scholarly journals Drosophila BEACH domain autophagic adaptor blue cheese shuttles between vesicle populations and is required for an early step in autophagy

2016 ◽  
Author(s):  
Joan Sim ◽  
Kathleen A. Osborne ◽  
Irene Argudo Garcia ◽  
Artur S. Matysik ◽  
Rachel Kraut
Keyword(s):  
Drosophila Melanogaster ◽  
Neuronal Death ◽  
Adaptor Protein ◽  
Genetic Evidence ◽  
Wild Type ◽  
Human Homologue ◽  
Early Step ◽  
Blue Cheese ◽  
Family Protein ◽  
Different Parts

AbstractDrosophila melanogaster blue cheese (bchs) encodes a large BEACH (Beige and Chediak-Higashi) family protein that is postulated to function as an adaptor protein with roles in vesicle trafficking. Mutation in bchs leads to the accumulation of ubiquitinated aggregates in aged brains, presumably because of a conserved function with its human homologue Autophagy-Linked FYVE (ALFY), which interacts with Atg5 and p62 to promote the clearance of aggregate-prone proteins. In this study, we present pharmacological and genetic evidence using a well-defined larval motorneuron paradigm that in Drosophila bchs mutants, autophagic deficit contributes to neurodegeneration. Specifically, we show that motorneuron death in larvae is accompanied by the accumulation of prominent ubiquitinated aggregates in synaptic termini, and that these are sensitive to autophagy modulating drugs. In primary bchs neurons, early autophagic compartments increase in number and intensity based on Atg5 expression, but fail to progress to Atg8-labelled compartments, indicating non-clearance. A rescuing transgene encoding the longest Bchs BEACH domain isoform not only reverses this defect, but also greatly increases Atg8 compartment number and rescues neuronal death. Although only a small fraction of Bchs colocalizes with these markers under wild-type conditions, the population of Bchs that does associate with autophagosomes shuttles between different locations depending on how autophagy is induced. These observations, together with epistatic relationships between bchs mutant alleles and autophagy-modulating drugs and genetic backgrounds, points to a model whereby BEACH domain isoforms of Bchs participate in the early steps of autophagy by recruiting Atg5 to target substrates for clearance, and that Bchs’ association with different parts of the autophagy machinery depends upon the type of autophagic stress imposed upon the neuron.

An alternative processing pathway of APP reveals two distinct cleavage modes for rhomboid protease RHBDL4

2018 ◽  
Vol 399 (12) ◽  
pp. 1399-1408 ◽  
Author(s):  
Sherilyn Junelle Recinto ◽  
Sandra Paschkowsky ◽  
Lisa Marie Munter
Keyword(s):  
Drosophila Melanogaster ◽  
Amino Acid Residues ◽  
Wild Type ◽  
Human Homologue ◽  
App Processing ◽  
Rhomboid Protease ◽  
Alternative Processing ◽  
Intramembrane Proteases ◽  
Rhomboid Proteases ◽  
Positively Charged

AbstractSince the first genetic description of a rhomboid inDrosophila melanogaster, tremendous efforts have been geared towards elucidating the proteolytic mechanism of this particular class of intramembrane proteases. In particular, mammalian rhomboid proteases sparked our interest and we aimed to investigate the human homologue RHBDL4. In light of our recent finding of the amyloid precursor protein (APP) family as efficient substrates of RHBDL4, we were enticed to further study the specific proteolytic mechanism of this enzyme by comparing cleavage patterns of wild type APP and APP TMS chimeras. Here, we demonstrate that the introduction of positively charged amino acid residues in the TMS redirects the RHBDL4-mediated cleavage of APP from its ectodomain closer towards the TMS, possibly inducing an ER-associated degradation (ERAD) of the substrate. In addition, we concluded that the cytoplasmic tail and proposed palmitoylation sites in the ectodomain of APP are not essential for the RHBDL4-mediated APP processing. In summary, our previously identified APP ectodomain cleavages by RHBDL4 are a subsidiary mechanism to the proposed RHBDL4-mediated ERAD of substrates likely through a single cleavage near or within the TMS.

