人肌营养不良蛋白聚糖：骨骼肌cDNA、基因组结构、组织特异性同工型的起源及染色体定位。

Human dystroglycan: skeletal muscle cDNA, genomic structure, origin of tissue specific isoforms and chromosomal localization.

作者信息

Ibraghimov-Beskrovnaya O, Milatovich A, Ozcelik T, Yang B, Koepnick K, Francke U, Campbell K P

机构信息

Howard Hughes Medical Institute, University of Iowa College of Medicine, Iowa City 52242.

出版信息

Hum Mol Genet. 1993 Oct;2(10):1651-7. doi: 10.1093/hmg/2.10.1651.

DOI:10.1093/hmg/2.10.1651

PMID:8268918

Abstract

Dystroglycan is a novel laminin binding component of the dystrophin-glycoprotein complex which provides a linkage between the subsarcolemmal cytoskeleton and the extracellular matrix. Here we report the cDNA and genomic structure of human dystroglycan. The human dystroglycan is encoded by a single gene (DAG1) mapped to chromosome 3 band p21. The coding sequence is organized into two exons, separated by a large intron. The predicted amino acid sequence of human and rabbit dystroglycan are 93% identical with predicted glycosylation sites being conserved. Human dystroglycan is expressed in a variety of fetal and adult tissues. Our data suggest that muscle and non-muscle isoforms of dystroglycan differ by carbohydrate moieties but not protein sequence. Therefore, we hypothesize that variable glycosylation of the conserved protein core might modulate laminin binding. The relationship of dystroglycan to human diseases is discussed.

摘要

肌营养不良蛋白聚糖是肌营养不良蛋白 - 糖蛋白复合物中一种新的层粘连蛋白结合成分，它在肌膜下细胞骨架与细胞外基质之间提供了一种连接。在此我们报告人类肌营养不良蛋白聚糖的cDNA和基因组结构。人类肌营养不良蛋白聚糖由一个定位于3号染色体p21带的单基因（DAG1）编码。编码序列被组织成两个外显子，由一个大的内含子隔开。人类和兔肌营养不良蛋白聚糖的预测氨基酸序列有93%相同，预测的糖基化位点是保守的。人类肌营养不良蛋白聚糖在多种胎儿和成人组织中表达。我们的数据表明，肌营养不良蛋白聚糖的肌肉和非肌肉同工型在碳水化合物部分不同，但蛋白质序列相同。因此，我们推测保守蛋白质核心的可变糖基化可能调节层粘连蛋白结合。文中还讨论了肌营养不良蛋白聚糖与人类疾病的关系。