Bodmann Eva-Lisa, Krett Anna-Lena, Bünemann Moritz
Department of Pharmacology and Clinical Pharmacy, Philipps University of Marburg, Marburg, Germany.
Department of Pharmacology and Clinical Pharmacy, Philipps University of Marburg, Marburg, Germany
FASEB J. 2017 Aug;31(8):3663-3676. doi: 10.1096/fj.201700026R. Epub 2017 May 2.
Diverse cellular functions are controlled by RhoA-GTPases, which are activated by trimeric G proteins RhoGEFs, among others. In this study, we focused on the signaling from GPCRs to RhoA Gα and leukemia-associated RhoGEF (LARG). The activation of Gα was elucidated in living cells with high temporal and spatial resolution by means of FRET. The inactivation after agonist withdrawal occurred in the same range ( = 25.3 ± 2.2 s; mean ± sem; 22) as described for other Gα proteins. The interaction of Gα and LARG and the thereby-induced LARG translocation to the plasma membrane were at least 1 order of magnitude more stable after agonist withdrawal, exceeding Gα deactivation in the absence of LARG several fold. Consequently, we observed an almost 100-fold higher agonist sensitivity of the Gα LARG interaction compared to the Gα activation in the absence of LARG.-Bodmann, E.-L., Krett, A.-L., Bünemann, M. Potentiation of receptor responses induced by prolonged binding of Gα and leukemia-associated RhoGEF.
多种细胞功能受RhoA - GTPases控制，RhoA - GTPases可被三聚体G蛋白、Rho鸟嘌呤核苷酸交换因子（RhoGEFs）等激活。在本研究中，我们聚焦于从G蛋白偶联受体（GPCRs）到RhoA、Gα以及白血病相关RhoGEF（LARG）的信号传导。通过荧光共振能量转移（FRET），在活细胞中以高时空分辨率阐明了Gα的激活过程。激动剂撤除后的失活发生在与其他Gα蛋白相同的范围内（= 25.3 ± 2.2秒；平均值±标准误；n = 22）。激动剂撤除后，Gα与LARG的相互作用以及由此诱导的LARG向质膜的转位至少比其稳定1个数量级，比不存在LARG时Gα的失活高出数倍。因此，我们观察到与不存在LARG时Gα的激活相比，Gα - LARG相互作用的激动剂敏感性几乎高出100倍。 - 博德曼，E.-L.，克雷特，A.-L.，比内曼，M. Gα与白血病相关RhoGEF的长时间结合诱导受体反应的增强。
