Tanaka H, Ishiguro T, Eguchi C, Saito K, Ozawa E
National Institute of Neuroscience NCNP, Tokyo, Japan.
Histochemistry. 1991;96(1):1-5. doi: 10.1007/BF00266753.
We previously reported that a protein which has immunological cross-reactivity with and a molecular weight similar to dystrophin, the Duchenne muscular dystrophy (DMD) gene product, is expressed on the muscle cell membrane (Tanaka et al. 1989b). To examine if this is the translation product of the autosomal transcript with homology to dystrophin mRNA identified by Love et al. (1989), we raised an antibody (PDRP) against a synthetic peptide corresponding to the putative protein (DRP) and examined its expression and cellular localization in human and murine skeletal muscle samples. In immunoblotting, PDRP stained a band with a similar molecular weight to dystrophin in samples from DMD and Becker muscular dystrophy (BMD) patients and control (non-DMD/BMD) human. PDRP was expected not to cross-react with dystrophin because the antigenic peptide was not homologous to dystrophin. In fact, PDRP did not cross-react with dystrophin present in a BMD patient. Immunohistochemically, PDRP stained the muscle cell membrane in samples from DMB and BMD patients and from mdx mice. Only a slight staining was observed in muscles from control human and wild type mice. Our results confirm the presence of DRP in human and murine skeletal muscles, and further demonstrate that it is localized on the cell membrane. The abundance of DRP in dystrophin deficient muscles might be related to some compensatory mechanisms.
我们之前报道过，一种与杜兴氏肌营养不良症（DMD）基因产物肌营养不良蛋白具有免疫交叉反应性且分子量相似的蛋白质，在肌细胞膜上表达（Tanaka等人，1989b）。为了检验这是否是Love等人（1989）鉴定出的与肌营养不良蛋白mRNA具有同源性的常染色体转录本的翻译产物，我们针对对应于假定蛋白质（DRP）的合成肽制备了一种抗体（PDRP），并检测了其在人和小鼠骨骼肌样本中的表达及细胞定位。在免疫印迹中，PDRP在DMD和贝克氏肌营养不良症（BMD）患者以及对照（非DMD/BMD）人类的样本中，染出了一条与肌营养不良蛋白分子量相似的条带。由于抗原肽与肌营养不良蛋白不同源，预计PDRP不会与肌营养不良蛋白发生交叉反应。事实上，PDRP并未与一名BMD患者体内的肌营养不良蛋白发生交叉反应。免疫组织化学检测显示，PDRP在DMB和BMD患者以及mdx小鼠的样本中染出了肌细胞膜。在对照人类和野生型小鼠的肌肉中仅观察到轻微染色。我们的结果证实了DRP在人和小鼠骨骼肌中的存在，并进一步证明它定位于细胞膜上。肌营养不良蛋白缺陷肌肉中DRP的丰度可能与某些补偿机制有关。
