@article {1458, title = {The Hox gene uses Doublesex as a cofactor to promote neuroblast apoptosis in the central nervous system [Transgenic Fly Facility]}, journal = {Development}, volume = {146}, year = {2019}, month = {2019 08 22}, abstract = {

Highly conserved DM domain-containing transcription factors (Doublesex/MAB-3/DMRT1) are responsible for generating sexually dimorphic features. In the central nervous system, a set of Doublesex (Dsx)-expressing neuroblasts undergo apoptosis in females whereas their male counterparts proliferate and give rise to serotonergic neurons crucial for adult mating behaviour. Our study demonstrates that the female-specific isoform of Dsx collaborates with Hox gene () to bring about this apoptosis. Biochemical results suggest that proteins AbdB and Dsx interact through their highly conserved homeodomain and DM domain, respectively. This interaction is translated into a cooperative binding of the two proteins on the apoptotic enhancer in the case of females but not in the case of males, resulting in female-specific activation of apoptotic genes. The capacity of AbdB to use the sex-specific isoform of Dsx as a cofactor underlines the possibility that these two classes of protein are capable of cooperating in selection and regulation of target genes in a tissue- and sex-specific manner. We propose that this interaction could be a common theme in generating sexual dimorphism in different tissues across different species.

}, keywords = {Animals, Apoptosis, DNA-Binding Proteins, Drosophila, Drosophila Proteins, Female, Gene Expression Regulation, Developmental, Genes, Homeobox, Homeodomain Proteins, Male, Neural Stem Cells, Protein Isoforms, Sex Characteristics}, issn = {1477-9129}, doi = {10.1242/dev.175158}, author = {Ghosh, Neha and Bakshi, Asif and Khandelwal, Risha and Rajan, Sriivatsan Govinda and Joshi, Rohit} } @article {683, title = {Combinatorial action of Grainyhead, Extradenticle and Notch in regulating Hox mediated apoptosis in Drosophila larval CNS.}, journal = {PLoS Genet}, volume = {13}, year = {2017}, month = {2017 Oct}, pages = {e1007043}, abstract = {

Hox mediated neuroblast apoptosis is a prevalent way to pattern larval central nervous system (CNS) by different Hox genes, but the mechanism of this apoptosis is not understood. Our studies with Abdominal-A (Abd-A) mediated larval neuroblast (pNB) apoptosis suggests that AbdA, its cofactor Extradenticle (Exd), a helix-loop-helix transcription factor Grainyhead (Grh), and Notch signaling transcriptionally contribute to expression of RHG family of apoptotic genes. We find that Grh, AbdA, and Exd function together at multiple motifs on the apoptotic enhancer. In vivo mutagenesis of these motifs suggest that they are important for the maintenance of the activity of the enhancer rather than its initiation. We also find that Exd function is independent of its known partner homothorax in this apoptosis. We extend some of our findings to Deformed expressing region of sub-esophageal ganglia where pNBs undergo a similar Hox dependent apoptosis. We propose a mechanism where common players like Exd-Grh-Notch work with different Hox genes through region specific enhancers to pattern respective segments of larval central nervous system.

}, keywords = {Amino Acid Sequence, Animals, Apoptosis, Central Nervous System, DNA-Binding Proteins, Drosophila, Drosophila Proteins, Enhancer Elements, Genetic, Female, Gene Expression Regulation, Developmental, Genes, Homeobox, Homeodomain Proteins, Larva, Male, Nuclear Proteins, Receptors, Notch, Transcription Factors}, issn = {1553-7404}, doi = {10.1371/journal.pgen.1007043}, author = {Khandelwal, Risha and Sipani, Rashmi and Govinda Rajan, Sriivatsan and Kumar, Raviranjan and Joshi, Rohit} } @article {737, title = {Lipid metabolic perturbation is an early-onset phenotype in adultmutants: amodel for lysosomal storage disorders. [Mass Spectrometry - Lipidomics]}, journal = {Mol Biol Cell}, volume = {28}, year = {2017}, month = {2017 Dec 15}, pages = {3728-3740}, abstract = {

