Project description:To understand gene regulation and function requires a genome-wide method capable of capturing both gene expression levels and isoform diversity at the single-cell level.
Project description:LNPs have been demonstrated to hold great promise for the clinical advancement of RNA therapeutics. Continued exploration of LNPs for application in new disease areas requires identification and optimisation of leads in a high throughput way. Currently available high throughput in vivo screening platforms are well suited to screen for cellular uptake but less so for functional cargo delivery. We report on a platform which measures functional delivery of LNPs using unique peptide ‘barcodes’. We describe the design and selection of the peptide barcodes and the evaluation of these for the screening of LNPs. We show that proteomic analysis of peptide barcodes correlates with quantification and efficacy of barcoded reporter proteins both in vitro and in vivo and, that the ranking of selected LNPs using peptide barcodes in a pool correlates with ranking using alternative methods in groups of animals treated with individual LNPs. We show that this system is sensitive, selective, and capable of reducing the size of an in vivo study by screening up to 10 unique formulations in a single pool, thus accelerating the discovery of new technologies for mRNA delivery.
Project description:Chemokine receptors (CKRs), a class of G protein-coupled receptors (GPCRs), interact with transducers like G proteins and β-arrestins. Many chemokines act as “biased agonists” that activate certain transducers over others. There has been limited success in pharmacologically targeting CKRs, with little evidence that differential receptor phosphorylation, or “phosphorylation barcodes,” direct biased responses. Here, we used mass spectrometry to demonstrate that CXCR3 chemokines generate different phosphorylation barcodes associated with differential activation of transducers. Chemokine stimulation resulted in distinct changes throughout the kinome in global phosphoproteomic studies. Mutation of CXCR3 phosphosites altered β-arrestin conformation and activation in molecular dynamics simulations. T-cells expressing phosphorylation-deficient CXCR3 mutants resulted in agonist- and receptor-specific chemotactic profiles not completely explained by engagement of G proteins and β-arrestins. Our results demonstrate that CXCR3 chemokines act as biased agonists through differential encoding of phosphorylation barcodes, and highlight the limitations of assessing GPCR physiology with proximal effector activity alone.
Project description:Using microfluidics, well-defined barcodes were generated on the slide surface by cross-amplification, followed by high-throughput sequencing using Novaseq to detect spatial transcriptomic information in the mouse brain.