TGF-beta receptor family

See also: TGF beta receptor and TGFβ signaling pathway

The transforming growth factor beta (TGFβ) receptors are a family of serine/threonine kinase receptors involved in TGF beta signaling pathway. These receptors bind growth factor and cytokine signaling proteins in the TGF-beta family such as TGFβs (TGFβ1, TGFβ2, TGFβ3), bone morphogenetic proteins (BMPs), growth differentiation factors (GDFs), activin and inhibin, myostatin, anti-Müllerian hormone (AMH), and NODAL.^[1]

Ser/Thr protein kinase, TGFB receptor
Identifiers
Symbol	TGFb_receptor
InterPro	IPR000333
SCOP2	1B6C / SCOPe / SUPFAM
Membranome	1216

TGFβ family receptors

TGFβ family receptors are grouped into three types, type I, type II, and type III. There are seven type I receptors, termed the activin-like receptors (ALK1–7), five type II receptors, and one type III receptor, for a total of 13 TGFβ superfamily receptors.^[2][3] In the transduction pathway, ligand-bound type II receptors activate type I receptors by phosphorylation, which then autophosphorylate and bind SMAD.^[4] The Type I receptors have a glycine-serine (GS, or TTSGSGSG) repeat motif of around 30 AA, a target of type II activity. At least three, and perhaps four to five of the serines and threonines in the GS domain, must be phosphorylated to fully activate TbetaR-1.^[5]

Type I

Transforming growth factor beta type I GS-motif
Identifiers
Symbol	TGF_beta_GS
Pfam	PF08515
InterPro	IPR003605
Available protein structures: Pfam   structures / ECOD   PDB RCSB PDB; PDBe; PDBj PDBsum structure summary

• ALK1 (ACVRL1)
• ALK2 (ACVR1A)
• ALK3 (BMPR1A)
• ALK4 (ACVR1B)
• ALK5 (TGFβR1)
• ALK6 (BMPR1B)
• ALK7 (ACVR1C)

Type II

• TGFβR2
• BMPR2
• ACVR2A
• ACVR2B
• AMHR2 (AMHR)

Type III

Unlike the Type I and II receptors which are kinases, TGFBR3 has a Zona pellucida-like domain. Its core domain binds TGF-beta family ligands and its heparan sulfate chains bind bFGF. It acts as a reservoir of ligand for TGF-beta receptors.^[6][7]

• TGFβR3 (β-glycan)