Molecular evolution and expression pattern of Toll-like receptor 3 from the lamprey Lampetra japonica  

作　　者：Jian Quan Ming Geng Xueting Hu Shaoshu Feng Yu Liu Fan Hui Meiao Li Jinzhao Liu Peng Su Xin Liu Qingwei Li Ting Zhu 

机构地区：[1]College of Life Science,Liaoning Normal University,Dalian 116081,China [2]Lamprey Research Center,Liaoning Normal University,Dalian 116081,China [3]Collaborative Innovation Center of Seafood Deep Processing,Dalian Polytechnic University,Dalian 116081,China [4]Shuangqiao Primary School,Zhengzhou 450044,China

出　　处：《Acta Biochimica et Biophysica Sinica》2021年第2期258-261,共4页生物化学与生物物理学报（英文版）

基　　金：This work was supported by the grants from the National Natural Science Foundation of China(No.31601044);the China Postdoctoral Science Foundation(No.2016M591454);the Scientific Research Foundation of the Higher Education Institutions of Liaoning Province,China(No.LQ2020025);the Undergraduate Innovation and Entrepreneurship Training Program Support Project(No.S202010165041).

摘　　要：Toll-like receptors(TLRs)are type I transmembrane proteins that are important components of innate immunity and play essential roles in inducing acquired immune responses[1].These proteins consist of three parts:the cytoplasmic domain,transmembrane domain,and extracellular domain.The extracellular domain is composed of 18–33 leucine-rich repeat(LRR)sequences that enable the host to specifically recognize pathogen-associated molecular patterns and are the core of TLR recognition ligands[2].The cytoplasmic domain is homologous with the interleukin 1 receptor(IL-1R)family and known as the Toll-IL-1 receptor homology domain,which is highly conserved and plays a key role in signal transduction[1].TLR3 recognizes viral dsRNA during immune protection from viruses[3].After the host is infected by a virus,the LRR region of TLR3 recognizes the viral dsRNA,and the Toll/IL-1 receptor(TIR)domain recruits the adaptor protein TIR domain-containing molecule 1(also known as TRIF)for signal cascade transmission[4].The activation of TLR3 finally leads to cytokine secretion,especially the production of type I interferon[4].Lamprey,the most primitive marine jawless vertebrate,is an ideal model for studying vertebrate embryo development,organ differentiation,and immune system evolution[5].Although jawless vertebrates contain three variable lymphocyte receptors,they have not been found to possess the recombinational antigen receptors shared by all jawed vertebrates[6].Compared with that in higher vertebrates,the mechanism of acquired immunity in lampreys is still not complete,and lampreys rely mainly on innate immunity to fight against pathogenic microorganisms.Although TLR3 has been extensively studied in jawed vertebrates,little is known about the molecular evolutionary history and expression patterns of TLR3 in jawless vertebrates.

关 键 词：IMMUNITY evolution PATTERN 

分 类 号：Q48[生物学—生理学]