THE MODULAR ARCHITECTURE OF A NEW FAMILY OF GROWTH-REGULATORS RELATEDTO CONNECTIVE-TISSUE GROWTH-FACTOR

Recently, several groups have characterized and sequenced members of a new family of growth regulators (originally called cef10, connective tissue growth factor, fisp-12, cyr61, or, alternatively, betaIG-M1 and betaIG-M2), all of which belong to immediate-early genes expressed af ter induction by growth factors or certain oncogenes. Sequence analysi s of this family revealed the presence of four distinct modules. Each module has homologues in other extracellular mosaic proteins such as V on Willebrand factor, slit, thrombospondins, fibrillar collagens, IGF- binding proteins and mucins. Classification and analysis of these modu les suggests the location of binding regions and, by analogy to better characterized modules in other proteins, sheds some light onto the st ructure of this new family.