BMP Signaling Pathway_Aravind Reddy Tarugu

Bone morphogenetic proteins (BMPs) are members of the transforming growth factor-β (TGF-β) superfamily proteins. Primarily discovered for their ability to induce bone formation, they are now known to mediate embryogenesis, osteogenesis, skeletogenesis, cellular differentiation, organogenesis, etc., by regulating the expression of specific target genes—BMPs signal via the canonical, SMAD-dependent pathway or numerous non-canonical pathways. In the SMAD-dependent, BMPs initiate the signal transduction by interacting with type II and type I receptors, causing their hetero-tetrameric-complexation. The type II receptor phosphorylates the type I receptor, which then phosphorylates the R-SMADs (SMAD1/5/8). Phosphorylated R-SMADs (SMAD1/5/8) associate with common-mediator SMAD (Co SMAD) such as SMAD4 and translocate into the nucleus, where it binds with respective coactivators or corepressors to regulate target gene expression.