Characterization of primary structure and tissue expression profile of the chicken apical sodium-dependent bile acid transporter mRNA
Characterization of primary structure and tissue expression profile of the chicken apical sodium-dependent bile acid transporter mRNA
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DOI：
10.3382/ps/pev027
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发表时间：
2015-04-01
期刊：
影响因子：
4.4
通讯作者：
Tanaka, M.
中科院分区：
文献类型：
--
作者：
Nakao, N.;Kaneda, H.;Tanaka, M.
回肠顶端钠依赖性胆汁酸协同转运蛋白（ASBT）在胆汁酸的吸收过程中起重要作用。已从哺乳动物和鱼类中克隆了ASBT cDNA，并对蛋白质的一级结构和mRNA的表达特性进行了表征。本研究利用cDNA克隆技术对鸡ASBT mRNA进行了鉴定。鸡ASBT cDNA由91 bp的5 '非翻译区、1，083 bp的编码区和1，896 bp的3'非翻译区组成。该cDNA编码一个360个氨基酸的蛋白质，与哺乳动物和鱼类ASBT具有显著的序列同一性。已知参与哺乳动物ASBT功能的氨基酸残基在鸡ASBT中是保守的。实时聚合酶链反应分析表明，鸡ASBT mRNA的表达水平显着较高的回肠和近端结肠/直肠，相对较低的水平，在肾脏，空肠和盲肠的水平非常低。回肠中的表达水平在孵化后显著增加，在孵化后第7天达到最高水平，然后下降到成人水平。在近端结肠/直肠中观察到类似的表达模式，除了从孵化后第7天到孵化后第21天显著降低。这些结果表明，鸡ASBT功能作为胆汁酸转运体在回肠和近端结肠/直肠，特别是在早期postthatching期间。
The ileal apical sodium-dependent bile acid cotransporter (ASBT) plays an essential role in the absorption of bile acids from intestinal lumina. ASBT cDNA has been cloned from mammalian and fish species, and the primary structure of the protein and expression properties of the mRNA have been characterized. In this study, we identified chicken ASBT mRNA by cDNA cloning. Chicken ASBT cDNA consisted of 91 bp of the 5'-untranslated region, 1,083 bp of the coding region, and 1,896 bp of the 3'-untranslated region. The cDNA encoded a protein of 360 amino acids showing significant sequence identity with mammalian and fish ASBT. The amino acid residues known to participate in the functions of mammalian ASBT were conserved in chicken ASBT. Real-time polymerase chain reaction analysis revealed that chicken ASBT mRNA was expressed at markedly higher levels in the ileum and proximal colon/rectum, relatively lower levels in the kidney, and very low levels in the jejunum and cecum. Expression levels in the ileum markedly increased after hatching, reached the highest levels on day 7 posthatching, and then decreased to adult levels. A similar expression pattern was observed in the proximal colon/rectum except for the significant decrease from day 7 posthatching to day 21 posthatching. These results suggest that chicken ASBT functions as a bile acid transporter in the ileum and proximal colon/rectum, particularly during the early posthatching period.