College of Fishery, Guangdong Ocean University, Zhanjiang 524088, PR China; Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals, Zhanjiang 524088, PR China; Guangdong Key Laboratory of Control for Diseases of Aquatic Economic Animals, Zhanjiang 524088, PR China.
College of Marine Sciences, South China Agricultural University, Guangzhou 510642, PR China.
Fish Shellfish Immunol. 2018 Jul;78:91-99. doi: 10.1016/j.fsi.2018.04.020. Epub 2018 Apr 18.
Bax inhibitor-1 (BI-1) is a conserved anti-apoptotic protein that suppresses endoplasmic reticulum (ER) stress-induced cell death. However, the function of fish BI-1 is not quite clear. In the present study, a bi-1 homolog (Ecbi-1) from orange spotted grouper, Epinephelus coioides was identified and its roles in viral infection were investigated. EcBI-1 encoded 237 amino acids protein, contained six transmembrane regions and a conservative C-terminus motif. Ecbi-1 predominantly expressed in kidney and spleen of healthy grouper. After SGIV stimulation, Ecbi-1 transcript was significantly increased in vitro. Subcellular localization analysis revealed that EcBI-1 was localized throughout the cytoplasm and co-localized with ER. Furthermore, overexpression of EcBI-1 suppressed SGIV infection induced cell death, caspase-3 activity and viral genes transcription. And C-terminus motif was critical for regulation roles of EcBI-1 during SGIV infection. In addition, EcBI-1 could interact with EcBNIP3 in vitro. Together, our data firstly demonstrated that fish BI-1 play important roles in response to viral infection.
Bax 抑制剂-1（BI-1）是一种保守的抗细胞凋亡蛋白，可抑制内质网（ER）应激诱导的细胞死亡。然而，鱼类 BI-1 的功能尚不清楚。在本研究中，从橙斑石斑鱼（Epinephelus coioides）中鉴定出 BI-1 的同源物（Ecbi-1），并研究了其在病毒感染中的作用。EcBI-1 编码 237 个氨基酸的蛋白质，包含六个跨膜区域和一个保守的 C 末端基序。Ecbi-1 在健康石斑鱼的肾脏和脾脏中表达为主。SGIV 刺激后，Ecbi-1 转录本在体外显著增加。亚细胞定位分析显示 EcBI-1 定位于整个细胞质并与 ER 共定位。此外，EcBI-1 的过表达抑制了 SGIV 感染诱导的细胞死亡、半胱天冬酶-3 活性和病毒基因转录。C 末端基序对于 EcBI-1 在 SGIV 感染期间的调节作用至关重要。此外，EcBI-1 可以在体外与 EcBNIP3 相互作用。总之，我们的数据首次表明鱼类 BI-1 在应对病毒感染中发挥重要作用。
