Abstract
Bacterial ribosome requires elongation factor P to translate fragments harbouring consecutive proline codons. Given the abundance of ORFs with potential EF-P regulated sites, EF-P was assumed to be constitutively expressed. Here, we report that the intracellular pathogen Salmonella enterica serovar Typhimurium decreases efp mRNA levels during course of infection. We determined that the decrease in efp mRNA is triggered by low levels of charged tRNAPro, a condition that Salmonella experiences when inside a macrophage phagosome. Surprisingly, downregulation of EF-P selectively promotes expression of the virulence mgtC gene and contributes to Salmonella's ability to survive inside macrophages. The decrease in EF-P levels induces ribosome stalling at the consecutive proline codons of the mgtP open reading frame in the mgtCBR leader RNA, and thus allows formation of a stem-loop structure promoting transcription of the mgtC gene. The substitution of proline codons in the mgtP gene eliminates EF-P-mediated mgtC expression and thus Salmonella's survival inside macrophages. Our findings indicate that Salmonella benefits virulence genes by decreasing EF-P levels and inducing the stringent response inside host.
| Original language | English |
|---|---|
| Pages (from-to) | 221-232 |
| Number of pages | 12 |
| Journal | Molecular Microbiology |
| Volume | 102 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - 2016 Oct 1 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Microbiology
- Molecular Biology
Cite this
tRNAPro-mediated downregulation of elongation factor P is required for mgtCBR expression during Salmonella infection. / Nam, Daesil; Choi, Eunna; Shin, Dongwoo; Lee, Eun-Jin.
In: Molecular Microbiology, Vol. 102, No. 2, 01.10.2016, p. 221-232.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - tRNAPro-mediated downregulation of elongation factor P is required for mgtCBR expression during Salmonella infection
AU - Nam, Daesil
AU - Choi, Eunna
AU - Shin, Dongwoo
AU - Lee, Eun-Jin
PY - 2016/10/1
Y1 - 2016/10/1
N2 - Bacterial ribosome requires elongation factor P to translate fragments harbouring consecutive proline codons. Given the abundance of ORFs with potential EF-P regulated sites, EF-P was assumed to be constitutively expressed. Here, we report that the intracellular pathogen Salmonella enterica serovar Typhimurium decreases efp mRNA levels during course of infection. We determined that the decrease in efp mRNA is triggered by low levels of charged tRNAPro, a condition that Salmonella experiences when inside a macrophage phagosome. Surprisingly, downregulation of EF-P selectively promotes expression of the virulence mgtC gene and contributes to Salmonella's ability to survive inside macrophages. The decrease in EF-P levels induces ribosome stalling at the consecutive proline codons of the mgtP open reading frame in the mgtCBR leader RNA, and thus allows formation of a stem-loop structure promoting transcription of the mgtC gene. The substitution of proline codons in the mgtP gene eliminates EF-P-mediated mgtC expression and thus Salmonella's survival inside macrophages. Our findings indicate that Salmonella benefits virulence genes by decreasing EF-P levels and inducing the stringent response inside host.
AB - Bacterial ribosome requires elongation factor P to translate fragments harbouring consecutive proline codons. Given the abundance of ORFs with potential EF-P regulated sites, EF-P was assumed to be constitutively expressed. Here, we report that the intracellular pathogen Salmonella enterica serovar Typhimurium decreases efp mRNA levels during course of infection. We determined that the decrease in efp mRNA is triggered by low levels of charged tRNAPro, a condition that Salmonella experiences when inside a macrophage phagosome. Surprisingly, downregulation of EF-P selectively promotes expression of the virulence mgtC gene and contributes to Salmonella's ability to survive inside macrophages. The decrease in EF-P levels induces ribosome stalling at the consecutive proline codons of the mgtP open reading frame in the mgtCBR leader RNA, and thus allows formation of a stem-loop structure promoting transcription of the mgtC gene. The substitution of proline codons in the mgtP gene eliminates EF-P-mediated mgtC expression and thus Salmonella's survival inside macrophages. Our findings indicate that Salmonella benefits virulence genes by decreasing EF-P levels and inducing the stringent response inside host.
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UR - http://www.scopus.com/inward/citedby.url?scp=84990184634&partnerID=8YFLogxK
U2 - 10.1111/mmi.13454
DO - 10.1111/mmi.13454
M3 - Article
C2 - 27350030
AN - SCOPUS:84990184634
VL - 102
SP - 221
EP - 232
JO - Molecular Microbiology
JF - Molecular Microbiology
SN - 0950-382X
IS - 2
ER -