Biology subjects

Binari, R.

Publications and source records attributed to Binari, R..

7 recordsLinked to original sources

bioRxiv2025

Hepatic ceramide synthesis links systemic inflammation to organelle dysfunction in cancer

Paraneoplastic syndromes arise when tumor-derived cytokines reprogram distant organs. Although mediators such as Interleukin-6 have been implicated, how these signals impair host organ function remains incompletely defined. Here, we identify a cytokine-lipid axis that drives hepatic autophagy dysfunction. Specifically, in Drosophila, the gut tumor-derived interleukin-like cytokine Upd3 induces the expression of the triglyceride lipase CG5SCC, which we named "cancer-associated lipid mobilizer (calm)", and the ceramide synthase schlank in the fat body. This upregulation rewires fat body lipid metabolism, resulting in an autophagic-flux blockade. Genetic reduction of either CG5SCC or schlank restores organelle homeostasis and mitigates paraneoplastic phenotypes. This mechanism is conserved in mammals: in mice, IL-6 upregulates the lipoprotein lipase Lpl and ceramide synthases which in turn trigger a hepatic autophagy-flux blockade; in humans, hepatic LPL and ceramide synthases expression correlates with poorer survival in hepatocellular carcinoma. Our findings position hepatic lipid metabolism rewiring, especially ceramide synthesis as a critical, conserved node coupling systemic inflammation to organelle dysfunction, and suggest this pathway as a possible therapeutic entry point for cancer-associated liver disorders.

genetics↗

bioRxiv2025

The epigenetic factor Zrf1 regulates intestinal stem cell proliferation during midgut regeneration

Stem cells are essential for tissue maintenance and regeneration, balancing self-renewal and differentiation to support homeostasis and repair. Through an RNAi screen in the Drosophila midgut, we identified the epigenetic factor Zrf1 as a critical regulator of intestinal stem cell (ISC) proliferation. Functional analyses reveal that Zrf1 integrates inputs from multiple signaling pathways and interacts with components of the RNA-induced silencing complex (RISC). Zrf1 mutants exhibit elevated expression of transposable elements (TEs) and chromatin disruption, highlighting a broader role in genome stability. Single-nuclei RNA sequencing (snRNA-seq) further demonstrated the influence of Zrf1 on chromatin organization and TE repression, particularly within stem cell progenitors. Our findings suggest that Zrf1 is potentially a key chromatin regulator necessary for maintaining stem cell proliferation and genome integrity, enhancing our understanding of the molecular controls underlying stem cell function and chromatin dynamics.

genetics↗

bioRxiv2022

Next-generation large-scale binary protein interaction network for Drosophila

Generating reference maps of the interactome networks underlying most cellular functions can greatly illuminate genetic studies by providing a protein-centric approach to finding new components of existing pathways, complexes, and processes. Here, we applied state-of-the-art experimental and bioinformatics methods to identify high-confidence binary protein-protein interactions (PPIs) for Drosophila melanogaster. We performed four all-by-all yeast two-hybrid (Y2H) screens of >10,000 Drosophila proteins, resulting in the FlyBi dataset of 8,723 PPIs among 2,939 proteins. As part of this effort, we tested subsets of our data and data from previous PPI datasets using an orthogonal assay, which allowed us to normalize data quality across datasets. Next, we integrated our FlyBi data with previous PPI data, resulting in an expanded, high-confidence binary Drosophila reference interaction network, DroRI, comprising 17,232 interactions among 6,511 proteins. These data are accessible through the Molecular Interaction Search Tool (MIST) and other databases. To assess the utility of the PPI resource, we used novel interactions from the FlyBi dataset to generate an autophagy interaction network that we validated in vivo using two different autophagy-related assays. We found that deformed wings (dwg) encodes a protein that is both a regulator and a target of autophagy. Altogether, the resources generated in this project provide a strong foundation for building high-confidence new hypotheses regarding protein networks and function.

