A cysteine-rich protein from an arthropod stabilizes clotting mesh and immobilizes bacteria at injury sites
A cysteine-rich protein from an arthropod stabilizes clotting mesh and immobilizes bacteria at injury sites
复制标题
DOI：
10.1074/jbc.m705854200
复制
发表时间：
2007-11-16
影响因子：
4.8
通讯作者：
Kawabata, Shun-Ichiro
中科院分区：
文献类型：
--
作者：
Matsuda, Yasuyuki;Osaki, Tsukasa;Kawabata, Shun-Ichiro
节肢动物的血淋巴凝固在宿主防御中起着关键作用，包括封闭伤口以止血和固定入侵的微生物。我们以前曾报道过，鲎转氨酶（TGase）促进凝血蛋白（凝固蛋白）与血细胞衍生蛋白（凝血酶）的交联，导致形成稳定的凝固蛋白原纤维。在这里，我们表明，TGase也交联的另一种血细胞衍生的蛋白质命名为稳定蛋白。Stablin是一种富含半胱氨酸的蛋白质，具有131个残基。表面等离子体共振分析表明，stablin与proxin-1在Kd = 4.0 × 10（-9）M时发生特异性相互作用。Stablin主要定位于血细胞的大颗粒中，并通过脂多糖诱导的胞吐分泌。有趣的是，通过使用石英晶体微量天平测定，stablin与几丁质的结合Kd = 1.5 × 10（-8）M。Stablin还与脂多糖和脂磷壁酸相互作用，并表现出对革兰氏阳性和阴性细菌的细菌凝集活性。免疫染色显示，stablin与凝血蛋白共定位于有效捕获细菌的凝血原纤维中。此外，抗稳定蛋白抗体强烈抑制凝血原纤维的适当形成。这些数据表明，stablin促进了凝血网的形成和损伤部位入侵微生物的固定。在节肢动物中，TGase介导的交联可能在宿主防御、伤口闭合和愈合的初始阶段起重要作用，如在哺乳动物的情况下。
Hemolymph coagulation in arthropods plays key roles in host defense, including sealing wounds to staunch bleeding and immobilizing invading microorganisms. We have previously reported that horseshoe crab transglutaminase ( TGase) promotes cross-linking of a clotting protein ( coagulin) with hemocyte-derived proteins (proxins), resulting in the formation of stable coagulin fibrils. Here we show that TGase also cross-links proxins to another hemocyte-derived protein named stablin. Stablin is a cysteine-rich protein of 131 residues. Surface plasmon resonance analysis revealed the specific interaction of stablin with proxin-1 at K-d = 4.0 X 10(-9) M. Stablin was predominantly localized in the large granules of hemocytes and secreted by lipopolysaccharide-induced exocytosis. Interestingly, stablin bound to chitin at K-d = 1.5 x 10(-8) M, as determined by using a quartz-crystal microbalance. Stablin also interacted with lipopolysaccharides and lipoteichoic acids and exhibited bacterial agglutinating activity against Gram-positive and -negative bacteria. Immunostaining showed that stablin is co-localized with coagulin in the clotting fibrils that effectively trap bacteria. Moreover, an anti-stablin antibody strongly inhibited the proper formation of the clotting fibrils. These data suggest that stablin promotes the formation of the clotting mesh and the immobilization of invading microbes at injury sites. In arthropods, the TGase-mediated cross-linking may play an important role in the initial stage of host defense, wound closure, and healing, as in the case of mammals.