Biological Roles of Nontypeable Haemophilus influenzae Type IV Pilus Proteins Encoded by the pil and com Operons
Biological Roles of Nontypeable Haemophilus influenzae Type IV Pilus Proteins Encoded by the pil and com Operons
复制标题
由 pil 和 com 操作子编码的非类型流感嗜血杆菌 IV 型 Pilus 蛋白的生物学作用
DOI：
10.1128/jb.06540-11
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发表时间：
2012-04-01
影响因子：
3.2
通讯作者：
Bakaletz, Lauren O.
中科院分区：
文献类型：
--
作者：
Carruthers, Michael D.;Tracy, Erin N.;Bakaletz, Lauren O.
我们以前证明，一个或多个产品的基因在人类呼吸道机会致病菌不可分型的流感嗜血杆菌（NTHI）的pGEX和COM基因簇中的基因是IV型菌毛（TFP）的生物发生和功能所必需的。在这里，我们现在已经证明了pilABCD和comABCDEF基因簇是操纵子，并且每个基因的产物对于正常的菌毛功能是必需的。当原代人气道细胞被用作靶细胞时，10个p53和com基因中每一个具有非极性缺失的突变体具有粘附缺陷。这些突变体在体外形成生物膜的能力也降低，此外，在自然转化中也有缺陷。总的来说，我们的数据表明，这些操纵子内的每个基因的产物是NTHI Tfp的正常生物发生和/或功能所必需的。基于PilA与其他IV型菌毛蛋白的相似性，我们进一步预测PilA基因的产物将是主要的菌毛蛋白亚基。为此，我们还通过免疫金标记和质谱法证明PilA确实是NTHI表达的大多数IV型菌毛蛋白。这些新的观察结果为实验奠定了基础，这些实验旨在剖析玉米和玉米基因簇内基因编码的每种蛋白质的功能。表征在NTHI定殖或发病机制中具有重要作用的单个蛋白质的能力具有通过开发Tfp衍生的疫苗或菌毛导向的治疗剂来减少NTHI诱导的疾病的负担的潜力。
We previously demonstrated that one or more products of the genes in the pil and com gene clusters of the opportunistic human respiratory pathogen nontypeable Haemophilus influenzae (NTHI) are required for type IV pilus (Tfp) biogenesis and function. Here, we have now demonstrated that the pilABCD and comABCDEF gene clusters are operons and that the product of each gene is essential for normal pilus function. Mutants with nonpolar deletions in each of the 10 pil and com genes had an adherence defect when primary human airway cells were used as the target. These mutants were also diminished in their ability to form a biofilm in vitro and, additionally, were deficient in natural transformation. Collectively, our data demonstrate that the product of each gene within these operons is required for the normal biogenesis and/or function of NTHI Tfp. Based on the similarity of PilA to other type IV pilins, we further predicted that the product of the pilA gene would be the major pilin subunit. Toward that end, we also demonstrated by immunogold labeling and mass spectrometry that PilA is indeed the majority type IV pilin protein expressed by NTHI. These new observations set the stage for experiments designed to dissect the function of each of the proteins encoded by genes within the pil and com gene clusters. The ability to characterize individual proteins with vital roles in NTHI colonization or pathogenesis has the potential to reduce the burden of NTHI-induced diseases through development of a Tfp-derived vaccine or a pilus-directed therapeutic.