A novel protein tyrosine kinase Tec identified in lamprey, Lampetra japonica  

作　　者：Ranran Li Peng Su Chang Liu Qiong Zhang Ting Zhu Yue Pang Xin Liu Qingwei Li 

机构地区：[1]College of Life Science, Liaoning Normal University, Dalian 116029, China [2]Lamprey Research Center, Liaoning Normal University, Dalian 116029, China

出　　处：《Acta Biochimica et Biophysica Sinica》2015年第8期639-646,共8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 Program on Key Basic Research Project （No. 2013CB835304）, the National Natural Science Foundation of China （No. 31271323）, and the Natural Science Foundation of Liaoning Province （No. 2014029203）.

摘　　要：Protein tyrosine kinase Tec, a kind of non-receptor tyrosine kinase, is primarily found to be expressed in T cells, B cells, hematopoietic cells, and liver cells as a cytoplasmic protein. Tec has been proved to be a critical modulator of T cell receptor signaling pathway. In the present study, a homolog of Tec was identified in the lamprey, Lampetra japonica. The full-length Tec cDNA of L. japonica （Lja-Tec） contains a 1923 bp open reading frame that encodes a 641-amino acid protein. The multi-alignment of the deduced amino acid sequence of Lja-Tec with typical vertebrate Tecs showed that it possesses all conserved domains of the Tec family proteins, indicating that an ortholog of Tec exists in the ex- tant jawless vertebrate. In the phylogenetic tree that was reconstructed with 24 homologs of jawless and jawed vertebrates, the Tecs from lampreys and hagfish were clustered as a single clade. The gen- etic distance between the outgroup and agnathan Tecs＇ group is closer than that between outgroup and gnathostome Tecs＇ group, indicating that its origin was far earlier than any of the jawed verte- brates. The mRNA levels of Lja-Tec in lymphocyte-like cells and gills were detected by real-time quantitative polymerase chain reaction. Results showed that it was significantly upregulated under stimulation with mixed pathogens. This result was further confirmed by western blot analysis. All these results indicated that Lja-Tec plays an important role in immune response. Our data will provide a reference for the further study of lamprey Tec and its immunological function in jawless vertebrates.Protein tyrosine kinase Tec, a kind of non-receptor tyrosine kinase, is primarily found to be expressed in T cells, B cells, hematopoietic cells, and liver cells as a cytoplasmic protein. Tec has been proved to be a critical modulator of T cell receptor signaling pathway. In the present study, a homolog of Tec was identified in the lamprey, Lampetra japonica. The full-length Tec cDNA of L. japonica （Lja-Tec） contains a 1923 bp open reading frame that encodes a 641-amino acid protein. The multi-alignment of the deduced amino acid sequence of Lja-Tec with typical vertebrate Tecs showed that it possesses all conserved domains of the Tec family proteins, indicating that an ortholog of Tec exists in the ex- tant jawless vertebrate. In the phylogenetic tree that was reconstructed with 24 homologs of jawless and jawed vertebrates, the Tecs from lampreys and hagfish were clustered as a single clade. The gen- etic distance between the outgroup and agnathan Tecs＇ group is closer than that between outgroup and gnathostome Tecs＇ group, indicating that its origin was far earlier than any of the jawed verte- brates. The mRNA levels of Lja-Tec in lymphocyte-like cells and gills were detected by real-time quantitative polymerase chain reaction. Results showed that it was significantly upregulated under stimulation with mixed pathogens. This result was further confirmed by western blot analysis. All these results indicated that Lja-Tec plays an important role in immune response. Our data will provide a reference for the further study of lamprey Tec and its immunological function in jawless vertebrates.

关 键 词：tyrosine-protein kinase Tec Lampetra japonica expression pattern molecular evolution 

分 类 号：Q51[生物学—生物化学] Q915.2[天文地球—古生物学与地层学]