Human Dentin Matrix Protein 1,DMP1 ELI

May have a dual function during osteoblast differentiation.

In the nucleus of undifferentiated osteoblasts, unphosphorylated form acts as a transcriptional component for activation of osteoblast-specific genes like osteocalcin.

During the osteoblast to osteocyte transition phase it is phosphorylated and exported into the extracellular matrix, where it regulates nucleation of hydroxyapatite.

{ECO:0000269|PubMed:12615915}.