gp63 homologues in Trypanosoma cruzi:: Surface antigens with metalloprotease activity and a possible role in host cell infection
gp63 homologues in Trypanosoma cruzi:: Surface antigens with metalloprotease activity and a possible role in host cell infection
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DOI：
10.1128/iai.71.10.5739-5749.2003
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发表时间：
2003-10-01
影响因子：
3.1
通讯作者：
Sánchez, DO
中科院分区：
文献类型：
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作者：
Cuevas, IC;Cazzulo, JJ;Sánchez, DO
Gp63是一种高度丰富的糖基磷脂酰肌醇(GPI)锚定的膜蛋白，主要在利什曼原虫的前鞭毛体中表达，但也在无鞭毛体阶段表达。在利什曼原虫中，gp63参与了感染建立的多个步骤。在这里，我们证明了查加斯病的病原体克氏锥虫具有一个由多个组组成的gp63基因家族。其中两个组，Tcgp63-I和-II，以高拷贝数基因的形式存在。每组的基因组结构和mRNA表达模式都是特定的。Tcgp63-I被广泛表达，而Tcgp63-II组在Northern blots中很少检测到，尽管Tcgp63-II组在T.ruzi基因组中有很好的代表性。用针对合成肽的血清进行的免疫印迹表明，Tcgp63-I组产生了类似于78 kDa的蛋白质，在生命周期中差异表达。免疫荧光染色和磷脂酰肌醇特异性磷脂酶C消化证实，Tcgp63-I组成员是通过GPI锚点结合到膜上的表面蛋白。我们还证明了金属蛋白酶活性的存在，这至少部分归因于Tcgp63-I基团。由于针对Tcgp63-I的抗体部分阻断了锥虫对Vero细胞的感染，因此这一组可能在感染中发挥作用。
gp63 is a highly abundant glycosylphosphatidylinositol (GPI)-anchored membrane protein expressed predominantly in the promastigote but also in the amastigote stage of Leishmania species. In Leishmania spp., gp63 has been implicated in a number of steps in establishment of infection. Here we demonstrate that Trypanosoma cruzi, the etiological agent of Chagas' disease, has a family of gp63 genes composed of multiple groups. Two of these groups, Tcgp63-I and -II, are present as high-copy-number genes. The genomic organization and mRNA expression pattern were specific for each group. Tcgp63-I was widely expressed, while the Tcgp63-II group was scarcely detected in Northern blots, even though it is well represented in the T. cruzi genome. Western blots using sera directed against a synthetic peptide indicated that the Tcgp63-I group produced proteins of similar to78 kDa, differentially expressed during the life cycle. Immunofluorescence staining and phosphatidylinositol-specific phospholipase C digestion confirmed that Tcgp63-I group members are surface proteins bound to the membrane by a GPI anchor. We also demonstrate the presence of metalloprotease activity which is attributable, at least in part, to Tcgp63-I group. Since antibodies against Tcgp63-I partially blocked infection of Vero cells by trypomastigotes, a possible role for this group in infection is suggested.