Vasopressin-like peptide and its receptor function in an indirect diuretic signaling pathway in the red flour beetle
Vasopressin-like peptide and its receptor function in an indirect diuretic signaling pathway in the red flour beetle
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DOI：
10.1016/j.ibmb.2008.04.006
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发表时间：
2008-07-01
影响因子：
3.8
通讯作者：
Park, Yoonseong
中科院分区：
文献类型：
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作者：
Aikins, Michael J.;Schooley, David A.;Park, Yoonseong
昆虫精氨酸抗利尿素样肽（AVPL）因其在利尿调节中的潜在功能而受到特别关注。红粉甲虫Tribolium castaneum的基因组序列获得了编码AVPL和AVPL受体的基因，而果蝇、疟蚊、家蚕和蜜蜂的基因组中没有同源序列，尽管最近的一项研究发现了一个AVPL序列。AVPL的Tribolium受体是第一个在昆虫中发现的此类受体，在报告系统中表达，并对AVPL F1（具有分子内二硫键的单体形式）表现出强烈的响应（EC50 = 1.5 nM）。除了鉴定AVPL受体外，我们还证明了它具有体内利尿活性，但它对马氏小管没有直接作用。然而，当中枢神经系统、心体和缓动体与肽和马氏小管一起孵育时，后者受到AVPL肽的刺激，提示其间接作用。综上所述，我们认为AVPL在Tribolium中作为单体发挥作用，通过中枢神经系统包括心体和异形体在内的内分泌器官间接刺激马氏小管。在幼虫后期的RNA干扰成功地抑制了avpl和avpl受体的mRNA水平，但没有导致死亡或表型异常，这意味着avpl信号通路在全代谢昆虫的早期谱系中几乎是不可缺少的。(C) 2008 Elsevier Ltd版权所有。
The insect arginine vasopressin-like (AVPL) peptide is of special interest because of its potential function in the regulation of diuresis. Genome sequences of the red flour beetle Tribolium castaneum yielded the genes encoding AVPL and AVPL receptor, whereas the homologous sequences are absent in the genomes of the fruitfly, malaria mosquito, silkworm, and honeybee, although a recent genome sequence of the jewel wasp revealed an AVPL sequence. The Tribolium receptor for the AVPL, the first such receptor identified in any insect, was expressed in a reporter system, and showed a strong response (EC50 = 1.5 nM) to AVPL F1, the monomeric form having an intramolecular disulfide bond. In addition to identifying the AVPL receptor, we have demonstrated that it has in vivo diuretic activity, but that it has no direct effect on Malpighian tubules. However, when the central nervous system plus corpora cardiaca and corpora allata are incubated along with the peptide and Malpighian tubules, the latter are stimulated by the AVPL peptide, suggesting it acts indirectly. Summing up all the results from this study, we conclude that AVPL functions as a monomer in Tribolium, indirectly stimulating the Malpighian tubules through the central nervous system including the endocrine organs corpora cardiaca and corpora allata. RNA interference in the late larval stages successfully suppressed mRNA levels of avpl and avpl receptor, but with no mortality or abnormal phenotype, implying that the AVPL signaling pathway may have been near-dispensable in the early lineage of holometabolous insects. (C) 2008 Elsevier Ltd. All rights reserved.