| First Author | Ravindran S | Year | 2012 |
| Journal | Histochem Cell Biol | Volume | 138 |
| Issue | 1 | Pages | 113-25 |
| PubMed ID | 22527697 | Mgi Jnum | J:316597 |
| Mgi Id | MGI:6840169 | Doi | 10.1007/s00418-012-0952-1 |
| Citation | Ravindran S, et al. (2012) Expression and distribution of grp-78/bip in mineralizing tissues and mesenchymal cells. Histochem Cell Biol 138(1):113-25 |
| abstractText | Glucose-regulated protein 78 (GRP-78) is one of the many endoplasmic reticulum chaperone proteins that have been shown to possess multifunctional roles. We have previously demonstrated that GRP-78 functions as a receptor for dentin matrix protein 1 (DMP1) and is required for DMP1-mediated calcium release; that it is a secreted protein and can bind to type I collagen and DMP1 extracellularly and aid in the nucleation of calcium phosphate. We provide evidence in this study that tyrosine phosphorylation is required for DMP1/GRP-78-mediated calcium release in mesenchymal cells. We further demonstrate that GRP-78 is localized in the nucleus of mesenchymal cells and that the cell surface GRP-78 is not associated with the G-protein Galphaq in mesenchymal cells. Results from this study show that during development of mineralized tissues, increased expression of GRP-78 can be observed in condensing cartilage and mesenchymal cells of the alveolar bone, endochondral bone and dental pulp. Additionally, we show that GRP-78 is present in the mineralizing matrices of teeth, bone and in the extracellular matrix of differentiating human marrow stromal cells and dental pulp stem cells. Collectively, our observations provide a new perspective on GRP-78 with respect to mineralized matrix formation. |
