Characterization of the anticoagulant protein Rhipilin-1 from the Rhipicephalus haemaphysaloides tick
Characterization of the anticoagulant protein Rhipilin-1 from the Rhipicephalus haemaphysaloides tick
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血蜱扇头蜱抗凝蛋白 Rhipilin-1 的表征。
DOI：
10.1016/j.jinsphys.2010.12.001
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发表时间：
2011-02-01
影响因子：
2.2
通讯作者：
Zhou, Jinlin
中科院分区：
文献类型：
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作者：
Gao, Xiao;Shi, Lei;Zhou, Jinlin
为了了解蜱吸血的分子机制，在蜱Rhipicephalus haemaphysaloides中鉴定了抗凝蛋白Rhipilin-1。Rhipilin-1的cDNA序列为620 bp，编码164个氨基酸，分子量为18 kDa。生物信息学分析表明，Rhipilin-1属于Kunitz型抑制剂家族，含有一个与组织因子途径抑制剂（TFPI）高度同源的Kunitz结构域。重组蛋白在大肠杆菌中表达后，在凝血时间（RI）和活化部分凝血活酶时间（APTT）试验中均能延迟家兔血浆的正常凝血。用RT-PCR，Rhipilin-1的mRNA转录检测到在进食蜱，而不是在未进食蜱。用RNAi破坏Rhipilin-1基因导致引入兔耳后24 h蜱附着率降低52.7%，蜱的平均饱血体重降低21.9%。这些结果表明，Rhipilin-1是一种新的抗凝蛋白参与蜱血喂养与未来可能的应用作为疫苗候选。Rhipilin-1的发现是关于该种蜱中抗凝血基因的首次报道。(C)2010爱思唯尔有限公司保留所有权利。
To understand the molecular mechanism of tick blood feeding, an anticoagulant protein, Rhipilin-1, was identified in the tick Rhipicephalus haemaphysaloides. The cDNA sequence of Rhipilin-1 is 620 bp, and it encodes a deduced 164 amino acid protein with a size of 18 kDa. Bioinformatic analysis shows that Rhipilin-1 belongs to the Kunitz-type family of inhibitors, containing one Kunitz domain with high homology to the tissue factor pathway inhibitor (TFPI). The recombinant protein expressed in Escherichia coli delayed normal clotting of rabbit plasma both in the recalcification time (RI) and the activated partial thromboplastin time (APTT) tests. Using RT-PCR, mRNA transcripts of Rhipilin-1 were detected in fed but not in unfed ticks. Disruption of the Rhipilin-1 gene with RNAi led to a 52.7% decrease in the tick attachment rate 24 h after introduction in the rabbit ears and a 21.9% decrease in the average engorged body weight of ticks. These results indicate that Rhipilin-1 is a novel anticoagulant protein involved in tick blood feeding with possible future application as a vaccine candidate. The discovery of Rhipilin-1 is the first report on anticoagulant genes in this species of tick. (C) 2010 Elsevier Ltd. All rights reserved.