학술논문
The PapB/FocB family protein TosR acts as a positive regulator of flagellar expression and is required for optimal virulence of uropathogenic Escherichia coli .
Document Type
Academic Journal
Author
Hirakawa H; Department of Bacteriology, Graduate School of Medicine, Gunma University, Maebashi, Gunma, Japan.; Shimokawa M; Department of Bacteriology, Graduate School of Medicine, Gunma University, Maebashi, Gunma, Japan.; Noguchi K; Department of Bacteriology, Graduate School of Medicine, Gunma University, Maebashi, Gunma, Japan.; Tago M; Department of Bacteriology, Graduate School of Medicine, Gunma University, Maebashi, Gunma, Japan.; Matsuda H; Department of Bacteriology, Graduate School of Medicine, Gunma University, Maebashi, Gunma, Japan.; Takita A; Department of Bacteriology, Graduate School of Medicine, Gunma University, Maebashi, Gunma, Japan.; Suzue K; Department of Infectious Diseases and Host Defense, Graduate School of Medicine, Gunma University, Maebashi, Gunma, Japan.; Tajima H; Department of Frontier Bioscience and Research Center for Micro-Nano Technology, Hosei University, Tokyo, Japan.; Kawagishi I; Department of Frontier Bioscience and Research Center for Micro-Nano Technology, Hosei University, Tokyo, Japan.; Tomita H; Department of Bacteriology, Graduate School of Medicine, Gunma University, Maebashi, Gunma, Japan.; Laboratory of Bacterial Drug Resistance, Graduate School of Medicine, Gunma University, Maebashi, Gunma, Japan.
Source
Publisher: Frontiers Research Foundation Country of Publication: Switzerland NLM ID: 101548977 Publication Model: eCollection Cited Medium: Print ISSN: 1664-302X (Print) Linking ISSN: 1664302X NLM ISO Abbreviation: Front Microbiol Subsets: PubMed not MEDLINE
Subject
Language
English
ISSN
1664-302X
Abstract
Uropathogenic Escherichia coli (UPEC) is a major causative agent of urinary tract infections. The bacteria internalize into the uroepithelial cells, where aggregate and form microcolonies. UPEC fimbriae and flagella are important for the formation of microcolonies in uroepithelial cells. PapB/FocB family proteins are small DNA-binding transcriptional regulators consisting of approximately 100 amino acids that have been reported to regulate the expression of various fimbriae, including P, F1C, and type 1 fimbriae, and adhesins. In this study, we show that TosR, a member of the PapB/FocB family is the activator of flagellar expression. The tosR mutant had similar expression levels of type 1, P and F1C fimbriae as the parent strain, but flagellar production was markedly lower than in the parent strain. Flagellin is a major component of flagella. The gene encoding flagellin, fliC , is transcriptionally activated by the sigma factor FliA. The fliA expression is induced by the flagellar master regulator FlhDC. The flhD and flhC genes form an operon. The promoter activity of fliC, fliA and flhD in the tosR mutant was significantly lower than in the parent strain. The purified recombinant TosR does not bind to fliC and fliA but to the upstream region of the flhD gene. TosR is known to bind to an AT-rich DNA sequence consisting of 29 nucleotides. The characteristic AT-rich sequence exists 550-578 bases upstream of the flhD gene. The DNA fragment lacking this sequence did not bind TosR. Furthermore, loss of the tosR gene reduced motility and the aggregation ability of UPEC in urothelial cells. These results indicate that TosR is a transcriptional activator that increases expression of the flhDC operon genes, contributing to flagellar expression and optimal virulence.
Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
(Copyright © 2023 Hirakawa, Shimokawa, Noguchi, Tago, Matsuda, Takita, Suzue, Tajima, Kawagishi and Tomita.)
Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
(Copyright © 2023 Hirakawa, Shimokawa, Noguchi, Tago, Matsuda, Takita, Suzue, Tajima, Kawagishi and Tomita.)