Biology subjects

Roschitzki, B.

Publications and source records attributed to Roschitzki, B..

5 recordsLinked to original sources

bioRxiv2025

Lysosomal escape and TMEM106B fibrillar core determine TDP-43 seeding outcomes

Frontotemporal lobar degeneration with TDP-43 inclusions (FTLD-TDP) shows striking clinical and neuropathological heterogeneity, yet a systematic analysis of subtype-specific features and inter-patient variability was missing. We treated human neurons and neuron-like cells with 30 postmortem brain samples and quantified neoaggregate formation, loss of function and changes in the TDP-43 interactome to define determinants of seeding outcomes. Potent FTLD-TDP-A seeds drove a progressive collapse of physiological TDP-43 interactions accompanied by functional loss. Beyond the burden of pathological TDP-43, we identified the fibrillar core of the lysosomal protein TMEM106B as a critical pro-seeding factor. Transient lysosomal injury markedly enhanced neoaggregation and loss of function, likely by promoting fibril interactions with native TDP-43. Our work establishes a mechanistic link between TMEM106B and TDP-43 aggregation, identifies lysosomal escape as a key driver of pathology and introduces the strongest model yet for seeded TDP-43 aggregation and loss of function, to enable discovery of disease modifiers.

neuroscience↗

bioRxiv2024

Quantitative proteome of bacterial periplasmic predation reveals a prey damaging protease

The rise of antimicrobial resistant pathogens calls for novel ways to kill and damage bacteria. A rich source for bacterial cell-damaging proteins is periplasmic predatory bacterium Bdellovibrio bacteriovorus, which invades, kills and subsequently exits the Gram-negative prey cell. An increased understanding of predatory protein function can be achieved by analyzing their relative abundance at key stages of predation. Here, we present the first quantitative proteome covering the complete predatory life cycle of the bacterial predator B. bacteriovorus killing Escherichia coli, quantifying 2195 predator proteins. From these proteins, nine protein clusters sharing similar expression patterns were identified. Towards the end of the life cycle when the predator exits prey remnants, we identified significant amounts of protease Bd2269. Gene knockout and heterologous expression experiments revealed that Bd2269 is involved in the prey exit process and damages E. coli from within. This quantitative predator proteome is a valuable resource to unravel bacterial predator-prey interactions and advances the search for novel antimicrobial enzymes.

microbiology↗

bioRxiv2020

Diurnal Dynamics of the Arabidopsis Rosette Proteome and Phosphoproteome

Plant growth depends on the diurnal regulation of cellular processes, but it is not well understood if and how transcriptional regulation controls diurnal fluctuations at the protein-level. Here we report a high-resolution Arabidopsis thaliana (Arabidopsis) leaf rosette proteome acquired over a 12 h light : 12 h dark diurnal cycle and the phosphoproteome immediately before and after the light-to-dark and dark-to-light transitions. We quantified nearly 5000 proteins and 800 phosphoproteins, of which 288 fluctuated in their abundance and 226 fluctuated in their phosphorylation status. Of the phosphoproteins, 60% were quantified for changes in protein abundance. This revealed six proteins involved in nitrogen and hormone metabolism that had concurrent changes in both protein abundance and phosphorylation status. The diurnal proteome and phosphoproteome changes involve proteins in key cellular processes, including protein translation, light perception, photosynthesis, metabolism and transport. The phosphoproteome at the light-dark transitions revealed the dynamics at phosphorylation sites in either anticipation of or response to a change in light regime. Phosphorylation site motif analyses implicate casein kinase II and calcium/calmodulin dependent kinases among the primary light-dark transition kinases. The comparative analysis of the diurnal proteome and diurnal and circadian transcriptome established how mRNA and protein accumulation intersect in leaves during the diurnal cycle of the plant. Summary StatementThe manuscript provides quantitative information of diurnal changes in the accumulation and phosphorylation of proteins in Arabidopsis thaliana rosettes grown in a 12 h photoperiod. The highly resolved time-scale of the datasets offer new proteome-level insights for future targeted studies.

plant biology↗

bioRxiv2018

Engineered Peptide Barcodes for In-Depth Analyses of Binding Protein Ensembles

Binding protein generation relies on laborious screening cascades that process candidate molecules individually. To break with this paradigm, we developed NestLink, a binder selection and identification technology able to biophysically characterize thousands of library members at once without handling individual clones at any stage of the process. NestLink builds on genetically fused barcoding peptides, termed flycodes, which are designed for maximal detectability by mass spectrometry and serve as unique molecular identifiers for accurate deep sequencing. We applied NestLink to overcome current limitations of binder generation. Rare binders against an integral membrane protein were identified directly in the cellular environment of a human pathogen. Hundreds of binder candidates were simultaneously ranked according to kinetic parameters. Adverse effects of target immobilization were overcome by selecting nanobodies against an ABC transporter entirely in solution. NestLink may provide a basis for the selection of tailored binder characteristics directly in tissues or in living organisms.

bioengineering↗

bioRxiv2017

Rats and axolotls share a common molecular signature after spinal cord injury enriched in collagen-1

Spinal cord injury (SCI) in mammals leads to irreversible tissue damage and loss of function. In contrast, axolotls are able to regenerate scar-free the injured spinal cord. To explore new pathological mechanisms, we compared rat versus axolotl transcriptomics and isolated genes shared between species post-SCI. Unexpectedly, multiple transcripts involved in extracellular matrix remodelling, in particular collagen-1, were upregulated in both species after SCI. Proteomics validated persistent expression of the collagen-enriched matrix signature at the protein level. Collagen-1 accumulated in early and advanced rat lesions. Importantly, collagen-1 was likely associated with pathological vascular remodelling rather than classic fibrosis and the transcription factor SP1 was predicted and validated to regulate, at least in part, the expression of collagen-1 in rat lesions.

pathology↗