Genomic organization and tissue-specific expression of hepcidin in the pacific mutton hamlet, Alphestes immaculatus (Breder, 1936).
Genomic organization and tissue-specific expression of hepcidin in the pacific mutton hamlet, Alphestes immaculatus (Breder, 1936).
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DOI：
10.1016/j.fsi.2011.10.007
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发表时间：
2011-12
影响因子：
4.7
通讯作者：
J. Masso-Silva;G. Diamond;M. Macías-Rodríguez;F. Ascencio
中科院分区：
文献类型：
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作者：
J. Masso-Silva;G. Diamond;M. Macías-Rodríguez;F. Ascencio
Hepcidin 是一种富含半胱氨酸的肽，参与铁代谢、炎症反应和抗菌肽。尽管已在多种鱼类中发现了铁调素，但只有少数鱼类得到了完全表征。本研究描述了 Alphestes immaculatus 铁调素抗菌肽 1 (HAMP1) 基因的鉴定和完整分子特征。此外，还通过实时PCR测定了不同组织中其在基础条件和脂多糖（LPS）诱导条件下的特异性表达水平。结果显示，HAMP1基因由3个外显子和2个内含子组成，编码由90个氨基酸组成的前铁调素（24个氨基酸为信号肽，40个氨基酸为前结构域，26个氨基酸为成熟肽）。启动子区域分析揭示了 TATA 盒序列和几个假定的转录因子结合位点。比较分析显示CEBPα、CEBPβ、NF-kB、HNF3、GATA-1和c-Rel是鱼类中最常见的。成熟肽的等电点为8.34，这是鱼类铁调素的平均值。此外，结构模型显示了具有四个假定二硫键的发夹结构。系统发育分析表明，该hepcidin基因属于HAMP1类，与蛇科鱼类Epinephelus moara和南极鱼类Lycodichthys Dearborni归为同一类。最后，肝脏和肌肉中的相对表达水平显示出较高的基础值，而在LPS诱导的鱼中，相对表达趋势发生了变化，其中脾脏和头肾组织中的相对表达水平最高。这项研究描述了 A. immaculatus 的完整特征 HAMP1 基因及其在不同条件和不同组织中的表达水平模式，首次表明肌肉铁调素表达可能与鱼类的免疫反应相关。
Hepcidin is a cysteine-rich peptide involved in iron metabolism, inflammatory response and as antimicrobial peptide. Despite the fact that hepcidins have been identified in several fish species, only few have been completely characterized. This study, described the identification and complete molecular characterization of the hepcidin antimicrobial peptide 1 (HAMP1) gene of Alphestes immaculatus. Moreover, its specific expression level at both basal and lipopolysaccharide (LPS)-induced conditions in different tissues was also determined by real-time PCR. Results showed that the HAMP1gene consists of three exons and two introns encoding a preprohepcidin composed of 90 aa (24 aa for signal peptide, 40 aa for prodomain and 26 aa for mature peptide). The promoter region analysis revealed a TATA box sequence and several putative transcription factor binding sites. A comparative analysis showed CEBPα, CEBPβ, NF-kB, HNF3, GATA-1 and c-Rel as the most common found in fishes. The mature peptide possesses a pI of 8.34, which is the average among fish hepcidin. In addition, the structural modeling showed a hairpin structure with four putative disulfide bonds. A phylogenetic analysis revealed that this hepcidin gene is a HAMP1 class, and is clustered into the same group with the Serranid fish Epinephelus moara and the Antarctic fish Lycodichthys dearborni. Finally, the relative expression levels showed high basal values in liver and muscle, whereas in LPS-induced fish the relative expression tendency changed, with the highest values in spleen and head kidney tissues. This study describes the completely characterized HAMP1 gene of A. immaculatus and their patterns of expression level at different conditions and in different tissues, showing by first time muscle hepcidin expression could be relevant in the immune response in fish.