相扑蛋白
HEK 293细胞
转染
医学
生物物理学
钠通道
膜片钳
免疫沉淀
上皮钠通道
钠
心肌细胞
分子生物学
细胞生物学
内科学
细胞培养
泛素
生物
电生理学
生物化学
化学
抗体
遗传学
基因
受体
免疫学
有机化学
作者
Jin‐Young Yoon,Alexander Greiner,Julia S. Jacobs,William Kutschke,Young‐Rae Kim,Daniel S. Matasic,Haider Mehdi,Kaikobad Irani,Barry London
出处
期刊:Circulation
[Ovid Technologies (Wolters Kluwer)]
日期:2021-11-16
卷期号:144 (Suppl_1)
标识
DOI:10.1161/circ.144.suppl_1.14053
摘要
Introduction: The sodium current (I Na ) controlling cardiac cell excitability is conducted via the Na + channel Na V 1.5 (encoded by SCN5A ). Dysregulation of Na V 1.5 has been implicated in arrhythmia, with increased late Na V 1.5 current (I Na,L ) causing long QT type 3. Many Na V 1.5 post-translational modifications have been reported by us and others, including SUMOylation, the addition of a Small Ubiquitin-like MOdifier (SUMO) at K442-Na V 1.5. Plant et al. (2020) recently reported that hypoxia increases I Na,L by increased Na V 1.5 SUMOylation. Hypothesis: SUMOylation modifies peak but not late Na V 1.5 currents through membrane localization. Methods: SUMOylation of Na V 1.5 by SUMO1 was detected by immunoprecipitation and immunoblot. The effects of SUMOylation on peak I Na and I Na,L were measured using patch clamp in HEK293 cells transfected with wild type (WT) or mutant K442R-Na V 1.5 with/without the β1 subunit and in neonatal rat cardiac myocytes (NRCMs). Tetrodotoxin (TTX) was used to quantitate I Na,L in NRCMs. Na V 1.5 trafficking was detected by immunofluorescence. Results: Na V 1.5 was SUMOylated by SUMO1 in HEK cells, NRCMs, and human heart samples. Overexpressing or directly applying SUMO1 induced hyperSUMOylation of Na V 1.5 at K442 and increased the amplitude of peak I Na in NRCMs and in HEK cells overexpressing WT but not K442R-Na v 1.5. SUMOylation did not affect I Na,L in HEK293 cells expressing Na V 1.5 with/without the β1 subunit or in NRCMs (Fig. 1A, B). SUMO1 enhanced membrane localization of Na V 1.5 in HEK293 cells (Fig. 1C) with minimal changes to steady state activation, inactivation or channel kinetics. Conclusion: SUMOylation of Na v 1.5 at K442 increases peak I Na without changing I Na,L , at least in part by altering membrane abundance. Our findings do not support SUMOylation as a mechanism for changes in I Na,L .
科研通智能强力驱动
Strongly Powered by AbleSci AI