The bone morphogenetic protein I/Tolloid-like metalloproteinases

A decade ago, bone morphogenetic protein 1 (BMP1) was shown to provide the activity necessary for proteolytic removal of the C-propeptides of procollagens I-III: precursors of the major fibrillar collagens. Subsequent studies have shown BMP1 to be the prototype of a small group of extracellular metalloproteinases that play manifold roles in regulating formation of the extracellular matrix (ECM). Soon after initial cloning of BMP1, genetic studies showed the related Drosophila proteinase Tolloid (TLD) to be necessary for the formation of the dorsal-ventral axis in early embryogenesis. It is now clear that the BMP1/TLD-like protemases, conserved in species ranging from Drosophila to humans, act in dorsal-ventral patterning via activation of transforming growth factor beta (TGF beta)-like proteins BMP2, BMP4 (vertebrates) and decapentaplegic (arthropods). More recently, it has become apparent that the BMP1/TLD-like protemases are activators of a broader subset of the TGF beta superfamily of proteins, with implications that these protemases may be key in orchestrating the fort-nation of ECM with growth factor activation and BMP signaling in morphogenetic processes. (c) 2007 Elsevier B.V./International Society of Matrix Biology. All rights reserved.