Intracellular accumulation of lipids and swollen dysfunctional lysosomes are linked to several neurodegenerative diseases, including lysosomal storage disorders (LSD). Detailed characterization of lipid metabolic changes in relation to the onset and progression of neurodegeneration is currently missing. We systematically analyzed lipid perturbations inmutants, amodel of LSD-like neurodegeneration. Our results highlight an imbalance in brain ceramide and sphingosine in the early stages of neurodegeneration, preceding the accumulation of endomembranous structures, manifestation of altered behavior, and buildup of lipofuscin. Manipulating levels ofand altering these lipids inmutants allowed us to conclude that ceramide homeostasis is the driving force in disease progression and is integral tofunction in the adult nervous system. We identified 29 novel physical interaction partners of Spin and focused on the lipid carrier protein, Lipophorin (Lpp). A subset of Lpp and Spin colocalize in the brain and within organs specialized for lipid metabolism (fat bodies and oenocytes). Reduced Lpp protein was observed inmutant tissues. Finally, increased levels of lipid metabolites produced by oenocytes inmutants allude to a functional interaction between Spin and Lpp, underscoring the systemic nature of lipid perturbation in LSD.

}, keywords = {Animals, Carrier Proteins, Disease Models, Animal, Drosophila, Drosophila Proteins, Lipid Metabolism, Lipids, Lipoproteins, Lysosomal Storage Diseases, Lysosomes, Membrane Proteins, Mutation, Nervous System, Neurodegenerative Diseases, Phenotype}, issn = {1939-4586}, doi = {10.1091/mbc.E16-09-0674}, author = {Hebbar, Sarita and Khandelwal, Avinash and Jayashree, R and Hindle, Samantha J and Chiang, Yin Ning and Yew, Joanne Y and Sweeney, Sean T and Schwudke, Dominik} } @article {473, title = {A dPIP5K dependent pool of phosphatidylinositol 4,5 bisphosphate (PIP2) is required for G-protein coupled signal transduction in Drosophila photoreceptors.[Drosophila facility]}, journal = {PLoS Genet}, volume = {11}, year = {2015}, month = {2015 Jan}, pages = {e1004948}, abstract = {

Multiple PIP2 dependent molecular processes including receptor activated phospholipase C activity occur at the neuronal plasma membranes, yet levels of this lipid at the plasma membrane are remarkably stable. Although the existence of unique pools of PIP2 supporting these events has been proposed, the mechanism by which they are generated is unclear. In Drosophila photoreceptors, the hydrolysis of PIP2 by G-protein coupled phospholipase C activity is essential for sensory transduction of photons. We identify dPIP5K as an enzyme essential for PIP2 re-synthesis in photoreceptors. Loss of dPIP5K causes profound defects in the electrical response to light and light-induced PIP2 dynamics at the photoreceptor membrane. Overexpression of dPIP5K was able to accelerate the rate of PIP2 synthesis following light induced PIP2 depletion. Other PIP2 dependent processes such as endocytosis and cytoskeletal function were unaffected in photoreceptors lacking dPIP5K function. These results provide evidence for the existence of a unique dPIP5K dependent pool of PIP2 required for normal Drosophila phototransduction. Our results define the existence of multiple pools of PIP2 in photoreceptors generated by distinct lipid kinases and supporting specific molecular processes at neuronal membranes.

}, keywords = {Animals, Cell Membrane, Cytoskeleton, Drosophila, Drosophila melanogaster, Light Signal Transduction, Membrane Proteins, Ocular Physiological Phenomena, Phosphatidylinositol 4,5-Diphosphate, Phosphoinositide Phospholipase C, Phosphotransferases (Alcohol Group Acceptor), Photoreceptor Cells, Retina, Signal Transduction}, issn = {1553-7404}, doi = {10.1371/journal.pgen.1004948}, author = {Chakrabarti, Purbani and Kolay, Sourav and Yadav, Shweta and Kumari, Kamalesh and Nair, Amit and Trivedi, Deepti and Raghu, Padinjat} } @article {684, title = {Role of Homothorax in region specific regulation of Deformed in embryonic neuroblasts.}, journal = {Mech Dev}, volume = {138 Pt 2}, year = {2015}, month = {2015 Nov}, pages = {190-7}, abstract = {

