Modulation of FGF pathway signaling and vascular differentiation using designed oligomeric assemblies

Area of Science:

• Molecular biology
• Cell signaling
• Developmental biology

Background:

• Growth factors and cytokines activate cellular signaling pathways through receptor binding and tyrosine kinase domain phosphorylation.
• Understanding how receptor valency and geometry influence signaling outcomes is crucial for deciphering complex biological processes.

Purpose of the Study:

• To design and create synthetic signaling ligands with controlled valency and geometry.
• To investigate the impact of these designed ligands on fibroblast growth factor receptor (FGFR) signaling pathways.
• To elucidate the roles of specific FGFR splice variants in early vascular development.

Main Methods:

• Construction of cyclic homo-oligomeric protein scaffolds with up to 8 subunits.
• Incorporation of a de novo-designed fibroblast growth factor receptor (FGFR)-binding module.
• Assessment of calcium (Ca2+) release and mitogen-activated protein kinase (MAPK) pathway activation in response to designed ligands.

Main Results:

• Designed cyclic homo-oligomers demonstrated potent valency- and geometry-dependent Ca2+ release and MAPK pathway activation.
• High specificity of the designed agonists identified distinct roles for two FGFR splice variants.
• Demonstrated influence of FGFR signaling on arterial endothelium and perivascular cell fates during early vascular development.

Conclusions:

• Modular protein assemblies provide a versatile platform for exploring receptor signaling dynamics.
• Designed synthetic ligands offer precise control over signaling pathways, enabling the study of developmental processes.
• This approach holds promise for unraveling signaling complexities and developing novel therapeutic strategies.