Location and functions of Inebriated in the eye.

Histamine (HA) is a neurotransmitter in arthropod photoreceptors. It is recycled via conjugation to β-alanine to form β-alanylhistamine (carcinine). Conjugation occurs in epithelial glia that surround photoreceptor terminals in the first optic neuropil, and carcinine (CA) is then transported back to photoreceptors and cleaved to liberate HA and β-alanine.

Human R1441C LRRK2 regulates the synaptic vesicle proteome and phosphoproteome in a Drosophila model of Parkinson's disease.

Mutations in leucine-rich repeat kinase 2 (LRRK2) cause late-onset, autosomal dominant familial Parkinson`s disease (PD) and variation at the LRRK2 locus contributes to the risk for idiopathic PD. LRRK2 can function as a protein kinase and mutations lead to increased kinase activity. To elucidate the pathophysiological mechanism of the R1441C mutation in the GTPase domain of LRRK2, we expressed human wild-type or R1441C LRRK2 in dopaminergic neurons of Drosophila and observe reduced locomotor activity, impaired survival and an age-dependent degeneration of dopaminergic neurons thereby creating a new PD-like model.

Drosophila Ebony: a novel type of nonribosomal peptide synthetase related enzyme with unusually fast peptide bond formation kinetics.

Drosophila Ebony is a β-alanyl biogenic amine synthetase with proven function in cuticle and in glia of the nervous system. It is closely related to nonribosomal peptide synthetases (NRPSs), which typically consist of at least an adenylation, a peptidyl carrier protein and a peptide bond forming condensation domain. Besides its role in cuticle formation, Ebony is in most glia of the brain thought to convert biogenic amines to β-alanyl conjugates.

Separate roles of PKA and EPAC in renal function unraveled by the optogenetic control of cAMP levels in vivo.

Cyclic AMP (cAMP) is a ubiquitous second messenger that regulates a variety of essential processes in diverse cell types, functioning via cAMP-dependent effectors such as protein kinase A (PKA) and/or exchange proteins directly activated by cAMP (EPAC). In an intact tissue it is difficult to separate the contribution of each cAMP effector in a particular cell type using genetic or pharmacological approaches alone. We, therefore, utilized optogenetics to overcome the difficulties associated with examining a multicellular tissue.

Activity and coexpression of Drosophila black with ebony in fly optic lobes reveals putative cooperative tasks in vision that evade electroretinographic detection.

Drosophila mutants black and ebony show pigmentation defects in the adult cuticle, which disclose their cooperative activity in β-alanyl-dopamine formation. In visual signal transduction, Ebony conjugates β-alanine to histamine, forming β-alanyl-histamine or carcinine. Mutation of ebony disrupts signal transduction and reveals an electroretinogram (ERG) phenotype.

Endogenous ciliary neurotrophic factor modulates anxiety and depressive-like behavior.

On a molecular level, depression is characterized by an altered monoaminergic neurotransmission as well as a modulation of cytokines and other mediators in the central nervous system. In particular, neurotrophic factors may influence affective behavior including depression and anxiety. Ciliary neurotrophic factor (CNTF) plays an important role in the regulation of neuronal development, neuroprotection and may also influence cognitive processes.

Inflammation modulates anxiety in an animal model of multiple sclerosis.

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS) characterized by inflammation, but also degenerative changes. Besides neurological deficits, the rate of affective disorders such as depression and anxiety is at least six fold increased. Many aspects of MS can be mimicked in the animal model of myelin oligodendrocyte glycoprotein experimental autoimmune encephalomyelitis (MOG-EAE).

Alternative tasks of Drosophila tan in neurotransmitter recycling versus cuticle sclerotization disclosed by kinetic properties.

Upon a stimulus of light, histamine is released from Drosophila photoreceptor axonal endings. It is taken up into glia where Ebony converts it into beta-alanyl-histamine (carcinine). Carcinine moves into photoreceptor cells and is there cleaved into beta-alanine and histamine by Tan activity.

A glial variant of the vesicular monoamine transporter is required to store histamine in the Drosophila visual system.

