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ELife Jun 2024The Wnt/Wg pathway controls myriads of biological phenomena throughout the development and adult life of all organisms across the phyla. Thus, an aberrant Wnt signaling...
E3 ubiquitin ligase Deltex facilitates the expansion of Wingless gradient and antagonizes Wingless signaling through a conserved mechanism of transcriptional effector Armadillo/β-catenin degradation.
The Wnt/Wg pathway controls myriads of biological phenomena throughout the development and adult life of all organisms across the phyla. Thus, an aberrant Wnt signaling is associated with a wide range of pathologies in humans. Tight regulation of Wnt/Wg signaling is required to maintain proper cellular homeostasis. Here, we report a novel role of E3 ubiquitin ligase Deltex in Wg signaling regulation. genetically interacts with nd its pathway components. Furthermore, Dx LOF results in a reduced spreading of Wg while its over-expression expands the diffusion gradient of the morphogen. We attribute this change in Wg gradient to the endocytosis of Wg through Dx which directly affects the short- and long-range Wg targets. We also demonstrate the role of Dx in regulating Wg effector Armadillo where Dx down-regulates Arm through proteasomal degradation. We also showed the conservation of Dx function in the mammalian system where DTX1 is shown to bind with β-catenin and facilitates its proteolytic degradation, spotlighting a novel step that potentially modulates Wnt/Wg signaling cascade.
Topics: Animals; Wnt1 Protein; Drosophila Proteins; Ubiquitin-Protein Ligases; Armadillo Domain Proteins; Proteolysis; Wnt Signaling Pathway; beta Catenin; Drosophila melanogaster; Signal Transduction; Humans; Drosophila; Transcription Factors
PubMed: 38900140
DOI: 10.7554/eLife.88466 -
Addiction Biology Jun 2024Alcohol consumption occurring in a social or solitary setting often yields different behavioural responses in human subjects. For example, social drinking is associated...
Alcohol consumption occurring in a social or solitary setting often yields different behavioural responses in human subjects. For example, social drinking is associated with positive effects while solitary drinking is linked to negative effects. However, the neurobiological mechanism by which the social environment during alcohol intake impacts on behavioural responses remains poorly understood. We investigated whether distinct social environments affect behavioural responses to ethanol and the role of the dopamine system in this phenomenon in the fruit fly Drosophila melanogaster. The wild-type Canton-S (CS) flies showed higher locomotor response when exposed to ethanol in a group setting than a solitary setting, and there was no difference in females and males. Dopamine signalling is crucial for the locomotor stimulating effect of ethanol. When subjected to ethanol exposure alone, the dopamine transport mutant flies fumin (fmn) with hyper dopamine displayed the locomotor response similar to CS. When subjected to ethanol in a group setting, however, the fmn's response to the locomotor stimulating effect was substantially augmented compared with CS, indicating synergistic interaction of dopamine signalling and social setting. To identify the dopamine signalling pathway important for the social effect, we examined the flies defective in individual dopamine receptors and found that the D1 receptor dDA1/Dop1R1 is the major receptor mediating the social effect. Taken together, this study underscores the influence of social context on the neural and behavioural responses to ethanol.
Topics: Animals; Ethanol; Dopamine; Drosophila melanogaster; Male; Female; Drosophila Proteins; Receptors, Dopamine D1; Social Environment; Signal Transduction; Locomotion; Receptors, Dopamine; Behavior, Animal; Central Nervous System Depressants; Social Behavior; Dopamine Plasma Membrane Transport Proteins; Motor Activity
PubMed: 38898729
DOI: 10.1111/adb.13420 -
Open Biology Jun 2024The transition from oocyte to embryo requires translation of maternally provided transcripts that in is activated by Pan Gu kinase to release a rapid succession of 13...
