Ethanol-modulated camouflage response screen in zebrafish uncovers a novel role for cAMP and extracellular signal-regulated kinase signaling in behavioral sensitivity to ethanol.
Ethanol-modulated camouflage response screen in zebrafish uncovers a novel role for cAMP and extracellular signal-regulated kinase signaling in behavioral sensitivity to ethanol.
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DOI：
10.1523/jneurosci.0714-09.2009
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发表时间：
2009-07-01
期刊：
影响因子：
--
通讯作者：
Guo S
中科院分区：
文献类型：
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作者：
Peng J;Wagle M;Mueller T;Mathur P;Lockwood BL;Bretaud S;Guo S
乙醇是一种被广泛滥用的物质，在体内以浓度依赖的方式引起进化保守的行为反应。对乙醇的这种行为敏感性背后的分子机制知之甚少。虽然基于运动的行为遗传筛选在无脊椎动物模型中识别基因是成功的，但这种复杂的基于行为的筛选被证明很难恢复脊椎动物的基因。在这里，我们报告了斑马鱼对乙醇的一种新的、易处理的反应。利用这种乙醇调节的伪装反应作为筛选实验，我们已经鉴定出一个名为凡塔斯玛(FAN)的斑马鱼突变体，它对乙醇的行为敏感性降低。定位克隆表明，FAN编码5型腺酰环化酶(AC5)。在包括端脑和下丘脑在内的前脑结构中，需要FAN/AC5来维持细胞外信号调节激酶(ERK)的磷酸化。部分抑制野生型斑马鱼ERK的磷酸化类似于在FAN突变体中观察到的对乙醇刺激效应的敏感性降低，而引人注目的是，对ERK磷酸化的强烈抑制使乙醇镇静的刺激量增加。由于之前在果蝇和小鼠身上的研究表明cAMP信号在抑制对乙醇的行为敏感性中起作用，我们的发现揭示了AC信号在促进乙醇敏感性中的一种新的、异构体特异性的作用，并表明下游效应分子ERK的磷酸化水平是行为对乙醇敏感性的关键“把关人”。
Ethanol, a widely abused substance, elicits evolutionarily conserved behavioral responses in a concentration-dependent manner in vivo. The molecular mechanisms underlying such behavioral sensitivity to ethanol are poorly understood. While locomotor-based behavioral genetic screening is successful in identifying genes in invertebrate models, such complex behavior-based screening has proven difficult for recovering genes in vertebrates. Here we report a novel and tractable ethanol response in zebrafish. Using this ethanol-modulated camouflage response as a screening assay, fwe have identified a zebrafish mutant named fantasma (fan), which displays reduced behavioral sensitivity to ethanol. Positional cloning reveals that fan encodes type 5 adenylyl cyclase (AC5). fan/ac5 is required to maintain the phosphorylation of Extracellular-signal-Regulated-Kinase (ERK) in the forebrain structures including the telencephalon and hypothalamus. Partial inhibition of phosphorylation of ERK in wildtype zebrafish mimics the reduction in sensitivity to stimulatory effects of ethanol observed in the fan mutant, whereas, strikingly, strong inhibition of phosphorylation of ERK renders a stimulatory dose of ethanol sedating. Since previous studies in Drosophila and mice show a role of cAMP signaling in suppressing behavioral sensitivity to ethanol, our findings reveal a novel, isoform-specific role of AC signaling in promoting ethanol sensitivity, and suggest that the phosphorylation level of the downstream effector ERK is a critical “gatekeeper” of behavioral sensitivity to ethanol.