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Fetuin and alpha-2HS glycoprotein induce alkaline phosphatase in epiphyseal growth plate chondrocytes.
- Source :
-
Journal of cellular physiology [J Cell Physiol] 1991 Nov; Vol. 149 (2), pp. 222-34. - Publication Year :
- 1991
-
Abstract
- A previously described chondrocyte alkaline phosphatase induction factor (CAP-IF) for chicken epiphyseal growth plate chondrocytes has been purified to SDS-PAGE homogeneity from fetal bovine serum by ammonium sulfate precipitation and by dye-ligand affinity (Affi-Gel Blue and Reactive Green-19 agarose) and hydroxyapatite column chromatographies. As determined by immunoprecipitation of [35S]methionine-labeled cellular proteins after 3 day treatment, this highly purified CAP-IF increases the level of AP and certain other membrane proteins 2- to 3-fold over control values. The pure protein of apparent 64.5 kDa molecular weight has been identified as fetuin by N-terminal amino acid sequencing. This was confirmed by the finding that high alkaline phosphatase (AP)-inducing activity is present in fetuin prepared by the Spiro method. However, fetuins prepared by the Pedersen or Deutsch procedures are inactive. At least half of the CAP-IF activity of fetuin was irreversibly destroyed by treatment with EDTA and addition of Zn2+ did not reactivate the EDTA-treated fetuin. Ascorbate synergistically enhanced the effect of fetuin on chondrocyte AP activity by over 8-fold during 3 day exposure. Because of the very high homology between fetuin and the A-chain of alpha 2-HS glycoprotein, we also tested and found that alpha 2HS glycoproteins from human serum and bovine bone are both strong AP inducers. Our findings suggest that the AP-inducing activity resides in a labile, cystatin/Zn(2+)-binding domain common to these related serum glycoproteins. These proteins appear to play a role in enhancing AP expression in normal growth plate cartilage differentiation.
- Subjects :
- Amino Acid Sequence
Animals
Ascorbic Acid pharmacology
Chickens
Drug Synergism
Enzyme Induction
Membrane Proteins biosynthesis
Molecular Sequence Data
Phosphatidylinositols metabolism
alpha-Fetoproteins isolation & purification
Alkaline Phosphatase biosynthesis
Fibronectins pharmacology
Growth Plate enzymology
alpha-Fetoproteins pharmacology
Subjects
Details
- Language :
- English
- ISSN :
- 0021-9541
- Volume :
- 149
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- Journal of cellular physiology
- Publication Type :
- Academic Journal
- Accession number :
- 1721070
- Full Text :
- https://doi.org/10.1002/jcp.1041490208