Identification of Osteoblast/Osteocyte Factor 45 (OF45), a Bone-specific cDNA Encoding an RGD-containing Protein That Is Highly Expressed in Osteoblasts and Osteocytes
| Autor: | George T. Tkalcevic, Thomas A. Brown, Donna N. Petersen, Ramon Rivera-Gonzalez, Amy L. Mansolf |
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| Rok vydání: | 2000 |
| Předmět: |
Molecular Sequence Data
Osteocalcin Bone Marrow Cells Osteocytes Biochemistry Bone and Bones Bone remodeling Nucleotidases Complementary DNA medicine Animals Amino Acid Sequence RNA Messenger Cloning Molecular Molecular Biology Cells Cultured Glycoproteins Extracellular Matrix Proteins Osteoblasts Base Sequence Sequence Homology Amino Acid Tibia Chemistry Gene Expression Profiling Cell Differentiation Osteoblast Cell Biology Phosphoproteins Immunohistochemistry Molecular biology Rats Bone morphogenetic protein 7 medicine.anatomical_structure Organ Specificity Suppression subtractive hybridization Osteocyte MEPE Protein Expression Analysis Oligopeptides |
| Zdroj: | Journal of Biological Chemistry. 275:36172-36180 |
| ISSN: | 0021-9258 |
| Popis: | We describe the cloning and characterization of a novel bone-specific cDNA predicted to encode an extracellular matrix protein. This cDNA was identified by subtractive hybridization based upon its high expression in bone marrow-derived osteoblasts. By Northern blot analysis, we detected a single 2-kilobase mRNA transcript in bone, whereas no expression was detected in other tissues. Immunohistochemistry revealed that the protein was expressed highly in osteocytes within trabecular and cortical bone. RNA and protein expression analysis using in vivo marrow ablation as a model of bone remodeling demonstrated that this gene was expressed only in cells that were embedded within bone matrix in contrast to the earlier expression of known osteoblast markers. The cDNA was predicted to encode a serine/glycine-rich secreted peptide containing numerous potential phosphorylation sites and one RGD sequence motif. The interaction of RGD domain-containing peptides with integrins has been shown previously to regulate bone remodeling by promoting recruitment, attachment, and differentiation of osteoblasts and osteoclasts. Secretion of this RGD-containing protein from osteocytes has the potential to regulate cellular activities within the bone environment and thereby may impact bone homeostasis. We propose the name OF45 (osteoblast/osteocyte factor of 45 kDa) for this novel cDNA. |
| Databáze: | OpenAIRE |
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