The transition from oocyte to embryo requires translation of maternally provided transcripts that in is activated by Pan Gu kinase to release a rapid succession of 13 mitotic cycles. Mitotic entry is promoted by several protein kinases that include Greatwall/Mastl, whose Endosulfine substrates antagonize Protein Phosphatase 2A (PP2A), facilitating mitotic Cyclin-dependent kinase 1/Cyclin B kinase activity. Here we show that hyperactive can not only be suppressed by mutants in its Endos substrate but also by mutants in Pan Gu kinase subunits. Conversely, mutants in or which encode a complex that represses hundreds of maternal mRNAs, enhance . Me31B and Trailer Hitch proteins, known substrates of Pan Gu kinase, copurify with Endos. This echoes findings that budding yeast Dhh1, orthologue of Me31B, associates with Igo1/2, orthologues of Endos and substrates of the Rim15, orthologue of Greatwall. derived mutant embryos show reduced Me31B and elevated transcripts for the mitotic activators Cyclin B, Polo and Twine/Cdc25. Together, our findings demonstrate a previously unappreciated conservation of the Greatwall-Endosulfine pathway in regulating translational repressors and its interactions with the Pan Gu kinase pathway to regulate translation and/or stability of maternal mRNAs upon egg activation.
Topics: Animals; Drosophila Proteins; Oocytes; Protein Phosphatase 2; Gene Expression Regulation, Developmental; Protein Biosynthesis; Drosophila melanogaster; Mutation; Female; Protein Serine-Threonine Kinases; Embryo, Nonmammalian; RNA Stability; RNA, Messenger, Stored; DEAD-box RNA Helicases
PubMed: 38896085
DOI: 10.1098/rsob.240065 -
Biology of the Cell Jun 2024The Endosomal Sorting Complex Required for Transport (ESCRT) is a highly conserved cellular machinery essential for many cellular functions, including transmembrane...
BACKGROUND
The Endosomal Sorting Complex Required for Transport (ESCRT) is a highly conserved cellular machinery essential for many cellular functions, including transmembrane protein sorting, endosomal trafficking, and membrane scission. CHMP4B is a key component of ESCRT-III subcomplex and has been thoroughly studied in the meroistic ovaries of Drosophila melanogaster showing its relevance in maintaining this reproductive organ during the life of the fly. However, the role of the CHMP4B in the most basal panoistic ovaries remains elusive.
RESULTS
Using RNAi, we examined the function of CHMP4B in the ovary of Blattella germanica in two different physiological stages: in last instar nymphs, with proliferative follicular cells, and in vitellogenic adults when follicular cells enter in polyploidy and endoreplication. In Chmp4b-depleted specimens, the actin fibers change their distribution, appearing accumulated in the basal pole of the follicular cells, resulting in an excess of actin bundles that surround the basal ovarian follicle and modifying their shape. Depletion of Chmp4b also determines an actin accumulation in follicular cell membranes, resulting in different cell morphologies and sizes. In the end, these changes disrupt the opening of intercellular spaces between the follicular cells (patency) impeding the incorporation of yolk proteins to the growing oocyte and resulting in female sterility. In addition, the nuclei of follicular cells appeared unusually elongated, suggesting an incomplete karyokinesis.
CONCLUSIONS
These results proved CHMP4B essential in preserving the proper expression of cytoskeleton proteins vital for basal ovarian follicle growth and maturation and for yolk protein incorporation. Moreover, the correct distribution of actin fibers in the basal ovarian follicle emerged as a critical factor for the successful completion of ovulation and oviposition.
SIGNIFICANCE
The overall results, obtained in two different proliferative stages, suggest that the requirement of CHMP4B in B. germanica follicular epithelium is not related to the proliferative stage of the tissue.
PubMed: 38895958
DOI: 10.1111/boc.202400010 -
International Journal of Molecular... Jun 2024Aging, marked by a gradual decline in physiological function and heightened vulnerability to age-related diseases, remains a complex biological process with multifaceted...
Aging, marked by a gradual decline in physiological function and heightened vulnerability to age-related diseases, remains a complex biological process with multifaceted regulatory mechanisms. Our study elucidates the critical role of poly(ADP-ribose) glycohydrolase (PARG), responsible for catabolizing poly(ADP-ribose) (pADPr) in the aging process by modulating the expression of age-related genes in . Specifically, we uncover the regulatory function of the uncharacterized PARG C-terminal domain in controlling PARG activity. Flies lacking this domain exhibit a significantly reduced lifespan compared to wild-type counterparts. Furthermore, we observe progressive dysregulation of age-related gene expression during aging, accelerated in the absence of PARG activity, culminating in a premature aging phenotype. Our findings reveal the critical involvement of the pADPr pathway as a key player in the aging process, highlighting its potential as a therapeutic target for mitigating age-related effects.
