On ligand binding, ALKs family form 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. ALK2 is receptor for activin. ALK3 is receptor for BMP-2 and BMP-4. May be involved for left-right pattern formation during embryogenesis By similarity.
 DeltaNp63alpha-mediated activation of bone morphogenetic protein signaling governs stem cell activity and plasticity in normal and malignant mammary epithelial cells.
Balboni, A. L., et al. (2013). Cancer Res 73(2): 1020-1030.. [ 23243027 ]