Bone Morphogenetic Protein-1: The Type I Procollagen C-Proteinase

TLDR

Bone morphogenetic proteins induce ectopic bone formation, and BMP‑1, a unique BMP‑1/TLD‑like protease, is implicated in developmental patterning and cleaves procollagen propeptides to produce extracellular matrix components. BMP‑1 and the procollagen C‑proteinase are identical, linking matrix‑deposition enzymes to genes involved in pattern formation.

Abstract

Bone morphogenetic proteins (BMPs) are bone-derived factors capable of inducing ectopic bone formation. Unlike other BMPs, BMP-1 is not like transforming growth factor-β (TGF-β), but it is the prototype of a family of putative proteases implicated in pattern formation during development in diverse organisms. Although some members of this group, such as Drosophila tolloid (TLD), are postulated to activate TGF-β-like proteins, actual substrates are unknown. Procollagen C-proteinase (PCP) cleaves the COOH-propeptides of procollagens I, II, and III to yield the major fibrous components of vertebrate extracellular matrix. Here it is shown that BMP-1 and PCP are identical. This demonstration of enzymatic activity for a BMP-1/TLD-like protein links an enzyme involved in matrix deposition to genes involved in pattern formation.