Biology subjects

Goletz, S.

Publications and source records attributed to Goletz, S..

6 recordsLinked to original sources

bioRxiv2026

BNIP3L/NIX-mediated mitophagy limits Alzheimer disease pathology and preserves neuronal function

Defective mitophagy is emerging as a key contributor to Alzheimer disease (AD), but the neuronal pathways governing mitochondrial clearance and their contribution to disease progression remain poorly understood. Here, we identify BNIP3L/NIX-dependent mitophagy as a conserved neuronal quality control pathway that maintains mitochondrial fitness and constrains AD-associated proteotoxicity. Loss of BNIP3L/NIX or its C. elegans orthologue DCT-1 impaired basal and stressed-induced mitophagy, disrupted mitochondrial homeostasis, enhanced Tau and Amyloid-beta pathology and compromised neuronal network, synaptic and behavioral function across human neuronal and in vivo models. Conversely, restoring BNIP3L/NIX and DCT-1 activity improved neuronal function under proteotoxic stress in vivo, reduced disease-associated Tau phosphorylation in human neurons and markedly suppressed seeded Tau aggregation in primary mouse neurons. Together, these findings identify BNIP3L/NIX-mediated mitophagy as a mechanistic link between mitochondrial quality control, proteostasis and neuronal function, and establish its restoration as a potential strategy for counteracting AD-associated pathology.

cell biology↗

bioRxiv2026

In Vitro Assessment of chemically-modified probiotics astoxin decoys for cholera infections

Gastrointestinal infections remain a major cause of morbidity and mortality worldwide. Conventional antibiotic treatment can be ineffective or inappropriate in some settings, particularly in the context of increasing antimicrobi-al resistance. In many enteric infections, an early step in pathogenesis involves binding of pathogens or their toxins to oligosaccharide receptors on host-cell surfaces, making these interactions attractive targets for antimicrobial strategies that do not rely on conventional antibiotics. Here, we developed a non-recombinant, microbiome-based chemical engineering approach in which cholesteryl-peptides serve as flexible chemical scaffolds for displaying GM1 receptor mimics on probiotic bacteria. The GM1-cholesteryl-peptides generated surface-accessible GM1 on both the Gram-positive probiotic Lactobacillus reuteri DSM 17938 and the Gram-negative probiotic Escherichia coli Nissle 1917. The resulting GM1-decorated bacteria showed concentration-dependent binding and sequestration of cholera toxin B subunit (CTB) in vitro and reduced CTB binding to Vero cells. These findings establish an in vitro proof-of-concept for a modular, non-recombinant bacterial decoy platform and may provide a basis for the future development of receptor-mimic strategies against toxin-mediated gastrointestinal infections.

bioengineering↗

bioRxiv2026

Development and Characterisation of a Versatile Single-Domain Antibody Specific for M1-linked Ubiquitin Chains

Ubiquitin signalling is mediated by structurally distinct polyubiquitin chains that encode discrete cellular functions. Progress in deciphering this ubiquitin code, particularly for the less abundant atypical chain types, has been hindered by limited availability of versatile chain type-specific affinity reagents. Here, we demonstrate that human single-domain antibodies (sdAbs) provide a versatile scaffold for the generation of ubiquitin linkage-specific binders. Using phage display and synthetic human sdAb libraries, we identified 2A6, an sdAb that specifically recognises methionine-1 (M1)-linked ubiquitin chains. To our knowledge, 2A6 represents the first reported sdAb with specificity for a defined homotypic ubiquitin chain linkage. 2A6 bound M1-linked ubiquitin chains with nanomolar affinity and was specific for M1-linked chains at the level of both diubiquitin and long polyubiquitin chains. AlphaFold3 modelling, supported by saturation mutagenesis, predicted that 2A6 recognises the proximal and distal ubiquitin moieties together with the region near the M1 linkage. Functionally, 2A6 enabled specific detection and enrichment of M1-linked ubiquitin across multiple applications, including ELISA, immunoblotting, immunoprecipitation under semi-denaturing conditions, substrate ubiquitination analysis, and immunofluorescence microscopy. The sdAb can be readily produced in E. coli from a single expression plasmid, providing a tractable, cost-effective and versatile reagent for investigating M1-linked ubiquitin signalling. Our work establishes sdAbs as a versatile scaffold for ubiquitin linkage-specific affinity reagents, providing a framework for the development of analogous binders specifically targeting additional ubiquitin linkages or architectures.

biochemistry↗

bioRxiv2026

Glycoengineering of extracellular vesicles enhances cellular uptake and cargo delivery to target cells

The glycocalyx is a major regulator of membrane recognition, yet its specific influence on extracellular vesicles (EVs) cellular uptake remains poorly defined. We established a genetic glycoengineering platform to systematically investigate how the major glycan classes on small EVs (sEVs) modulate cell interactions and functional cargo delivery. Using an isogenic panel of HEK293F lines lacking distinct glycan biosynthetic pathways, we find that removing glycosaminoglycans ({Delta}GAG-sEVs) yields a strong increase in cellular uptake and delivery of diverse cargos, including DNA oligonucleotides, siRNA, proteins, and plasmid DNA. Glycan-modified recipient cells show that sEV-cell communication and internalization is jointly governed by glycan features on both membranes. {Delta}GAG-sEVs strongly improve gene delivery and expression in recipient cells and in a physiologically relevant human airway epithelial model. These findings establish glycan structures as tunable regulators of sEV uptake and position {Delta}GAG-sEVs as potent vehicles for improved drug delivery and gene therapy.

bioengineering↗

bioRxiv2025

Antibody-based signal amplification for single-cell proteomics by mass spectrometry

Single-cell proteomics by mass spectrometry (scp-MS) detects thousands of proteins per cell, yet low-abundant proteins routinely detected by antibody-based methods are challenging to quantify in the single-cell proteome. To address this, we developed antibody peptide tags (AbTags) - MS detectable tandem peptide barcodes coupled to antibodies which provide signal amplification, enable absolute quantification, and are quantified alongside endogenous proteomes by scp-MS. As proof-of-concept, AbTags quantify cytokine-induced PDL1 expression, undetectable by scp-MS.

systems biology↗

bioRxiv2025

Multi-omics analysis of keratinocytes reveals dermokine-dependent regulation of cell-cell adhesion via p120

Loss of keratinocyte differentiation is a leading cause in several skin diseases and needs to be controlled in adult homeostasis by for instance growth factors and proteases. Among them, we studied the role of isoform-rich dermokine - a wound- and tumour-related matrix metalloproteinase 10 substrate - via functional multi-omics. We generated dermokine isoform-dependent keratinocyte knockouts and three dimensional (3D) organotypic skin cultures and analyzed changes in their proteome and phosphoproteome by quantitative mass spectrometry. Through functional in vitro assays, we demonstrate that in the absence of dermokine-isoforms, p120 phosphorylation increases while cell-cell adhesion decreases in keratinocytes. Furthermore, we validate the link between decreased dermokine expression and phosphorylated p120-mediated adhesion in non-healing wounds samples derived from patients. Our data reveal a novel dermokine-p120-dependent cell-cell adhesion phenotype in keratinocytes and improve our understanding of wound-edge keratinocytes, expanding the hypothesis that dysregulated wounds resemble cancer.

cell biology↗