CNRS, IPBS (Institut De Pharmacologie Et De Biologie Structurale) 205 Route De Narbonne, 31077 Toulouse, Cedex 4, France; Université Paul Sabatier Toulouse III, F-31300 Toulouse, France.
CNRS, IPBS (Institut De Pharmacologie Et De Biologie Structurale) 205 Route De Narbonne, 31077 Toulouse, Cedex 4, France; Université Paul Sabatier Toulouse III, F-31300 Toulouse, France.
Peptides. 2020 Dec;134:170406. doi: 10.1016/j.peptides.2020.170406. Epub 2020 Sep 10.
The neuropeptide FF2 (NPFF) receptor, predominantly expressed in the central nervous system, plays an important role in the modulation of sensory input and opioid analgesia, as well as in locomotion, feeding, intestinal motility, reward, and the control of obesity. The NPFF receptor belongs to the RFamide peptide receptor family and to the G protein coupled receptor (GPCR) super family, but contrary to many other class A GPCRs, no 3D structure has been solved. Thus, it is essential to perform mutagenesis to gain information on the fine functioning of the NPFF receptor. In this study, we examined the role of aspartic acid (D) from the "D/ERY/F" motif found in the second intracellular loop (ICL2) and the role of the C-terminal end of the receptor in ligand binding and signal transduction. We found that mutation D3.49A does not impair binding capacities but inhibits G protein activation as well as adenylyl cyclase regulation. Truncation of the C terminal part of the receptor has different effects depending on the position of truncation. When truncation was realized downstream of the putative acylation site, ligand binding and signal transduction capabilities were not lost, contrary to total deletion of the C terminus, which totally impairs the activity of the receptor.
神经肽 FF2（NPFF）受体主要在中枢神经系统中表达，在调节感觉输入和阿片类镇痛、运动、进食、肠道动力、奖赏以及肥胖控制方面发挥着重要作用。NPFF 受体属于 RFamide 肽受体家族和 G 蛋白偶联受体（GPCR）超家族，但与许多其他 A 类 GPCR 不同，其三维结构尚未解决。因此，进行突变研究对于了解 NPFF 受体的精细功能至关重要。在这项研究中，我们研究了第二细胞内环（ICL2）中“D/ERY/F”基序中的天冬氨酸（D）和受体 C 末端在配体结合和信号转导中的作用。我们发现突变 D3.49A 不会损害结合能力，但会抑制 G 蛋白激活和腺苷酸环化酶调节。受体 C 末端的截断会根据截断的位置产生不同的效果。当在假定的酰化位点下游进行截断时，配体结合和信号转导能力不会丧失，而 C 末端的完全缺失则会完全损害受体的活性。
