Identification of cathepsin B from large yellow croaker (Pseudosciaena crocea) and its role in the processing of MHC class II-associated invariant chain
In teleost,cathepsin B has been identified from several species and shown to play roles in the host immune response during pathogen challenge.However,the mechanism of how cathepsin B modulates the immune response in teleosts remains poorly understood.In this study,we identified and characterized cathepsin B (LycCatB) and invariant chain (LycIi) from the large yellow croaker (Pseudosciaena crocea).Sequence comparison and phylogenetic analysis indicated that LycCatB and LycIi are highly conserved within teleosts.Quantitative RT-PCR analysis showed that LycCatB mRNA was widely expressed in all examined tissues.We then recombinantly expressed LycCatB and Lyc-TR-Ii (transmembrane domain removed Ii chain) in Pichia pastoris and E.coli,respectively.The recombinant LycCatB (rLycCatB) can hydrolyze the substrate Z-FR-AMC with a Km value of 40.68 μM.Furthermore,co-incubation of rLycCatB with rLyc-TR-Ii led to an efficient cleavage of rLyc-TR-Ii in a time-dependant manner.These results indicated that cathepsin B may be involved in MHC class II-associated Ii processing in large yellow croaker,and provide new information helping to elucidate the immunological functions of teleost cathepsin B.
Cathepsin B invariant chain processing Antigen presentation Large yellow croaker
Mingyu Li Qiuhua Li Zhijun Yang Guohai Hu Ting Li Xinhua Chen Jingqun Ao
Key laboratory of Marine Biogenetics and Resources,Third Institute of Oceanography,State Oceanic Administration,Xiamen 361005,China
国内会议
福建省海洋学会2014年学术年会暨福建省科协第十四届学术年会分会场
福建平潭
英文
375-396
2014-09-01（万方平台首次上网日期，不代表论文的发表时间）