PT - JOURNAL ARTICLE AU - Natasha I Edman AU - Rachel L Redler AU - Ashish Phal AU - Thomas Schlichthaerle AU - Sanjay R Srivatsan AU - Ali Etemadi AU - Seong J An AU - Andrew Favor AU - Devon Ehnes AU - Zhe Li AU - Florian Praetorius AU - Max Gordon AU - Wei Yang AU - Brian Coventry AU - Derrick R. Hicks AU - Longxing Cao AU - Neville Bethel AU - Piper Heine AU - Analisa Murray AU - Stacey Gerben AU - Lauren Carter AU - Marcos Miranda AU - Babak Negahdari AU - Sangwon Lee AU - Cole Trapnell AU - Lance Stewart AU - Damian C. Ekiert AU - Joseph Schlessinger AU - Jay Shendure AU - Gira Bhabha AU - Hannele Ruohola-Baker AU - David Baker TI - Modulation of FGF pathway signaling and vascular differentiation using designed oligomeric assemblies AID - 10.1101/2023.03.14.532666 DP - 2023 Jan 01 TA - bioRxiv PG - 2023.03.14.532666 4099 - http://biorxiv.org/content/early/2023/03/15/2023.03.14.532666.short 4100 - http://biorxiv.org/content/early/2023/03/15/2023.03.14.532666.full AB - Growth factors and cytokines signal by binding to the extracellular domains of their receptors and drive association and transphosphorylation of the receptor intracellular tyrosine kinase domains, initiating downstream signaling cascades. To enable systematic exploration of how receptor valency and geometry affects signaling outcomes, we designed cyclic homo-oligomers with up to 8 subunits using repeat protein building blocks that can be modularly extended. By incorporating a de novo designed fibroblast growth-factor receptor (FGFR) binding module into these scaffolds, we generated a series of synthetic signaling ligands that exhibit potent valency- and geometry-dependent Ca2+ release and MAPK pathway activation. The high specificity of the designed agonists reveal distinct roles for two FGFR splice variants in driving endothelial and mesenchymal cell fates during early vascular development. The ability to incorporate receptor binding domains and repeat extensions in a modular fashion makes our designed scaffolds broadly useful for probing and manipulating cellular signaling pathways.HighlightsDe novo designed cyclic oligomers with tunable geometric propertiesCyclic, homo-oligomeric FGFR binding modules induce geometry- and valency-dependent activity of isoform-specific FGF signalingModulation of FGFR isoform activity controls bifurcation of endothelial and mesenchymal fate during vascular developmentC-isoform activation favors arterial endothelial cell formation while B-isoform induces pericyte differentiationCompeting Interest StatementThe authors filed a patent application.