SIGNAL TRANSDUCTION OF THE D2 DOPAMINE RECEPTOR SUBTYPES

描述：(改编自申请者的摘要)这一目标 研究建议是阐明两种异构体的信号转导。 D2多巴胺受体。这些受体是另一种剪接形式的 相同的基因，在蛋白质水平上不同，增加了29个氨基酸 在第三个细胞质环中的酸，产生长和短的形式。这个 两种异构体在所有组织中共表达，尽管比例不同。 先前的研究表明，这两种受体与不同的胃肠道结合 调节细胞效应物的蛋白质，如腺苷环化酶。这 提案将侧重于阐明每个亚型的区域，这些区域是 负责其与G蛋白的特异性相互作用。该方法 提出了在异构体和表达中创建点突变 在特定的胃肠道疾病背景下评估这些突变体的功能。vbl.使用 这种方法将允许定义氨基酸，它规定了 受体-G蛋白相互作用的特异性。最终，我们的目标是 阐明这些异构体的哪些氨基酸残基负责 受体-G蛋白界面的特异性。的具体目标 这一建议是为了：1)在D2s和D2s中创建相同的点突变 D2L2)在胃肠道特异性背景中表达突变受体3)评估 突变对腺苷环化酶信号的影响评估其影响 突变对G蛋白物理相互作用的影响。D2多巴胺 受体与几种疾病有关，如帕金森氏症和 精神分裂症；了解支配精神分裂症特异性的机制 D2多巴胺受体的信号传递可能具有重要意义 被认为是由多巴胺能功能障碍引起的疾病。

DESCRIPTION: (adapted from the applicant's abstract) The goal of this research proposal is to elucidate the signaling of the two isoforms of the D2 dopamine receptor. These receptors are alternative splice forms of the same gene, which differ at the protein level by the addition of 29 amino acids in the third cytoplasmic loop, generating a long and short form. The two isoforms are co-expressed in all tissues, albeit in varying ratios. Previous work has shown that these two receptors couple to distinct Gi proteins to regulate cellular effectors, such as adenylyl cyclase. This proposal will focus on elucidating the regions of each isoform which are responsible for its specific interaction with G proteins. The approach proposed is the creation of point mutations in both isoforms and expression of these mutants in a Gi-specific background to assess functionality. Using this approach will allow the definition of amino acids which dictate the specificity of receptor-G protein interaction. Ultimately, the goal is to elucidate which amino acids residues of these isoforms are responsible for the specificity at the receptor-G protein interface. The specific aims of this proposal are to: 1) create identical point mutations in both D2s and D2l 2) express the mutant receptors in a Gi specific background 3) assess the effect of mutation on signaling to adenylyl cyclase 4) assess the effect of mutation on the physical interaction with G proteins. The D2 dopamine receptors are implicated in several diseases, such as Parkinson's and schizophrenia; understanding the mechanisms that govern the specificity of the signaling of the D2 dopamine receptors may have important implications in disorders thought to result from dopaminergic dysfunction.