DHHC5 Mediates β-Adrenergic Signaling in Cardiomyocytes by Targeting Gα Proteins
DHHC5 Mediates β-Adrenergic Signaling in Cardiomyocytes by Targeting Gα Proteins
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DOI：
10.1016/j.bpj.2019.08.018
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发表时间：
2020-02-25
影响因子：
3.4
通讯作者：
Boehning, Darren
中科院分区：
文献类型：
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作者：
Chen, Jessica J.;Marsden, Autumn N.;Boehning, Darren
S-棕榈酰化是一种可逆的翻译后修饰，在调节蛋白质定位、运输和稳定性方面发挥着重要作用。最近的研究表明，一些蛋白质在细胞刺激后经历极快的棕榈酰化/去棕榈酰化循环，支持这种翻译后修饰的直接信号传导作用。在这里，我们研究了心肌细胞的β-肾上腺素能刺激是否导致下游信号蛋白的刺激依赖性棕榈酰化。我们发现β-肾上腺素能刺激导致Gαs和Gαi棕榈酰化迅速增加。棕榈酰化的动力学在时间上与 cAMP 的下游产生和收缩反应一致。我们发现质膜定位的棕榈酰酰基转移酶 DHHC5 是心肌细胞中刺激依赖性棕榈酰化的重要介质。 DHHC5 的敲除表明该酶对于 G α s、G α i 的棕榈酰化以及 β-肾上腺素能刺激下游的功能反应是必需的。对纯化组分进行的棕榈酰化测定表明，G α s 和 G α i 是 DHHC5 的直接底物。最后，我们提供的证据表明，DHHC5 的 C 末端尾部可以响应刺激而被棕榈酰化，这种修饰对于其在质膜中的动态定位和功能非常重要。我们的结果表明 DHHC5 是心肌细胞中 β-肾上腺素能受体下游信号传导的中心调节因子。
S-palmitoylation is a reversible posttranslational modification that plays an important role in regulating protein localization, trafficking, and stability. Recent studies have shown that some proteins undergo extremely rapid palmitoylation/depalmitoylation cycles after cellular stimulation supporting a direct signaling role for this posttranslational modification. Here, we investigated whether beta-adrenergic stimulation of cardiomyocytes led to stimulus-dependent palmitoylation of downstream signaling proteins. We found that beta-adrenergic stimulation led to rapidly increased G alpha s and G alpha i palmitoylation. The kinetics of palmitoylation was temporally consistent with the downstream production of cAMP and contractile responses. We identified the plasma membrane-localized palmitoyl acyltransferase DHHC5 as an important mediator of the stimulus-dependent palmitoylation in cardiomyocytes. Knockdown of DHHC5 showed that this enzyme is necessary for palmitoylation of G alpha s, G alpha i, and functional responses downstream of beta-adrenergic stimulation. A palmitoylation assay with purified components revealed that G alpha s and G alpha i are direct substrates of DHHC5. Finally, we provided evidence that the C-terminal tail of DHHC5 can be palmitoylated in response to stimulation and such modification is important for its dynamic localization and function in the plasma membrane. Our results reveal that DHHC5 is a central regulator of signaling downstream of beta-adrenergic receptors in cardiomyocytes.