Unlike other monoamine neurotransmitters, the mechanism by which the brain's histamine content is regulated remains unclear. In mammals, vesicular monoamine transporters (VMATs) are expressed exclusively in neurons and mediate the storage of histamine and other monoamines. We have studied the visual system of Drosophila melanogaster in which histamine is the primary neurotransmitter released from photoreceptor cells.

Drosophila photoreceptors express cysteine peptidase tan.

The Drosophila mutant tan (t) shows reciprocal pigmentation defects compared with the ebony (e) mutant. Visual phenotypes, however, are similar in both flies: Electroretinogram (ERG) recordings lack "on" and "off" transients, an indication of impaired synaptic transmission to postsynaptic cells L1 and L2. Cloning of tan revealed transcription of the gene in the retina, apparently in photoreceptor cells.

High efficiency of a double-screening method on single P-element insertion lines to identify quantitative trait mutants in Drosophila melanogaster.

Enhancer trap P-element insertion has become a common method for generating new mutations in Drosophila melanogaster. When this method is used to isolate mutants for quantitative traits, an appropriate control must be established to define normal and mutant phenotypes. Considering that enhancer-trap lines are generated by crossing several strains, usually with no homogeneous genetic background, no clear control strain can be selected.

Drosophila tan encodes a novel hydrolase required in pigmentation and vision.

Many proteins are used repeatedly in development, but usually the function of the protein is similar in the different contexts. Here we report that the classical Drosophila melanogaster locus tan encodes a novel enzyme required for two very different cellular functions: hydrolysis of N-beta-alanyl dopamine (NBAD) to dopamine during cuticular melanization, and hydrolysis of carcinine to histamine in the metabolism of photoreceptor neurotransmitter. We characterized two tan-like P-element insertions that failed to complement classical tan mutations.

An increased receptive field of olfactory receptor Or43a in the antennal lobe of Drosophila reduces benzaldehyde-driven avoidance behavior.

Most animals orient themselves in their environment through the perception of olfactory cues. In order to gain insight into the principles of olfactory processing in Drosophila, we misexpressed olfactory receptor Or43a in additional olfactory receptor neurons of the third antennal segment using enhancer trap line GH320. The behavioral response of GH320/UAS-or43a flies was changed upon benzaldehyde application.

Ebony, a novel nonribosomal peptide synthetase for beta-alanine conjugation with biogenic amines in Drosophila.

Using Ebony protein either expressed in Escherichia coli or in Schneider S2 cells, we provide evidence for its substrate specificity and reaction mechanism. Ebony activates beta-alanine to aminoacyladenylate by an adenylation domain and covalently attaches it as a thioester to a thiolation domain in a nonribosomal peptide synthetase (NRPS) related mechanism. In a second reaction, biogenic amines act as external nucleophiles on beta-alanyl-S-pantetheine-Ebony, thereby releasing in a fast reaction the dipeptide (peptidoamine) in a process that is novel in higher eucaryotes.

Molecular cloning of a putative voltage- and cyclic nucleotide-gated ion channel present in the antennae and eyes of Drosophila melanogaster.

The amino acid sequence BCNG-1 (brain cyclic nucleotide gated 1, of the mouse), the first member of mamalian I(h) channels, was used to construct a set of polymerase chain reaction (PCR) primers from possibly conserved regions. Reverse transcription-PCR with Drosophila melanogaster mRNA yielded in a PCR product, which exhibited a high homology to BCNG-1. Using these PCR products to screen a D.

Ebony protein in the Drosophila nervous system: optic neuropile expression in glial cells.

The Drosophila ebony mutation (Bridges and Morgan, [1923] Publs Carnegie Inst Wash 327:50) reveals a pleiotropic phenotype with cuticular and behavioral defects. To understand Ebony function in the nervous system, particularly in transmission of the visual signal, it is essential to know the cell type and temporal characteristics of its expression throughout development. Therefore, we raised an antiserum against an Ebony peptide to detect the protein in whole-mount and slice preparations of Drosophila.

Factor analysis of olfactory responses in Drosophila melanogaster enhancer-trap lines as a method for ascertaining common reception components for different odorants.

