Litopenaeus vannamei Smad5 (LvSmad5) in cytoplasm has been proved to be involved in environmental stress response. As LvSmad5 could also locate in nucleus under specific stress, it was conjectured that LvSmad5 might participate in environmental stress response. While, the experimental evidence is still lacking. In this study, cytosolic LvSmad5 mutant or nuclear LvSmad5 mutant was expressed in Drosophila S2 cells, and then transcriptomic analysis of mentioned cells was performed using Illumina HiSeq based RNA-Seq, to reveal the function of LvSmad5 in nucleus. By comparing the two groups of cDNA libraries from S2 cells with cytosolic or nucleus LvSmad5 mutant, 86 differentially expressed genes as well as 765 differentially expressed transcripts were found. It was revealed that genes in the ER-stress response pathway, such as unfolded protein response and ER-associated degradation (ERAD) were enriched. Additionally, some kinds of metabolic reprogramming occurred in S2 cells with over-expressing nuclear LvSmad5, for significant changes in the expression of some metabolism-related genes. To test our infer that nuclear LvSmad5 was engaged in environmental stress response, homologous gene of Drosophila translocation in renal carcinoma on chromosome 8 in L.vannamei (LvTRC8) was chosen for further investigation. And studies about LvTRC8, a member of ERAD showed that it was induced by ER-stress or heat shock treatment. Suppressed the expression of LvTRC8 increased the cumulative mortality of shrimp upon stress. In some degree, these results support our speculation that nuclear LvSmad5 are involved in the environmental stress response of L. vannamei in fact.

细胞质中的南美白对虾Smad5 (LvSmad5) 已被证明参与环境胁迫反应。由于LvSmad5在特定胁迫下也可定位于细胞核，推测LvSmad5可能参与了环境胁迫反应。同时，还缺乏实验证据。在这项研究中，细胞溶质 LvSmad5 突变体或细胞核 LvSmad5 突变体在果蝇中表达S2 细胞，然后使用基于 Illumina HiSeq 的 RNA-Seq 对上述细胞进行转录组学分析，以揭示 LvSmad5 在细胞核中的功能。通过比较两组来自具有细胞溶质或细胞核LvSmad5突变体的S2细胞的cDNA文库，发现了86个差异表达基因和765个差异表达转录本。据透露，ER 应激反应途径中的基因，如未折叠蛋白反应和 ER 相关降解 (ERAD) 被丰富了。此外，在核 LvSmad5 过表达的 S2 细胞中发生了一些代谢重编程，一些代谢相关基因的表达发生了显着变化。为了验证我们推断核 LvSmad5 参与环境应激反应，同源基因选择凡纳滨对虾( LvTRC8 )肾癌中果蝇易位进行进一步研究。而对ERAD 成员LvTRC8的研究表明，它是由 ER 应激或热休克处理诱导的。抑制LvTRC8的表达增加了虾在应激时的累积死亡率。在某种程度上，这些结果支持了我们的推测，即核 LvSmad5实际上参与了南美白对虾的环境胁迫反应。