Members of the BMP family were originally found to induce bone formation, as their name suggests. However, BMPs are very multifunctional and can also regulate apoptosis, cell migration, cell division, and differentiation. They also specify the anterior/posterior axis, induce growth, and regulate homeostasis.
The BMPs bind to the bone morphogenetic protein receptor type II (BMPR2). Some of the proteins of the BMP family are BMP4 and BMP7. BMP4 promotes bone formation, causes cell death, or signals the formation of epidermis, depending on the tissue it is acting on. BMP7 is crucial for kidney development, sperm synthesis, and neural tube polarization. Both BMP4 and BMP7 regulate mature ligand stability and processing, including degrading ligands in lysosomes. BMPs act by diffusing from the cells that create them.