◽  
Alexander Parshikov ◽  
Pavel Georgiev ◽  
...  
Keyword(s):  
Protein Complexes ◽  
Specific Interaction ◽  
Btb Domain ◽  
Rich Domain ◽  
Blocking Activity ◽  
Transgenic Lines ◽  
Enhancer Blocking ◽  
Specific Association ◽  
Protein Variants ◽  
Multiple Interactions

The best-studied Drosophila insulator complex consists of two BTB-containing proteins, the Mod(mdg4)-67.2 isoform and CP190, which are recruited to the chromatin through interactions with the DNA-binding Su(Hw) protein. It was shown previously that Mod(mdg4)-67.2 is critical for the enhancer-blocking activity of the Su(Hw) insulators and it differs from more than 30 other Mod(mdg4) isoforms by the C-terminal domain required for a specific interaction with Su(Hw) only. The mechanism of the highly specific association between Mod(mdg4)-67.2 and Su(Hw) is not well understood. Therefore, we have performed a detailed analysis of domains involved in the interaction of Mod(mdg4)-67.2 with Su(Hw) and CP190. We found that the N-terminal region of Su(Hw) interacts with the glutamine-rich domain common to all the Mod(mdg4) isoforms. The unique C-terminal part of Mod(mdg4)-67.2 contains the Su(Hw)-interacting domain and the FLYWCH domain that facilitates a specific association between Mod(mdg4)-67.2 and the CP190/Su(Hw) complex. Finally, interaction between the BTB domain of Mod(mdg4)-67.2 and the M domain of CP190 has been demonstrated. By using transgenic lines expressing different protein variants, we have shown that all the newly identified interactions are to a greater or lesser extent redundant, which increases the reliability in the formation of the protein complexes.

Cell cycle progression and cell division are sensitive to hypoxia in Drosophila melanogaster embryos

2001 ◽  
Vol 280 (5) ◽  
pp. R1555-R1563 ◽  
Author(s):  
Robert M. Douglas ◽  
Tian Xu ◽  
Gabriel G. Haddad
Keyword(s):  
Cell Cycle ◽  
Drosophila Melanogaster ◽  
Mammalian Cells ◽  
Fluorescent Protein ◽  
Immunoblot Analysis ◽  
Embryonic Cell ◽  
Cell Cycle Checkpoints ◽  
Cycle Phase ◽  
Embryonic Cells

We and others recently demonstrated that Drosophila melanogaster embryos arrest development and embryonic cells cease dividing when they are deprived of O2. To further characterize the behavior of these embryos in response to O2 deprivation and to define the O2-sensitive checkpoints in the cell cycle, embryos undergoing nuclear cycles 3–13 were subjected to O2deprivation and examined by confocal microscopy under control, hypoxic, and reoxygenation conditions. In vivo, real-time analysis of embryos carrying green fluorescent protein-kinesin demonstrated that cells arrest at two major points of the cell cycle, either at the interphase (before DNA duplication) or at metaphase, depending on the cell cycle phase at which O2 deprivation was induced. Immunoblot analysis of embryos whose cell divisions are synchronized by inducible String (cdc25 homolog) demonstrated that cyclin B was degraded during low O2 conditions in interphase-arrested embryos but not in those arrested in metaphase. Embryos resumed cell cycle activity within ∼20 min of reoxygenation, with very little apparent change in cell cycle kinetics. We conclude that there are specific points during the embryonic cell cycle that are sensitive to the O2 level in D. melanogaster. Given the fact that O2deprivation also influences the growth and development of other species, we suggest that similar hypoxia-sensitive cell cycle checkpoints may also exist in mammalian cells.

scholarly journals The three-dimensional genome organization of Drosophila melanogaster through data integration

2017 ◽  
Vol 18 (1) ◽  
Author(s):  
Qingjiao Li ◽  
Harianto Tjong ◽  
Xiao Li ◽  
Ke Gong ◽  
Xianghong Jasmine Zhou ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Data Integration ◽  
Genome Organization ◽  
Genome Structure ◽  
Three Dimensional ◽  
Structural Features ◽  
Embryonic Cells ◽  
Data Types ◽  
Chromosome Conformation ◽  
Topological Domains

