摘要 |
<p>Three genes encoding membrane-secreted proteins have been successfully isolated from osteoblast-like cell lines by using a method for specifically cloning membrane-secreted proteins. As the result of subsequent analysis on one of these genes, it has been found out that the protein encoded by this gene is a novel receptor protein which has an extracellular region alone, binds to cell membranes via a GPI anchor and carries therein a cysteine-rich repetitive region conserved in the TNF receptor super family. It has been also found out that when this protein is largely expressed in an osteoblast-like cell line, the proliferation of the cells are suppressed, the cells are morphologically changed, and the alkaline phosphatase activity which is one of the indications of the differentiation of osteoblasts is elevated.</p> |