School of Pharmaceutical Sciences, Guizhou University, Guiyang, China.
Mitchell Cancer Institute, School of Medicine, University of South Alabama, Mobile, AL, USA.
FEBS J. 2023 Nov;290(21):5204-5233. doi: 10.1111/febs.16921. Epub 2023 Aug 11.
Dopamine D receptor (D R) has been shown to activate extracellular signal-regulated kinases (ERKs) via distinct pathways dependent on either G-protein or β-arrestin. However, there has not been a systematic study of the regulatory process of D R-mediated ERKs activation by G protein- versus β-arrestin-dependent signaling since D R stimulation of ERKs reflects the simultaneous action of both pathways. Here, we investigated that differential regulation of D R-mediated ERKs activation via these two pathways. Our results showed that G protein-dependent ERKs activation was transient, rapid, reached maximum level at around 2 min, and importantly, the activated ERKs were entirely confined to the cytoplasm. In contrast, β-arrestin-dependent ERKs activation was more sustained, slower, reached maximum level at around 10 min, and phosphorylated ERKs translocated into the nucleus. Src was found to be commonly involved in both the G protein- and β-arrestin-dependent pathway-mediated ERKs activation. Pertussis toxin Gi/o inhibitor, GRK2-CT, AG1478 epidermal growth factor receptor inhibitor, and wortmannin phosphoinositide 3-kinase inhibitor all blocked G protein-dependent ERKs activation. In contrast, GRK2 and β-Arr2 played a main role in β-arrestin-dependent ERKs activation. Receptor endocytosis showed minimal effect on the activation of ERKs mediated by both pathways. Furthermore, we found that the formation of a complex composed of phospho-ERKs, β-Arr2, and importinβ1 promoted the nuclear translocation of activated ERKs. The differential regulation of various cellular components, as well as temporal and spatial patterns of ERKs activation via these two pathways, suggest the existence of distinct physiological outcomes.
多巴胺 D 受体（D R）已被证明可通过依赖于 G 蛋白或β-arrestin 的不同途径激活细胞外信号调节激酶（ERKs）。然而，由于 D R 刺激 ERKs 反映了这两种途径的同时作用，因此尚未对 G 蛋白与β-arrestin 依赖性信号传导介导的 D R 介导的 ERKs 激活的调节过程进行系统研究。在这里，我们研究了这两种途径对 D R 介导的 ERKs 激活的差异调节。我们的结果表明，通过这两种途径对 D R 介导的 ERKs 激活的差异调节。我们的结果表明，G 蛋白依赖性 ERKs 激活是短暂的，迅速的，在大约 2 分钟时达到最大水平，重要的是，激活的 ERKs 完全局限于细胞质中。相比之下，β-arrestin 依赖性 ERKs 激活更为持续，较慢，在大约 10 分钟时达到最大水平，并且磷酸化的 ERKs 易位到细胞核中。发现Src 通常涉及 G 蛋白和β-arrestin 依赖性途径介导的 ERKs 激活。百日咳毒素 Gi/o 抑制剂，GRK2-CT，AG1478 表皮生长因子受体抑制剂和wortmannin 磷脂酰肌醇 3-激酶抑制剂均阻断了 G 蛋白依赖性 ERKs 激活。相反，GRK2 和β-Arr2 在β-arrestin 依赖性 ERKs 激活中起主要作用。受体内吞作用对两条途径介导的 ERKs 激活的作用最小。此外，我们发现由磷酸化 ERKs，β-Arr2 和 importinβ1 组成的复合物的形成促进了激活的 ERKs 的核易位。通过这两种途径对各种细胞成分的差异调节以及 ERKs 激活的时间和空间模式表明存在不同的生理结果。
