Identification and functional characterization of Dicer2 and five single VWC domain proteins of Litopenaeus vannamei

详细信息    查看全文

• 作者：Yi-Hong Chen^a ; Xiao-Ting Jia^a ; Li Zhao^a ; Chao-Zheng Li^a ; Shuang Zhang^a ; Yong-Gui Chen^b ; Shao-Ping Weng^a ; Jian-Guo He^a ; ^b ; ^{lsshjg@mail.sysu.edu.cn}
• 关键词：Litopenaeus vannamei ; Dicer2 ; WSSV ; Single VWC domain protein ; RNA interference ; Vago
• 刊名：Developmental and Comparative Immunology
• 出版年：2011
• 出版时间：June 2011
• 年：2011
• 卷：35
• 期：6
• 页码：661-671
• 全文大小：1902 K

文摘

Dicer (Dcr) is the key protein of the RNA interference (RNAi) pathway. To investigate the role of the RNAi pathway in shrimp anti-viral immunity, Litopenaeus vannamei Dcr2 (designated as LvDcr2) was identified and characterized. The full-length cDNA of LvDcr2 was 5513 bp long, with an open reading frame encoding a putative protein of 1502 amino acids. In addition, five proteins homologous to the single von Willebrand factor type C (VWC) domain protein (SVC) were also identified in L. vannamei and named LvSVC1-5. These LvSVCs were between 102 and 190 amino acids in length and all contained a motif similar to Drosophila melanogaster SVC proteins (DmSVCs). By co-immunoprecipitation assays and pull-down assays, we demonstrated that LvDcr2, L. vannamei Argonaute 2 (LvAgo2), and L. vannamei transactivating response RNA-binding protein isoform 1 (LvTRBP1) interacted with each other. A luciferase reporter assay indicated that the promoters of LvSVC1, LvSVC4, LvSVC5, and DmSVC Vago (DmVago) were activated by LvDcr2 as well as by Drosophila Dcr2 (DmDcr2). Real-time RT-PCR showed that LvDcr2 and LvSVCs were up-regulated in immune responses against Poly(C-G) or WSSV challenge. These results suggested that LvDcr2 formed complexes with LvAgo2 and LvTRBP1 to act as the cores of shrimp small interfering RNA (siRNA)-induced silencing complex (siRISC)/siRISC-loading complex (siRLC), role in shrimp siRNA pathway. Furthermore, these results also suggested that LvDcr2 may engage in non-specific activation of anti-viral immunity.