Specific expression of BMP2/4 ortholog in biomineralizing tissues of corals and action on mouse BMP receptor

Abstract

Bone morphogenetic proteins (BMPs) are members of the transforming growth factor β superfamily, and have been identified by their ability to induce bone formation in vertebrates. The biomineral-forming process, called biomineralization, is a widespread process, present in all kingdoms of living organisms and among which stony corals are one of the major groups of calcifying animals. Here, we report the presence of a BMP2/4 ortholog in eight species of adult corals. The synthesis of such a protein by the calcifying epithelium of corals suggests that coral BMP2/4 plays a role in skeletogenesis, making BMP the first common protein involved in biomineralization among Eumetazoans. In addition we show that recombinant coral BMP2/4 is able to inhibit human BMP2-induced osteoblastic differentiation in mesenchymal C2C12 cells. We suggest that this inhibition results from a competition between coral BMP2/4 and human BMP2, indicating conservation of binding affinity of BMP and its receptor during evolution from corals to vertebrates. Further studies are needed to understand interactions between coral BMP2/4 and its receptors, and, thus, the action of BMP2/4 in adult corals. © 2008 Springer Science+Business Media, LLC.