Seitenhistorie

Bone Morphogenetic Proteins (BMPs) are a family of ligands that belong to the Transforming Growth Factor β (TGFβ) superfamily (Ref). They were originally recognized for their ability to induce endochondral bone formation (Ref).

...

Processing

Like all members of the TGFβ superfamily, BMPs are expressed as long precursor proteins, carrying an N-terminal signal peptide, a prodomain and the C-terminal mature peptide. The signal peptide directs the protein to the secretory pathway, while the prodomain mediates proper folding (Ref). BMP monomers are stabilized by a structure known as cystine knot motif: six highly conserved cysteines form three intramolecular disulfide bonds. BMPs are typically secreted as homomeric dimers. Stabilization of the dimer is mediated through an additional cysteine bridge, requiring a seventh cysteine within each monomer (Ref, Ref). Some members of the BMP family, e.g. GDF3 (Ref), GDF9 (Ref), and GDF9B (BMP15; Ref) lack the seventh cysteine. However, they are biologically active and may form non-covalent dimers (Ref). Furthermore, several studies report that BMP heterodimers are more potent than their corresponding homodimers (Ref). The secretion of heterodimers was observed for BMP4/7 (Ref, Ref, Ref), BMP2/5 (Ref), BMP2/6 (Ref), BMP2/7 (Ref), BMP15/GDF9 (Ref), and BMP2b/7 (Ref). Serine endoproteases cleave the proprotein within the trans-Golgi network, producing the mature protein that is subsequently secreted (Ref). For some BMPs, e.g. BMP7 (OP1; Ref) and GDF8 (Myostatin; Ref) the proregion was shown to remain attached to the mature protein even after secretion.

...

Table: Binding affinities of BMP family ligands to BMP receptors.

a) BMPs

...

Estimation of binding affinities:
n/a, none, very weak (kD > 1µM), weak (kD 1µM - 100nM), medium (kD 99nM - 50nM), solid (kD 49 -10nM), strong (kD 10nM - 0.5nM), very strong (kD < 0.5nM)

Comment: Please correct the given values!

...

Further reading: