Di Xiao-Jing, Han Dong-Yun, Wang Ya-Juan, Chance Mark R, Mu Ting-Wei
Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.
Center for Proteomics and Bioinformatics, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.
Chem Biol. 2013 Dec 19;20(12):1456-68. doi: 10.1016/j.chembiol.2013.09.020. Epub 2013 Nov 7.
GABA(A) receptors are the primary inhibitory ion channels in the mammalian central nervous system. The A322D mutation in the α1 subunit of GABA(A) receptors is known to result in its degradation and reduce its cell surface expression, leading to loss of GABAA receptor function in autosomal dominant juvenile myoclonic epilepsy. Here, we show that SAHA, a FDA-approved drug, increases the transcription of the α1(A322D) subunit, enhances its folding and trafficking posttranslationally, increases its cell surface level, and restores the GABA-induced maximal current in HEK293 cells expressing α1(A322D)β2γ2 receptors to 10% of that for wild-type receptors. To enhance the trafficking efficiency of the α1(A322D) subunit, SAHA increases the BiP protein level and the interaction between the α1(A322D) subunit and calnexin. SAHA is a drug that enhances epilepsy-associated GABAA receptor proteostasis.
GABA(A)受体是哺乳动物中枢神经系统中的主要抑制性离子通道。已知GABA(A)受体α1亚基中的A322D突变会导致其降解并降低其细胞表面表达,从而导致常染色体显性青少年肌阵挛性癫痫中GABAA受体功能丧失。在此,我们表明,一种美国食品药品监督管理局(FDA)批准的药物SAHA可增加α1(A322D)亚基的转录,在翻译后增强其折叠和转运,提高其细胞表面水平,并将表达α1(A322D)β2γ2受体的HEK293细胞中GABA诱导的最大电流恢复至野生型受体的10%。为提高α1(A322D)亚基的转运效率,SAHA增加了BiP蛋白水平以及α1(A322D)亚基与钙连蛋白之间的相互作用。SAHA是一种可增强癫痫相关GABAA受体蛋白质稳态的药物。