Morand P C, Tattevin P, Eugene E, Beretti J L, Nassif X
INSERM U411, Faculté de Médecine Necker-Enfants Malades, 156 rue de Vaugirard, 75015 Paris, France.
Mol Microbiol. 2001 May;40(4):846-56. doi: 10.1046/j.1365-2958.2001.02452.x.
Neisserial PilC proteins are key elements in type IV pili biogenesis and adhesion. Two pilC alleles are usually present in Neisseria meningitidis. At least one of the PilC proteins is required for pilus assembly and competence for transformation. In addition, meningococcal PilC1, but not PilC2, modulates adhesiveness, whereas, in N. gonorrhoeae, both alleles are adhesive. The meningococcal pilC genes are differently regulated, and it was shown that the expression of pilC1, but not that of pilC2, is transiently induced by bacteria-cell contact. The aim of this work was to determine whether, besides regulation, PilC1-mediated adhesion was conferred by some specific protein pattern not present in the meningococcal PilC2 protein. We demonstrate first that differences within the primary sequence of the meningococcal PilC1 and PilC2 are responsible for different adhesion phenotypes, thus eliminating the regulation of transcription being solely responsible for the adhesive phenotype of PilC1. To identify the regions of PilC1 responsible for adhesion, we engineered meningococcal strains expressing various PilC1-PilC2 hybrids at the pilC1 locus. Our data demonstrate that the specific PilC1 adhesion-promoting regions are located in the amino-terminal part of the molecule and that several domains within this region probably interact with each other to promote adhesion to human cells.
奈瑟菌属菌毛蛋白 PilC 是 IV 型菌毛生物合成和黏附中的关键元件。脑膜炎奈瑟菌通常存在两个 pilC 等位基因。菌毛组装和转化能力至少需要一种 PilC 蛋白。此外，脑膜炎奈瑟菌的 PilC1 而非 PilC2 调节黏附性，而在淋病奈瑟菌中，两个等位基因都具有黏附性。脑膜炎奈瑟菌的 pilC 基因受到不同的调控，研究表明，细菌与细胞接触可短暂诱导 pilC1 的表达，而非 pilC2 的表达。本研究的目的是确定除调控外，PilC1 介导的黏附是否由脑膜炎奈瑟菌 PilC2 蛋白中不存在的某些特定蛋白模式所赋予。我们首先证明，脑膜炎奈瑟菌 PilC1 和 PilC2 一级序列的差异导致了不同的黏附表型，从而排除了转录调控是 PilC1 黏附表型的唯一原因。为了确定 PilC1 中负责黏附的区域，我们构建了在 pilC1 位点表达各种 PilC1 - PilC2 杂交体的脑膜炎奈瑟菌菌株。我们的数据表明，PilC1 促进黏附的特定区域位于分子的氨基末端部分，并且该区域内的几个结构域可能相互作用以促进对人类细胞的黏附。
