The activin A receptor also known as ACVR1C or ALK-7 is a protein that in humans is encoded by the ACVR1C gene. ACVR1C is a type I receptor for the TGFB family of signaling molecules.
ACVR1C transduces signals of Nodal. Nodal binds to ACVR2B and then forms a complex with ACVR1C. These go on to recruit the R-SMADs SMAD2 or SMAD3.
Upon ligand binding, type I receptors phosphorylate cytoplasmic SMAD family transcription factors, which then translocate to the nucleus and interact directly with DNA or in complex with other transcription factors.