Department of Medical Microbiology and Hygiene, Institute of Medical Microbiology and Hygiene, University Hospital Freiburg, Freiburg, Germany.
PLoS Pathog. 2009 Nov;5(11):e1000669. doi: 10.1371/journal.ppat.1000669. Epub 2009 Nov 20.
Pathogenicity of the human pathogen Helicobacter pylori relies upon its capacity to adapt to a hostile environment and to escape from the host response. Therefore, cell shape, motility, and pH homeostasis of these bacteria are specifically adapted to the gastric mucus. We have found that the helical shape of H. pylori depends on coiled coil rich proteins (Ccrp), which form extended filamentous structures in vitro and in vivo, and are differentially required for the maintenance of cell morphology. We have developed an in vivo localization system for this pathogen. Consistent with a cytoskeleton-like structure, Ccrp proteins localized in a regular punctuate and static pattern within H. pylori cells. Ccrp genes show a high degree of sequence variation, which could be the reason for the morphological diversity between H. pylori strains. In contrast to other bacteria, the actin-like MreB protein is dispensable for viability in H. pylori, and does not affect cell shape, but cell length and chromosome segregation. In addition, mreB mutant cells displayed significantly reduced urease activity, and thus compromise a major pathogenicity factor of H. pylori. Our findings reveal that Ccrp proteins, but not MreB, affect cell morphology, while both cytoskeletal components affect the development of pathogenicity factors and/or cell cycle progression.
幽门螺杆菌（Helicobacter pylori）是一种人类病原体，其致病性依赖于它适应恶劣环境和逃避宿主反应的能力。因此，这些细菌的细胞形状、运动性和 pH 平衡特别适应胃黏液。我们发现，幽门螺杆菌的螺旋形状取决于富含卷曲螺旋的蛋白质（Ccrp），这些蛋白质在体外和体内形成延伸的丝状结构，并且对维持细胞形态有不同的要求。我们为这种病原体开发了一种体内定位系统。与细胞骨架样结构一致，Ccrp 蛋白在幽门螺杆菌细胞内以规则的点状和静态模式定位。Ccrp 基因显示出高度的序列变异，这可能是幽门螺杆菌菌株之间形态多样性的原因。与其他细菌不同，肌动蛋白样 MreB 蛋白对于幽门螺杆菌的生存能力是可有可无的，它不会影响细胞形状，但会影响细胞长度和染色体分离。此外，mreB 突变细胞的脲酶活性显著降低，从而削弱了幽门螺杆菌的主要致病性因素。我们的研究结果表明，Ccrp 蛋白而非 MreB 蛋白影响细胞形态，而这两种细胞骨架成分都影响致病性因素的发展和/或细胞周期进程。
