Activin receptor type-1 (ACVR1)

On ligand binding, forms a receptor complex consisting of two type II and two type I transmembrane serine/threonine kinases. Type II receptors phosphorylate and activate type I receptors which autophosphorylate, then bind and activate SMAD transcriptional regulators.

Receptor for activin. May be involved for left-right pattern formation during embryogenesis (By similarity).