Abstract
Ameloblastin, the most abundant nonamelogenin enamel matrix protein, plays a role in ameloblast differentiation. Here, we found that ameloblastin was expressed in osteosarcoma cells; to explore the potential functions of ameloblastin in osteoblasts, we investigated whether this protein is involved in osteogenic differentiation and bone formation on the premise that CD63, a member of the transmembrane-4 glycoprotein superfamily, interacts with integrins in the presence of ameloblastin. Ameloblastin bound to CD63 and promoted CD63 binding to integrin β1. The interaction between CD63 and integrin β1 induced Src kinase inactivation via the binding of CD63 to Src. The reduction of Src activity and osteogenic differentiation mediated by ameloblastin were abrogated by treatment with anti-CD63 antibody and overexpression of constitutively active Src, respectively. Therefore, our results suggest that ameloblastin is expressed in osteoblasts and functions as a promoting factor for osteogenic differentiation via a novel pathway through the interaction between CD63 and integrin β1.
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Animals
-
Antigens, CD / genetics
-
Antigens, CD / metabolism*
-
Base Sequence
-
Cell Line
-
Cell Line, Tumor
-
Cells, Cultured
-
DNA Primers / genetics
-
Dental Enamel Proteins / genetics
-
Dental Enamel Proteins / metabolism*
-
Humans
-
Integrin beta1 / metabolism*
-
Minerals / metabolism
-
Models, Biological
-
Osteoblasts / cytology
-
Osteoblasts / metabolism
-
Osteogenesis / physiology*
-
Osteosarcoma / genetics
-
Osteosarcoma / metabolism
-
Osteosarcoma / pathology
-
Platelet Membrane Glycoproteins / antagonists & inhibitors
-
Platelet Membrane Glycoproteins / genetics
-
Platelet Membrane Glycoproteins / metabolism*
-
RNA, Small Interfering / genetics
-
Rats
-
Recombinant Proteins / genetics
-
Recombinant Proteins / metabolism
-
Signal Transduction
-
Tetraspanin 30
-
src-Family Kinases / antagonists & inhibitors*
-
src-Family Kinases / metabolism
Substances
-
AMBN protein, human
-
Ambn protein, rat
-
Antigens, CD
-
CD63 protein, human
-
Cd63 protein, rat
-
DNA Primers
-
Dental Enamel Proteins
-
Integrin beta1
-
Minerals
-
Platelet Membrane Glycoproteins
-
RNA, Small Interfering
-
Recombinant Proteins
-
Tetraspanin 30
-
src-Family Kinases