Activin types I and II receptor domain (IPR000472)

Short name: Activin_recp

Overlapping homologous superfamilies


Domain relationships



This is a hydrophilic cysteine-rich ligand-binding domain found in both TGF-beta receptor types (type I and II). In both types, this domain posses a 9 amino acid cysteine box, with the the consensus CCX{4-5}CN. The type I receptors also possess 7 extracellular residues preceding the cysteine box [PMID: 9309176, PMID: 8299934, PMID: 8397373].

The Transforming growth factor-beta superfamily of ligands include: bone morphogenetic proteins (BMPs), growth and differentiation factors (GDFs), anti-mullerian hormone (AMH), activin, nodal and TGF-beta. Signalling begins with the binding of a TGF-beta superfamily ligand to a TGF-beta type II receptors. The type II receptors phosphorylate and activate type I receptors which autophosphorylate, then bind and activate SMAD transcriptional regulators [PMID: 9759503].

The receptors for most of the members of this growth factor family are related. They are receptor-type kinases of Ser/Thr type, which have a single transmembrane domain and a specific hydrophilic Cys-rich ligand-binding domain [PMID: 9023056, PMID: 8047140, PMID: 8909794].

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0004675 transmembrane receptor protein serine/threonine kinase activity

Cellular Component

GO:0016020 membrane

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.