Department of Biochemistry, Indian Institute of Science, Bangalore, India.
PLoS One. 2012;7(8):e42303. doi: 10.1371/journal.pone.0042303. Epub 2012 Aug 3.
Helicobacter pylori is an important human pathogen and one of the most successful chronic colonizers of the human body. H. pylori uses diverse mechanisms to modulate its interaction with the host in order to promote chronic infection and overcome host immune response. Restriction-modification genes are a major part of strain-specific genes present in H. pylori. The role of N(6)--adenine methylation in bacterial gene regulation and virulence is well established but not much is known about the effect of C(5) -cytosine methylation on gene expression in prokaryotes. In this study, it was observed by microarray analysis and RT-PCR, that deletion of an orphan C(5) -cytosine methyltransferase, hpyAVIBM in H. pylori strains AM5and SS1 has a significant effect on the expression of number of genes belonging to motility, adhesion and virulence. AM5ΔhpyAVIBM mutant strain has a different LPS profile and is able to induce high IL-8 production compared to wild-type. hpyAVIBM from strain 26695 is able to complement mutant SS1 and AM5 strains. This study highlights a possible significance of cytosine methylation in the physiology of H. pylori.
幽门螺杆菌是一种重要的人类病原体，也是人体中最成功的慢性定植菌之一。幽门螺杆菌利用多种机制来调节其与宿主的相互作用，以促进慢性感染并克服宿主的免疫反应。限制修饰基因是存在于幽门螺杆菌中的菌株特异性基因的主要部分。N(6)--腺嘌呤甲基化在细菌基因调控和毒力中的作用已得到充分证实，但关于 C(5) -胞嘧啶甲基化对原核生物基因表达的影响知之甚少。在这项研究中，通过微阵列分析和 RT-PCR 观察到，幽门螺杆菌菌株 AM5 和 SS1 中孤儿 C(5) -胞嘧啶甲基转移酶 hpyAVIBM 的缺失对运动性、粘附性和毒力相关基因的表达有显著影响。与野生型相比，AM5ΔhpyAVIBM 突变株的 LPS 图谱不同，能够诱导产生更高水平的 IL-8。来自菌株 26695 的 hpyAVIBM 能够互补突变株 SS1 和 AM5。这项研究强调了胞嘧啶甲基化在幽门螺杆菌生理中的可能意义。
