@article{ref1,
title="Identification of Sigma N signaling system target genes in Leptospira interrogans",
journal="Chinese Journal of Microbiology and Immunology",
year="2020",
author="Ding, Shibiao and Li, Kaixuan and Li, Shupei and Chen, Xuhong and Gao, Shuai and Yan, Jie and Hu, Weilin",
volume="",
number="12",
pages="600-606",
abstract="OBJECTIVE:To confirm the Sigma N transcription factor activity of a gene product encoded by LA2404 gene of Leptospira interrogans ( L. interrogans) and to identify the target genes of Sigma N signaling system. <br><br>METHODS:L. interrogans LA2404 gene and its regulated target genes were predicted using bioinformatic analysis according to the promoter sequence signature in Sigma N-regulated genes. A LA2404 gene-knockout (&Delta;LA2404) strain of L. interrogans was constructed based on homologous sequence recombinant of suicide plasmid. Real-time fluorescent quantitative RT-PCR (qRT-PCR) was used to detect the changes in the expression of target genes at mRNA level in the &Delta;LA2404 mutant. A prokaryotic expression system for LA2404 gene was established and the target recombinant protein rSigma N was extracted by Ni-NTA affinity chromatography. Gel electrophoresis mobility shift assay (EMSA) was used to screen out the target genes regulated by rSigma N. <br><br>RESULTS:Pathogenic L. interrogans serogroup Icterohaemorrhagiae serovar Lai strain Lai carried one Sigma N gene and 22 Sigma N promoter sequence-containing target genes. Qualitative examination of the &Delta;LA2404 mutant by microscopy revealed no defect in motility and appearance. Expression of LA1188, LA2306, LA3426, LA1968, LA1313, LA3806 and LA0773 genes at mRNA level in the &Delta;LA2404 mutant was significantly down-regulated ( P&lt;0.05), but no significant changes in the expression of other target genes at mRNA level were detected. EMSA results confirmed that rSigma N could bind to the promotor sequences of the target genes mentioned above. <br><br>CONCLUSIONS:Sigma N transcription factor was encoded by LA2404 gene. LA1188, LA2306, LA3426, LA1968, LA1313, LA3806 and LA0773 genes contained Sigma N promoter sequence and the expression of them was regulated by Sigma N signaling system.<p /><p>Language: zh</p>",
language="zh",
issn="0254-5101",
doi="10.3760/cma.j.cn112309-20200616-00318",
url="http://dx.doi.org/10.3760/cma.j.cn112309-20200616-00318"
}