The major structural components of two cell surface filaments of Porphyromonas gingivalis are matured through lipoprotein precursors
The major structural components of two cell surface filaments of Porphyromonas gingivalis are matured through lipoprotein precursors
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DOI：
10.1111/j.1365-2958.2004.04105.x
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发表时间：
2004-06-01
影响因子：
3.6
通讯作者：
Nakayama, K
中科院分区：
文献类型：
--
作者：
Shoji, M;Naito, M;Nakayama, K
细菌细胞表面细丝在细菌对宿主细胞的粘附和侵袭中起着重要作用。它们由分子伴侣/引导途径系统（I类菌毛）、II型分泌系统（IV型皮利）和成核依赖性聚合系统（卷曲丝）产生，这些系统根据其表达和组装模式分类。在这项研究中，我们发现，牙周病原体牙龈卟啉单胞菌表达的主要结构成分的两个细胞表面丝（fimbrilin和75 kDa的蛋白质），在其初级基因产物中有非常长的前序列。前序列的N-末端氨基酸测序、用脂蛋白特异性信号肽酶抑制剂球霉素处理牙龈卟啉单胞菌细胞、菌毛蛋白前序列的半胱氨酸残基的氨基酸取代和[H-3]-棕榈酸标记暗示菌毛蛋白和75 kDa蛋白通过其脂蛋白前体形式成熟。fimbrilin的前体形式和gingipain无效突变体的细胞表面上的75 kDa蛋白质的积累显示，Arg-gingipain处理这些前体的表面上产生其成熟的形式，随后组装成丝状结构，这表明主要组分蛋白质的运输和组装似乎是新颖的。
Bacterial cell surface filaments play significant roles in adherence to and invasion of host cells. They are generated by the chaperone/usher pathway system (class I fimbriae), the type II secretion system (type IV pili) and the nucleation-dependent polymerization system (Curli filaments) that are categorized by their modes of expression and assembly. In this study, we found that the periodontal pathogen Porphyromonas gingivalis expressed the major structural components of two cell surface filaments (fimbrilin and the 75 kDa protein) that had extremely long prosequences in their primary gene products. N-terminal amino acid sequencing of the prosequences, treatment of P. gingivalis cells with globomycin, an inhibitor for lipoprotein-specific signal peptidase, amino acid substitution of the cysteine residue of the prosequence of fimbrilin and [H-3]-palmitic acid labelling implied that fimbrilin and the 75 kDa protein were matured through their lipoprotein precursor forms. Accumulation of precursor forms of fimbrilin and the 75 kDa protein on the cell surface of the gingipain-null mutant revealed that Arg-gingipain processed these precursors on the surface to yield their mature forms, which subsequently assembled into the filamentous structures, suggesting that the transport and assembly of the major component proteins appear to be novel.