Bone morphogenetic protein receptor type-1B also known as CDw293 (cluster of differentiation w293) is a protein that in humans is encoded by the BMPR1B gene.[1] [2]
BMPR1B is a member of the bone morphogenetic protein (BMP) receptor family of transmembrane serine/threonine kinases. The ligands of this receptor are BMPs, which are members of the TGF-beta superfamily. BMPs are involved in endochondral bone formation and embryogenesis. These proteins transduce their signals through the formation of heteromeric complexes of 2 different types of serine (threonine) kinase receptors: type I receptors of about 50-55 kD and type II receptors of about 70-80 kD. Type II receptors bind ligands in the absence of type I receptors, but they require their respective type I receptors for signaling, whereas type I receptors require their respective type II receptors for ligand binding.[3]
The BMPR1B receptor plays a role in the formation of middle and proximal phalanges.[4]
Mutations in this gene have been associated with primary pulmonary hypertension.[3]
In the chick embryo, it has been shown that BMPR1B is found in precartilaginous condensations.[5] BMPR1B is the major transducer of signals in these condensations as demonstrated in experiments using constitutively active BMPR1B receptors.[5] BMPR1B is a more effective transducer of GDF5 than BMPR1A.[5] Unlike BMPR1A null mice, which die at an early embryonic stage, BMPR1B null mice are viable.[5]