Molecular characterization and dietary regulation of aminopeptidase N (APN) in the grass carp (Ctenopharyngodon idella)
Molecular characterization and dietary regulation of aminopeptidase N (APN) in the grass carp (Ctenopharyngodon idella)
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草鱼（Ctenopharyngodon idella）氨肽酶 N（APN）的分子特征和饮食调节
DOI：
10.1016/j.gene.2016.01.046
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发表时间：
2016
期刊：
影响因子：
3.5
通讯作者：
Liu Zhen
中科院分区：
文献类型：
--
作者：
Tang Jianzhou;Qu Fufa;Tang Xiangbei;Zhao Qiong;Wang Yonghong;Zhou Yi;Feng Junchang;Lu Shuangqing;Hou Dexing;Liu Zhen
氨肽酶N （APN）是肽酶M1家族的一员，在蛋白质消化中起重要作用。本研究从棘球绦虫（Ctenopharyngodon idellus）肠道中克隆了一个APN基因。APN全长cDNA序列编码一个892个氨基酸的肽，包含一个螺旋跨膜区。系统发育分析表明，APN序列与最近邻的丹尼奥变种聚类，序列相似性为81.5%。APN mRNA在不同组织中的表达存在差异，在前肠、后肠、肝脏、中肠、肾脏、肌肉、脾脏和心脏组织中呈现由高到低的表达梯度。草鱼APN的表达具有昼夜节律规律，在06:00 ~ 18:00表达量较高，在18:00 ~ 06:00表达量较低。此外，饲料调节APN表达的蛋白质水平和来源表明，低粗蛋白质（CP）水平和鱼粉刺激了APN基因的表达。此外，高浓度谷氨酰胺和谷氨酰胺二肽分别显著抑制了肠道APN mRNA的表达。该研究为硬骨鱼APN的表达调控提供了有价值的知识，并在改善鱼类饲料配方方面具有潜在的应用价值。
Aminopeptidase N (APN) is a member of the peptidase M1 family and plays an important role in protein digestion. In the present study, an APN gene was cloned from the intestine of Ctenopharyngodon idellus. The full-length cDNA sequence of APN encodes an 892-amino-acid peptide that includes one helix trans-membrane region. Phylogenetic analysis showed that the APN sequence clustered withDanio rerioas its closest neighbor, sharing a sequence similarity of 81.5%. APN mRNA was differentially expressed in different tissues, with a gradient expression from high to low in the tissues of the fore-intestine, hind-intestine, liver, mid-intestine, kidney, muscle, spleen and heart. APN expression in grass carp had a circadian pattern, showing time-dependent higher expression between 06:00 and 18:00 and lower expression between 18:00 and 06:00. In addition, the protein levels and resource in the diet-regulated APN expression suggested that low crude protein (CP) level and fish meal stimulated APN gene expression. Furthermore, the mRNA expression of APN in the intestine was significantly suppressed by high concentrations of glutamine and glutamine dipeptides, respectively. This study may provide valuable knowledge on the regulation of APN expression in teleost, which has potential applications for improving fish dietary formulations.