Transforming growth factor beta-2 proprotein (IPR003940)

Short name: TGFb2

Overlapping homologous superfamilies


Family relationships


The transforming growth factors-beta constitute a family of multi-functional cytokines that regulate cell growth and differentiation [PMID: 8424942]. Many cells synthesise TGF-beta, and essentially all have specific receptors for this peptide [PMID: 2879635]. TGF-beta regulates the actions of many other peptide growth factors and determines a positive or negative direction of their effects.

The protein functions as a disulphide-linked homodimer. Its sequence is characterised by the presence of several C-terminal cysteine residues, which form interlocking disulphide links arranged in a knot-like topology. A similar "cystine-knot" arrangement has been noted in the structures of some enzyme inhibitors and neurotoxins that bind to voltage-gated Ca2+ channels, although the precise topology differs.

The three-dimensional structures of several members of the TGF-beta super-family have been deduced [PMID: 8819159, PMID: 8679613, PMID: 1631557]. TGF-beta genes are expressed differentially, suggesting that the various TGF- beta species may have distinct physiological roles in vivo.

The complete amino acid sequence of human beta 2 transforming growth factor (hTGF-beta 2) has been determined by automated Edman degradation [PMID: 2879635]. Human TGF-beta 2 consists of 2 identical disulphide-linked subunits that share a high degree of similarity with the functionally related TGF-beta 1, and reveal lower levels of similarity to porcine inhibins and activins, the C-terminal regions of human Mullerian inhibiting substance, and the putative decapentaplegic gene complex protein of Drosophila melanogaster.

The crystal structure of the TGF-beta 2 monomer lacks a well-defined hydrophobic core and displays an unusual elongated non-globular fold [PMID: 1631557]. Eight cysteine residues form 4 intra-chain disulphide bonds, creating the characteristic knotted arrangement. The dimer is stabilised by a ninth cysteine, which forms an inter-chain disulphide bond, and by 2 identical hydrophobic interfaces. Other members of the TGF-beta superfamily, including activins, inhibins and various developmental factors, are also likely to adopt the TGF-beta fold.

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0005160 transforming growth factor beta receptor binding

Cellular Component

No terms assigned in this category.

Contributing signatures

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