Department of Biological Sciences, University of Texas, El Paso, TX, 79968, USA.
Department of Biological Sciences, University of Texas, El Paso, TX, 79968, USA; Border Biomedical Research Center, University of Texas, El Paso, TX, 79968, USA.
Biochem Biophys Res Commun. 2021 Apr 16;549:98-104. doi: 10.1016/j.bbrc.2021.02.095. Epub 2021 Mar 2.
The βγ subunit of heterotrimeric G proteins, a key molecule in the G protein-coupled receptors (GPCRs) signaling pathway, has been shown to be an important factor in the modulation of the microtubule cytoskeleton. Gβγ has been shown to bind to tubulin, stimulate microtubule assembly, and promote neurite outgrowth of PC12 cells. In this study, we demonstrate that in addition to microtubules, Gβγ also interacts with actin filaments, and this interaction increases during NGF-induced neuronal differentiation of PC12 cells. We further demonstrate that the Gβγ-actin interaction occurs independently of microtubules as nocodazole, a well-known microtubule depolymerizing agent did not inhibit Gβγ-actin complex formation in PC12 cells. A confocal microscopic analysis of NGF-treated PC12 cells revealed that Gβγ co-localizes with both actin and microtubule cytoskeleton along neurites, with specific co-localization of Gβγ with actin at the distal end of these neuronal processes. Furthermore, we show that Gβγ interacts with the actin cytoskeleton in primary hippocampal and cerebellar rat neurons. Our results indicate that Gβγ serves as an important modulator of the neuronal cytoskeleton by interacting with both microtubules and actin filaments, and is likely to participate in various aspects of neuronal differentiation including axon and growth cone formation.
三聚体 G 蛋白的βγ亚基是 G 蛋白偶联受体（GPCRs）信号通路中的关键分子，已被证明是调节微管细胞骨架的重要因素。Gβγ已被证明可以结合微管蛋白，刺激微管组装，并促进 PC12 细胞的突起生长。在这项研究中，我们证明了 Gβγ除了与微管相互作用之外，还与肌动蛋白丝相互作用，并且这种相互作用在 NGF 诱导的 PC12 细胞神经元分化过程中增加。我们进一步证明，Gβγ-肌动蛋白相互作用独立于微管发生，因为微管解聚剂诺考达唑不会抑制 PC12 细胞中 Gβγ-肌动蛋白复合物的形成。用 NGF 处理的 PC12 细胞的共聚焦显微镜分析显示，Gβγ与突起中的肌动蛋白和微管细胞骨架共定位，在这些神经元突起的远端，Gβγ与肌动蛋白有特定的共定位。此外，我们还表明 Gβγ与原代海马和小脑大鼠神经元中的肌动蛋白细胞骨架相互作用。我们的结果表明，Gβγ通过与微管和肌动蛋白丝相互作用，充当神经元细胞骨架的重要调节剂，并且可能参与神经元分化的各个方面，包括轴突和生长锥的形成。
