Predicted to enable SMAD binding activity and transforming growth factor beta receptor activity, type I. Acts upstream of or within several processes, including artery morphogenesis; blood vessel endothelial cell migration; and determination of ventral identity. Predicted to be located in membrane. Predicted to be part of BMP receptor complex. Predicted to be active in plasma membrane. Is expressed in cardiovascular system and liver. Used to study arteriovenous malformation. Human ortholog(s) of this gene implicated in hereditary hemorrhagic telangiectasia and pulmonary hypertension. Orthologous to human ACVRL1 (activin A receptor like type 1).