| First Author | Rifas L | Year | 1997 |
| Journal | Calcif Tissue Int | Volume | 61 |
| Issue | 3 | Pages | 256-9 |
| PubMed ID | 9262518 | Mgi Jnum | J:57350 |
| Mgi Id | MGI:1344324 | Doi | 10.1007/s002239900331 |
| Citation | Rifas L, et al. (1997) Skeletal casein kinase activity defect in the HYP mouse. Calcif Tissue Int 61(3):256-9 |
| abstractText | The Hyp mouse, a model for human X-linked hypophosphatemia (XLH), is characterized by phosphate wasting and defective mineralization. Since osteopontin (OPN) is considered pivotal for biological mineralization, we examined the biosynthesis of OPN in osteoblasts of +/Y and Hyp/Y mice. Immunoprecipitation analyses using a specific antibody to OPN revealed that Hyp/Y and +/Y osteoblasts secrete similar levels of OPN as determined by [35S]-methionine biosynthetic labeling, but a reduced phosphorylation was noted after 32P-PO4 biosynthetic labeling. Northern blot hybridization analysis of +/Y and Hyp/Y mice osteoblast mRNAs, using a cDNA probe for mouse OPN, revealed no difference in the steady state levels of osteopontin mRNA. Analysis of casein kinase II activity in +/Y and Hyp/Y mice osteoblast, kidney, heart and liver membrane fractions revealed that casein kinase II activity in the Hyp/Y mice osteoblasts and kidney is only 35%-50%, respectively, of that of the +/Y mice tissues. The accumulated data are consistent with a post-translation defect in the Hyp/Y mouse osteoblast which results in the under-phosphorylation of osteopontin and subsequent under-mineralization of bone matrix. |
