Abstract
SsrA RNA of Escherichia coli, also known as 10Sa RNA or tmRNA, acts both as tRNA and mRNA when ribosomes are paused at the 3' end of an mRNA lacking a stop codon. This process, referred to as trans-translation, leads to the addition of a short peptide tag to the C-terminus of the incomplete nascent polypeptide. The tagged polypeptide is then degraded by C-terminal-specific proteases. Here, we focused on endogenous targets for the SsrA system and on a potential regulatory role of SsrA RNA. First, we show that trans-translation events occur frequently in normally growing E. coli cells. More specifically, we report that the lacI mRNA encoding Lac repressor (LacI) is a specific natural target for trans-translation. The binding of LacI to the lac operators results in truncated lacI mRNAs that are, in turn, recognized by the SsrA system. The SsrA-mediated tagging and proteolysis of LacI appears to play a role in cellular adaptation to lactose availability by supporting a rapid induction of lac operon expression.
| Original language | English |
|---|---|
| Pages (from-to) | 3762-3769 |
| Number of pages | 8 |
| Journal | EMBO Journal |
| Volume | 19 |
| Issue number | 14 |
| Publication status | Published - Jul 17 2000 |
| Externally published | Yes |
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Keywords
- lac operon
- Lac repressor
- tmRNA
- trans-translation
- Transcriptional roadblock
ASJC Scopus subject areas
- Genetics
- Cell Biology
Cite this
SsrA-mediated tagging and proteolysis of Lacl and its role in the regulation of lac operon. / Abo, Tatsuhiko; Inada, Toshifumi; Ogawa, Kazuko; Aiba, Hiroji.
In: EMBO Journal, Vol. 19, No. 14, 17.07.2000, p. 3762-3769.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - SsrA-mediated tagging and proteolysis of Lacl and its role in the regulation of lac operon
AU - Abo, Tatsuhiko
AU - Inada, Toshifumi
AU - Ogawa, Kazuko
AU - Aiba, Hiroji
PY - 2000/7/17
Y1 - 2000/7/17
N2 - SsrA RNA of Escherichia coli, also known as 10Sa RNA or tmRNA, acts both as tRNA and mRNA when ribosomes are paused at the 3' end of an mRNA lacking a stop codon. This process, referred to as trans-translation, leads to the addition of a short peptide tag to the C-terminus of the incomplete nascent polypeptide. The tagged polypeptide is then degraded by C-terminal-specific proteases. Here, we focused on endogenous targets for the SsrA system and on a potential regulatory role of SsrA RNA. First, we show that trans-translation events occur frequently in normally growing E. coli cells. More specifically, we report that the lacI mRNA encoding Lac repressor (LacI) is a specific natural target for trans-translation. The binding of LacI to the lac operators results in truncated lacI mRNAs that are, in turn, recognized by the SsrA system. The SsrA-mediated tagging and proteolysis of LacI appears to play a role in cellular adaptation to lactose availability by supporting a rapid induction of lac operon expression.
AB - SsrA RNA of Escherichia coli, also known as 10Sa RNA or tmRNA, acts both as tRNA and mRNA when ribosomes are paused at the 3' end of an mRNA lacking a stop codon. This process, referred to as trans-translation, leads to the addition of a short peptide tag to the C-terminus of the incomplete nascent polypeptide. The tagged polypeptide is then degraded by C-terminal-specific proteases. Here, we focused on endogenous targets for the SsrA system and on a potential regulatory role of SsrA RNA. First, we show that trans-translation events occur frequently in normally growing E. coli cells. More specifically, we report that the lacI mRNA encoding Lac repressor (LacI) is a specific natural target for trans-translation. The binding of LacI to the lac operators results in truncated lacI mRNAs that are, in turn, recognized by the SsrA system. The SsrA-mediated tagging and proteolysis of LacI appears to play a role in cellular adaptation to lactose availability by supporting a rapid induction of lac operon expression.
KW - lac operon
KW - Lac repressor
KW - tmRNA
KW - trans-translation
KW - Transcriptional roadblock
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UR - http://www.scopus.com/inward/citedby.url?scp=0343627965&partnerID=8YFLogxK
M3 - Article
VL - 19
SP - 3762
EP - 3769
JO - EMBO Journal
JF - EMBO Journal
SN - 0261-4189
IS - 14
ER -