摘要
嗅觉受体是参与昆虫嗅觉识别过程的一类重要蛋白。在昆虫的众多嗅觉受体中,有一类受体明显不同于其他受体,被称为Orco。该受体基因在不同昆虫种间高度保守,且表达广泛。Orco在昆虫嗅觉识别过程中发挥关键作用。采用基因突变或RNAi等技术使Orco基因沉默后,昆虫会出现严重的嗅觉缺陷,但Orco本身不与气味配体结合,它与传统嗅觉受体形成复合体Or-Orco,促进传统嗅觉受体在神经元树突膜上的定位并维持其稳定性,提高传统嗅觉受体对气味反应的效率。昆虫嗅觉受体的结构与脊椎动物的G蛋白偶联受体相似,均有7个跨膜区,但二者的膜拓扑结构相反,昆虫嗅觉受体的N末端位于细胞质膜内,C末端在细胞质膜外,Orco与传统嗅觉受体通过保守的C末端区域相互作用形成一种新型的配体门控离子通道——Or-Orco复合体。阐明Orco在昆虫嗅觉识别中的功能机制,可为开创基于昆虫嗅觉行为干扰的新的害虫防治措施提供基础。
Insect olfactory receptors are important proteins which are required for the insect olfactory identification process. As a receptor strikingly different from all other insect olfactory receptors, Orco is highly conserved in insect species and widely expressed. Orco plays a critical role in insect olfaction. Insects show severe olfaction defects when Orco is silenced by gene targeting or RNA interference. Orco can form heteromeric complexes by binding the conventional olfactory receptors rather than binding odorant ligands to facilitate the localization and stability of the conventional olfactory receptors in the olfactory sensory neurons （OSNs） dendrites and improve efficient odor response of conventional olfactory receptors. The structure of insect olfactory receptors is similar to the G protein-coupled receptors （GPCRs） of vertebrates with seven transmembrane regions. However, they adopt a membrane topology distinct from that of GPCRs, with their N-termini located intracellularly and C-termini located extracellularly. Orco interacts with the conventional olfactory receptors forming the Or-Orco complexes by the conserved C-terminal region wihch is a new ligand-gated ion channel. Clarifying the functional mechanism of Orco in insect olfaction recognition may provide the basis for developing a new pest control measures based on insect olfactory behavior interference.
出处
《昆虫学报》
CAS
CSCD
北大核心
2013年第10期1208-1216,共9页
Acta Entomologica Sinica
基金
国家重点基础研究发展规划("973"计划)项目(2012CB114603)
国家自然科学基金项目(31240037)
山东省海外高层次人才专项基金项目(72019)
关键词
昆虫
嗅觉受体
Orco
表达特征
功能
结构
Insect
olfactory receptor
Orco
expression characterization
function
structure
作者简介
尹淑艳，女，1973年生，山东莱阳人，博士，副教授，研究方向为昆虫（螨类）化学生态学，E-mml：shuyany@163．com
通讯作者Corresponding author，E—mail：liuqingxin@sdau．edu．cn