The expression and regulation of Hox genes in developing central nervous system (CNS) lack important details like specific cell types where Hox genes are expressed and the transcriptional regulatory players involved in these cells. In this study we have investigated the expression and regulation of Drosophila Hox gene Deformed (Dfd) in specific cell types of embryonic CNS. Using Dfd neural autoregulatory enhancer we find that Dfd autoregulates itself in cells of mandibular neuromere. We have also investigated the role of a Hox cofactor Homothorax (Hth) for its role in regulating Dfd expression in CNS. We find that Hth exhibits a region specific role in controlling the expression of Dfd, but has no direct role in mandibular Dfd neural autoregulatory circuit. Our results also suggest that homeodomain of Hth is not required for regulating Dfd expression in embryonic CNS.

}, keywords = {Animals, Central Nervous System, Drosophila, Drosophila Proteins, Enhancer Elements, Genetic, Gene Expression Regulation, Developmental, Genes, Homeobox, Homeodomain Proteins, Neural Stem Cells, Organogenesis}, issn = {1872-6356}, doi = {10.1016/j.mod.2015.09.003}, author = {Kumar, Raviranjan and Chotaliya, Maheshvari and Vuppala, Sruthakeerthi and Auradkar, Ankush and Palasamudrum, Kalyani and Joshi, Rohit} } @article {475, title = {Genetic transformation of structural and functional circuitry rewires the Drosophila brain. [Drosophila Facility]}, journal = {Elife}, volume = {3}, year = {2014}, month = {2014 Dec 29}, abstract = {

Acquisition of distinct neuronal identities during development is critical for the assembly of diverse functional neural circuits in the brain. In both vertebrates and invertebrates, intrinsic determinants are thought to act in neural progenitors to specify their identity and the identity of their neuronal progeny. However, the extent to which individual factors can contribute to this is poorly understood. We investigate the role of orthodenticle in the specification of an identified neuroblast (neuronal progenitor) lineage in the Drosophila brain. Loss of orthodenticle from this neuroblast affects molecular properties, neuroanatomical features, and functional inputs of progeny neurons, such that an entire central complex lineage transforms into a functional olfactory projection neuron lineage. This ability to change functional macrocircuitry of the brain through changes in gene expression in a single neuroblast reveals a surprising capacity for novel circuit formation in the brain and provides a paradigm for large-scale evolutionary modification of circuitry.

}, keywords = {Animals, Brain, Cell Lineage, Drosophila, Morphogenesis, Neurons}, issn = {2050-084X}, doi = {10.7554/eLife.04407}, author = {Sen, Sonia and Cao, Deshou and Choudhary, Ramveer and Biagini, Silvia and Wang, Jing W and Reichert, Heinrich and VijayRaghavan, K} } @article {715, title = {Dynamic imaging of homo-FRET in live cells by fluorescence anisotropy microscopy.}, journal = {Methods Enzymol}, volume = {505}, year = {2012}, month = {2012}, pages = {291-327}, abstract = {

Multiple lipid and protein components of the plasma membrane of a living cell are organized, both compositionally and functionally, at different spatial and temporal scales. For instance, Rab protein domains in membranes the clathrin-coated pit, or the immunological synapse are exquisite examples of functional compartmentalization in cell membranes. These assemblies consist in part of nanoscale complexes of lipids and proteins and are necessary to facilitate some specific sorting and signaling functions. It is evident that cellular functions require a regulated spatiotemporal organization of components at the nanoscale, often comprising of countable number of molecular species. Here, we describe multiple homo-FRET-based imaging methods that provide information about nanoscale interactions between fluorescently tagged molecules in live cells, at optically resolved spatial resolution.

