Allelic expression imbalance of human mu opioid receptor (OPRM1) caused by variant A118G
Allelic expression imbalance of human mu opioid receptor (OPRM1) caused by variant A118G
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DOI：
10.1074/jbc.m504942200
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发表时间：
2005-09-23
影响因子：
4.8
通讯作者：
Sadée, W
中科院分区：
文献类型：
--
作者：
Zhang, Y;Wang, DX;Sadée, W
作为阿片类药物和肽的主要靶点，μ阿片受体（OPRM 1）在疼痛感知和成瘾中起着关键作用。OPRM 1的遗传变异与药物成瘾的易感性有关，特别是单核苷酸多态性A118 G，导致N40 D取代，等位基因频率为10 - 32%，功能不确定。我们以A118 G为标记物，检测了人尸检脑组织中OPRM 1的等位基因特异性mRNA表达。在8个杂合子样本中，A118 mRNA等位基因的丰度是G118等位基因的1.5 - 2.5倍。转染到中国仓鼠卵巢细胞的cDNA仅代表OPRM 1的编码区，携带腺苷，鸟苷，胞苷，和胸苷的位置118，导致1.5倍的低mRNA水平仅为OPRM 1- G118，和超过10倍的低OPRM 1蛋白质水平，通过蛋白质印迹和受体结合测定。转染后，抑制转录与放线菌素D，mRNA周转分析未能揭示A118和G118等位基因之间的mRNA稳定性的差异，表明在转录或mRNA成熟的缺陷。这些结果表明，OPRM 1- G118是对mRNA和蛋白质产量具有有害影响的功能变体。阐明与复杂疾病（如药物成瘾）易感性相关的多态性的功能相关性为临床关联研究提供了基础。
As a primary target for opioid drugs and peptides, the mu opioid receptor ( OPRM1) plays a key role in pain perception and addiction. Genetic variants of OPRM1 have been implicated in predisposition to drug addiction, in particular the single nucleotide polymorphism A118G, leading to an N40D substitution, with an allele frequency of 10 - 32%, and uncertain functions. We have measured allele- specific mRNA expression of OPRM1 in human autopsy brain tissues, using A118G as a marker. In 8 heterozygous samples measured, the A118 mRNA allele was 1.5 - 2.5- fold more abundant than the G118 allele. Transfection into Chinese hamster ovary cells of a cDNA representing only the coding region of OPRM1, carrying adenosine, guanosine, cytidine, and thymidine in position 118, resulted in 1.5- fold lower mRNA levels only for OPRM1- G118, and more than 10- fold lower OPRM1 protein levels, measured by Western blotting and receptor binding assay. After transfection and inhibition of transcription with actinomycin D, analysis of mRNA turnover failed to reveal differences in mRNA stability between A118 and G118 alleles, indicating a defect in transcription or mRNA maturation. These results indicate that OPRM1- G118 is a functional variant with deleterious effects on both mRNA and protein yield. Clarifying the functional relevance of polymorphisms associated with susceptibility to a complex disorder such as drug addiction provides a foundation for clinical association studies.