When is an obscurin variant pathogenic? The impact of Arg4344Gln and Arg4444Trp variants on protein-protein interactions and protein stability.
When is an obscurin variant pathogenic? The impact of Arg4344Gln and Arg4444Trp variants on protein-protein interactions and protein stability.
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DOI：
10.1093/hmg/ddab010
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发表时间：
2021-06-09
影响因子：
3.5
通讯作者：
Gautel M
中科院分区：
文献类型：
--
作者：
Fukuzawa A;Koch D;Grover S;Rees M;Gautel M
暗纹蛋白是一种连接肌节和肌浆网的巨大肌肉蛋白，对其结构和信号功能了解甚少。越来越多的研究表明，暗色蛋白变异与心血管疾病的病理生理有关。最初在一名肥厚性心肌病患者中发现的obscurin结构域Ig58中的Arg4344Gln变体（R4344Q），已被报道减少了与titin结构域Z8-Z9的结合，损害了obscurin的z盘定位。R4344Q敲入小鼠出现心肌病样表型，伴有异常的Ca2+处理和心律失常，这是由于R4344Q变异导致的模糊蛋白Ig58和磷蛋白（PLN）之间推测的相互作用的亲和力增强。然而，在15%的非裔美国人中发现了R4344Q变体，这就反驳了它的致病性。为了解决这一明显的矛盾，我们使用下拉法和微尺度热电泳法量化了R4344Q变体（以及另一个潜在致病变体Arg4444Trp (R4444W)）对titin Z8-Z9、novx -3和PLN结合的影响，并使用差示扫描荧光法表征了对结构域稳定性的影响。我们发现两种变体的titin结合和热稳定性没有变化，PLN对R4344Q和R4444W的亲和力略有增加。虽然我们无法证实novex-3/obscurin相互作用，但PLN/obscurin相互作用依赖于PLN的跨膜区域，并且在哺乳动物细胞中不可复制，这表明它是体外人工产物。没有明确的临床证据表明疾病的累及，我们建议不要将这些蒙克林变异体归类为致病性的。
Obscurin is a giant muscle protein that connects the sarcomere with the sarcoplasmic reticulum, and has poorly understood structural and signalling functions. Increasingly, obscurin variants are implicated in the pathophysiology of cardiovascular diseases. The Arg4344Gln variant (R4344Q) in obscurin domain Ig58, initially discovered in a patient with hypertrophic cardiomyopathy, has been reported to reduce binding to titin domains Z8-Z9, impairing obscurin’s Z-disc localization. An R4344Q knock-in mouse developed a cardiomyopathy-like phenotype with abnormal Ca2+-handling and arrhythmias, which were attributed to an enhanced affinity of a putative interaction between obscurin Ig58 and phospholamban (PLN) due to the R4344Q variant. However, the R4344Q variant is found in 15% of African Americans, arguing against its pathogenicity. To resolve this apparent paradox, we quantified the influence of the R4344Q variant (alongside another potentially pathogenic variant: Arg4444Trp (R4444W)) on binding to titin Z8-Z9, novex-3 and PLN using pull-down assays and microscale thermophoresis and characterized the influence on domain stability using differential scanning fluorimetry. We found no changes in titin binding and thermostability for both variants and modestly increased affinities of PLN for R4344Q and R4444W. While we could not confirm the novex-3/obscurin interaction, the PLN/obscurin interaction relies on the transmembrane region of PLN and is not reproducible in mammalian cells, suggesting it is an in vitro artefact. Without clear clinical evidence for disease involvement, we advise against classifying these obscurin variants as pathogenic.
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影响因子：
12.7
作者：
Rees M;Nikoopour R;Fukuzawa A;Kho AL;Fernandez-Garcia MA;Wraige E;Bodi I;Deshpande C;Özdemir Ö;Daimagüler HS;Pfuhl M;Holt M;Brandmeier B;Grover S;Fluss J;Longman C;Farrugia ME;Matthews E;Hanna M;Muntoni F;Sarkozy A;Phadke R;Quinlivan R;Oates EC;Schröder R;Thiel C;Reimann J;Voermans N;Erasmus C;Kamsteeg EJ;Konersman C;Grosmann C;McKee S;Tirupathi S;Moore SA;Wilichowski E;Hobbiebrunken E;Dekomien G;Richard I;Van den Bergh P;Domínguez-González C;Cirak S;Ferreiro A;Jungbluth H;Gautel M
通讯作者：
Gautel M
影响因子：
--
作者：
Marston S
通讯作者：
Marston S
影响因子：
62.1
作者：
Schreiber, G.;Haran, G.;Zhou, H-X
通讯作者：
Zhou, H-X
影响因子：
3.7
作者：
Marston S;Montgiraud C;Munster AB;Copeland O;Choi O;Dos Remedios C;Messer AE;Ehler E;Knöll R
通讯作者：
Knöll R
DOI：
10.1083/jcb.200102110
发表时间：
2001-07-09
期刊：
The Journal of cell biology
影响因子：
--
作者：
Young P;Ehler E;Gautel M
通讯作者：
Gautel M