}, keywords = {Animals, Cell Membrane, Cell Tracking, Drosophila, Fluorescence Polarization, Fluorescence Resonance Energy Transfer, Green Fluorescent Proteins, Image Processing, Computer-Assisted, Lipid Metabolism, Microscopy, Confocal, Microscopy, Fluorescence}, issn = {1557-7988}, doi = {10.1016/B978-0-12-388448-0.00024-3}, author = {Ghosh, Subhasri and Saha, Suvrajit and Goswami, Debanjan and Bilgrami, Sameera and Mayor, Satyajit} } @article {481, title = {Dysregulation of core components of SCF complex in poly-glutamine disorders. [Drosophila facility]}, journal = {Cell Death Dis}, volume = {3}, year = {2012}, month = {2012 Nov 22}, pages = {e428}, abstract = {

Poly-glutamine (polyQ) diseases are neurodegenerative disorders characterised by expanded CAG repeats in the causative genes whose proteins form inclusion bodies. Various E3 ubiquitin ligases are implicated in neurodegenerative disorders. We report that dysfunction of the SCF (Skp1-Cul1-F-box protein) complex, one of the most well-characterised ubiquitin ligases, is associated with pathology in polyQ diseases like Huntington{\textquoteright}s disease (HD) and Machado-Joseph disease (MJD). We found that Cullin1 (Cul1) and Skp1, core components of the SCF complex, are reduced in HD mice brain. A reduction in Cul1 levels was also observed in cellular HD model and fly models of both HD and MJD. We show that Cul1 is able to genetically modify mutant huntingtin aggregates because its silencing results in increased aggregate load in cultured cells. Moreover, we demonstrate that silencing dCul1 and dSkp1 in Drosophila results in increased aggregate load and enhanced polyQ-induced toxicity. Our results imply that reduced levels of SCF complex might contribute to polyQ disease pathology.

}, keywords = {Animals, Cullin Proteins, Drosophila, Female, Humans, Huntington Disease, Machado-Joseph Disease, Male, Mice, Mice, Transgenic, Peptides, SKP Cullin F-Box Protein Ligases}, issn = {2041-4889}, doi = {10.1038/cddis.2012.166}, author = {Bhutani, S and Das, A and Maheshwari, M and Lakhotia, S C and Jana, N R} } @article {478, title = {Functional implementation of Drosophila itpr mutants by rat Itpr1. [Drosophila facility]}, journal = {J Neurogenet}, volume = {26}, year = {2012}, month = {2012 Sep}, pages = {328-37}, abstract = {

The Drosophila inositol 1,4,5-trisphosphate receptor (IP(3)R) and mammalian type-1 IP(3)Rs have 57-60\% sequence similarity and share major domain homology with each other. Mutants in the single Drosophila IP(3)R gene, itpr, and Itpr1 knockout mice both exhibit lethality and defects in motor coordination. Here the authors show that the rat type-1 IP(3)R, which is the major neuronal isoform, when expressed in the pan-neuronal domain in Drosophila, functionally complements Drosophila IP(3)R function at cellular and systemic levels. It rescues the established neuronal phenotypes of itpr mutants in Drosophila, including wing posture, flight, electrophysiological correlates of flight maintenance, and intracellular calcium dynamics. This is the first in vivo demonstration of functional homology between a mammalian and fly IP(3)R. This study also paves the way for cellular and molecular analyses of the spinocerebellar ataxias in Drosophila, since SCA15/16 is known to be caused by heterozygosity of human ITPR1.

}, keywords = {Animals, Animals, Genetically Modified, Calcium, Cells, Cultured, Cytosol, Drosophila, Drosophila Proteins, Flight, Animal, Gene Expression Regulation, Genetic Therapy, Inositol 1,4,5-Trisphosphate Receptors, Larva, Movement Disorders, Mutation, Neurons, Physical Stimulation, Rats, Transcription Factors, Wings, Animal}, issn = {1563-5260}, doi = {10.3109/01677063.2012.697501}, author = {Chakraborty, Sumita and Hasan, Gaiti} } @article {479, title = {Interaction with a kinesin-2 tail propels choline acetyltransferase flow towards synapse. [Drosophila facility]}, journal = {Traffic}, volume = {13}, year = {2012}, month = {2012 Jul}, pages = {979-91}, abstract = {

