1. Academic Validation
  2. Molecular identification and functional analysis of Niemann-Pick type C2 proteins,carriers for semiochemicals and other hydrophobic compounds in the brown dog tick, Rhipicephalus linnaei

Molecular identification and functional analysis of Niemann-Pick type C2 proteins,carriers for semiochemicals and other hydrophobic compounds in the brown dog tick, Rhipicephalus linnaei

  • Pestic Biochem Physiol. 2023 Jun:193:105451. doi: 10.1016/j.pestbp.2023.105451.
Dejuan Liang 1 Huaqing Chen 1 Liping An 1 Yao Li 1 Peizhen Zhao 1 Archana Upadhyay 1 Bill S Hansson 2 Jianguo Zhao 3 Qian Han 4
Affiliations

Affiliations

  • 1 Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life Sciences, Hainan University, Haikou, Hainan 570228, China; One Health Institute, Hainan University, Haikou, Hainan 570228, China.
  • 2 Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany.
  • 3 Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life Sciences, Hainan University, Haikou, Hainan 570228, China; One Health Institute, Hainan University, Haikou, Hainan 570228, China. Electronic address: jianguolxx@hainanu.edu.cn.
  • 4 Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life Sciences, Hainan University, Haikou, Hainan 570228, China; One Health Institute, Hainan University, Haikou, Hainan 570228, China. Electronic address: qianhan@hainanu.edu.cn.
Abstract

Ticks are important vectors of many pathogens with tremendous impact on human and animal health. Studies of semiochemical interactions and mechanisms underlying chemoreception can provide important tools in tick management. Niemann-Pick type C2 (NPC2) proteins have been proposed as one type of chemoreceptor in arthropods. Here, we cloned two NPC2 genes in the brown dog tick, Rhipicephalus linnaei, the tropical lineage previously named R. sanguineus sensu lato and characterized them functionally. R.linNPC2a and R.linNPC2b genes were found to be expressed at each developmental stage with the highest level in adult males. By using quantitative Real-Time PCR we revealed expression in multiple tissues, including midgut, ovary, salivary glands and legs. Ligand binding analysis revealed that R.linNPC2b bound a wide spectrum of compounds, with β-ionone, α-amylcinnamaldehyde, 2-nitrophenol and benzaldehyde displaying the strongest binding affinity (Ki < 10 μM), whereas R.linNPC2a showed a more narrow ligand binding range, with intermediate binding affinity to α-amylcinnamaldehyde and 2-nitrophenol (Ki < 20 μM). Molecular docking indicated that the amino acid residue Phe89, Leu77 and Val131 of R.linNPC2a and Phe70, Leu132 and Phe73 of R.linNPC2b could bind multiple ligands. These residues might thus play a key role in the identification of the volatiles. Our results contribute to the understanding of olfactory mechanisms of R. linnaei and can offer new pathways towards new management strategies.

Keywords

Binding sites; Molecular docking; Niemann-Pick type C2 protein; Rhipicephalus; Semiochemical; Tick.

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