作为离子通道贩运的新型调节剂,DENND3的分子和功能表征
Shan Gao1, Dan Ye1, Raquel Neves1
1Windland Smith Rice Sudden Death Genomics Laboratory, Department of Molecular Pharmacology & Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota.
Heart rhythm
|May 27, 2025
概括
一种罕见的DENND3基因变异 (p.R534S) 破坏Rab GTPase通路,改变心脏离子通道功能并增加心律失常风险. 这一发现将DENND3和Rab GTPases与致死性心律失常综合征联系起来.
科学领域:
- 心血管遗传学 心血管遗传学
- 分子细胞生物学 分子细胞生物学
- 节律失常学 节律失常学
背景情况:
- 与超罕见的DENND3基因误解变异 (p.R534S) 相关的家族心房动.
- DENND3作为拉布GTPases的关氨酸核酸交换因子,调节心脏离子通道的膜贩运.
研究的目的:
- 调查DENND3作为致死性心律失常综合征的基因修饰剂的作用,特别是家族心房动.
- 阐明DENND3-p.R534S变异对心脏离子通道调节和细胞节律失常性的功能影响.
主要方法:
- 利用诱导多能干细胞衍生的心肌细胞 (iPSC-CMs) 和TSA201细胞来评估DENND3-p.R534S变体的影响.
- 采用超高分辨率成像和GTPase-Glo测试来分析Rab蛋白的分布和活性.
- 进行了电生理学分析,以测量离子通道电流和心律失常性.
主要成果:
- DENND3-p.R534S变异增加了膜局部化和关键心脏离子通道 (KCNQ1,KCNH2,SCN5A,CACNA1C) 的功能.
- 具有该变异的iPSC-CMs显示出异常的电活动,包括不规则的殴打和后去极化.
- 这种变异破坏了Rab5的分布,改变了Rab5/Rab12的GTPase活性,这意味着Rab介导的贩运.
结论:
- DENND3-p.R534S变种破坏了Rab介导的贩运,影响了离子通道分布和心脏细胞功能.
- 这项研究在DENND3,Rab GTPases和心脏生理学之间建立了新的联系,突出了它们在心律失常风险中的作用.
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