Bulk flow constitutes a substantial part of the slow transport of soluble proteins in axons. Though the underlying mechanism is unclear, evidences indicate that intermittent, kinesin-based movement of large protein-aggregates aids this process. Choline acetyltransferase (ChAT), a soluble enzyme catalyzing acetylcholine synthesis, propagates toward the synapse at an intermediate, slow rate. The presynaptic enrichment of ChAT requires heterotrimeric kinesin-2, comprising KLP64D, KLP68D and DmKAP, in Drosophila. Here, we show that the bulk flow of a recombinant Green Fluorescent Protein-tagged ChAT (GFP::ChAT), in Drosophila axons, lacks particulate features. It occurs for a brief period during the larval stages. In addition, both the endogenous ChAT and GFP::ChAT directly bind to the KLP64D tail, which is essential for the GFP::ChAT entry and anterograde flow in axon. These evidences suggest that a direct interaction with motor proteins could regulate the bulk flow of soluble proteins, and thus establish their asymmetric distribution.

}, keywords = {Animals, Animals, Genetically Modified, Axonal Transport, Carrier Proteins, Choline O-Acetyltransferase, Cholinergic Neurons, Drosophila, Drosophila Proteins, Fluorescence Recovery After Photobleaching, Kinesin, Larva, Microtubule-Associated Proteins, Protein Interaction Domains and Motifs, Synapses}, issn = {1600-0854}, doi = {10.1111/j.1600-0854.2012.01361.x}, author = {Sadananda, Aparna and Hamid, Runa and Doodhi, Harinath and Ghosal, Debnath and Girotra, Mukul and Jana, Swadhin Chandra and Ray, Krishanu} } @article {483, title = {Inositol 1,4,5-trisphosphate receptor and dSTIM function in Drosophila insulin-producing neurons regulates systemic intracellular calcium homeostasis and flight. [Drosophila facility]}, journal = {J Neurosci}, volume = {30}, year = {2010}, month = {2010 Jan 27}, pages = {1301-13}, abstract = {

Calcium (Ca(2+)) signaling is known to regulate the development, maintenance and modulation of activity in neuronal circuits that underlie organismal behavior. In Drosophila, intracellular Ca(2+) signaling by the inositol 1,4,5-trisphosphate receptor and the store-operated channel (dOrai) regulates the formation and function of neuronal circuits that control flight. Here, we show that restoring InsP(3)R activity in insulin-producing neurons of flightless InsP(3)R mutants (itpr) during pupal development can rescue systemic flight ability. Expression of the store operated Ca(2+) entry (SOCE) regulator dSTIM in insulin-producing neurons also suppresses compromised flight ability of InsP(3)R mutants suggesting that SOCE can compensate for impaired InsP(3)R function. Despite restricted expression of wild-type InsP(3)R and dSTIM in insulin-producing neurons, a global restoration of SOCE and store Ca(2+) is observed in primary neuronal cultures from the itpr mutant. These results suggest that restoring InsP(3)R-mediated Ca(2+) release and SOCE in a limited subset of neuromodulatory cells can influence systemic behaviors such as flight by regulating intracellular Ca(2+) homeostasis in a large population of neurons through a non-cell-autonomous mechanism.

}, keywords = {Animals, Calcium, Calcium Signaling, Cell Membrane, Cells, Cultured, Central Nervous System, Drosophila, Drosophila Proteins, Flight, Animal, Homeostasis, Inositol 1,4,5-Trisphosphate Receptors, Insulin, Intracellular Fluid, Membrane Proteins, Mutation, Neural Pathways, Neurons, Pupa, Stromal Interaction Molecule 1}, issn = {1529-2401}, doi = {10.1523/JNEUROSCI.3668-09.2010}, author = {Agrawal, Neha and Venkiteswaran, Gayatri and Sadaf, Sufia and Padmanabhan, Nisha and Banerjee, Santanu and Hasan, Gaiti} }