水产学报2024，Vol.48Issue(1)：26-39,14.DOI:10.11964/jfc.20211013107
赤眼鳟LGP2序列结构、组织表达及与MDA5互作特征
Sequence structure,tissue expression of LGP2,and its interaction with MDA5 in Squaliobarbus curriculus
摘要
Abstract
Grass carp(Ctenopharyngodon idella)are susceptible to grass carp reovirus(GCRV)and exhibit severe hemorrhage when infected.In contrast,Squaliobarbus curriculus(Sc)are resistant to GCRV.We have generated C.idella/S.curriculus hybrid fish which are relatively more resistant to GCRV than C.idella.These fish popula-tions provide valuable resources for investigating the genetic mechanisms of the antiviral immunity.The laborat-ory of genetics and physiology 2(LGP2)is a member of RIG-Ⅰlike receptor family and is involved in recogni-tion of viral nuclear acid at the first line of defense.Understanding its functions in antiviral immunity will have a significant impact on the molecular breeding of fish with resistant traits.In this study,the full-length cDNA(2 940 bp)and the 5′upstream sequence(721 bp)of the S.curriculus lgp2(Sclgp2)gene were sequenced.The 5'upstream region contains several putative transcription factor binding sites for MafB(muscle aponeurosis fibromatosis B)and IRF3(interferon regulatory factor 3).The Sclgp2 encodes a protein of 680 amino acids which consists of conserved DEXD/H(DExD/H-box helicase domain),HELICc(helicase superfamily C-terminal domain)and CTD(C-terminal regulatory domain).The functional domains and the number of predicted phos-phorylation sites are similar to that in other fish species,with differences in domain arrangement and amino acid sequences.Furthermore,by comparing the sequences of C.idella and S.curriculus LGP2 proteins,two GCRV sites associated with GCRV resistance in the RNA binding region were identified.In the phylogenetic tree,ScLGP2 was clustered in a clade containing the homologs from C.idella,Carassius auratus and Mylopharyn-godon piceus,forming an expanded clade with the homologs from other cyprinid fish.Quantitative PCR analysis revealed that the mRNA expression level of Sclgp2 was the highest in the spleen,followed by muscle and heart,whereas the lowest was detected in the intestine.The expression levels of Sclgp2 and ifn1 remained unchanged in most tissues except that the ifn1 expression was significantly down-regulated in the liver at 24-72 h after GCRV infection.Interestingly,the mRNA expression levels of Sclgp2 in the muscle positively correlated with that of ifn1(0.999,P<0.01).ScLGP2 weakly interacted with ScMDA5,yet DEXDc(1-201 aa),HELICc(390-476 aa)and CTD(553-668 aa)were not engaged in such interaction.Taken together,the present study provides basis for studying the functions of ScLGP2 and exploring the Sclgp2 gene as a potential marker for genetic breeding of dis-ease resistant C.idella.关键词
赤眼鳟/生理学实验室蛋白2(LGP2)/序列结构/表达特征/蛋白互作/GCRV抗性Key words
Squaliobarbus curriculus/laboratory of genetics and physiology 2/sequence structure/expression characteristic/protein interaction/GCRV resistance分类
生物科学引用本文复制引用
李耀国,廖依静,王静安,肖调义..赤眼鳟LGP2序列结构、组织表达及与MDA5互作特征[J].水产学报,2024,48(1):26-39,14.基金项目
国家自然科学基金(32172966,31802288,U20A2063) （32172966,31802288,U20A2063）
湖南省教育厅资助科研项目(19B265) （19B265）
中央引导地方科技发展资金(2022ZYC085) National Natural Science Foundation of China(32172966,31802288,U20A2063) （2022ZYC085）
The Sci-entific Research Fund of Hunan Provincial Education Department(19B265) （19B265）
the Central Guidance on Local Sci-ence and Technology Development Fund of Hunan Province(2022ZYC085) （2022ZYC085）
