DMD基因位于X染色体上(Xp21.2),编码抗肌萎缩蛋白(dystrophin),这是一种对维持肌肉细胞膜稳定性至关重要的细胞骨架蛋白。抗肌萎缩蛋白主要分布于骨骼肌、心肌和平滑肌,通过与肌动蛋白、肌营养不良蛋白糖蛋白复合物(DGC)结合,在肌肉收缩时保护肌纤维免受机械损伤。DMD基因突变(如缺失、重复或点突变)会导致抗肌萎缩蛋白功能缺失,引发杜氏肌营养不良症(DMD),表现为进行性肌肉萎缩、心肌病和呼吸衰竭;若产生部分功能性蛋白则可能引起较温和的贝克型肌营养不良症(BMD)。该基因属于肌营养不良蛋白基因家族,成员均含有串联的spectrin样重复结构域,参与细胞骨架与细胞外基质的连接。DMD过表达在动物模型中显示可改善肌肉功能,但人类罕见;而表达降低或缺失会引发肌膜脆弱、钙离子内流异常、肌肉坏死,并伴随继发性炎症反应。DMD突变还可能影响DGC复合物中其他蛋白(如肌聚糖)的稳定性,导致信号传导紊乱。此外,抗肌萎缩蛋白在大脑皮层和海马体也有表达,其缺失可能引起认知障碍。基因治疗策略如外显子跳跃、微型抗肌萎缩蛋白递送或CRISPR编辑正在临床试验中。
The dystrophin gene is the largest gene found in nature, measuring 2.4 Mb. The gene was identified through a positional cloning approach, targeted at the isolation of the gene responsible for Duchenne (DMD) and Becker (BMD) Muscular Dystrophies. DMD is a recessive, fatal, X-linked disorder occurring at a frequency of about 1 in 3,500 new-born males. BMD is a milder allelic form. In general, DMD patients carry mutations which cause premature translation termination (nonsense or frame shift mutations), while in BMD patients dystrophin is reduced either in molecular weight (derived from in-frame deletions) or in expression level. The dystrophin gene is highly complex, containing at least eight independent, tissue-specific promoters and two polyA-addition sites. Furthermore, dystrophin RNA is differentially spliced, producing a range of different transcripts, encoding a large set of protein isoforms. Dystrophin (as encoded by the Dp427 transcripts) is a large, rod-like cytoskeletal protein which is found at the inner surface of muscle fibers. Dystrophin is part of the dystrophin-glycoprotein complex (DGC), which bridges the inner cytoskeleton (F-actin) and the extra-cellular matrix. [provided by RefSeq, Jul 2008]
的dystrophin基因是自然界中发现的最大的基因,measu环2.4 MB。该基因是通过一个定位克隆方法鉴定,定位于负责杜氏(DMD)和贝克尔(BMD)肌营养不良基因的分离。 DMD是一种隐性,致命的,X连锁在约1在3500新出生的男性的频率发生紊乱。 BMD是一个温和的等位基因形式。在一般情况下,DMD患者携带这导致过早翻译终止(无义或移码突变),而在BMD患者肌养要么在分子量(从帧缺失衍生)或表达水平降低的突变。肌营养不良蛋白基因是高度复杂的,含有至少8个独立的组织特异性启动子和两个聚腺苷酸加成位点。此外,抗肌萎缩蛋白的RNA剪接的差异,产生了一系列不同的成绩单,编码大组蛋白亚型。肌营养不良蛋白(如由Dp427转录编码的)是其在肌肉纤维的内表面发现了一个大的,杆状细胞骨架蛋白。肌营养不良是肌养蛋白糖蛋白复合物(DGC),该桥接内细胞骨架(F-肌动蛋白)和细胞外基质的一部分。 [由RefSeq的,2008年7月提供]
DMD基因(以及对应的蛋白质)的细胞分布位置:
DMD基因的本体(GO)信息:
名称 |
---|
5410 Hypertrophic cardiomyopathy (HCM) [PATH:hsa05410] |
5412 Arrhythmogenic right ventricular cardiomyopathy (ARVC) [PATH:hsa05412] |
5414 Dilated cardiomyopathy (DCM) [PATH:hsa05414] |
5416 Viral myocarditis [PATH:hsa05416] |
名称 |
---|
Extracellular matrix organization |
Muscle contraction |
Non-integrin membrane-ECM interactions |
Striated Muscle Contraction |
疾病名称 | 关系值 | NofPmids | NofSnps | 来源 |
Muscular Dystrophy, Duchenne | 0.730349803 | 535 | 175 | BeFree_CLINVAR_CTD_human_GAD_LHGDN_MGD_ORPHANET_UNIPROT |
Becker Muscular Dystrophy | 0.497741174 | 205 | 136 | BeFree_CLINVAR_GAD_MGD_ORPHANET_UNIPROT |
Dmd-Associated Dilated Cardiomyopathy | 0.371596056 | 35 | 213 | BeFree_CLINVAR_CTD_human_GAD_UNIPROT |
Muscular Dystrophy | 0.222732561 | 455 | 0 | BeFree_CTD_human_GAD_LHGDN |
Status Epilepticus | 0.2 | 1 | 0 | CTD_human_RGD |
Cardiomyopathy, Dilated | 0.138130524 | 40 | 0 | BeFree_CTD_human_GAD_LHGDN |
Cardiomyopathies | 0.131053172 | 36 | 0 | BeFree_CTD_human_GAD |
Rhabdomyosarcoma, Embryonal | 0.120271442 | 2 | 0 | BeFree_CTD_human |
Gastrointestinal Stromal Tumors | 0.120271442 | 1 | 0 | BeFree_CTD_human |
Calcinosis | 0.12 | 1 | 0 | CTD_human |
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