Olfactory information is transmitted to the brain using combinatorial receptor codes; consequently, a single reception element can be activated by different odorants. Several methods have been applied to describe from a functional point of view those odorants sharing olfactory reception components. A genetic approach in Drosophila melanogaster used correlation between behavioral responses to different odorants for deducing common olfactory pathway-genes.

Two cDNAs coding for histamine-gated ion channels in D. melanogaster.

Histamine, a neurotransmitter and neuroregulatory compound in diverse species, serves as the neurotransmitter of photoreceptors in insects and other arthropods by directly activating a chloride channel. By systematic expression screening of novel putative ligand-gated anion channels, we identified two cDNAs (DM-HisCl-alpha 1 and-alpha 2) coding for putative histamine-gated chloride channels by functional expression in Xenopus laevis oocytes. DM-HisCl-alpha 1 mRNA localizes in the lamina region of the Drosophila eye, supporting the idea that DM-HisCl-alpha 1 may be a neurotransmitter receptor for histamine in the visual system.

Functional expression and characterization of a Drosophila odorant receptor in a heterologous cell system.

Odorant receptors (ORs) constitute the molecular basis for the detection of volatile odorous molecules and the perception of smell. Our understanding of chemical senses has been greatly expanded by the discovery of the OR gene families in vertebrates and in the nematode Caenorhabditis elegans. Recently, candidate Drosophila OR genes have been identified.

The protein Hrb57A of Drosophila melanogaster closely related to hnRNP K from vertebrates is present at sites active in transcription and coprecipitates with four RNA-binding proteins.

The hnRNP K protein is among the major hnRNA-binding proteins with a strong preference for cytidine-rich sequences. We have cloned a Drosophila hnRNP protein closely related to this vertebrate protein. The protein first identified by the monoclonal antibody Q18 is encoded by a gene located in 57A on polytene chromosomes and has been consequently named Hrb57A.

Olfactory adaptation depends on the Trp Ca2+ channel in Drosophila.

Olfactory adaptation is shown to occur in Drosophila, at both behavioral and physiological levels. In a behavioral paradigm, the extent of adaptation is shown to depend on the dose and duration of the adapting stimulus. Half-maximal adaptation occurred after 15 sec of exposure to an odor, and recovery occurred with a half-time of 1.

The Drosophila ebony gene is closely related to microbial peptide synthetases and shows specific cuticle and nervous system expression.

The previously detected ebony (e) locus (Caizzi et al., 1987) consists of a complex gene structure that is divided into seven exons. An open reading frame encoding the putative Ebony protein of 98.

Drosophila melanogaster NADPH-cytochrome P450 oxidoreductase: pronounced expression in antennae may be related to odorant clearance.

Insects perceive a large number of airborne chemicals as olfactory components mainly through the antenna. It is thought that detection of the odorants by specific receptors is followed by a degradative pathway that clears the olfactory organ from accumulating chemicals. In Drosophila, a number of P450 monooxygenases are involved in the metabolism of foreign chemicals [Dunkov et al.

Drosophila snRNP associated protein P11 which specifically binds to heat shock puff 93D reveals strong homology with hnRNP core protein A1.

We have isolated cDNAs coding for a ribonucleoprotein of Drosophila melanogaster that is distinguished by its nearly exclusive presence at only one of the several heat shock puffs in polytene chromosomes of third instar larvae. We determined the nucleotide sequence and deduced the corresponding amino acid sequence. Its coding capacity for a 39 kDa protein is consistent with the size of the protein detected by the monoclonal antibody P11 used for expression cloning.

Apis mellifera cytoplasmic elongation factor 1 alpha (EF-1 alpha) is closely related to Drosophila melanogaster EF-1 alpha.

Using low stringency hybridisation with a Drosophila melanogaster EF-1 alpha gene fragment we have isolated a genomic DNA clone encoding elongation factor 1 alpha (EF-1 alpha) from Apis mellifera. The hybridising Apis mellifera sequence could be delineated to two small EcoRI fragments that were also revealed by genomic Southern hybridisation. By comparison with the corresponding Drosophila melanogaster data the complete translational reading frame has been deduced.