Kim Gyeongwha, Jung Soonwoong, Son Hyeonwi, Kim Sujeong, Choi Jungil, Lee Dong Hoon, Roh Gu Seob, Kang Sang Soo, Cho Gyeong Jae, Choi Wan Sung, Kim Hyun Joon
Department of Anatomy and Neurobiology, Institute of Health Sciences, Medical Research Center for Neural Dysfunction, School of Medicine, Gyeongsang National University, Jinju 660-290, Korea.
BMB Rep. 2014 Jun;47(6):324-9. doi: 10.5483/bmbrep.2014.47.6.162.
Regulators of G-protein signaling (RGS) proteins regulate certain G-protein-coupled receptor (GPCR)-mediated signaling pathways. The GABA(B) receptor (GABA(B)R) is a GPCR that plays a role in the stress response. Previous studies indicate that acute immobilization stress (AIS) decreases RGS4 in the prefrontal cortex (PFC) and hypothalamus (HY) and suggest the possibility of a signal complex composed of RGS4 and GABA(B)R. Therefore, in the present study, we tested whether RGS4 associates with GABA(B)R in these brain regions. We found the co-localization of RGS4 and GABA(B)R subtypes in the PFC and HY using double immunohistochemistry and confirmed a direct association between GABA(B2)R and RGS4 proteins using co-immunoprecipitation. Furthermore, we found that AIS decreased the amount of RGS4 bound to GABA(B2)R and the number of double-positive cells. These results indicate that GABA(B)R forms a signal complex with RGS4 and suggests that RGS4 is a regulator of GABA(B)R.
G蛋白信号调节蛋白（RGS）可调节某些G蛋白偶联受体（GPCR）介导的信号通路。γ-氨基丁酸B型受体（GABA(B)R）是一种GPCR，在应激反应中发挥作用。先前的研究表明，急性固定应激（AIS）会降低前额叶皮质（PFC）和下丘脑（HY）中的RGS4，并提示存在由RGS4和GABA(B)R组成信号复合物的可能性。因此，在本研究中，我们测试了RGS4在这些脑区中是否与GABA(B)R相关联。我们使用双重免疫组织化学法发现了PFC和HY中RGS4与GABA(B)R亚型的共定位，并使用免疫共沉淀法证实了GABA(B2)R与RGS4蛋白之间存在直接关联。此外，我们发现AIS减少了与GABA(B2)R结合的RGS4的量以及双阳性细胞的数量。这些结果表明，GABA(B)R与RGS4形成了信号复合物，并提示RGS4是GABA(B)R的一种调节因子。
