RUFFLED BORDER CHLORIDE CHANNEL: REGULATION AND CLONING

描述(来自申请者的逐字)：骨骼的持续翻转是 保持骨骼完整性所必需的。骨的周转是通过 破骨细胞的吸收和成骨细胞的合成。当这两个人 过程是不平衡的，严重的病理通常结果，例如。 骨质疏松。破骨细胞体积大，终末分化，多核。 单核细胞系的细胞，通过附着在骨上而局部吸收骨 表面，酸化封闭的再吸收空间以溶解矿物和 分泌酸性水解酶进入空隙以消化有机骨基质。这个 调控骨吸收的分子基础尚不清楚，但重要步骤 包括破骨细胞数量和排酸率。在其早期 吸收周期，破骨细胞增加皱纹边缘的表达 质子泵。然而，电生v-H+-ATPase的酸分泌是有限的 没有短路电流路径。我的实验室已经确定， 外向整流型氯化物的鉴定、纯化和部分克隆 通道，Cl.62，这是有效分泌酸性物质所必需的 破骨细胞。Cl.62的表达与破骨细胞 吸收骨。因此，Clor.62活性的表达和调控是 这项提案的重点。癌基因src对破骨细胞是必不可少的。 骨吸收表型。我实验室的研究表明，src SH2和SH3 域绑定Clor.62。在培养的小鼠骨髓细胞中，我们观察到 依赖于OPGL(158-315)的Cl.62表达，这是HCl所必需的 分泌物。我们的假设是src和OPGL(恍惚)在 Cl.62的晚期表达，这是HCl分泌所必需的。我们 建议开展研究，通过以下方式阐明Cl.62表达的分子基础 破骨细胞以支持骨吸收中盐酸的分泌。

DESCRIPTION (Verbatim from the Applicant): A constant turnover of bone is required to maintain skeletal integrity. Bone turnover is accomplished with resorption by osteoclasts and synthesis by osteoblasts. When these two processes are not balanced, severe pathology commonly results, e.g. osteoporosis. Osteoclasts are large, terminally differentiated, multinucleated cells of monocytic lineage that resorb bone locally by attaching to the bone surface, acidifying the enclosed resorption space to dissolve mineral and secreting acid hydrolases into the space to digest the organic bone matrix. The molecular basis for regulating bone resorption is unknown, but important steps include the number of osteoclasts and the rate of acid secretion. Early in its resorption cycle, the osteoclast increases expression of the ruffled border proton pump. However, acid secretion by an electrogenic v-H+-ATPase is limited without a short circuit current pathway. My laboratory has identified, characterized, purified and partially cloned an outwardly rectifying chloride channel, Clor.62, that is required for the effective secretion of acid by osteoclasts. Expression of Clor.62 coincides with the ability of osteoclasts to resorb bone. Therefore, the expression and regulation of Clor.62 activity is the focus of this proposal. The oncogene src is essential to the osteoclast bone resorbing phenotype. Work in my laboratory has shown that src SH2 and SH3 domains bind Clor.62. In cultured mouse bone marrow cells, we have observed OPGL(158-315)-dependent Clor.62 expression, which is required for HCl secretion. Our hypothesis is that src and OPGL (TRANCE) are important in the late stage expression of Clor.62, which is required for HCl secretion. We propose studies to clarify the molecular basis for Clor.62 expression by osteoclasts in order to support HCl secretion in bone resorption.