College of Oceanography, Hohai University, 1 Xikang Road, Nanjing, 210098, Jiangsu, China.
College of Marine Science and Engineering, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, Jiangsu, China.
Vet Res. 2021 Jun 2;52(1):76. doi: 10.1186/s13567-021-00945-7.
The Hippo signalling pathway plays a vital role in organ size control, cell proliferation, apoptosis, and immune regulation. In this study, a Hippo homologue with three isoforms (named MnHippo-a, MnHippo-b, and MnHippo-c) was isolated and characterized for the first time from the freshwater prawn Macrobrachium nipponense. The deduced amino acid sequences of MnHippo-a (698 aa), MnHippo-b (688 aa), and MnHippo-c (656 aa) were highly similar, and they all contained an N-terminal S_TKc (serine/threonine protein kinase catalytic) domain and a C-terminal Mst1_SARAH (Sav/Rassf/Hpo) domain. MnHippo-a and MnHippo-c were derived from alternative splicing. Phylogenetic analysis was performed, and the results revealed that MnHippo was a member of the clade containing STPK4 and Hippo of Penaeus vannamei. The expression distribution showed that MnHippo was constitutively expressed in various tissues of uninfected prawns and highly expressed in the hepatopancreas and intestine. In prawns challenged with Vibrio parahaemolyticus and Staphylococcus aureus, the expression of MnHippo in haemocytes was significantly upregulated. Furthermore, in MnHippo-knockdown prawns injected with V. parahaemolyticus or S. aureus, the transcription levels of five antimicrobial peptides were downregulated. MnHippo silencing weakened the clearance of V. parahaemolyticus and S. aureus in prawns. The survival rate of the MnHippo-dsRNA group was obviously decreased from 2 to 6 days post-injection with V. parahaemolyticus or S. aureus. Hence, MnHippo might be involved in the antibacterial immune defence of M. nipponense.
Hippo 信号通路在器官大小控制、细胞增殖、凋亡和免疫调节中发挥着重要作用。本研究首次从淡水虾日本沼虾中分离并鉴定了 Hippo 同源物的三个同工型（命名为 MnHippo-a、MnHippo-b 和 MnHippo-c）。MnHippo-a（698 aa）、MnHippo-b（688 aa）和 MnHippo-c（656 aa）的推导氨基酸序列高度相似，均含有一个 N 端 S_TKc（丝氨酸/苏氨酸蛋白激酶催化）结构域和一个 C 端 Mst1_SARAH（Sav/Rassf/Hpo）结构域。MnHippo-a 和 MnHippo-c 来源于选择性剪接。系统发育分析表明，MnHippo 是包含 STPK4 和凡纳滨对虾 Hippo 的分支的成员。表达分布表明，MnHippo 在未感染虾的各种组织中持续表达，在肝胰腺和肠道中高度表达。在对副溶血弧菌和金黄色葡萄球菌进行攻毒的虾中，血细胞中 MnHippo 的表达显著上调。此外，在注射副溶血弧菌或金黄色葡萄球菌的 MnHippo 敲低虾中，五种抗菌肽的转录水平下调。MnHippo 沉默削弱了虾对副溶血弧菌和金黄色葡萄球菌的清除能力。MnHippo-dsRNA 组的存活率从注射副溶血弧菌或金黄色葡萄球菌后的 2 天到 6 天明显下降。因此，MnHippo 可能参与了日本沼虾的抗菌免疫防御。
