protein_function: Type I receptor for TGF-beta family ligands BMP9,GDF2and BMP10 and important regulator of normal blood vesseldevelopment. On ligand binding, forms a receptor complexconsisting of two type II and two type I transmembraneserine,threonine kinases. Type II receptors phosphorylate andactivate type I receptors which autophosphorylate, then bind andactivate SMAD transcriptional regulators. May bind activin aswell..
Serine,threonine-protein kinase receptor R3 is an enzyme that in humans is encoded by the ACVRL1 gene. It is also known as activin receptor-like kinase 1, or ALK1. This gene encodes a type I cell-surface receptor for the TGF-beta superfamily of ligands. It shares with other type I receptors a high degree of similarity in serine-threonine kinase subdomains, a glycine- and serine-rich region (called the GS domain) preceding the kinase domain, and a short C-terminal tail. The encoded protein shares similar domain structures with other closely related ALK or activin receptor-like kinase proteins that form a subfamily of receptor serine,threonine kinases. Mutations in this gene are associated with hemorrhagic telangiectasia type 2, also known as Rendu-Osler-Weber syndrome 2.