DMP-1 is a member of the SIBLING (small integrin-binding ligand, N-linked glycoprotein) family of ECM molecules. It is produced by osteoblasts and is found both intracellularly and extracellularly. Intracellularly, it exists in the nucleus where it acts as a transcriptional regulator. Following osteoblast activation, DMP-1 undergoes Ca2+-mediated phosphorylation, which induces its secretion into the ECM. There, it participates in mineralized matrix formation.