BMPR1B also known as bone morphogenetic protein receptor type-1B isoform b. BMPR1B is on ligand binding, forms a receptor complex consisting of two type II and two type I transmembrane serine/threonine kinases. Type II receptors phosphorylate and activate type I receptors which autophosphorylate, then bind and activate SMAD transcriptional regulators. It's receptor for BMP7/OP-1 and GDF5. Recombinant human BMPR1B was expressed in E.coli and purified by using conventional chromatography techniques