Interallelic Complementation at the suppressor of forked Locus of Drosophila Reveals Complementation Between Suppressor of forked Proteins Mutated in Different Regions

Genetics ◽  
1996 ◽  
Vol 142 (4) ◽  
pp. 1225-1235
Author(s):  
Martine Simonelig ◽  
Kate Elliott ◽  
Andrew Mitchelson ◽  
Kevin O'Hare
Keyword(s):  
Drosophila Melanogaster ◽  
Gene Product ◽  
Protein Interaction ◽  
Wild Type ◽  
Type Function ◽  
Protein Protein Interaction ◽  
Molecular Complexity ◽  
Interallelic Complementation ◽  
Cleavage Stimulation Factor ◽  
Different Parts

Abstract The Su(f) protein of Drosophila melanogaster shares extensive homologies with proteins from yeast (RNA14) and man (77 kD subunit of cleavage stimulation factor) that are required for 3′ end processing of mRNA. These homologies suggest that su(f) is involved in mRNA 3′ end formation and that some aspects of this process are conserved throughout eukaryotes. We have investigated the genetic and molecular complexity of the su(f) locus. The su(f) gene is transcribed to produce three RNAs and could encode two proteins. Using constructs that contain different parts of the locus, we show that only the larger predicted gene product of 84 kD is required for the wild-type function of su(f). Some lethal alleles of su(f) complement to produce viable combinations. The structures of complementing and noncomplementing su(f) alleles indicate that 84-kD Su(f) proteins mutated in different domains can act in combination for partial su(f) function. Our results suggest protein-protein interaction between or within wild-type Su(f) molecules.

scholarly journals The hobo Transposable Element Excises and Has Related Elements in Tephritid Species

Genetics ◽  
1996 ◽  
Vol 143 (3) ◽  
pp. 1339-1347
Author(s):  
Alfred M Handler ◽  
Sheilachu P Gomez
Keyword(s):  
Drosophila Melanogaster ◽  
Ceratitis Capitata ◽  
Bactrocera Dorsalis ◽  
Parsimony Analysis ◽  
Wild Type ◽  
Anastrepha Suspensa ◽  
Tephritid Species ◽  
Mutant Strains ◽  
Almost All ◽  
Horizontal Transfers

Abstract Function of the Drosophila melanogaster hobo transposon in tephritid species was tested in transient embryonic excision assays. Wild-type and mutant strains of Anastrepha suspensa, Bactrocera dorsalis, B. cucurbitae, Ceratitis capitata, and Toxotrypana curvicauda all supported hobo excision or deletion both in the presence and absence of co-injected hobo transposase, indicating a permissive state for hobo mobility and the existence of endogenous systems capable of mobilizing hobo. In several strains hobo helper reduced excision. Excision depended on hobo sequences in the indicator plasmid, though almost all excisions were imprecise and the mobilizing systems appear mechanistically different from hobo. hobe-related sequences were identified in all species except T. curvicauda. Parsimony analysis yielded a subgroup including the B. cucurbitae and C. capitata sequences along with hobo and Hermes, and a separate, more divergent subgroup including the A. suspensa and B. dorsalis sequences. All of the sequences exist as multiple genomic elements, and a deleted form of the B. cucurbitae element exists in B. dorsalis. The hobo-related sequences are probably members of the hAT transposon family with some evolving from distant ancestor elements, while others may have originated from more recent horizontal transfers.

scholarly journals Production and scavenging of reactive oxygen species both affect reproductive success in male and female Drosophila melanogaster

2021 ◽  
Author(s):  
Biz R. Turnell ◽  
Luisa Kumpitsch ◽  
Klaus Reinhardt
Keyword(s):  
Reactive Oxygen Species ◽  
Drosophila Melanogaster ◽  
Reactive Oxygen ◽  
Cellular Aging ◽  
Ros Production ◽  
Oxygen Species ◽  
Wild Type ◽  
Ros Scavenging ◽  
Respiratory Pathway ◽  
Male And Female

AbstractSperm aging is accelerated by the buildup of reactive oxygen species (ROS), which cause oxidative damage to various cellular components. Aging can be slowed by limiting the production of mitochondrial ROS and by increasing the production of antioxidants, both of which can be generated in the sperm cell itself or in the surrounding somatic tissues of the male and female reproductive tracts. However, few studies have compared the separate contributions of ROS production and ROS scavenging to sperm aging, or to cellular aging in general. We measured reproductive fitness in two lines of Drosophila melanogaster genetically engineered to (1) produce fewer ROS via expression of alternative oxidase (AOX), an alternative respiratory pathway; or (2) scavenge fewer ROS due to a loss-of-function mutation in the antioxidant gene dj-1β. Wild-type females mated to AOX males had increased fecundity and longer fertility durations, consistent with slower aging in AOX sperm. Contrary to expectations, fitness was not reduced in wild-type females mated to dj-1β males. Fecundity and fertility duration were increased in AOX and decreased in dj-1β females, indicating that female ROS levels may affect aging rates in stored sperm and/or eggs. Finally, we found evidence that accelerated aging in dj-1β sperm may have selected for more frequent mating. Our results help to clarify the relative roles of ROS production and ROS scavenging in the male and female reproductive systems.

