Translational analysis of functional variation in human dopamine beta?hydroxylase

描述（由申请人提供）： 项目概要：多巴胺2-羟化酶（DBH）催化多巴胺（DA）合成神经递质去甲肾上腺素（NE），从而调节两种分子的水平。DBH在人血清中是可检测的，其中其活性在很大程度上反映了结构基因座DBH处的序列变异。我们鉴定了转录起始位点上游970 bp的单核苷酸多态性（SNP）（-970C>T），其占血清DBH活性总变异的30-50%，其中“T”等位基因与比“C”等位基因低的活性相关，呈共显性模式。我们在群体遗传水平上的工作和来自另一个实验室的分子实验提供了强有力的证据，证明-970C>T是一个真正的调节变体，影响DBH的转录。然而，分子实验表明，低血清DBH T等位基因与更大的转录。因此，-970 C>T如何在体内调节DBH表达尚不清楚。本项目提出使用BAC转基因，然后与缺乏内源性DBH表达的Dbh -/-小鼠杂交，以研究脑、肾上腺髓质和血清中与T或C等位基因相关的DBH表达，所述等位基因在~170 kb的其他方面相同的人类序列背景下。该项目将为公共卫生研究的多个领域提供信息，包括精神病，情绪障碍，药物成瘾，神经退行性疾病和人类血压疾病的研究，因为血清DBH和/或-970C>T的变化与所有这些疾病相关的人类表型的重要方面有关。拟议的工作将产生一个有价值的和创新的动物模型，调查NE介导的神经传递的遗传变异的许多方面。

DESCRIPTION (provided by applicant): Project Summary: Dopamine 2-hydroxylase (DBH) catalyzes synthesis of the neurotransmitter norepinephrine (NE) from dopamine (DA), and thereby regulates levels of both molecules. DBH is detectable in human serum, where its activity largely reflects sequence variation at the structural locus DBH. We identified a single nucleotide polymorphism (SNP) 970 bp upstream of the transcriptional start site (-970C>T) that accounts for 30-50% of the total variance in serum DBH activity, with the "T" allele being associated with lower activity than the "C" allele, in a co-dominant pattern. Our work on a population-genetic level, and molecular experiments from another laboratory provide strong evidence that -970C>T is a true regulatory variant, affecting transcription of DBH. However, the molecular experiments suggested that the low-serum-DBH T allele associates with greater transcription. Thus, how -970C>T regulates DBH expression in vivo is not clear. The present project proposes to use BAC transgenesis, followed by crossing with Dbh -/- mice lacking endogenous DBH expression, to investigate DBH expression in brain, adrenal medulla and serum, associated with either the T or C allele in an otherwise identical human-sequence context of ~170 kb. This project will inform multiple areas of public health research, including studies of psychosis, mood disorders, drug addiction, neuro-degenerative disorders, and disorders of human blood pressure, as variation in serum DBH and/or -970C>T associates with important aspects of human phenotypes related to all of those disorders. The proposed work will produce a valuable and innovative animal model for investigation of many aspects of genetic variation in NE-mediated neurotransmission.