Dentin matrix acidic phosphoprotein is an extracellular
matrix protein and a member of the small integrin binding ligand
N-linked glycoprotein family. This protein, which is critical for
proper mineralization of bone and dentin, is present in diverse
cells of bone and tooth tissues. The protein contains a large
number of acidic domains, multiple phosphorylation sites, a
functional arg-gly-asp cell attachment sequence, and a DNA binding
domain. In undifferentiated osteoblasts it is primarily a nuclear
protein that regulates the expression of osteoblast-specific genes.
During osteoblast maturation the protein becomes phosphorylated and
is exported to the extracellular matrix, where it orchestrates
mineralized matrix formation. Mutations in the gene are known to
cause autosomal recessive hypophosphatemia, a disease that
manifests as rickets and osteomalacia. The gene structure is
conserved in mammals. Two transcript variants encoding different
isoforms have been described for this gene.
