Hlcyst-1 and Hlcyst-2 are Potential Inhibitors of HlCPL-A in the Midgut of the Ixodid Tick Haemaphysalis longicornis
Hlcyst-1 and Hlcyst-2 are Potential Inhibitors of HlCPL-A in the Midgut of the Ixodid Tick Haemaphysalis longicornis
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DOI：
10.1292/jvms.09-0561
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发表时间：
2010-05-01
影响因子：
1.2
通讯作者：
Fujisaki, Kozo
中科院分区：
文献类型：
--
作者：
Yamaji, Kayoko;Tsuji, Naotoshi;Fujisaki, Kozo
尽管半胱氨酸蛋白酶的作用部分由来自胱抑素超家族的内源性紧密结合半胱氨酸蛋白酶抑制剂控制，但蜱用于控制蛋白酶活性的调节机制尚不清楚。本文报道了长角血蜱中两种内源性中肠半胱氨酸蛋白酶抑制剂Hlcyst-1和Hlcyst-2与内源性中肠半胱氨酸蛋白酶HlCPL-A的相互作用。体外抑制实验表明，Hlcyst-1和Hlcyst-2对HlCPL-A的水解活性有明显的抑制作用，并呈剂量依赖性。免疫荧光研究显示，Hlcyst-1和Hlcyst-2与HlCPL-A共定位于中肠上皮细胞中。Hlcyst-1和Hlcyst-2呈剂量依赖性抑制HlCPL-A的血红蛋白降解活性。这些结果表明，Hlcyst-1和Hlcyst-2可能是HlCPL-A的抑制剂，在蜱血红蛋白降解过程的调控机制中起关键作用。
Although the actions of cysteine proteases are controlled in part by endogenous tight-binding cysteine protease inhibitors from the cystatin superfamily, regulatory mechanisms used by ticks to control protease activities are unknown. We report here the interaction of 2 endogenous midgut cysteine protease inhibitors, Hlcyst-1 and Hlcyst-2, with an endogenous midgut cysteine protease, HlCPL-A in Haemaphysalis longicornis. In vitro inhibition assays demonstrated that the hydrolytic activity of HlCPL-A was inhibited by Hlcyst-1 and Hlcyst-2 in dose dependent manner. Immunofluorescent studies revealed that Hlcyst-1 and Hlcyst-2 are co-localized with HlCPL-A in the epithelial cells of the midgut. The hemoglobin degradation activity of HlCPL-A was dose-dependently inhibited by Hlcyst-1 and Hlcyst-2. These results strongly indicate that, Hlcyst-1 and Hlcyst-2 are possible inhibitor of HlCPL-A and play a key role in regulatory mechanisms of hemoglobin degradation process in ticks.