Primary characterization of a putative novel TBC1 domain family member 13 from Haemaphysalis qinghaiensis

Abstract

A putative novel TBC1 domain family member 13 (HqTBC1D13) from Haemaphysalis qinghaiensis was cloned using rapid amplification of the cDNA ends (RACE), the HqTBC1D13 cDNA is 1702bp in length and encodes 396 amino acid residues with predicted molecular weight of 46.09kDa. The TBC-domain containing protein has a catalytic 'arginine finger' analogous to those of Ras and Rho family GAPs, which is critical determinants of GAP activity. The amino acid sequences of TBC domain were evolutionarily highly conserved across species. The partial coding sequence of HqTBC1D13 with the predicted molecular weight of 37.2kDa was expressed and purified in the PGEX-4T-1 vector. Real-time RT PCR analysis showed that the HqTBC1D13 was extensively expressed in the tested organs (salivary glands, midguts, ovaries and cuticles), and its transcriptional levels in salivary glands were significantly up-regulate induced by blood-feeding. The recombinant HqTBC1D13 protein vaccination in the rabbit model resulted in the extension of the duration of feeding and the reduction of 37% female engorgement and 14.8% oviposition compared to the control group. These results indicated that the HqTBC1D13 in ticks could be invovled in the regulation of feeding and oviposition.

Keywords: Characterization; Haemaphysalis qinghaiensis; TBC1D13; Tick; Vaccination.