Superbacteria Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806, Korea.
BMC Microbiol. 2013 Nov 24;13:266. doi: 10.1186/1471-2180-13-266.
Ribonuclease III (RNase III) activity modulates hundreds of genes in Escherichia coli (E. coli). YmdB, a member of the macrodomain protein family, is one of known trans-acting regulators of RNase III activity; however, the significance of its regulatory role in specific bacterial cellular processes and related genes has not been determined. YmdB overexpression was used to model YmdB-induced RNase III inhibition in vivo, and microarray analysis identified gene targets and cellular processes related to RNase III inhibition.
The expression of >2,000 E. coli genes was modulated by YmdB induction; 129 genes were strongly regulated, of which 80 have not been reported as RNase III targets. Of these, ten are involved in biofilm formation. Significantly, YmdB overexpression also inhibited biofilm formation via a process that is not uniquely dependent upon RNase III inhibition. Moreover, biofilm formation is interdependently regulated by RpoS, a known stress response regulator and biofilm inhibitor, and by YmdB.
This is the first global profile of target genes modulated by YmdB-induced RNase III inhibition in E. coli, and the data reveal a novel, hitherto unrecognized regulatory role for YmdB in biofilm modulation.
核糖核酸酶 III（RNase III）活性调节大肠杆菌（E. coli）中的数百个基因。YmdB 是宏结构域蛋白家族的成员之一，是已知的 RNase III 活性反式作用调节剂之一；然而，其在特定细菌细胞过程和相关基因中的调节作用的意义尚未确定。通过过表达 YmdB 来模拟体内 YmdB 诱导的 RNase III 抑制，并通过微阵列分析鉴定与 RNase III 抑制相关的基因靶标和细胞过程。
YmdB 诱导使 >2000 个大肠杆菌基因的表达发生了调节；129 个基因受到强烈调节，其中 80 个尚未被报道为 RNase III 靶标。其中，十个与生物膜形成有关。重要的是，YmdB 过表达还通过一种不依赖于 RNase III 抑制的独特过程抑制生物膜形成。此外，生物膜形成受到 RpoS 的相互调节，RpoS 是一种已知的应激反应调节剂和生物膜抑制剂，并且受到 YmdB 的调节。
这是首次对 YmdB 诱导的 RNase III 抑制在大肠杆菌中调节的靶基因进行的全局分析，该数据揭示了 YmdB 在生物膜调节中的一种新的、迄今为止尚未被认识的调节作用。
