Ozawa Eijiro, Mizuno Yuji, Hagiwara Yasuko, Sasaoka Toshikuni, Yoshida Mikiharu
National Institute of Neuroscience, National Center of Neurology and Psychiatry, Ogawahigashi-cho, Kodaira, Tokyo, Japan.
Muscle Nerve. 2005 Nov;32(5):563-76. doi: 10.1002/mus.20349.
The original sarcoglycan (SG) complex has four subunits and comprises a subcomplex of the dystrophin-dystrophin-associated protein complex. Each SG gene has been shown to be responsible for limb-girdle muscular dystrophy, called sarcoglycanopathy (SGP). In this review, we detail the characteristics of the SG subunits, and the mechanism of the formation of the SG complex and various molecules associated with this complex. We discuss the molecular mechanisms of SGP based on studies mostly using SGP animal models. In addition, we describe other SG molecules, epsilon- and zeta-SGs, with special reference to their expression and roles in vascular smooth muscle, which are currently in dispute. We further consider the maternally imprinted nature of the epsilon-SG gene. Finally, we stress that the SG complex cannot work by itself and works in a larger complex system, called the transverse fixation system, which forms an array of molecules responsible for various muscular dystrophies.
原始肌聚糖（SG）复合体有四个亚基，是肌营养不良蛋白 - 肌营养不良蛋白相关蛋白复合体的一个亚复合体。每个SG基因都已被证明与肢带型肌营养不良症有关，称为肌聚糖病（SGP）。在这篇综述中，我们详细阐述了SG亚基的特征、SG复合体的形成机制以及与该复合体相关的各种分子。我们基于大多使用SGP动物模型的研究来讨论SGP的分子机制。此外，我们描述了其他SG分子，即ε-和ζ-SG，特别提及它们在血管平滑肌中的表达和作用，目前这方面存在争议。我们进一步探讨了ε-SG基因的母系印记性质。最后，我们强调SG复合体自身无法发挥作用，而是在一个更大的复合体系统中发挥作用，这个系统称为横向固定系统，它形成了一系列负责各种肌营养不良症的分子阵列。
