Identification of the Translation Start Site of the Human Melanocortin 3 Receptor
Identification of the Translation Start Site of the Human Melanocortin 3 Receptor
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DOI：
10.1159/000336070
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发表时间：
2012-03-01
期刊：
影响因子：
3.6
通讯作者：
Biebermann, Heike
中科院分区：
文献类型：
--
作者：
Tarnow, Patrick;Rediger, Anne;Biebermann, Heike
背景：黑素皮质素-3受体(MC3R)是参与下丘脑能量代谢的G蛋白偶联受体。到目前为止，人们认为人MC3R的翻译始于非保守的第一个ATG，然而，第二个进化保守的ATG位于下游37个氨基酸。一种常见的多态T6K位于这两个ATG之间。方法：将编码较长和较短形式的人MC3R的真核表达载体分别导入COS-7细胞，以鉴定两种可能的起始ATG。对cAMP的信号转导特性进行了测定。用双抗体夹心法测定细胞表面表达。用基于GFP的方法研究了MC3R的翻译起点。结果：长受体和短受体的信号转导具有可比性。通过氨基末端血凝素标记的细胞表面表达只能在较短的形式中检测到，而在较长的形式中不能检测到。在我们的研究中，我们发现人类MC3R蛋白的翻译始于进化保守的ATG密码子，这导致了比先前假设的更短的蛋白质。结论：T6K基因多态不位于人类MC3R的编码区，对翻译起始没有影响，因此不太可能对体重产生影响。版权所有(C)2012 S.Karger GmbH，Freiburg
Background: The melanocortin-3-receptor (MC3R) is a G-protein coupled receptor participating in hypothalamic energy metabolism. So far, it was assumed that the translation of the human MC3R starts at the non-conserved first ATG, however, a second evolutionary conserved ATG is located 37 amino acids downstream. One frequent polymorphism, T6K, is located between these two ATGs. Methods: For characterization of the two potential start ATGs, COS-7 cells were transfected with plasmids encoding the longer and the shorter form of the human MC3R. For signal transduction properties, cAMP was measured. Cell surface expression was determined by using an ELISA method. The translational start point of the MC3R was investigated by a GFP-based method. Results: Signal transduction was comparable for the long and the short receptor form. Cell surface expression via aminoterminal hemagglutinin tag could only be detected in the shorter form, but not in the longer one. In our study we show that the translation of the human MC3R protein starts at the evolutionary conserved ATG codon which results in a shorter protein than previously assumed. Conclusion: The polymorphism T6K is not located in the coding region of the human MC3R and has no influence on translation initiation which makes an impact on body weight unlikely. Copyright (C) 2012 S. Karger GmbH, Freiburg