RUFFLED BORDER CHLORIDE CHANNEL: REGULATION AND CLONING

描述（来自申请人的逐字记录）：骨的恒定周转是 维持骨骼完整性所必需的。骨转换是通过 破骨细胞的吸收和成骨细胞的合成。当这两 过程是不平衡的，严重的病理结果通常，例如， 骨质疏松破骨细胞体积大，终末分化，多核 通过附着于骨而局部吸收骨的单核细胞谱系细胞 酸化封闭的再吸收空间以溶解矿物质， 分泌酸性水解酶进入该空间以消化有机骨基质。的 调节骨吸收的分子基础尚不清楚，但重要的步骤 包括破骨细胞的数量和酸分泌的速率。会早期阶段 在骨吸收周期中，破骨细胞增加皱褶边缘的表达， 质子泵然而，产电v-H+-ATP酶的酸分泌是有限的 而没有短路电流路径。我的实验室已经确认， 经表征、纯化和部分克隆， 通道，Clor.62，这是所需的有效分泌的酸， 破骨细胞Clor.62的表达与破骨细胞的能力一致， 再吸收骨因此，Clor.62活性的表达和调节是 这一提案的重点。癌基因src对破骨细胞是必需的 骨吸收表型我的实验室工作表明src SH 2和SH 3 结构域结合Clor.62。在培养的小鼠骨髓细胞中，我们观察到 OPGL（158-315）依赖性Clor.62表达，这是HCl所必需的 分泌物我们的假设是src和OPGL（TRANCE）在 Clor.62的晚期表达，这是HCl分泌所需的。我们 提出研究，以澄清Clor.62表达的分子基础， 破骨细胞以支持骨吸收中的HCl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.