Molecular mechanism of cell curvature in the spiral-shaped bacterium Rhodospirillum rubrum

螺旋状细菌红色红螺菌细胞曲率的分子机制

• 批准号: 450420164
• 负责人: Professor Dr. Martin Rudolf Thanbichler
• 金额: --
• 依托单位: Arbeitsgruppe Prokaryotische Zellbiologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/450420164?language=en
• 关键词: Molecular; mechanism; cell; curvature; spiral

Bacteria show a high diversity of cell shapes, which in most cases are determined by the peptidoglycan cell wall. Previous work has revealed that the prototypical rod-shaped morphologies of standard model organisms are generated by two major peptidoglycan biosynthetic complexes, the elongasome and the divisome. In these complexes, synthetic, lytic and regulatory proteins are combined to coordinately remodel the peptidoglycan layer in order to generate the cylindrical and spherical elements of the cell, respectively. However, the mechanisms underlying the establishment of more complex morphologies are still poorly understood. Widespread variations of the common rod shape are curved or spiral morphologies, which arise by differential growth of the rod-shaped peptidoglyan layer at the inner and outer curvature. Curved shapes are commonly found among bacteria, and it appears that the underlying shape-generating mechanisms differ fundamentally between different lineages. However, even for well-investigated systems, the precise modes of action of the shape determinants identified are still unclear. Here, we propose to study the establishment of cell curvature in the spiral-shaped bacterium Rhodospirillum rubrum. In preliminary work, we have identified a novel peptidoglycan-binding outer-membrane lipoprotein, PapS, which forms a filament-like structure at the outer curvature of the R. rubrum cell and is essential for its spiral morphology. PapS is highly conserved among the members of the Rhodospirillaceae, a family comprising a large number of curved and spiral-shaped species, suggesting that it represents a key cell shape determinant in this lineage. We propose to unravel the function of PapS using a combination of cell biological, genetic, biochemical and biophysical approaches. These studies will provide insight into a novel and widespread pathway of shape determination in bacteria and thus significantly further our understanding of bacterial cell wall biosynthesis and morphogenesis.

细菌显示出高度多样性的细胞形状，这在大多数情况下是由肽聚糖细胞壁决定的。先前的工作已经揭示，标准模式生物的原型杆状形态是由两个主要的肽聚糖生物合成复合物，延长体和分裂体产生的。在这些复合物中，合成的、裂解的和调节的蛋白质被组合以协调地重塑肽聚糖层，以便分别产生细胞的圆柱形和球形元件。然而，建立更复杂的形态的机制仍然知之甚少。常见棒状的广泛变化是弯曲或螺旋形态，这是由于棒状肽聚糖层在内部和外部曲率处的差异生长引起的。弯曲的形状在细菌中很常见，而且不同谱系之间的潜在形状生成机制似乎根本不同。然而，即使是充分调查的系统，确定的形状决定因素的确切作用模式仍然不清楚。在这里，我们建议研究建立细胞曲率的螺旋形细菌Rhodocellum rubrum。在初步工作中，我们已经确定了一种新的肽聚糖结合外膜脂蛋白，PapS，它在R.红细胞，是其螺旋形态所必需的。PapS是高度保守的成员之间的杜鹃花科，一个家庭，包括大量的弯曲和螺旋形的物种，这表明它代表了一个关键的细胞形状决定因素，在这个谱系。我们建议使用细胞生物学、遗传学、生物化学和生物物理学方法的组合来解开PapS的功能。这些研究将提供深入了解一个新的和广泛的途径，形状决定在细菌，从而显着进一步了解细菌细胞壁的生物合成和形态发生。