Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan.
PLoS One. 2013 Aug 1;8(8):e71208. doi: 10.1371/journal.pone.0071208. Print 2013.
In the model organism Escherichia coli, Min proteins are involved in regulating the division of septa formation. The computational genome analysis of Helicobacter pylori, a gram-negative microaerophilic bacterium causing gastritis and peptic ulceration, also identified MinC, MinD, and MinE. However, MinC (HP1053) shares a low identity with those of other bacteria and its function in H. pylori remains unclear. In this study, we used morphological and genetic approaches to examine the molecular role of MinC. The results were shown that an H. pylori mutant lacking MinC forms filamentous cells, while the wild-type strain retains the shape of short rods. In addition, a minC mutant regains the short rods when complemented with an intact minCHp gene. The overexpression of MinCHp in E. coli did not affect the growth and cell morphology. Immunofluorescence microscopy revealed that MinCHp forms helix-form structures in H. pylori, whereas MinCHp localizes at cell poles and pole of new daughter cell in E. coli. In addition, co-immunoprecipitation showed MinC can interact with MinD but not with FtsZ during mid-exponential stage of H. pylori. Altogether, our results show that MinCHp plays a key role in maintaining proper cell morphology and its function differs from those of MinCEc.
在模式生物大肠杆菌中，Min 蛋白参与调节隔膜形成的分裂。对引起胃炎和消化性溃疡的革兰氏阴性微需氧细菌幽门螺杆菌的计算基因组分析也鉴定出 MinC、MinD 和 MinE。然而，MinC（HP1053）与其他细菌的同源性较低，其在幽门螺杆菌中的功能尚不清楚。在这项研究中，我们使用形态学和遗传学方法来研究 MinC 的分子作用。结果表明，缺乏 MinC 的幽门螺杆菌突变体形成丝状细胞，而野生型菌株保持短杆形状。此外，当用完整的 minCHp 基因互补时，minC 突变体恢复为短杆。MinCHp 在大肠杆菌中的过表达不会影响生长和细胞形态。免疫荧光显微镜显示 MinCHp 在幽门螺杆菌中形成螺旋形结构，而 MinCHp 在大肠杆菌中定位于细胞两极和新子细胞的极。此外，共免疫沉淀表明 MinC 可以在幽门螺杆菌的指数中期与 MinD 相互作用，但不能与 FtsZ 相互作用。总之，我们的结果表明 MinCHp 在维持适当的细胞形态方面发挥着关键作用，其功能不同于 MinCEc。
