Osteopontin, a substrate for transglutaminase and factor XIII activity.
Osteopontin (OPN), an extracellular matrix cell adhesion protein, was found to serve as a substrate for the incorporation of radiolabelled putrescine mediated by a commercial preparation of guinea pig liver transglutaminase. Preliminary evidence also suggests that OPN serves as a substrate for the plasma transglutaminase, Factor XIIIa. While the protein substrates to which OPN is linked in vivo have not been identified, it is reasonable to speculate that this capacity of OPN may dictate its extracellular location and thereby affect its role in bone homeostasis, tumorigenesis, metastasis, resistance to bacterial infections or, perhaps, wound repair.
Department of Nutrition Sciences, University of Alabama, Birmingham 35294.
C W
CW
Prince
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Dickie
C L
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Krumdieck
D000595:Amino Acid Sequence; D000818:Animals; D001842:Bone and Bones / Q000378:metabolism; D002417:Cattle; D005176:Factor XIII / Q000378:metabolism*; D006168:Guinea Pigs; D006801:Humans; D008099:Liver / Q000201:enzymology; D008969:Molecular Sequence Data; D008970:Molecular Weight; D053495:Osteopontin; D010750:Phosphoproteins / Q000378:metabolism; D051381:Rats; D012689:Sequence Homology, Nucleic Acid; D012795:Sialoglycoproteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D013379:Substrate Specificity; D011503:Transglutaminases / Q000378:metabolism*
D010750:Phosphoproteins; C506895:SPP1 protein, human; D012795:Sialoglycoproteins; C506897:Spp1 protein, rat; D053495:Osteopontin; D005176:Factor XIII; D011503:Transglutaminases