Localization of Kv1.5 channels in rat and canine myocyte sarcolemma
Localization of Kv1.5 channels in rat and canine myocyte sarcolemma
复制标题
DOI：
10.1016/j.febslet.2006.09.069
复制
发表时间：
2006-11-13
期刊：
影响因子：
3.5
通讯作者：
Fedida, David
中科院分区：
文献类型：
--
作者：
Eldstrom, Jodene;Van Wagoner, David R.;Fedida, David
电压门控钾（Kv）通道亚型定位于许多细胞类型的质膜和肌细胞中的肌膜。由于许多信号分子集中在质膜的亚结构域，Kv通道定位于这些位点可能对通道功能和调节具有重要意义。在这项研究中，协会的电压门控钾通道Kv1.5与特定亚型的脂筏，小窝，在大鼠和犬心肌细胞进行了研究。在免疫共沉淀实验中，很容易检测到小窝蛋白-3和β-肌营养不良蛋白聚糖或eNOS之间的相互作用，以及Kv1.5和α-辅肌动蛋白之间的相互作用，而Kv1.5和小窝蛋白-3之间没有明显的关联。宽视野显微镜和去卷积技术显示，KvI.5与小窝蛋白-3的共定位百分比在大鼠和犬心脏的心房肌细胞中极低（分别为8 +/- 1%和12.2 +/-2%），在心室肌细胞中有限（大鼠和犬分别为11 +/- 4%和20 +/- 3%）。大鼠心房和心室组织的免疫电镜成像显示，Kv1.5和小窝蛋白-3标记一般不重叠。在稳定表达通道的REK 293细胞中，KvI.5不与漂浮蛋白一起沿着靶向低浮力密度筏部分，而是与非筏相关的转铁蛋白受体一起沿着分级。总之，这些结果表明，Kv1.5是不存在于大鼠和犬心脏的小窝。(c)2006年欧洲生物化学学会联合会。Elsevier B. V.出版，保留所有权利。
Voltage-gated potassium (Kv) channel subtypes localize to the plasma membrane of a number of cell types, and the sarcolemma in myocytes. Because many signaling molecules concentrate in subdomains of the plasma membrane, the localization of Kv channels to these sites may have important implications for channel function and regulation. In this study, the association of the voltage-gated potassium channel Kv1.5 with a specific subtype of lipid rafts, caveolae, in rat and canine cardiac myocytes has been investigated. Interactions between caveolin-3 and beta-dystroglycan or eNOS, as well as between KvI.5 and alpha-actinin were readily detected in co-immunoprecipitation experiments, whereas no association between Kv1.5 and caveolin-3 was evident. Wide-field microscopy and deconvolution techniques revealed that the percent co-localization of KvI.5 with caveolin-3 was extremely low in atrial myocytes from rat and canine hearts (8 +/- 1% and 12.2 +/- 2%, respectively), and limited in ventricular myocytes (11 +/- 4% and 20 +/- 3% in rat and canine, respectively). Immunoelectron microscopic imaging of rat atrial and ventricular tissues showed that Kv1.5 and caveolin-3 labeling generally did not overlap. In REK293 cells stably expressing the channel, KvI.5 did not target to the low buoyant density raft fraction along with flo-tillin but instead fractionated along with the non-raft associated transferrin receptor. Taken together, these results suggest that Kv1.5 is not present in caveolae of rat and canine heart. (c) 2006 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.