Search bioRxiv⌕ Search

Biology subjects

Lind, N. A.

Publications and source records attributed to Lind, N. A..

2 recordsLinked to original sources

Modified tau leads to neuronal and global ribosome dysfunction in C. elegans model of tauopathy

Alzheimers disease (AD) is a neurodegenerative disease characterized by an early loss of memory formation which requires protein synthesis. Tau is an intrinsically disordered protein and is subject to extensive post-translational modifications (PTMs). Some PTMs have been shown to alter localization of tau and allow tau to disrupt protein translation. Protein interactome studies indicate that tau might interact with ribosomal proteins. Therefore, we hypothesized that tau is causing ribosomal dysfunction as an early event and this interaction is dependent on taus PTMs. To test this, we used a C. elegans strain expressing single copy insertion of human tau as well as two of the most frequent modified versions of tau in mechanosensory neurons. With our assay to measure translation, we showed that in our T231 phosphorylation mimetic strain, there was a significant decrease in neuronal translation. This mimetic strain also showed a significant decrease in median lifespan and locomotion. Unexpectedly, in all our Tau-expressing strains, we detected a significant decrease in whole worm translation, suggesting a possible role of tau to influence translation in other tissues in worm. Our in vitro, in vivo and ex vivo efforts to demonstrate tau-ribosome association via fluorescent polysome profiling have shown that there is no direct association between tau and the ribosome. Ribosome dysfunction caused by modified tau could be an early event in AD pathology before the pathological hallmarks appear.

neuroscience↗

Catalytic degradation of circulating targets with FcRn-mediated cycling LYTACs

Circulating proteins are common targets for the discovery of occupancy-based inhibitors including monoclonal antibodies. Effective inhibition of target pathogenicity with blocking approaches, however, is often challenged by target parameters that lead to insufficient occupancy and/or incomplete pharmacology limited by only single site binding. Extracellular targeted protein degradation approaches, such as lysosomal targeting chimeras (LYTACs), offer an opportunity to minimize these challenges by an event-driven mechanism that selectively, thoroughly and irreversibly eliminates drivers of disease. First generation LYTACs, designed to traffic to the lysosome, show limited durability since the therapeutic is degraded along with the target protein of interest. Here we describe cataLYTACs, which overcome this limitation by combining stabilized asialoglycoprotein (ASGPR) ligands, pH-sensitive target binding and recycling via the neonatal Fc receptor (FcRn). These cataLYTACs degraded superstoichiometric levels of a target protein, IgE, in vitro and demonstrated deep and sustained clearance of human IgE in mouse models. In non-human primates, cataLYTACs resulted in >98% clearance of circulating endogenous IgE for 2 weeks and outperformed the standard of care blocking antibody, omalizumab (Xolair(R)), in both free IgE elimination and duration of action. CataLYTACs represent a new therapeutic modality for a wide range of disease states driven by circulating factors, with the potential for superior efficacy and duration of action compared to traditional inhibitors.

cell biology↗