Kveberg Lise, Ryan James C, Rolstad Bent, Inngjerdingen Marit
Department of Anatomy, University of Oslo, Oslo, Norway.
Immunology. 2005 Jul;115(3):358-65. doi: 10.1111/j.1365-2567.2005.02174.x.
The small GTPase accelerators regulator of G protein signalling (RGS) proteins are important regulators of proximal signalling from G protein coupled receptors. Although natural killer (NK) cells express a number of G-protein coupled receptors, expression of RGS proteins has not been investigated. We analysed the expression of RGS proteins in rat NK cells, and detected mRNA for RGS1, RGS2, RGS5, RGS8, RGS16, and RGS18. Interestingly, when we included a panel of different leucocyte subsets, we found that RGS8 was selectively expressed by NK cells. NK cells are under control of both activating and inhibitory receptors and, utilizing a xenogeneic system where the mouse activating Ly49D or inhibitory Ly49A receptors were transfected into the rat RNK-16 cell line, the potential regulation of RGS proteins by single NK cell receptors was studied. We found that ligation of Ly49D led to a rapid and transient increase in message for RGS2, while Ly49A ligation up-regulated RGS2, RGS16, and RGS18 mRNA. Both receptors also induced a prolonged increase in RGS2 endogenous protein levels. These findings suggest that RGS proteins may be influenced by or involved in NK cell receptor events, suggesting a crosstalk between G-protein coupled receptors and NK cell receptors.
小GTP酶激活蛋白信号调节因子（RGS）蛋白是G蛋白偶联受体近端信号的重要调节因子。尽管自然杀伤（NK）细胞表达多种G蛋白偶联受体，但尚未对RGS蛋白的表达进行研究。我们分析了大鼠NK细胞中RGS蛋白的表达，检测到RGS1、RGS2、RGS5、RGS8、RGS16和RGS18的mRNA。有趣的是，当我们纳入一组不同的白细胞亚群时，发现RGS8仅在NK细胞中选择性表达。NK细胞受激活受体和抑制受体的双重调控，利用一种将小鼠激活型Ly49D或抑制型Ly49A受体转染到大鼠RNK - 16细胞系的异种系统，研究了单个NK细胞受体对RGS蛋白的潜在调控作用。我们发现，Ly49D的结合导致RGS2的信使RNA迅速短暂增加，而Ly49A的结合则上调了RGS2、RGS16和RGS18的mRNA。两种受体还诱导RGS2内源性蛋白水平持续升高。这些发现表明，RGS蛋白可能受NK细胞受体事件影响或参与其中，提示G蛋白偶联受体与NK细胞受体之间存在相互作用。
