title: Identification and anticoagulant activity of a novel Kunitz-type protein HA11 from the salivary gland of the tick Hyalomma asiaticum.
abstract: Kunitz/bovine pancreatic trypsin inhibitor proteins are abundant in the salivary glands of ticks and perform multiple functions in blood feeding, including inhibiting blood coagulation, regulating host blood supply and disrupting host angiogenesis. In this study, we identified a novel gene designated HA11 (Hyalomma asiaticum 11 kDa protein) from the salivary gland of the tick H. asiaticum. HA11 is encoded by a gene with an open reading frame of 306 bp that is translated into a deduced 101 amino acid 11 kDa protein that shares 27% sequence identity with a Kunitz-like protease inhibitor precursor in Amblyomma variegatum. Bioinformatic analysis confirmed HA11 as a member of the Kunitz-type family of inhibitors. Real time-PCR detected HA11 mRNA transcripts in tick larvae and nymphae stages, with levels highest in salivary gland tissue, and transcription was induced by blood feeding. HA11 anticoagulant activity was demonstrated by its ability to delay normal clotting of rabbit plasma in an activated partial thromboplastin time assay. Furthermore, RNA interference confirmed that HA11 influences H. asiaticum development and blood feeding, and the recombinant protein exerted low hemolytic activity. These results suggest HA11 is a novel Kunitz-type anticoagulant protein involved in tick blood feeding that may have potential as an anticoagulant drug or vaccine.
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 518 Ziyue Road, Minhang District, Shanghai, 200241, China.
authors.forename: Houshuang
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 518 Ziyue Road, Minhang District, Shanghai, 200241, China.
authors.forename: Ruiqiong
authors.initials: R
authors.lastname: Qiao
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 518 Ziyue Road, Minhang District, Shanghai, 200241, China.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Gong
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 518 Ziyue Road, Minhang District, Shanghai, 200241, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Cao
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 518 Ziyue Road, Minhang District, Shanghai, 200241, China.
authors.forename: Yongzhi
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 518 Ziyue Road, Minhang District, Shanghai, 200241, China. jinlinzhou@shvri.ac.cn.|Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China. jinlinzhou@shvri.ac.cn.
authors.forename: Jinlin
authors.initials: J
authors.lastname: Zhou
mesh_terms: D000818:Animals; D000925:Anticoagulants / Q000302:isolation & purification* / Q000494:pharmacology; D015536:Down-Regulation; D005260:Female; D015723:Gene Library; D017344:Genes, Insect; D019476:Insect Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000494:pharmacology; D026863:Ixodidae / Q000737:chemistry* / Q000235:genetics; D008018:Life Cycle Stages; D034622:RNA Interference; D011817:Rabbits; D011994:Recombinant Proteins / Q000235:genetics; D012469:Salivary Glands / Q000737:chemistry
chemical_list: D000925:Anticoagulants; D019476:Insect Proteins; D011994:Recombinant Proteins
keywords: HA11; Hyalomma asiaticum; Kunitz-type anticoagulant protein; Salivary gland