Gong Haiyan, Liao Min, Zhou Jinlin, Hatta Tekeshi, Huang Penglong, Zhang Guohong, Kanuka Hirotaka, Nishikawa Yoshifumi, Xuan Xuenan, Fujisaki Kozo
National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan.
Vet Parasitol. 2008 Feb 14;151(2-4):268-78. doi: 10.1016/j.vetpar.2007.11.015. Epub 2007 Nov 19.
Ribosomal protein P0 has been demonstrated to be a multifunctional protein in the large subunit of eukaryotic ribosome. In this study, a gene encoding ribosomal protein P0 termed HlP0 was isolated from a full-length salivary gland cDNA library previously constructed from the tick Haemaphysalis longicornis. The full-length cDNA of the HlP0 gene is 1141 bp, with an open reading frame (ORF) of 963 bp. The ORF of the HlP0 gene encodes a putative protein of 320 amino acid residues, with a predicted molecular mass of 35 kDa. Reverse transcription-polymerase chain reaction (RT-PCR) analysis indicated that the HlP0 gene transcript was expressed in all developmental stages and all tissues dissected from 4-day-fed adult ticks. Antibodies raised against recombinant HlP0 recognized a native protein with an expected molecular size of 35 kDa in all tested tissues. RNA interference of HlP0 gene was carried out by injecting ticks with PBS, green fluorescent protein (GFP) dsRNA, and HlP0 dsRNA. The results showed that ticks treated with HlP0 dsRNA obtained a strikingly lower body weight (2.63+/-1.21 mg vs. 226.75+/-74.80 mg in the PBS-injected group and 231.15+/-51.32 mg in the GFP dsRNA-injected group, Student's t-test, P<0.01), a lower engorgement rate (4% vs. 100% and 94.11%, respectively), and higher mortality (96% vs. 2.5% and 10.4%, respectively) after blood-sucking than the control groups. This suggests that ribosomal protein P0 is required for the blood ingestion and subsequent viability of H. longicornis. This is the first report of ribosomal protein P0 from ticks.
核糖体蛋白P0已被证明是真核核糖体大亚基中的一种多功能蛋白。在本研究中，从先前构建的长角血蜱唾液腺全长cDNA文库中分离出一个编码核糖体蛋白P0的基因，命名为HlP0。HlP0基因的全长cDNA为1141 bp，开放阅读框（ORF）为963 bp。HlP0基因的ORF编码一个由320个氨基酸残基组成的推定蛋白，预测分子量为35 kDa。逆转录-聚合酶链反应（RT-PCR）分析表明，HlP0基因转录本在4日龄成年蜱虫的所有发育阶段和所有解剖组织中均有表达。针对重组HlP0产生的抗体在所有测试组织中识别出一种预期分子量为35 kDa的天然蛋白。通过向蜱虫注射PBS、绿色荧光蛋白（GFP）双链RNA和HlP0双链RNA对HlP0基因进行RNA干扰。结果显示，用HlP0双链RNA处理的蜱虫在吸血后的体重显著降低（2.63±1.21 mg，而注射PBS组为226.75±74.80 mg，注射GFP双链RNA组为231.15±51.32 mg，学生t检验，P<0.01），饱血率较低（分别为4%，而对照组为100%和94.11%），死亡率较高（分别为96%，而对照组为2.5%和10.4%）。这表明核糖体蛋白P0是长角血蜱吸血及后续生存所必需的。这是关于蜱虫核糖体蛋白P0的首次报道。
