Identification of σE-Dependent Promoter Upstream of clpB from the Pathogenic Spirochaete Leptospira interrogans by Applying an E. coli Two-Plasmid System

Sabina Kędzierska-Mieszkowska , Katarzyna Potrykus , Zbigniew Arent , Joanna Krajewska


There is limited information on gene expression in the pathogenic spirochaete Leptospira interrogans and genetic mechanisms controlling its virulence. Transcription is the first step in gene expression that is often determined by environmental effects, including infection-induced stresses. Alterations in the environment result in significant changes in the transcription of many genes, allowing effective adaptation of Leptospira to mammalian hosts. Thus, promoter and transcriptional start site identification are crucial for determining gene expression regulation and for the understanding of genetic regulatory mechanisms existing in Leptospira. Here, we characterized the promoter region of the L. interrogans clpB gene (clpBLi) encoding an AAA+ molecular chaperone ClpB essential for the survival of this spirochaete under thermal and oxidative stresses, and also during infection of the host. Primer extension analysis demonstrated that transcription of clpB in L. interrogans initiates at a cytidine located 41 bp upstream of the ATG initiation codon, and, to a lesser extent, at an adenine located 2 bp downstream of the identified site. Transcription of both transcripts was heat-inducible. Determination of clpBLi transcription start site, combined with promoter transcriptional activity assays using a modified two-plasmid system in E. coli, revealed that clpBLi transcription is controlled by the ECF σE factor. Of the ten L. interrogans ECF σ factors, the factor encoded by LIC_12757 (LA0876) is most likely to be the key regulator of clpB gene expression in Leptospira cells, especially under thermal stress. Furthermore, clpB expression may be mediated by ppGpp in Leptospira.
Author Sabina Kędzierska-Mieszkowska
Sabina Kędzierska-Mieszkowska,,
, Katarzyna Potrykus
Katarzyna Potrykus,,
, Zbigniew Arent (UAK)
Zbigniew Arent,,
- University of Agriculture in Krakow
, Joanna Krajewska
Joanna Krajewska,,
Journal seriesInternational Journal of Molecular Sciences, ISSN 1422-0067, (N/A 140 pkt)
Issue year2019
Publication size in sheets0.65
Keywords in EnglishclpB; Leptospira; leptospirosis; molecular chaperone; sigma factor; transcription
ASJC Classification2700 General Medicine; 1312 Molecular Biology; 1503 Catalysis; 1604 Inorganic Chemistry; 1605 Organic Chemistry; 1606 Physical and Theoretical Chemistry; 1607 Spectroscopy; 1706 Computer Science Applications
Languageen angielski
LicenseJournal (articles only); published final; Uznanie Autorstwa (CC-BY); after publication
Identification of σE-Dependent Promoter Upstream of clpB from the Pathogenic Spirochaete Leptospira interrogans by Applying an E. coli Two-Plasmid System of 08-01-2020
1,86 MB
Score (nominal)140
Score sourcejournalList
Publication indicators Scopus SNIP (Source Normalised Impact per Paper): 2018 = 1.224; WoS Impact Factor: 2018 = 4.183 (2) - 2018=4.331 (5)
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