PDF(Pubmed)
Abstract：
Mutation of the GABRA1 gene is associated with neurodevelopmental defects and epilepsy. GABRA1 encodes for the α1 subunit of the gamma-aminobutyric acid type A receptor (GABAAR), which regulates the fast inhibitory impulses of the nervous system. Multiple model systems have previously been developed to understand the function of GABRA1 during development, but these models have produced complex and at times incongruent data. Thus, additional model systems are required to validate and substantiate previously published results. We investigated the behavioral swim patterns associated with a nonsense mutation of the zebrafish gabra1 (sa43718 allele) gene. The sa43718 allele causes a decrease in gabra1 mRNA expression, which is associated with light induced hypermotility, one phenotype associated with seizure like behavior in zebrafish. Mutation of gabra1 was accompanied by decreased mRNA expression of gabra2, gabra3, and gabra5, indicating a reduction in the expression of additional alpha sub-units of the GABAAR. Although multiple sub-units were decreased in total expression, larvae continued to respond to pentylenetetrazole (PTZ) indicating that a residual GABAAR exists in the sa43718 allele. Proteomics analysis demonstrated that nonsense mutation of gabra1 is associated with abnormal expression of proteins that regulate proton transport, ion homeostasis, vesicle transport, and mitochondrial protein complexes. These data support previous studies performed in a zebrafish nonsense allele created by CRISPR/Cas9 and validate that loss of function mutations in the gabra1 gene result in seizure like phenotypes with abnormal function of inhibitory synapses.
摘要：
GABRA1基因的突变与神经发育缺陷和癫痫表型有关。GABRA1编码γ-氨基丁酸A型受体（GABAAR）的α1亚基，调节神经系统的快速抑制冲动。以前已经开发了多模型系统来了解GABRA1突变导致疾病的机制。但是这些模型产生了复杂和不一致的数据。因此，需要额外的模型系统来验证和证实以前发表的结果.我们调查了与斑马鱼gabra1（sa43718等位基因）基因的无义突变相关的行为模式。sa43718等位基因的总gabra1mRNA表达减少了90%，这与光诱发的癫痫样行为有关。gabra1的突变伴随着gabra4的mRNA表达增加，编码GABAAR的α-4亚基。尽管在RNA水平上表达增加，根据蛋白质组学分析，Gabra4蛋白没有增加。因此，这意味着α亚基的RNA表达模式可能无法准确反映癫痫发作的机制。有趣的是,蛋白质组学分析确定了调节质子运输的基因的显著富集，离子稳态，囊泡运输，和线粒体蛋白质复合物。总的来说，我们的分析验证了gabra1的突变导致癫痫发作样表型，并提供了可能在体内介导这些表型的推定蛋白的蓝图。