Abstract Background Genome structures are dynamic and non-randomly organized in the nucleus of higher eukaryotes. To maximize the accuracy and coverage of three-dimensional genome structural models, it is important to integrate all available sources of experimental information about a genome’s organization. It remains a major challenge to integrate such data from various complementary experimental methods. Here, we present an approach for data integration to determine a population of complete three-dimensional genome structures that are statistically consistent with data from both genome-wide chromosome conformation capture (Hi-C) and lamina-DamID experiments. Results Our structures resolve the genome at the resolution of topological domains, and reproduce simultaneously both sets of experimental data. Importantly, this data deconvolution framework allows for structural heterogeneity between cells, and hence accounts for the expected plasticity of genome structures. As a case study we choose Drosophila melanogaster embryonic cells, for which both data types are available. Our three-dimensional genome structures have strong predictive power for structural features not directly visible in the initial data sets, and reproduce experimental hallmarks of the D. melanogaster genome organization from independent and our own imaging experiments. Also they reveal a number of new insights about genome organization and its functional relevance, including the preferred locations of heterochromatic satellites of different chromosomes, and observations about homologous pairing that cannot be directly observed in the original Hi-C or lamina-DamID data. Conclusions Our approach allows systematic integration of Hi-C and lamina-DamID data for complete three-dimensional genome structure calculation, while also explicitly considering genome structural variability.

scholarly journals Developmentally regulated alterations in Polycomb repressive complex 1 proteins on the inactive X chromosome

2004 ◽  
Vol 167 (6) ◽  
pp. 1025-1035 ◽  
Author(s):  
Kathrin Plath ◽  
Dale Talbot ◽  
Karien M. Hamer ◽  
Arie P. Otte ◽  
Thomas P. Yang ◽  
...  
Keyword(s):  
X Chromosome ◽  
Protein Complexes ◽  
Histone H3 ◽  
X Inactivation ◽  
Polycomb Group ◽  
Epigenetic Mark ◽  
Embryonic Cells ◽  
Developmentally Regulated ◽  
Inactive X Chromosome ◽  
Multistep Process

Polycomb group (PcG) proteins belonging to the polycomb (Pc) repressive complexes 1 and 2 (PRC1 and PRC2) maintain homeotic gene silencing. In Drosophila, PRC2 methylates histone H3 on lysine 27, and this epigenetic mark facilitates recruitment of PRC1. Mouse PRC2 (mPRC2) has been implicated in X inactivation, as mPRC2 proteins transiently accumulate on the inactive X chromosome (Xi) at the onset of X inactivation to methylate histone H3 lysine 27 (H3-K27). In this study, we demonstrate that mPRC1 proteins localize to the Xi, and that different mPRC1 proteins accumulate on the Xi during initiation and maintenance of X inactivation in embryonic cells. The Xi accumulation of mPRC1 proteins requires Xist RNA and is not solely regulated by the presence of H3-K27 methylation, as not all cells that exhibit this epigenetic mark on the Xi show Xi enrichment of mPRC1 proteins. Our results implicate mPRC1 in X inactivation and suggest that the regulated assembly of PcG protein complexes on the Xi contributes to this multistep process.

scholarly journals Analysis of Notch Lacking the Carboxyl Terminus Identified in Drosophila Embryos

2000 ◽  
Vol 149 (3) ◽  
pp. 683-696 ◽  
Author(s):  
Cedric S. Wesley ◽  
Lino Saez
Keyword(s):  
Lateral Inhibition ◽  
Cultured Cells ◽  
Protein Complexes ◽  
Precursor Cells ◽  
Cell Surface Receptor ◽  
Carboxyl Terminus ◽  
Embryonic Cells ◽  
Surface Receptor ◽  
The Central Nervous System ◽  
Carboxy Terminal

The cell surface receptor Notch is required during development of Drosophila melanogaster for differentiation of numerous tissues. Notch is often required for specification of precursor cells by lateral inhibition and subsequently for differentiation of tissues from these precursor cells. We report here that certain embryonic cells and tissues that develop after lateral inhibition, like the connectives and commissures of the central nervous system, are enriched for a form of Notch not recognized by antibodies made against the intracellular region carboxy-terminal of the CDC10/Ankyrin repeats. Western blotting and immunoprecipitation analyses show that Notch molecules lacking this region are produced during embryogenesis and form protein complexes with the ligand Delta. Experiments with cultured cells indicate that Delta promotes accumulation of a Notch intracellular fragment lacking the carboxyl terminus. Furthermore, Notch lacking the carboxyl terminus functions as a receptor for Delta. These results suggest that Notch activities during development include generation and activity of a truncated receptor we designate NΔCterm.

scholarly journals Inferring interaction partners from protein sequences

2016 ◽  
Author(s):  
Anne-Florence Bitbol ◽  
Robert S. Dwyer ◽  
Lucy J. Colwell ◽  
Ned S. Wingreen
Keyword(s):  
Protein Interactions ◽  
Sequence Data ◽  
Protein Complexes ◽  
A Priori ◽  
Specific Interaction ◽  
Three Dimensional ◽  
Specific Protein ◽  
Protein Protein Interactions ◽  
Entropy Model ◽  
Interaction Partners

