Li Yiqun, Liu Yanan, Zhou Yong, Liu Wenzhi, Fan Yuding, Jiang Nan, Xue Mingyang, Meng Yan, Zeng Lingbing
Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan, 430223, China.
Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan, 430223, China.
Dev Comp Immunol. 2021 Mar;116:103935. doi: 10.1016/j.dci.2020.103935. Epub 2020 Nov 23.
Bid is a pro-apoptotic BH3-only member of the Bcl-2 superfamily that functions to link the extrinsic apoptotic pathway and the mitochondrial amplification loop of the intrinsic pathway. In this study, the expression and functions of Chinese giant salamander (Andrias davidianus) Bid (AdBid) were investigated. The AdBid cDNA sequence contains an open reading frame (ORF) of 576 nucleotides, encoding a putative protein of 191 aa. AdBid possesses the conserved BH3 interacting domain and shared 34-52% sequence identities with other amphibian Bid. mRNA expression of AdBid was most abundant in muscle. The expression level of AdBid in Chinese giant salamander muscle, kidney and spleen significantly increased after Chinese giant salamander iridovirus (GSIV) infection. Additionally, a plasmid expressing AdBid was constructed and transfected into the Chinese giant salamander muscle cell line (GSM cells). The morphology and cytopathic effect (CPE) and apoptotic process in AdBid over-expressed GSM cells was significantly enhanced during GSIV infection compared with that in control cells. Moreover, a higher level of the virus major capsid protein (MCP) gene copies and protein synthesis was confirmed in the AdBid over-expressed cells. These results indicated that AdBid played a positive role in GSIV induced apoptosis and the viral replication. This study may contribute to the better understanding on the infection mechanism of iridovirus-induced apoptosis.
Bid是Bcl-2超家族中仅含BH3结构域的促凋亡成员，其功能是连接外源性凋亡途径和内源性途径的线粒体放大环。在本研究中，对中国大鲵（Andrias davidianus）Bid（AdBid）的表达和功能进行了研究。AdBid cDNA序列包含一个576个核苷酸的开放阅读框（ORF），编码一个191个氨基酸的推定蛋白。AdBid具有保守的BH3相互作用结构域，与其他两栖动物Bid的序列同一性为34%-52%。AdBid的mRNA表达在肌肉中最为丰富。中国大鲵虹彩病毒（GSIV）感染后，中国大鲵肌肉、肾脏和脾脏中AdBid的表达水平显著增加。此外，构建了一个表达AdBid的质粒并将其转染到中国大鲵肌肉细胞系（GSM细胞）中。与对照细胞相比，在GSIV感染期间，AdBid过表达的GSM细胞中的形态、细胞病变效应（CPE）和凋亡过程显著增强。此外，在AdBid过表达的细胞中证实了更高水平的病毒主要衣壳蛋白（MCP）基因拷贝和蛋白合成。这些结果表明，AdBid在GSIV诱导的凋亡和病毒复制中发挥了积极作用。本研究可能有助于更好地理解虹彩病毒诱导凋亡的感染机制。
