Albrecht Douglas E, Sherman Diane L, Brophy Peter J, Froehner Stanley C
Department of Physiology and Biophysics, University of Washington, 1959 NE Pacific St, Box 357290, Seattle WA 98195-7290, USA
Glia. 2008 Apr 15;56(6):611-8. doi: 10.1002/glia.20636.
Cytoskeletal scaffolding complexes help organize specialized membrane domains with unique functions on the surface of cells. In this study, we define the scaffolding potential of the Schwann cell dystrophin glycoprotein complex (DGC) by establishing the presence of four syntrophin isoforms, (alpha1, beta1, beta2, and gamma2), and one dystrobrevin isoform, (alpha-dystrobrevin-1), in the abaxonal membrane. Furthermore, we demonstrate the existence of two separate DGCs in Schwann cells that divide the abaxonal membrane into spatially distinct domains, the DRP2/periaxin rich plaques and the Cajal bands that contain Dp116, utrophin, alpha-dystrobrevin-1 and four syntrophin isoforms. Finally, we show that the two different DGCs can scaffold unique accessory molecules in distinct areas of the Schwann cell membrane. Specifically, the cholesterol transporter ABCA1, associates with the Dp116/syntrophin complex in Cajal bands and is excluded from the DRP2/periaxin rich plaques.
细胞骨架支架复合物有助于在细胞表面组织具有独特功能的特化膜结构域。在本研究中，我们通过确定轴突外膜中存在四种肌养蛋白异构体（α1、β1、β2和γ2）和一种肌营养不良蛋白结合蛋白异构体（α-肌营养不良蛋白结合蛋白-1），来定义施万细胞肌营养不良蛋白糖蛋白复合物（DGC）的支架潜力。此外，我们证明了施万细胞中存在两种独立的DGC，它们将轴突外膜分隔成空间上不同的结构域，即富含DRP2/外周蛋白的斑块和包含Dp116、抗肌萎缩蛋白、α-肌营养不良蛋白结合蛋白-1和四种肌养蛋白异构体的卡哈尔带。最后，我们表明这两种不同的DGC可以在施万细胞膜的不同区域支架独特的辅助分子。具体而言，胆固醇转运蛋白ABCA1与卡哈尔带中的Dp116/肌养蛋白复合物相关联，并被排除在富含DRP2/外周蛋白的斑块之外。
