Cloning and functional characterization of α7 nicotinic acetylcholine receptor molecular chaperone Tmem35a
10.16438/j.0513-4870.2024-0121
- VernacularTitle:α7烟碱型乙酰胆碱受体分子伴侣Tmem35a的克隆及其功能研究
- Author:
Zi-han WANG
;
Jin-peng YU
;
Dong-ting ZHANGSUN
;
Xiao-peng ZHU
;
Su-lan LUO
- Publication Type:Research Article
- Keywords:
italic>α7 nicotinic acetylcholine receptor;
molecular chaperone NACHO;
gene cloning;
two-electrode voltage clamp;
rug screening model
- From:
Acta Pharmaceutica Sinica
2024;59(7):1993-2001
- CountryChina
- Language:Chinese
-
Abstract:
Nicotinic acetylcholine receptors (nAChRs) belong to ligand-gated ion channel receptors, of which α7 nAChR subtype is widely distributed in the cerebral cortex, thalamus, hippocampus, and also identified in microglia, macrophages, bone marrow cells, etc. Previous studies revealed that α7 nAChR is closely related to the function of the cholinergic anti-inflammatory pathway, and is a vital target for drug development of Alzheimer's disease and schizophrenia. The establishment of a stable α7 nAChR in vitro drug screening system is crucial for the efficient screening of novel drugs targeting this target. Recombinant expression of different subtypes of nAChRs on Xenopus laevis oocyte membranes and current detected by two-electrode voltage clamp (TEVC) is an advanced and complex model for novel drug screening. Molecular chaperones can assist the assembly of some nAChR subunits to form functional receptors, providing a stable expression model for the screening of compounds targeting this receptor. In this study, a molecular chaperone gene of α7 nAChR, transmembrane protein 35A (Tmem35a), was isolated and cloned from rats. We constructed the recombinant expression vector and obtained the cRNA of Tmem35a by in vitro transcription technique. Two cRNAs (Tmem35a and α7) were mixed and injected into X. laevis oocytes for expression. Then, the effects of this molecular chaperone on the current expression and pharmacological properties of α7 nAChR were evaluated by the TEVC. The results revealed that TMEM35A, also known as novel acetylcholine receptor chaperone (NACHO) could effectively increase the expression of α7 nAChR protein on oocyte membranes, and the amount of α7 nAChR protein was increased about 1-fold. The peak current induced by agonist acetylcholine (ACh) was increased about 10-fold. After injection of Tmem35a cRNA, the median effect concentration (EC50) value of α7 nAChR to agonist ACh is 228.5 μmol·L-1, which shows almost no difference from native α7 nAChR (EC50: 223.3 μmol·L-1), indicating the preservation of the normal properties of α7 nAChR. The results of this investigation indicate that the molecular chaperone NACHO effectively assists the heterologous expression of α7 nAChR in X. laevis oocytes, which provides a model for screening the potency of lead compounds targeting α7 nAChR. All animal experiments in this study were reviewed and approved by the Ethics Committee of Guangxi University (approval number: GXU-2023-0249).
