Expression of SIBLINGs and their partner MMPs in salivary glands.
Three members of the SIBLING family of integrin-binding phosphoglycoproteins (bone sialoprotein, BSP; osteopontin, OPN; and dentin matrix protein-1, DMP1) were recently shown to bind with high affinity (nM) and to activate 3 different matrix metalloproteinases (MMP-2, MMP-3, and MMP-9, respectively) in vitro. The current study was designed to document the possible biological relevance of the SIBLING-MMP activation pathway in vivo by showing that these 3 SIBLINGs and their known MMP partners are co-expressed in normal adult tissue. BSP, OPN, and DMP1 were invariably co-expressed with their partner MMPs in salivary glands of humans and mice. The 2 SIBLING proteins without known MMP partners, dentin sialophosphoprotein (DSPP) and matrix extracellular phosphoglycoprotein (MEPE), were also expressed in salivary glands. Expression of all SIBLINGs in this normal, non-mineralizing epithelial tissue suggests that they serve at least one function in vivo other than directly promoting matrix mineralization--a function we hypothesize involves local activation of MMPs.
Ogbureke
K U E
KU
Craniofacial and Skeletal Diseases Branch, Building 30, Room 228, National Institute of Dental and Craniofacial Research, National Institutes of Health, DHHS, 9000 Rockville Pike, Bethesda, MD 20892-4320, USA.
Fisher
L W
LW
D000328:Adult; D000818:Animals; D000911:Antibodies, Monoclonal; D002448:Cell Adhesion; D016326:Extracellular Matrix Proteins / Q000032:analysis*; D006023:Glycoproteins / Q000032:analysis; D006801:Humans; D007124:Immunoenzyme Techniques; D058574:Integrin-Binding Sialoprotein; D020778:Matrix Metalloproteinase 2 / Q000032:analysis; D019278:Matrix Metalloproteinase 3 / Q000032:analysis; D020780:Matrix Metalloproteinase 9 / Q000032:analysis; D020782:Matrix Metalloproteinases / Q000032:analysis*; D051379:Mice; D053495:Osteopontin; D010750:Phosphoproteins / Q000032:analysis*; D011498:Protein Precursors / Q000032:analysis; D011506:Proteins / Q000032:analysis*; D018987:Salivary Ducts / Q000166:cytology / Q000201:enzymology / Q000378:metabolism; D012469:Salivary Glands / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D012795:Sialoglycoproteins / Q000032:analysis*; D014157:Transcription Factors; D000099311:Dentin Sialophosphoprotein
D000911:Antibodies, Monoclonal; D016326:Extracellular Matrix Proteins; D006023:Glycoproteins; D058574:Integrin-Binding Sialoprotein; D020778:Matrix Metalloproteinase 2; D019278:Matrix Metalloproteinase 3; D020780:Matrix Metalloproteinase 9; D020782:Matrix Metalloproteinases; D053495:Osteopontin; D010750:Phosphoproteins; D011498:Protein Precursors; D011506:Proteins; D012795:Sialoglycoproteins; D014157:Transcription Factors; D000099311:Dentin Sialophosphoprotein; C513309:DMP1 protein, human; C513308:Dmp1 protein, mouse; C102116:Dmtf1 protein, mouse; C546871:IBSP protein, human; C546872:Ibsp protein, mouse; C546873:Ibsp protein, rat; C486579:MEPE protein, human; C506895:SPP1 protein, human; C506896:Spp1 protein, mouse; C506897:Spp1 protein, rat