scholarly journals INTRACISTRONIC MAPPING OF ELECTROPHORETIC SITES IN DROSOPHILA MELANOGASTER: FIDELITY OF INFORMATION TRANSFER BY GENE CONVERSION

Genetics ◽  
1974 ◽  
Vol 76 (2) ◽  
pp. 289-299
Author(s):  
Margaret McCarron ◽  
William Gelbart ◽  
Arthur Chovnick
Keyword(s):  
Drosophila Melanogaster ◽  
Information Transfer ◽  
Large Scale ◽  
Genetic Basis ◽  
Xanthine Dehydrogenase ◽  
Specific Protein ◽  
Wild Type ◽  
Electrophoretic Variation ◽  
The Stability ◽  
Recombination Experiments

ABSTRACT A convenient method is described for the intracistronic mapping of genetic sites responsible for electrophoretic variation of a specific protein in Drosophila melanogaster. A number of wild-type isoalleles of the rosy locus have been isolated which are associated with the production of electrophoretically distinguishable xanthine dehydrogenases. Large-scale recombination experiments were carried out involving null enzyme mutants induced on electrophoretically distinct wild-type isoalleles, the genetic basis for which is followed as a nonselective marker in the cross. Additionally, a large-scale recombination experiment was carried out involving null enzyme rosy mutants induced on the same wild-type isoallele. Examination of the electrophoretic character of crossover and convertant products recovered from the latter experiment revealed that all exhibited the same parental electrophoretic character. In addition to documenting the stability of the xanthine dehydrogenase electrophoretic character, this observation argues against a special mutagenesis hypothesis to explain conversions resulting from allele recombination studies.

scholarly journals Somatic production of reactive oxygen species does not predict its production in sperm cells across Drosophila melanogaster lines

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Biz R. Turnell ◽  
Luisa Kumpitsch ◽  
Anne-Cécile Ribou ◽  
Klaus Reinhardt
Keyword(s):  
Reactive Oxygen Species ◽  
Drosophila Melanogaster ◽  
Reactive Oxygen ◽  
Future Research ◽  
Ros Production ◽  
Oxygen Species ◽  
Loss Of Function ◽  
Wild Type ◽  
Ros Scavenging ◽  
Transport Chain

Abstract Objective Sperm ageing has major evolutionary implications but has received comparatively little attention. Ageing in sperm and other cells is driven largely by oxidative damage from reactive oxygen species (ROS) generated by the mitochondria. Rates of organismal ageing differ across species and are theorized to be linked to somatic ROS levels. However, it is unknown whether sperm ageing rates are correlated with organismal ageing rates. Here, we investigate this question by comparing sperm ROS production in four lines of Drosophila melanogaster that have previously been shown to differ in somatic mitochondrial ROS production, including two commonly used wild-type lines and two lines with genetic modifications standardly used in ageing research. Results Somatic ROS production was previously shown to be lower in wild-type Oregon-R than in wild-type Dahomey flies; decreased by the expression of alternative oxidase (AOX), a protein that shortens the electron transport chain; and increased by a loss-of-function mutation in dj-1β, a gene involved in ROS scavenging. Contrary to predictions, we found no differences among these four lines in the rate of sperm ROS production. We discuss the implications of our results, the limitations of our study, and possible directions for future research.

scholarly journals DIFFERENTIATION OF DROSOPHILA CELLS LACKING RIBOSOMAL DNA, IN VITRO

Genetics ◽  
1973 ◽  
Vol 73 (3) ◽  
pp. 429-434
Author(s):  
J James Donady ◽  
R L Seecof ◽  
M A Fox
Keyword(s):  
Drosophila Melanogaster ◽  
Ribosomal Rna ◽  
Ribosomal Dna ◽  
Rna Synthesis ◽  
Wild Type ◽  
Drosophila Cells

ABSTRACT Drosophila melanogaster embryos that lacked ribosomal DNA were obtained from appropriate crosses. Cells were taken from such embryos before overt differentiation took place and were cultured in vitro. These cells differentiated into neurons and myocytes with the same success as did wild-type controls. Therefore, ribosomal RNA synthesis is not necessary for the differentiation of neurons and myocytes in vitro.

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