Woo Soo Ji, Jo Hyae In, Lee Hyung Ho, Chung Joon Ki
Department of Aquatic Life Medicine, Pukyong National University, Busan 608-737, South Korea.
Gyeongbuk Native Fish Business Center, Uiseong 37366, South Korea.
Fish Shellfish Immunol. 2017 Apr;63:353-366. doi: 10.1016/j.fsi.2016.11.052. Epub 2016 Nov 25.
Phospholipase C gamma 1 and gamma 2 (PLCG1 and PLCG2) are influential in modulating Ca and diacylglycerol, second messengers involved in tyrosine kinase-dependent signaling, including growth factor activation. Here, we used RACE (rapid amplification of cDNA ends) to clone cDNA encoding PLCG1 (PoPLCG1) and PLCG2 (PoPLCG2) in the olive flounder (Paralichthys olivaceus). The respective 1313 and 1249 amino acid sequences share high identity with human PLCG1 and PLCG2, and contain the following domains: pleckstrin homology (PH), EF-hand, catalytic X and Y, Src homology 2 (SH2), Src homology 3 (SH3), and C2. Phylogenic analysis and sequence comparison of PoPLCG1 and PoPLCG2 with other PLC isozymes showed a close relationship between the two PLCGs, supported by structural analysis. In addition, tissue expression analysis showed that PoPLCG1 was expressed predominantly in the brain, eye, and heart, whereas PoPLCG2 was expressed principally in gills, esophagus, spleen, and kidney. Following stimulation with LPS and Poly I:C, PoPLCG expression was compared with the expression of inflammatory cytokines IL-1β, IL-6, and TNF-α via reverse transcription-PCR and real-time quantitative PCR. Our results suggest that PoPLCG isozymes perform a critical immune function in olive flounder, being active in pathogen resistance and the inflammation process.
磷脂酶Cγ1和γ2（PLCG1和PLCG2）在调节钙离子和二酰基甘油方面具有重要作用，这两种第二信使参与酪氨酸激酶依赖性信号传导，包括生长因子激活。在此，我们利用cDNA末端快速扩增技术（RACE）克隆了牙鲆（Paralichthys olivaceus）中编码PLCG1（PoPLCG1）和PLCG2（PoPLCG2）的cDNA。它们各自的1313和1249个氨基酸序列与人类PLCG1和PLCG2具有高度同源性，并包含以下结构域：普列克底物蛋白同源结构域（PH）、EF手结构、催化X和Y结构域、Src同源2结构域（SH2）、Src同源3结构域（SH3）和C2结构域。PoPLCG1和PoPLCG2与其他PLC同工酶的系统发育分析和序列比较表明，这两种PLCG之间关系密切，结构分析也支持这一点。此外，组织表达分析表明，PoPLCG1主要在脑、眼和心脏中表达，而PoPLCG2主要在鳃、食管、脾脏和肾脏中表达。在用脂多糖（LPS）和聚肌苷酸:聚胞苷酸（Poly I:C）刺激后，通过逆转录PCR和实时定量PCR比较了PoPLCG的表达与炎性细胞因子白细胞介素-1β（IL-1β）、白细胞介素-6（IL-6）和肿瘤坏死因子-α（TNF-α）的表达。我们的结果表明，PoPLCG同工酶在牙鲆中发挥关键的免疫功能，在病原体抗性和炎症过程中具有活性。
