Department of Entomology, Purdue University, 901 West State Street, West Lafayette, IN 47907, USA.
Insect Biochem Mol Biol. 2011 Aug;41(8):563-71. doi: 10.1016/j.ibmb.2011.03.008. Epub 2011 Mar 30.
Advancements in tick neurobiology may impact the development of acaricides to control those species that transmit human and animal diseases. Here, we report the first cloning and pharmacological characterization of two neurotransmitter binding G protein-coupled receptors in the Lyme disease (blacklegged) tick, Ixodes scapularis. The genes IscaGPRdop1 and IscaGPRdop2 were identified in the I. scapularis genome assembly and predicted as orthologs of previously characterized D(1)-like dopamine receptors in the fruit fly Drosophila melanogaster and honeybee Apis mellifera. Heterologous expression in HEK 293 cells demonstrated that each receptor functioned as a D(1)-like dopamine receptor because significant increases in levels of intracellular cyclic adenosine monophosphate (cAMP) were detected following dopamine treatment. Importantly, the receptors were distinct in their pharmacological properties regarding concentration-dependent response to dopamine, constitutive activity, and response to other biogenic amines. Exposure to a variety of dopamine receptor agonists and antagonists further demonstrated a D(1)-like pharmacology of these dopamine receptors and highlighted their differential activities in vitro.
蜱类神经生物学的进展可能会影响杀蜱剂的开发，以控制那些传播人类和动物疾病的蜱种。在这里，我们报告了莱姆病（黑腿）蜱（Ixodes scapularis）中两种神经递质结合 G 蛋白偶联受体的首次克隆和药理学特征。在 I. scapularis 基因组组装中鉴定出 IscaGPRdop1 和 IscaGPRdop2 基因，并预测为果蝇 Drosophila melanogaster 和蜜蜂 Apis mellifera 中先前表征的 D(1)-样多巴胺受体的同源物。在 HEK 293 细胞中的异源表达表明，每个受体都作为 D(1)-样多巴胺受体发挥作用，因为在多巴胺处理后检测到细胞内环腺苷酸（cAMP）水平显著增加。重要的是，这些受体在多巴胺浓度依赖性反应、组成性活性和对其他生物胺的反应方面具有不同的药理学特性。暴露于各种多巴胺受体激动剂和拮抗剂进一步证明了这些多巴胺受体具有 D(1)-样药理学，并突出了它们在体外的不同活性。
