Signal transduction pathway mediated by the novel regulator LoiA for low oxygen tension induced Salmonella Typhimurium invasion

• DOI: 10.1371/journal.ppat.1006429
• Publication Date: 2017-06-02T13:55:16Z
• Authors: Lingyan Jiang; Lu Feng; Bin Yang; Wenwen Zhang; Peisheng Wang; Xiaohan Jiang; Lei Wang
• Keywords: Pathogenicity island; Salmonella enterica; Response regulator; Transcription; Virulence factor

Salmonella enterica serovar Typhimurium (S. Typhimurium) is a major intestinal pathogen of both humans and animals. pathogenicity island 1 (SPI-1)-encoded virulence genes are required for S. invasion. While oxygen (O2) limitation an important signal SPI-1 induction under host conditions, how the received integrated to central regulatory system in not clear. Here, we report transduction pathway that activates expression response low O2. A novel regulator encoded within SPI-14 (STM14_1008), named LoiA (low induced factor A), directly binds promoter transcription hilD, leading activation hilA (the master activator SPI-1). Deletion loiA significantly decreased hilA, hilD other representative (sipB, spaO, invH, prgH invF) O2 conditions. The mediated by ArcB/ArcA two-component system. either arcA or arcB We also confirmed contributes affecting invasion, determinant SPI-14. Mice infection assays showed was severely attenuated deletion entire region single gene after oral infection, while affected intraperitoneal infection. described represents mechanism sense respond conditions tract SPI-14-encoded essential element this integrates into Acquisition therefore crucial evolution as pathogen.