Interaction between vacuolar H+-ATPase and microfilaments during osteoclast activation
Interaction between vacuolar H+-ATPase and microfilaments during osteoclast activation
复制标题
DOI：
10.1074/jbc.274.41.29164
复制
发表时间：
1999-10-08
影响因子：
4.8
通讯作者：
Holliday, LS
中科院分区：
文献类型：
--
作者：
Lee, BS;Gluck, SL;Holliday, LS
液泡H ~+-ATP酶（V-ATP酶）是一种多亚基酶，能酸化所有真核细胞液泡系统的各个部分。在破骨细胞中，降解骨的细胞，V-ATP酶，从细胞内膜区室被募集到皱褶膜（质膜的专门结构域），在那里它们被维持在高密度，用于酸化骨上破骨细胞附着位点处的再吸收湾（Blair，H. C，，Teitelbaum，S. L，，Ghiselli，R.，和Gluck，S. L.（1989）Science 249，855-857）。在这里，我们描述了一种新的机制，参与控制骨吸收细胞的活动。体外培养的破骨细胞中的V-ATP酶与肌动蛋白和肌球蛋白II形成一种不溶于洗涤剂的复合物，通过V-ATP酶与肌动蛋白丝的直接结合。将骨髓细胞接种到牙本质切片上，这是一种激活破骨细胞再吸收的生理刺激，通过共免疫沉淀和免疫细胞化学共定位破骨细胞中的肌动蛋白丝和V-ATP酶来测定，在V-ATP酶与肌动蛋白的结合中产生了深刻的变化。小鼠骨髓和牛肾V-ATP酶直接结合兔肌F-肌动蛋白，最大化学计量比为1 mol V-ATP酶/8 mol F-肌动蛋白，表观亲和力为0.05 μ M。负染色样品的电子显微镜检查证实了结合相互作用。这些发现将V-ATP酶的转运与破骨细胞活化过程中肌动蛋白细胞骨架的重组联系起来。
Vacuolar H+-ATPases (V-ATPases) are multisubunit enzymes that acidify compartments of the vacuolar system of all eukaryotic cells. In osteoclasts, the cells that degrade bone, V-ATPases, are recruited from intracellular membrane compartments to the ruffled membrane, a specialized domain of the plasma membrane, where they are maintained at high densities, serving to acidify the resorption bay at the osteoclast attachment site on bone (Blair, H. C,, Teitelbaum, S. L,, Ghiselli, R., and Gluck, S. L. (1989) Science 249, 855-857). Here, we describe a new mechanism involved in controlling the activity of the bone-resorptive cell. V-ATPase in osteoclasts cultured in vitro was found to form a detergent-insoluble complex with actin and myosin II through direct binding of V-ATPase to actin filaments. Plating bone marrow cells onto dentine slices, a physiologic stimulus that activates osteoclast resorption, produced a profound change in the association of the V-ATPase with actin, assayed by coimmunoprecipitation and immunocytochemical colocalization of actin filaments and V-ATPase in osteoclasts. Mouse marrow and bovine kidney V-ATPase bound rabbit muscle F-actin directly with a maximum stoichiometry of 1 mol of V-ATPase per 8 mol of F-actin and an apparent affinity of 0.05 mu M. Electron microscopy of negatively stained samples confirmed the binding interaction. These findings link transport of V-ATPase to reorganization of the actin cytoskeleton during osteoclast activation.