title: Primary structure and phosphorylation of dentin matrix protein 1 (DMP1) and dentin phosphophoryn (DPP) uniquely determine their role in biomineralization.
abstract: The SIBLING (small integrin-binding ligand N-linked glycoproteins) family is the major group of noncollagenous proteins in bone and dentin. These extremely acidic and highly phosphorylated extracellular proteins play critical roles in the formation of collagenous mineralized tissues. Whereas the lack of individual SIBLINGs causes significant mineralization defects in vivo, none of them led to a complete cessation of mineralization suggesting that these proteins have overlapping functions. To assess whether different SIBLINGs regulate biomineralization in a similar manner and how phosphorylation impacts their activity, we studied the effects of two SIBLINGs, dentin matrix protein 1 (DMP1) and dentin phosphophoryn (DPP), on mineral morphology and organization in vitro. Our results demonstrate distinct differences in the effects of these proteins on mineralization. We show that phosphorylation has a profound effect on the regulation of mineralization by both proteins. Specifically, both phosphorylated proteins facilitated organized mineralization of collagen fibrils and phosphorylated DMP1-induced formation of organized mineral bundles in the absence of collagen. In summary, these results indicate that the primary structure and phosphorylation uniquely determine functions of individual SIBLINGs in regulation of mineral morphology and organization.
authors: Department of Oral Biology, Center for Craniofacial Regeneration, University of Pittsburgh School of Dental Medicine, McGowan Institute for Regenerative Medicine, Pittsburgh, Pennsylvania, United States.
authors: Atul Suresh
authors: AS
authors: Deshpande
authors: Ping-An
authors: PA
authors: Fang
authors: Xiaoyuan
authors: X
authors: Zhang
authors: Thottala
authors: T
authors: Jayaraman
authors: Charles
authors: C
authors: Sfeir
authors: Elia
authors: E
authors: Beniash
mesh_terms: D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D016326:Extracellular Matrix Proteins / Q000737:chemistry* / Q000378:metabolism; D051379:Mice; D046529:Microscopy, Electron, Transmission; D010750:Phosphoproteins / Q000737:chemistry* / Q000378:metabolism; D010766:Phosphorylation; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D012795:Sialoglycoproteins / Q000737:chemistry* / Q000378:metabolism; D000099311:Dentin Sialophosphoprotein
chemical_list: D016326:Extracellular Matrix Proteins; D010750:Phosphoproteins; D011994:Recombinant Proteins; D012795:Sialoglycoproteins; D000099311:Dentin Sialophosphoprotein; C513308:Dmp1 protein, mouse