College of Animal Science and Technology, Hunan Agricultural University, Changsha, 410128, China.
Fish Shellfish Immunol. 2010 Aug;29(2):327-33. doi: 10.1016/j.fsi.2010.04.005. Epub 2010 May 4.
RanGTPase, one family of small G protein superfamily, has been widely demonstrated to be involved in transport system between cytoplasm and nucleus. However the knowledge about the function of RanGTPase in immunity remains limited. In this report, Ran gene (named LycRan) cDNA was cloned from the large yellow croaker, Pseudosciaena crocea, a marine fish. The full-length cDNA of LycRan was of 1033 bp, including a 5'-terminal untranslated region (UTR) of 43 bp, 3'-terminal UTR of 338 bp and an open reading frame (ORF) of 648 bp encoding a polypeptide of 216 amino acids. The deduced protein is highly homologous, it shares 90.74%, 88.89%, 89.35% and 85.20% identities with those of salmon, frog, human and fruit fly respectively. RT-PCR analysis indicated that LycRan gene was constitutively expressed in 9 tissues examined, including kidney, liver, gill, muscle, spleen, skin, heart, intestine and blood. The result of quantitative Real-Time RT-PCR analysis revealed the highest expression in kidney and the weakest expression in skin. Time course analysis showed that LycRan expression was obviously up-regulated in kidney, blood and spleen after immunization with either poly I:C or formalin-inactive Gram-negative bacterium Vibrio parahaemolyticus. It indicated that the highest expression was 2.8 times (at 48 h) as much as that in the control in the kidney (p < 0.05) challenged by poly I:C and 3.2 times (at 24 h) in the blood (p < 0.05) challenged by bacteria. These results suggested that LycRan might play an important role in large yellow croaker defense against the pathogen infection. Our study, therefore, might provide a clue to elucidate the large yellow croaker innate immunity.
RanGTPase 是小 G 蛋白超家族的一个家族，已被广泛证明参与细胞质和细胞核之间的运输系统。然而，关于 RanGTPase 在免疫中的功能的知识仍然有限。在本报告中，从大黄鱼（Pseudosciaena crocea）中克隆了 Ran 基因（命名为 LycRan）cDNA。LycRan 的全长 cDNA 为 1033bp，包括 5'-非翻译区（UTR）43bp、3'-UTR 338bp 和一个开放阅读框（ORF）648bp，编码 216 个氨基酸的多肽。推导的蛋白质高度同源，与鲑鱼、青蛙、人类和果蝇分别具有 90.74%、88.89%、89.35%和 85.20%的同一性。RT-PCR 分析表明，LycRan 基因在检测的 9 种组织中均呈组成型表达，包括肾脏、肝脏、鳃、肌肉、脾脏、皮肤、心脏、肠和血液。定量实时 RT-PCR 分析的结果显示，肾脏中的表达最高，皮肤中的表达最弱。时间过程分析表明，在用多聚 I:C 或福尔马林失活革兰氏阴性菌副溶血弧菌免疫后，LycRan 在肾脏、血液和脾脏中的表达明显上调。结果表明，多聚 I:C 刺激肾脏（p<0.05）的表达最高增加 2.8 倍，细菌刺激血液（p<0.05）的表达最高增加 3.2 倍。这些结果表明，LycRan 可能在大黄鱼抵御病原体感染的防御中发挥重要作用。因此，我们的研究可能为阐明大黄鱼先天免疫提供线索。
