biostudies-literatureZhao YTNCATS NIH HHSNIDCR NIH HHSInstitute of Translational Health SciencesNHLBI NIH HHSNINDS NIH HHSNational Institute of Dental and Craniofacial ResearchNational Institutes of HealthNIGMS NIH HHSe53471https://www.ebi.ac.uk/biostudies/studies/S-EPMC8647152biostudies-literatureUnknown22(12)Angiopoietins 1 and 2 (Ang1 and Ang2) regulate angiogenesis through their similar F-domains by activating Tie2 receptors on endothelial cells. Despite the similarity in the underlying receptor-binding interaction, the two angiopoietins have opposite effects: Ang1 induces phosphorylation of AKT, strengthens cell-cell junctions, and enhances endothelial cell survival while Ang2 can antagonize these effects, depending on cellular context. To investigate the molecular basis for the opposing effects, we examined the phenotypes of a series of computationally designed protein scaffolds presenting the Ang1 F-domain in a wide range of valencies and geometries. We find two broad phenotypic classes distinguished by the number of presented F-domains: Scaffolds presenting 3 or 4 F-domains have Ang2-likEMBO reportsF-domain valency determines outcome of signaling through the angiopoietin pathway.PMC8647152TR002318R01GM097372P01 GM081619U01HL0999971P01GM0816195R21NS099654R21 NS099654R01 GM0973721R01NS118247R01 GM083867R01GM083867DE021984UO1HL099993T90 DE021984U01 HL099997TL1 TR002318U01 HL099993R01 NS118247Xavier Raj IRuohola-Baker HSomasundaram LXu CBaker DFallas JAZhao YTSaini SZhou ZSellers DLMathieu JWrenn SCarter LUeda GfalseF-domain valency determines outcome of signaling through the angiopoietin pathway.Angiopoietins 1 and 2 (Ang1 and Ang2) regulate angiogenesis through their similar F-domains by activating Tie2 receptors on endothelial cells. Despite the similarity in the underlying receptor-binding interaction, the two angiopoietins have opposite effects: Ang1 induces phosphorylation of AKT, strengthens cell-cell junctions, and enhances endothelial cell survival while Ang2 can antagonize these effects, depending on cellular context. To investigate the molecular basis for the opposing effects, we examined the phenotypes of a series of computationally designed protein scaffolds presenting the Ang1 F-domain in a wide range of valencies and geometries. We find two broad phenotypic classes distinguished by the number of presented F-domains: Scaffolds presenting 3 or 4 F-domains have Ang2-lik2021-01-01T00:00:00Z2021 Dec2026-05-29T18:52:42.118Z2024-12-04T08:20:18.751ZS-EPMC86471523469843310.15252/embr.202153471