CAJ | 학술논문

背景：Duchenne型肌营养不良和Becker型进行性肌营养不良都是dystrophin基因突变所致，但后者临床表型较轻。“阅读框规则”可解释大部分基因型与临床型关系，但累及疏水区段的整码突变也可导致Duchenne型肌营养不良。因此很有必要了解疏水区域在dystrophin中的功能，且这些疏水区段的三维结构及功能在发病机制中所起的具体作用仍未阐明。 　　目的：通过Kyte&Doolittle平均疏水轮廓分析研究 dystrophin 的疏水区段。利用swiss-model三维重构dystrophin的疏水区段阐述其在发病机制中所起的作用。 　　方法：参考莱顿开放数据库(http：//www.dmd.nl/)及收集中山大学附属第一医院2002年至2013年确诊Duchenne 型进行性肌营养不良或Becker 型进行性肌营养不良的缺失型整码突变患者资料共1038例，分析其临床型与基因型关系。使用 bioedit 软件计算dystrophin 的平均疏水轮廓及利用swiss-model 三维重构疏水区段，结合临床型和基因型关系确定dystrophin重要功能区。 　　结果与结论：dystrophin存在4个疏水区段，分别为肌动蛋白结合区内的Calponin同源区2、中央棒区内的重复区16、第三铰链区和EF手型区。第1，2，4疏水区段是 dystrophin 糖蛋白复合物中dystrophin与其他糖蛋白的结合区域，其破坏严重影响dystrophin糖蛋白复合物功能，临床症状重。中央棒区在第三铰链区附近断裂后，HⅢ的无规则卷结构不容易与断端重复区的螺旋结构恢复连接。但第三铰链区同时缺失，其两端的重复区较容易重新连接，所以第3疏水区破坏后其临床症状反而较轻。提示dystrophin的疏水区段是其重要功能区，多是dystrophin糖蛋白复合物中dystrophin与相关蛋白的结合部位，在Duchenne型肌营养不良的发病机制中起重要作用。
배경：Duchenne형기영양불량화Becker형진행성기영양불량도시dystrophin기인돌변소치，단후자림상표형교경。“열독광규칙”가해석대부분기인형여림상형관계，단루급소수구단적정마돌변야가도치Duchenne형기영양불량。인차흔유필요료해소수구역재dystrophin중적공능，차저사소수구단적삼유결구급공능재발병궤제중소기적구체작용잉미천명。 　　목적：통과Kyte&Doolittle평균소수륜곽분석연구 dystrophin 적소수구단。이용swiss-model삼유중구dystrophin적소수구단천술기재발병궤제중소기적작용。 　　방법：삼고래돈개방수거고(http：//www.dmd.nl/)급수집중산대학부속제일의원2002년지2013년학진Duchenne 형진행성기영양불량혹Becker 형진행성기영양불량적결실형정마돌변환자자료공1038례，분석기림상형여기인형관계。사용 bioedit 연건계산dystrophin 적평균소수륜곽급이용swiss-model 삼유중구소수구단，결합림상형화기인형관계학정dystrophin중요공능구。 　　결과여결론：dystrophin존재4개소수구단，분별위기동단백결합구내적Calponin동원구2、중앙봉구내적중복구16、제삼교련구화EF수형구。제1，2，4소수구단시 dystrophin 당단백복합물중dystrophin여기타당단백적결합구역，기파배엄중영향dystrophin당단백복합물공능，림상증상중。중앙봉구재제삼교련구부근단렬후，HⅢ적무규칙권결구불용역여단단중복구적라선결구회복련접。단제삼교련구동시결실，기량단적중복구교용역중신련접，소이제3소수구파배후기림상증상반이교경。제시dystrophin적소수구단시기중요공능구，다시dystrophin당단백복합물중dystrophin여상관단백적결합부위，재Duchenne형기영양불량적발병궤제중기중요작용。
BACKGROUND:Duchenne muscular dystrophy is recognized as a fatal X-linked recessive inheritance. It is caused by the dystrophin gene mutation, resulting in the deficiency of dystrophin and consequent degeneration and necrosis of muscle fibers gradual y. Becker muscular dystrophy is also caused by the mutation of the same gene, but presented with less severe clinical symptoms compared with Duchenne muscular dystrophy. Frameshift mutation destroys the reading frames, and thus the translation cannot proceed smoothly to transcript functional proteins. In-frame mutation cannot destroy the reading frames and hence the translation can proceed smoothly. But in-frame mutation involves the whole hydrophobic regions. The three-dimensional structure of these regions and their functionality are not interpreted clearly. The effects of these regions on disease development need to be clarified in detail from the point of structure and function. OBJECTIVE:By analyzing Kate and Dolittle scale mean hydrophobicity profile, to investigate the dystrophin hydrophobic regions using Swiss-model so as to provide the supplement explanation on the reading frame rule. METHODS:Form 2002 to 2013, 1 038 cases diagnosed as Duchenne muscular dystrophy or Becker muscular dystrophy were col ected in the First Hospital of Sun Yat-sen University in China and Leiden DMD information database was searched with deletion of codon mutation information available. The correlation between clinical types and genotypes was analyzed upon resources col ected above. The mean hydrophobicity profile of dystrophin was analyzed by Bioedit as wel as the reconstruction of hydrophobic domains using Swiss-model. Thus, the important functional domain of dystrophin was confirmed by analysis and the correlation between clinical types and genotypes. RESULTS AND CONCLUSION:Four hydrophobic regions were confirmed:Calponin homology domain CH2 on actin-binding domain, repeat 16 domain, Hinge Ⅲ domain and EF Hand domain. Duchenne muscular dystrophy was developed as a result of the destruction of the 1st, 2nd and 4th hydrophobic regions which were the conjunction of dystrophin and associated protein in dystrophin-glycoprotein complex. When the 3rd hydrophobic was deleted, the repeat domain located on central rob domain remained its continuity so that the clinical symptoms were less severe. These findings indicate that the dystrophin hydrophobic regions act as an important role on the pathogenesis of Duchenne muscular dystrophy.