Apa is a trimeric autotransporter adhesin of Actinobacillus pleuropneumoniae responsible for autoagglutination and host cell adherence
Apa is a trimeric autotransporter adhesin of Actinobacillus pleuropneumoniae responsible for autoagglutination and host cell adherence
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Apa 是胸膜肺炎放线杆菌的三聚体自转运蛋白粘附素，负责自身凝集和宿主细胞粘附
DOI：
10.1002/jobm.201100365
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发表时间：
2012-10-01
影响因子：
3.1
通讯作者：
Lei, Liancheng
中科院分区：
文献类型：
--
作者：
Xiao, Longwen;Zhou, Liang;Lei, Liancheng
胸膜肺炎放射杆菌是猪胸膜肺炎的病原体，粘附宿主细胞是致病过程中的关键步骤。虽然近年来在许多病原菌中发现了三聚体自转运粘附素（TAAs），但在A.胸膜肺炎的特征。在这项研究中，我们确定了一个TAA从A。胸膜肺炎，阿帕，并表征了其氨基酸残基对粘附过程的贡献。对阿帕的C末端氨基酸残基的序列分析显示存在一个推定的转运域和六个保守的HsfBD 1样或HsfBD 2样结合域。Western blot分析表明，阿帕蛋白C末端的126个氨基酸可以形成三聚体分子。通过共聚焦激光扫描显微镜，这六个域之一（ApaBD 3）被确定为介导粘附上皮细胞。使用重组E. coli-ApaBD 3菌株，在E. coli中证实该结构域负责粘附活性。此外，细胞酶联免疫吸附试验表明ApaBD 3介导了对上皮细胞系的高水平粘附。有趣的是，用E. coli-ApaBD 3菌株中，并且这种现象依赖于表达的ApaBD 3与C末端转运结构域的缔合。（© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA，魏因海姆）
Actinobacillus pleuropneumoniae is the causative agent of porcine pleuropneumonia, and adherence to host cells is a key step in the pathogenic process. Although trimeric autotransporter adhesins (TAAs) were identified in many pathogenic bacteria in recent years, none in A. pleuropneumoniae have been characterized. In this study, we identified a TAA from A. pleuropneumoniae, Apa, and characterized the contribution of its amino acid residues to the adhesion process. Sequence analysis of the C‐terminal amino acid residues of Apa revealed the presence of a putative translocator domain and six conserved HsfBD1‐like or HsfBD2‐like binding domains. Western blot analysis revealed that the 126 C‐terminal amino acids of Apa could form trimeric molecules. By confocal laser scanning microscopy, one of these six domains (ApaBD3) was determined to mediate adherence to epithelial cells. Adherence assays and adherence inhibition assays using a recombinant E. coli‐ ApaBD3 strain which expressed ApaBD3 on the surface of E. coli confirmed that this domain was responsible for the adhesion activity. Moreover, cellular enzyme‐linked immunosorbent assays demonstrated that ApaBD3 mediated high‐level adherence to epithelial cell lines. Intriguingly, autoagglutination was observed with the E. coli‐ ApaBD3 strain, and this phenomenon was dependent upon the association of the expressed ApaBD3 with the C‐terminal translocator domain. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)