The Haemophilus influenzae Hap autotransporter mediates microcolony formation and adherence to epithelial cells and extracellular matrix via binding regions in the C-terminal end of the passenger domain
The Haemophilus influenzae Hap autotransporter mediates microcolony formation and adherence to epithelial cells and extracellular matrix via binding regions in the C-terminal end of the passenger domain
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DOI：
10.1046/j.1462-5822.2003.00266.x
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发表时间：
2003-03-01
影响因子：
3.4
通讯作者：
St Geme, JW
中科院分区：
文献类型：
--
作者：
Fink, DL;Buscher, AZ;St Geme, JW
非典型流感嗜血杆菌疾病的发病机制始于鼻咽的定植，并通过细菌粘附于呼吸道粘膜而促进。螺杆流感病毒Hap自转运蛋白是一种非菌毛粘附素，可促进对上皮细胞和选定细胞外基质蛋白的粘附，并介导细菌聚集和小菌落形成。此外，Hap具有丝氨酸蛋白酶活性。Hap含有一个110 kDa的内部乘客结构域称为Hap（S）和一个45 kDa的C-末端转运结构域称为Hapbeta。在本研究中，我们试图确定Hap粘附活性的结构基础。基于使用一组抗Hap（S）的单克隆抗体、缺失大部分Hap（S）的缺失衍生物和Hap（S）的纯化片段的实验，我们确定了对上皮细胞的粘附是由Hap（S）的C末端311个残基内的序列介导的。在另外的实验中，我们发现细菌聚集也由Hap（S）的C-末端311个残基内的序列介导，并且通过邻近生物体上的分子之间的Hap（S）-Hap（S）相互作用发生。最后，我们发现，对纤连蛋白、层粘连蛋白和胶原IV的粘附部分由Hap（S）的C-末端311个残基内的序列介导，完全由Hap（S）的C-末端511个残基内的序列介导。总之，这些结果表明，所有Hap粘附活性都存在于Hap（S）的C-末端部分。结合早期的观察，目前的结果确定Hap（S）粘附活性和Hap（S）蛋白酶活性包含在蛋白质的不同模块中。
The pathogenesis of non-typable Haemophilus influenzae disease begins with colonization of the nasopharynx and is facilitated by bacterial adherence to respiratory mucosa. The H. influenzae Hap autotransporter is a non-pilus adhesin that promotes adherence to epithelial cells and selected extracellular matrix proteins and mediates bacterial aggregation and microcolony formation. In addition, Hap has serine protease activity. Hap contains a 110 kDa internal passenger domain called Hap(S) and a 45 kDa C-terminal translocator domain called Hapbeta. In the present study, we sought to define the structural basis for Hap adhesive activities. Based on experiments using a panel of monoclonal antibodies against Hap(S) , a deletion derivative lacking most of Hap(S) and a purified fragment of Hap(S) , we established that adherence to epithelial cells is mediated by sequences within the C-terminal 311 residues of Hap(S). In additional experiments, we discovered that bacterial aggregation is also mediated by sequences within the C-terminal 311 residues of Hap(S) and occurs via Hap(S)-Hap(S) interaction between molecules on neighbouring organisms. Finally, we found that adherence to fibronectin, laminin and collagen IV is mediated in part by sequences within the C-terminal 311 residues of Hap(S) and in full by sequences within the C-terminal 511 residues of Hap(S). Taken together, these results demonstrate that all Hap adhesive activities reside in the C-terminal portion of Hap(S). Coupled with earlier observations, the current results establish that Hap(S) adhesive activities and Hap(S) protease activity are contained in separate modules of the protein.