Protein kinase RNA‐activated (PKR) is an important component of the innate immune system induced by interferon. This antiviral protein senses a variety of stresses and pathogen‐driven double‐stranded RNAs (dsRNAs). In the present study, we cloned and characterized the PKR gene from Dabry's sturgeon (Acipenser dabryanus). Bioinformatics analysis revealed that the AdPKR gene comprises a coding sequence (CDS) of 1848 bp, encoding a 616 amino acids (aa) polypeptide. AdPKR shares high aa identity/similarity with proteins from other fish, ranging from 33.4%/51.8% to 87.6%/91.2%, and relatively low aa identity (13.9%) and similarity (26.8%) with human PKR. The AdPKR polypeptide has two dsRNA‐binding motifs at the N‐terminus and a conserved catalytic kinase domain at the C‐terminus. The sturgeon PKR gene contains 17 exons split by 16 introns. Phylogenetic analysis clustered AdPKR together with its counterparts from other teleost fishes. Real‐time fluorescene quantitative PCR (RT‐qPCR) transcription profiles revealed highest AdPKR expression levels in brain, followed by middle kidney, skin, muscle and head kidney. AdPKR mRNA transcripts were significantly increased at 6 hr post‐stimulation (hps) with polyinosinic:polycytidylic acid (poly I:C), remained high at 24 hps, then decreased to normal levels at 48 hps. These results indicate that AdPKR might play a vital role in antiviral immune responses.

中文翻译：

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达布里y鱼（Acipenser dabryanus）中双链RNA依赖性蛋白激酶（PKR）的分子表征和表达分析

蛋白激酶RNA激活（PKR）是干扰素诱导的先天免疫系统的重要组成部分。这种抗病毒蛋白可感应多种压力和病原体驱动的双链RNA（dsRNA）。在本研究中，我们克隆并鉴定了达布里（鱼（Acipenser dabryanus）的PKR基因。）。生物信息学分析表明，AdPKR基因包含1848 bp的编码序列（CDS），编码616个氨基酸（aa）多肽。AdPKR与其他鱼类的蛋白质具有较高的氨基酸同一性/相似性，范围从33.4％/ 51.8％至87.6％/ 91.2％，与人类PKR的氨基酸同一性相对较低（13.9％）和相似性（26.8％）。AdPKR多肽在N端具有两个dsRNA结合基序，在C端具有保守的催化激酶结构域。st鱼PKR基因含有被16个内含子分裂的17个外显子。系统发育分析将AdPKR与其他硬骨鱼类的对应物聚在一起。实时荧光定量PCR（RT-qPCR）转录谱显示，大脑中AdPKR的表达水平最高，其次是中肾，皮肤，肌肉和头肾。多肌苷酸：聚胞苷酸（poly I：C）刺激后6小时，AdPKR mRNA转录显着增加（hps），保持高至24 hps，然后降至48 hps的正常水平。这些结果表明，AdPKR可能在抗病毒免疫反应中起着至关重要的作用。