Specific protein-protein interactions are crucial in the cell, both to ensure the formation and stability of multi-protein complexes, and to enable signal transduction in various pathways. Functional interactions between proteins result in coevolution between the interaction partners. Hence, the sequences of interacting partners are correlated. Here we exploit these correlations to accurately identify which proteins are specific interaction partners from sequence data alone. Our general approach, which employs a pairwise maximum entropy model to infer direct couplings between residues, has been successfully used to predict the three-dimensional structures of proteins from sequences. Building on this approach, we introduce an iterative algorithm to predict specific interaction partners from among the members of two protein families. We assess the algorithm's performance on histidine kinases and response regulators from bacterial two-component signaling systems. The algorithm proves successful without any a priori knowledge of interaction partners, yielding a striking 0.93 true positive fraction on our complete dataset, and we uncover the origin of this surprising success. Finally, we discuss how our method could be used to predict novel protein-protein interactions.

scholarly journals The Drosophila melanogaster PIF1 helicase promotes survival during replication stress and processive DNA synthesis during double-strand gap repair

2019 ◽  
Author(s):  
Ece Kocak ◽  
Sarah Dykstra ◽  
Alexandra Nemeth ◽  
Catherine G. Coughlin ◽  
Kasey Rodgers ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Dna Synthesis ◽  
Synthetic Lethality ◽  
Protein Complexes ◽  
Nuclear Genome ◽  
Replication Stress ◽  
Dna Helicase ◽  
Acid Protein ◽  
Brca2 Protein ◽  
High Concentrations

AbstractPIF1 is a 5’ to 3’ DNA helicase that can unwind double-stranded DNA and disrupt nucleic acid-protein complexes. In Saccharomyces cerevisiae, Pif1 plays important roles in mitochondrial and nuclear genome maintenance, telomere length regulation, unwinding of G-quadruplex structures, and DNA synthesis during break-induced replication. Some, but not all, of these functions are shared with other eukaryotes. To gain insight into the evolutionarily conserved functions of PIF1, we created pif1 null mutants in Drosophila melanogaster and assessed their phenotypes throughout development. We found that pif1 mutant larvae exposed to high concentrations of hydroxyurea, but not other DNA damaging agents, experience reduced survival to adulthood. Embryos lacking PIF1 fail to segregate their chromosomes efficiently during early nuclear divisions, consistent with a defect in DNA replication. Furthermore, loss of the BRCA2 protein, which is required for stabilization of stalled replication forks in metazoans, causes synthetic lethality in third instar larvae lacking either PIF1 or the polymerase delta subunit POL32. Interestingly, pif1 mutants have a reduced ability to synthesize DNA during repair of a double-stranded gap, but only in the absence of POL32. Together, these results support a model in which Drosophila PIF1 functions with POL32 during times of replication stress but acts independently of POL32 to promote synthesis during double-strand gap repair.

scholarly journals Streptococcus pyogenes forms serotype and local environment-dependent inter-species protein complexes

2021 ◽  
Author(s):  
Sounak Chowdhury ◽  
Hamed Khakzad ◽  
Gizem Ertürk Bergdahl ◽  
Rolf Lood ◽  
Simon Ekstrom ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Streptococcus Pyogenes ◽  
Protein Complexes ◽  
Specific Interaction ◽  
Plasma Concentrations ◽  
Mass Spectrometry Analysis ◽  
Secretory Iga ◽  
Structural Mass Spectrometry ◽  
Systemic Infections ◽  
Structural Mass

AbstractStreptococcus pyogenes is known to cause both mucosal and systemic infections in humans. In this study, we used a combination of quantitative and structural mass spectrometry techniques to determine the composition and structure of the interaction network formed between human plasma proteins and the surface of different S. pyogenes serotypes. Quantitative network analysis revealed that S. pyogenes form serotype-specific interaction networks that are highly dependent on the domain arrangement of the surface-attached M protein. Subsequent structural mass spectrometry analysis and computational modelling on one of the M proteins, M28 revealed that the network structure changes across different host microenvironments. We report that M28 binds secretory IgA via two separate binding sites with high affinity in saliva. During vascular leakage mimicked by increasing plasma concentrations in saliva, the binding of secretory IgA was replaced by binding of monomeric IgA and C4BP. This indicates that an upsurge of C4BP in the local microenvironment due to damage of the mucosal membrane drives binding of C4BP and monomeric IgA to M28. The results suggest that S. pyogenes has evolved to form microenvironment-dependent host-pathogen protein complexes to combat the human immune surveillance during both mucosal and systemic infections.

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