Honey Bee Dopamine and Octopamine Receptors Linked to Intracellular Calcium Signaling Have a Close Phylogenetic and Pharmacological Relationship
Honey Bee Dopamine and Octopamine Receptors Linked to Intracellular Calcium Signaling Have a Close Phylogenetic and Pharmacological Relationship
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DOI：
10.1371/journal.pone.0026809
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发表时间：
2011-11-11
期刊：
影响因子：
3.7
通讯作者：
Mercer, Alison R.
中科院分区：
文献类型：
--
作者：
Beggs, Kyle T.;Tyndall, Joel D. A.;Mercer, Alison R.
背景：已鉴定出三个在节肢动物物种中高度保守的多巴胺受体基因。其中一个基因，在蜜蜂中被称为Amdo2，显示出与α-肾上腺素能类章鱼胺受体家族的密切系统发育关系。在这项研究中，我们同时研究了AmDOP2和蜜蜂章鱼胺受体AmOA1的功能和药理特性。为了进行比较，我们还检测了蜜蜂多巴胺受体AmDOP1和AmDOP3以及酪胺受体AmTYR1的药理学特性。方法/主要研究结果：使用异源表达蜜蜂生物胺受体的HEK293细胞，我们发现AmDOP2受体的激活与AmOA1受体一样，启动了细胞内钙水平的快速增加。我们没有发现通过AmDOP1、AmDOP3或AmTYR1受体传递钙信号的证据。AMDOP2和AmOA1介导的细胞内钙的增加被10 mU的甲基磷脂抑制，这表明在这个信号通路中需要磷脂酶C-β的活性。Edelfosine对AmDOP2或AmOA1介导的细胞内cAMP升高无影响。合成的化合物米安色林和依匹斯汀，如顺式-(Z)-氟哌醇和螺环酮，被发现对AmDOP2受体有显著的拮抗作用。4个化合物均为AmOA1受体的有效拮抗剂。对可能的配体结合位点的分析提供了一个可能的解释，为什么依匹斯汀作为AmDOP2受体的拮抗剂，但不能阻断AmDOP1介导的反应。结论/意义：我们的结果表明，AmDOP2与AmOA1一样，不仅与cAMP偶联，还与钙信号转导有关，而且这两条信号通路独立于磷脂酶C-β活性的上游。这两种受体的药理特性之间惊人的相似性表明，与受体功能相关的结构特性具有潜在的保守性。综上所述，这些结果有力地支持了系统发育分析，即AmDOP2和AmOA1受体基因是直接平行的。
Background: Three dopamine receptor genes have been identified that are highly conserved among arthropod species. One of these genes, referred to in honey bees as Amdop2, shows a close phylogenetic relationship to the a-adrenergic-like octopamine receptor family. In this study we examined in parallel the functional and pharmacological properties of AmDOP2 and the honey bee octopamine receptor, AmOA1. For comparison, pharmacological properties of the honey bee dopamine receptors AmDOP1 and AmDOP3, and the tyramine receptor AmTYR1, were also examined.Methodology/Principal Findings: Using HEK293 cells heterologously expressing honey bee biogenic amine receptors, we found that activation of AmDOP2 receptors, like AmOA1 receptors, initiates a rapid increase in intracellular calcium levels. We found no evidence of calcium signaling via AmDOP1, AmDOP3 or AmTYR1 receptors. AmDOP2- and AmOA1-mediated increases in intracellular calcium were inhibited by 10 mu M edelfosine indicating a requirement for phospholipase C-beta activity in this signaling pathway. Edelfosine treatment had no effect on AmDOP2-or AmOA1-mediated increases in intracellular cAMP. The synthetic compounds mianserin and epinastine, like cis-(Z)-flupentixol and spiperone, were found to have significant antagonist activity on AmDOP2 receptors. All 4 compounds were effective antagonists also on AmOA1 receptors. Analysis of putative ligand binding sites offers a possible explanation for why epinastine acts as an antagonist at AmDOP2 receptors, but fails to block responses mediated via AmDOP1.Conclusions/Significance: Our results indicate that AmDOP2, like AmOA1, is coupled not only to cAMP, but also to calcium-signalling and moreover, that the two signalling pathways are independent upstream of phospholipase C-beta activity. The striking similarity between the pharmacological properties of these 2 receptors suggests an underlying conservation of structural properties related to receptor function. Taken together, these results strongly support phylogenetic analyses indicating that the AmDOP2 and AmOA1 receptor genes are immediate paralogs.