A MAMMALIAN SERINE THREONINE KINASE RECEPTOR SPECIFICALLY BINDS BMP-2AND BMP-4

Bone morphogenetic proteins (BMPs) are a class of related growth and d ifferentiation factors within the TGF-beta superfamily of proteins whi ch are known to induce cartilage and bone formation in adult animals a nd to be involved in many inductive events throughout embryonic develo pment. Here we describe the molecular cloning and characterization of a mammalian receptor, CFK-43a, which specifically binds BMP-2 and BMP- 4. This molecule is a member of the serine/threonine kinase receptor f amily which includes receptors for other TGF-beta superfamily members. CFK-43a binds other BMP family members with lower affinity, but does not bind TGF-beta. During embryogenesis, in situ hybridization analysi s indicates that CFK-43a mRNA is localized in developing skeletal tiss ues in a complementary fashion to the transcripts for its ligands. (C) 1994 Academic Press, Inc.