A novel strategy using cardiac sodium channel polymorphic fragments to rescue trafficking-deficient SCN5A mutations.
A novel strategy using cardiac sodium channel polymorphic fragments to rescue trafficking-deficient SCN5A mutations.
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DOI：
10.1161/circgenetics.111.960633
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发表时间：
2011-10
期刊：
影响因子：
--
通讯作者：
Deschênes I
中科院分区：
文献类型：
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作者：
Shinlapawittayatorn K;Dudash LA;Du XX;Heller L;Poelzing S;Ficker E;Deschênes I
Brugada综合征（BrS）与心脏钠通道（Nav1.5）突变有关。我们以前报道过，运输缺陷型BrS Nav1.5突变R282 H的功能可以通过与钠通道多态性H558 R共表达来恢复。在这里，我们测试的假设，从Nav1.5肽片段，跨越H558 R-多态性，可用于恢复运输缺陷型BrS钠通道突变的贩运。全细胞膜片钳显示，在HEK 293细胞的R282 H通道与40或20个氨基酸的cDNA片段的Nav1.5含有H558 R多态性的共转染恢复该突变体通道的运输。荧光共振能量转移（FRET）表明，运输缺陷的R282 H通道是错误折叠的，这是正确的共表达后与R558-含有肽恢复R282 H通道的运输。重要的是，我们还表达了跨越H558 R多态性的肽，其中8个额外的BrS Nav1.5突变具有降低的电流，并证明该肽能够恢复其中4个中的显著钠电流。在本研究中，我们证明了跨越H558 R多态性的小肽足以恢复BrS相关Nav1.5突变的运输缺陷。我们的研究结果表明，它可能是一种新的策略，是专门针对特定的致病突变体的BrS使用短cDNA构建体。
Brugada Syndrome (BrS) is associated with mutations in the cardiac sodium channel (Nav1.5). We previously reported that the function of a trafficking-deficient BrS Nav1.5 mutation, R282H, could be restored by co-expression with the sodium channel polymorphism H558R. Here, we tested the hypothesis that peptide fragments from Nav1.5, spanning the H558R-polymorphism, can be used to restore trafficking of trafficking-deficient BrS sodium channel mutations. Whole-cell patch-clamping revealed that co-transfection in HEK293 cells of the R282H channel with either the 40 or 20 amino acid cDNA fragments of Nav1.5 containing the H558R polymorphism restored trafficking of this mutant channel. Fluorescence Resonance Energy Transfer (FRET) suggested that the trafficking-deficient R282H channel was misfolded and this was corrected upon co-expression with R558-containing peptides which restored trafficking of the R282H channel. Importantly, we also expressed the peptide spanning the H558R-polymorphism with 8 additional BrS Nav1.5 mutations with reduced currents, and demonstrated that the peptide was able to restore significant sodium currents in 4 of them. In the present study, we demonstrated that small peptides, spanning the H558R-polymorphism, are sufficient to restore trafficking defect of BrS-associated Nav1.5 mutations. Our findings suggest that it might be possible to use short-cDNA constructs as a novel strategy that is tailored to specific disease-causing mutants of BrS.