Topics: Animals; Longevity; Drosophila melanogaster; Drosophila Proteins; Glycoside Hydrolases; Aging; Gene Expression Regulation; Poly Adenosine Diphosphate Ribose
PubMed: 38892377
DOI: 10.3390/ijms25116189 -
International Journal of Molecular... Jun 2024The occurrence of ovarian dysfunction is often due to the imbalance between the formation of reactive oxygen species (ROS) and the ineffectiveness of the antioxidative...
The occurrence of ovarian dysfunction is often due to the imbalance between the formation of reactive oxygen species (ROS) and the ineffectiveness of the antioxidative defense mechanisms. Primary sources of ROS are respiratory electron transfer and the activity of NADPH oxidases (NOX) while superoxide dismutases (SOD) are the main key regulators that control the levels of ROS and reactive nitrogen species intra- and extracellularly. Because of their central role SODs are the subject of research on human ovarian dysfunction but sample acquisition is low. The high degree of cellular and molecular similarity between ovaries and human ovaries provides this model organism with the best conditions for analyzing the role of ROS during ovarian function. In this study we clarify the localization of the ROS-producing enzyme dNox within the ovaries of and by a tissue-specific knockdown we show that dNox-derived ROS are involved in the chorion hardening process. Furthermore, we analyze the dSod3 localization and show that reduced activity of dSod3 impacts egg-laying behavior but not the chorion hardening process.
Topics: Animals; Drosophila melanogaster; Female; Superoxide Dismutase; Reactive Oxygen Species; Drosophila Proteins; Ovary; NADPH Oxidases; Reproduction; NADPH Oxidase 5; Oviposition; Chorion
PubMed: 38892326
DOI: 10.3390/ijms25116138 -
International Journal of Molecular... May 2024Pygopus (Pygo) has been identified as a specific nuclear co-activator of the canonical Wingless (Wg)/Wnt signaling pathway in . Pygo proteins consist of two conserved...
Pygopus (Pygo) has been identified as a specific nuclear co-activator of the canonical Wingless (Wg)/Wnt signaling pathway in . Pygo proteins consist of two conserved domains: an N-terminal homologous domain (NHD) and a C-terminal plant homologous domain (PHD). The PHD's ability to bind to di- and trimethylated lysine 4 of histone H3 (H3K4me2/3) appears to be independent of Wnt signaling. There is ongoing debate regarding the significance of Pygo's histone-binding capacity. Pygo orthologs have a tryptophan (W) > phenylalanine (F) substitution in their histone pocket-divider compared to vertebrates, leading to reduced histone affinity. In this research, we utilized CRISPR/Cas9 technology to introduce the Pygo-F773W point mutation in , successfully establishing a viable homozygous mutant line for the first time. Adult mutant flies displayed noticeable abnormalities in reproduction, locomotion, heart function, and lifespan. RNA-seq and cluster analysis indicated that the mutation primarily affected pathways related to immunity, metabolism, and posttranslational modification in adult flies rather than the Wnt signaling pathway. Additionally, a reduction in H3K9 acetylation levels during the embryonic stage was observed in the mutant strains. These findings support the notion that Pygo plays a wider role in chromatin remodeling, with its involvement in Wnt signaling representing only a specific aspect of its chromatin-related functions.
Topics: Animals; Drosophila Proteins; Wnt Signaling Pathway; Drosophila melanogaster; Histones; Intracellular Signaling Peptides and Proteins; Mutation; CRISPR-Cas Systems
PubMed: 38892188
DOI: 10.3390/ijms25115998 -
International Journal of Molecular... May 2024Species of the genus have served as favorite models in speciation studies; however, genetic factors of interspecific reproductive incompatibility are...
