Key Laboratory of Science and Technology for Aquaculture and Food Safety, Fisheries College, Jimei University, Xiamen 361021, China.
Fish Shellfish Immunol. 2011 Feb;30(2):501-8. doi: 10.1016/j.fsi.2010.11.020. Epub 2010 Dec 2.
The Rac proteins are members of the Rho family of small G proteins and are implicated in the regulation of several pathways, including those leading to cytoskeleton reorganization, gene expression, cell proliferation, cell adhesion and cell migration and survival. In this investigation, a Rac gene (named as LycRac gene) was obtained from the large yellow croaker and it was expressed in Escherichia coli and purified. Subsequently the specific antibody was raised using the purified fusion protein (GST-LycRac). Moreover, the GTP-binding assay showed that the LycRac protein had GTP-binding activity. The LycRac gene was ubiquitously transcribed and expressed in 9 tissues. Quantitative real-time RT-PCR and Western blot analysis revealed the highest expression in gill and the weakest expression in spleen. Time-course analysis revealed that LycRac expression was obviously up-regulated in blood, spleen and liver after immunization with polyinosinic polycytidynic acid (poly I:C), formalin-inactive Gram-negative bacterium Vibrio parahemolyticus and bacterial lipopolysaccharides (LPS). These results suggested that LycRac protein might play an important role in the immune response against microorganisms in large yellow croaker.
Rac 蛋白是 Rho 家族小 G 蛋白的成员，参与调节多种途径，包括细胞骨架重排、基因表达、细胞增殖、细胞黏附和细胞迁移和存活的途径。在这项研究中，从大黄鱼中获得了 Rac 基因（命名为 LycRac 基因），并在大肠杆菌中表达和纯化。随后，使用纯化的融合蛋白（GST-LycRac）制备了特异性抗体。此外，GTP 结合测定表明 LycRac 蛋白具有 GTP 结合活性。LycRac 基因在 9 种组织中广泛转录和表达。定量实时 RT-PCR 和 Western blot 分析显示，在鳃中表达最高，在脾中表达最弱。时程分析显示，在用多聚肌苷酸多胞嘧啶核苷酸（poly I:C）、甲醛失活革兰氏阴性菌副溶血弧菌和细菌脂多糖（LPS）免疫后，大黄鱼血液、脾脏和肝脏中的 LycRac 表达明显上调。这些结果表明，LycRac 蛋白可能在大黄鱼对微生物的免疫反应中发挥重要作用。
