title: The effect of carboxyl-terminal propeptide of type I collagen (c-propeptide) on collagen synthesis of preosteoblasts and osteoblasts.
abstract: Recently we found that the carboxyl-terminal propeptide of type I collagen (c-propeptide) is a major secretory protein of osteoblasts. Mature osteoblasts secreted 64 nM c-propeptide, and it was reported that 40 nM c-propeptide inhibited collagen synthesis at 80% of the control level. In this study, we investigated the effect of c-propeptide on collagen synthesis of preosteoblasts and osteoblasts, and found that preosteoblasts downregulated collagen synthesis by 40 nM c-propeptide, but osteoblasts were not affected by the same condition. When the binding activities of c-propeptide for preosteoblasts and osteoblasts were compared, osteoblasts showed weak affinity to c-propeptide compared with preosteoblasts, and the number of receptors for c-propeptide decreased in osteoblasts. These results imply that a decrease of receptors in osteoblasts might reduce the sensitivity of osteoblasts to c-propeptide.
authors.affiliation: Department of Biochemistry, School of Dentistry, Hokkaido University, Sapporo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Mizuno
authors.forename: R
authors.initials: R
authors.lastname: Fujisawa
authors.forename: Y
authors.initials: Y
authors.lastname: Kuboki
mesh_terms: D016475:3T3 Cells; D000818:Animals; D002454:Cell Differentiation; D003094:Collagen / Q000096:biosynthesis*; D017077:Culture Media, Conditioned; D051379:Mice; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism*; D011347:Procollagen / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*
chemical_list: D017077:Culture Media, Conditioned; D010446:Peptide Fragments; D011347:Procollagen; D011956:Receptors, Cell Surface; C042813:procollagen type I carboxy terminal peptide; D003094:Collagen