Species of the genus have served as favorite models in speciation studies; however, genetic factors of interspecific reproductive incompatibility are under-investigated. Here, we performed an analysis of hybrid female sterility by crossing females and males. Using transcriptomic data analysis and molecular, cellular, and genetic approaches, we analyzed differential gene expression, transposable element (TE) activity, piRNA biogenesis, and functional defects of oogenesis in hybrids. Premature germline stem cell loss was the most prominent defect of oogenesis in hybrid ovaries. Because of the differential expression of genes encoding piRNA pathway components, and , the functional RDC complex in hybrid ovaries was not assembled. However, the activity of the RDC complex was maintained in hybrids independent of the genomic origin of piRNA clusters. Despite the identification of a cohort of overexpressed TEs in hybrid ovaries, we found no evidence that their activity can be considered the main cause of hybrid sterility. We revealed a complicated pattern of Vasa protein expression in the hybrid germline, including partial piRNA targeting of the allele and a significant zygotic delay in expression. We arrived at the conclusion that the hybrid sterility phenotype was caused by intricate multi-locus differences between the species.
Topics: Animals; Female; Drosophila melanogaster; Male; Drosophila simulans; Drosophila Proteins; RNA, Small Interfering; DNA Transposable Elements; Ovary; Hybridization, Genetic; Oogenesis; Infertility; Crosses, Genetic; DEAD-box RNA Helicases
PubMed: 38891872
DOI: 10.3390/ijms25115681 -
International Journal of Molecular... May 2024The dynamic process of spermatogenesis involves asymmetric division, mitosis, and meiosis, which ultimately results in the production of mature spermatozoa. Disorders...
The dynamic process of spermatogenesis involves asymmetric division, mitosis, and meiosis, which ultimately results in the production of mature spermatozoa. Disorders of spermatogenesis can lead to infertility in males. ADAR (adenosine deaminase acting on RNA) mutations in cause male infertility, yet the causative factors remain unclear. In this study, immunofluorescence staining was employed to visualize endogenous ADAR proteins and assess protein levels via fluorescence-intensity analysis. In addition, the early differentiation disorders and homeostatic alterations during early spermatogenesis in the testes were examined through quantification of transit-amplifying region length, counting the number of GSCs (germline stem cells), and fertility experiments. Our findings suggest that deletion of ADAR causes testicular tip transit-amplifying cells to accumulate and become infertile in older male . By overexpressing ADAR in early germline cells, male infertility can be partially rescued. Transcriptome analysis showed that ADAR maintained early spermatogenesis homeostasis through the bone-morphogenetic-protein (BMP) signaling pathway. Taken together, these findings have the potential to help explore the role of ADAR in early spermatogenesis.
Topics: Animals; Male; Spermatogenesis; Drosophila melanogaster; Signal Transduction; Drosophila Proteins; Adenosine Deaminase; Bone Morphogenetic Proteins; Infertility, Male; RNA-Binding Proteins; Testis
PubMed: 38891830
DOI: 10.3390/ijms25115643 -
Fly Dec 2024Adenosine-to-inosine (A-to-I) RNA editing recodes the genome and confers flexibility for the organisms to adapt to the environment. It is believed that RNA recoding...
Adenosine-to-inosine (A-to-I) RNA editing recodes the genome and confers flexibility for the organisms to adapt to the environment. It is believed that RNA recoding sites are well suited for facilitating adaptive evolution by increasing the proteomic diversity in a temporal-spatial manner. The function and essentiality of a few conserved recoding sites are recognized. However, the experimentally discovered functional sites only make up a small corner of the total sites, and there is still the need to expand the repertoire of such functional sites with bioinformatic approaches. In this study, we define a new category of RNA editing sites termed 'conserved editing with non-conserved recoding' and systematically identify such sites in editomes, figuring out their selection pressure and signals of adaptation at inter-species and intra-species levels. Surprisingly, conserved editing sites with non-conserved recoding are not suppressed and are even slightly overrepresented in . DNA mutations leading to such cases are also favoured during evolution, suggesting that the function of those recoding events in different species might be diverged, specialized, and maintained. Finally, structural prediction suggests that such recoding in potassium channel Shab might increase ion permeability and compensate the effect of low temperature. In conclusion, conserved editing with non-conserved recoding might be functional as well. Our study provides novel aspects in considering the adaptive evolution of RNA editing sites and meanwhile expands the candidates of functional recoding sites for future validation.
Topics: Animals; RNA Editing; Inosine; Drosophila; Adenosine; Drosophila melanogaster; Evolution, Molecular; Drosophila Proteins
PubMed: 38889318
DOI: 10.1080/19336934.2024.2367359