Male tarsi specific odorant-binding proteins in the diving beetle Cybister japonicus sharp.
Male tarsi specific odorant-binding proteins in the diving beetle Cybister japonicus sharp.
复制标题
潜水甲虫 Cybister japonicus Sharp 中的雄性跗节特异性气味结合蛋白
DOI：
10.1038/srep31848
复制
发表时间：
2016-08-22
影响因子：
4.6
通讯作者：
Ban LP
中科院分区：
文献类型：
--
作者：
Song LM;Jiang X;Wang XM;Li JD;Zhu F;Tu XB;Zhang ZH;Ban LP
气味结合蛋白（OBPs）在昆虫的化学通讯中起着关键作用，因为它们识别环境化学信号并将其运输给受体。龙虱（Cybister japonicus Sharp）表现出显著的性别二态性。雄性的前足跗节配备有大吸盘，据信有助于在水下求偶和交配时抓住雌性。在此，我们鉴定出两种在雄性跗节中高度特异性表达的OBPs，这表明这些结构在化学通讯中具有重要功能。第一种蛋白质，CjapOBP1，具有经典OBPs的6个保守半胱氨酸基序，而第二种，CjapOBP2，仅含有4个半胱氨酸，可归为C - 缺失OBPs亚类。两种蛋白质都在细菌系统中表达，纯化的重组蛋白用于制备抗体。蛋白质印迹分析表明，CjapOBP1主要在雄性跗节中表达，在两性的触角和须中也可检测到，而CjapOBP2除了在雄性跗节中，在睾丸中也存在。配体结合实验表明，CjapOBP1、CjapOBP2分别与柠檬醛和松柏醛具有良好的结合亲和力。这些结果支持这两种OBPs在龙虱雄性前足跗节的化学通讯中可能具有的功能。
Odorant binding proteins (OBPs) play critical roles in chemical communication of insects, as they recognize and transport environmental chemical signals to receptors. The diving beetle Cybister japonicus Sharp shows a remarkable sexual dimorphism. The foreleg tarsi of males are equipped with large suction cups, believed to help holding the female during underwater courtship and mating. Here, we identified two OBPs highly and specifically expressed in male tarsi, suggesting important functions of these structures in chemical communication. The first protein, CjapOBP1, exhibits the 6 conserved cysteines motif of classic OBPs, while the second, CjapOBP2, contains only four cysteines and can be assigned to the sub-class of C-minus OBPs. Both proteins were expressed in a bacterial system and the purified recombinant proteins were used to for antibodies preparation. Western Blot analysis showed that CjapOBP1 is predominantly expressed in male tarsi and could be also detected in antennae and palpi of both sexes, while CjapOBP2, besides male tarsi, is also present in testis. Ligand-binding experiments showed a good binding affinity between CjapOBP1, CjapOBP2 and citral and coniferyl aldehyde, respectively. These results support a possible function of these two OBPs in the male foreleg tarsi of diving beetles in chemical communication.