Bone morphogenetic proteins (BMPs) were first identified as molecules that can induce ectopic bone and cartilage formation (1,2). BMPs belongs to the TGF-beta superfamily, playing many diverse functions during development (3). BMPs are synthesized as precursor proteins and then processed by cleavage to release the c-terminal mature BMP. BMPs initiate signaling by binding to a receptor complex containing type I and type II serine/threonine receptor kinases that then phosphorylate Smad (mainly Smad1, 5 and 8), resulting the translocation of Smad into the nucleus. BMP was also reported to activate MAPK pathways in some systems (3,4). BMP4 plays an essential role during development. Mouse embyros deficient in BMP4 die around the time of gastrulation (5). BMP4 regulates stem cell maintenance and differentiation in various systems (6-8).
Intended for research use only. Not for use in human, therapeutic, or diagnostic applications.