cell biology↗

bioRxiv2021

REPTOR/CREBRF encode key regulators of muscle energy metabolism

Metabolic flexibility of muscle tissue describes the capacity to use glucose or lipids as energy substrates and its disruption is associated with metabolic dysfunction. Cancer-induced cachexia is a metabolic syndrome linked with muscle wasting, changes in muscle energy metabolism and lower life expectancy in cancer patients. The molecular mechanisms driving metabolic changes in muscle, however, are poorly characterized. Here, using a Drosophila model of systemic metabolic dysfunction triggered by yorkie-induced gut tumors, we identify the transcription factor REPTOR as a key regulator of energy metabolism in muscle. We show that REPTOR is upregulated in muscles of adult flies with gut yorkie-tumors, where it is necessary to modulate glucose metabolism. REPTOR expression in muscles is induced by ImpL2, a tumor-derived insulin binding protein that reduces systemic insulin signaling, or by nutritional restriction. Further, in vitro and in vivo studies indicate that high activity of REPTOR is sufficient to increase glucose content, transcriptionally repress phosphofructokinase and increase mitochondrial respiration. Consistent with the fly studies, higher levels of CREBRF, the mammalian ortholog of REPTOR, reduce glycolysis in mouse myotubes while promoting an oxidative phenotype. Altogether, our results implicate REPTOR/CREBRF as key regulators of muscle metabolism and metabolic flexibility that share a conserved function as repressors of glycolysis and promoters of oxidative phosphorylation.

physiology↗

bioRxiv2021

Protein visualization and manipulation in Drosophila through the use of epitope tags recognized by nanobodies

Expansion of the available repertoire of reagents for visualization and manipulation of proteins will help understand their function. Short epitope tags linked to proteins of interest and recognized by existing binders such as nanobodies facilitate protein studies by obviating the need to isolate new antibodies directed against them. Nanobodies have several advantages over conventional antibodies, as they can be expressed and used as tools for visualization and manipulation of proteins in vivo. Here, we characterize two short (<15 aa) NanoTag epitopes, 127D01 and VHH05) and their corresponding high-affinity nanobodies. We demonstrate their use in Drosophila for in vivo protein detection and re-localization, direct and indirect immunofluorescence, immunoblotting, and immunoprecipitation. We further show that CRISPR-mediated gene targeting provides a straightforward approach to tagging endogenous proteins with the NanoTags. Single copies of the NanoTags, regardless of their location, suffice for detection. This versatile and validated toolbox of tags and nanobodies will serve as a resource for a wide array of applications, including functional studies in Drosophila and beyond.

genetics↗

bioRxiv2019

The RhoGEF Cysts couples apical polarity proteins to Rho and myosin activity at adherens junctions

The spatio-temporal regulation of small Rho GTPases is crucial for the dynamic stability of epithelial tissues. However, how RhoGTPase activity is controlled during development remains largely unknown. To explore the regulation of Rho GTPases in vivo we analyzed the Rho GTPase guanine nucleotide exchange factor (RhoGEF) Cysts, the Drosophila orthologue of mammalian p114RhoGEF, GEF-H1, p190RhoGEF, and AKAP-13. Loss of Cysts causes a phenotype that closely resemble the mutant phenotype of the apical polarity regulator Crumbs. This phenotype can be suppressed by the loss of basolateral polarity proteins suggesting that Cysts in an integral component of the apical polarity protein network. Cysts activates Rho at adherens junctions to promote junctional enrichment of myosin II, which requires the RhoGEF domain and the coiled-coil domain containing C-terminal region of Cysts. Cysts recruitment to the apico-lateral cortex depends on Crumbs and Bazooka/Par3 and requires multiple domains within Cysts including the C-terminal region. Together, our findings indicate that Cysts links apical polarity proteins to Rho1 and myosin activation at adherens junctions to support junctional and epithelial integrity in the Drosophila ectoderm.

cell biology↗

bioRxiv2019

In vivo study of gene expression with an enhanced dual-color fluorescent transcriptional timer

Fluorescent transcriptional reporters are widely used as signaling reporters and biomarkers to monitor pathway activities and determine cell type identities. However, a large amount of dynamic information is lost due to the long half-life of the fluorescent proteins. To better detect dynamics, fluorescent transcriptional reporters can be destabilized to shorten their half-lives. However, applications of this approach in vivo are limited due to significant reduction of signal intensities. To overcome this limitation, we enhanced translation of a destabilized fluorescent protein and demonstrate the advantages of this approach by characterizing spatio-temporal changes of transcriptional activities in Drosophila. In addition, by combining a fast-folding destabilized fluorescent protein and a slow-folding long-lived fluorescent protein, we generated a dual-color transcriptional timer that provides spatio-temporal information about signaling pathway activities. Finally, we demonstrate the use of this transcriptional timer to identify new genes with dynamic expression patterns.

developmental biology↗