Role of a Peptide Tagging System in Degradation of Proteins Synthesized from Damaged Messenger RNA

  title={Role of a Peptide Tagging System in Degradation of Proteins Synthesized from Damaged Messenger RNA},
  author={Kenneth C. Keiler and Patrick R. H. Waller and Robert T. Sauer},
  pages={990 - 993}
Variants of λ repressor and cytochrome b562 translated from messenger RNAs without stop codons were modified by carboxyl terminal addition of an ssrA-encoded peptide tag and subsequently degraded by carboxyl terminal-specific proteases present in both the cytoplasm and periplasm of Escherichia coli. The tag appears to be added to the carboxyl terminus of the nascent polypeptide chain by cotranslational switching of the ribosome from the damaged messenger RNA to ssrA RNA. 
When Proteins Receive Deadly Messages at Birth
A new prokaryotic protein tagging system reported by Keiler et al. involves nascent polypeptides, translated from truncated mRNAs lacking stop codons, receiving short COOH-terminal peptide tags encoded by a separate RNA, 10Sa RNA.
Proteolytic Adaptor for Transfer-Messenger RNA-Tagged Proteins from α-Proteobacteria
An analog of SspB, the proteolytic adaptor for transfer-messenger RNA (tmRNA)-tagged proteins, in Caulobacter crescentus is identified and is required for optimal proteolysis of tagged proteins in vivo.
The fate of extracellular proteins tagged by the SsrA system of Bacillus subtilis.
The polarity of the C-terminus of heterologous hIL-3 protein proved to be an important determinant for protein stability when produced by B. subtilis and it appears that intracellular proteins are the predominant natural substrates of SsrA.
Protein factors associated with the SsrA⋅SmpB tagging and ribosome rescue complex
  • A. W. Karzai, R. Sauer
  • Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 2001
Evidence is presented here for the existence of a larger ribonucleoprotein complex that contains ribosomal protein S1, phosphoribosyl pyrophosphate synthase, RNase R, and YfbG in addition to SsrA RNA and SmpB.
The SsrA–SmpB system for protein tagging, directed degradation and ribosome rescue
The structural, functional and phylogenetic properties of this unique RNA and its associated factors are reviewed, and the intracellular proteases that act to degrade the proteins tagged by this system are also discussed.
Bacterial SsrA system plays a role in coping with unwanted translational readthrough caused by suppressor tRNAs
The aim of the present study is to examine how translational readthrough by suppressor tRNAs affects trans‐translation in Escherichia coli.
Analysis of the Role of trans-Translation in the Requirement of tmRNA for l imm P 22 Growth in Escherichia coli
The small, stable RNA molecule encoded by ssrA, known as tmRNA or 10Sa RNA, is required for the growth of certain hybrid limm phages in Escherichia coli. tmRNA has been shown to tag partially
Lon Protease Degrades Transfer-Messenger RNA-Tagged Proteins
In vivo and in vitro evidence is presented that demonstrates a direct role for the Lon ATP-dependent protease in the degradation of tmRNA-tagged proteins, and highly purified Lon preferentially degraded the tm RNA-taged forms of proteins compared to the untagged forms.
A specificity-enhancing factor for the ClpXP degradation machine.
Here, a ribosome-associated protein, SspB, was found to bind specifically to ssrA-tagged proteins and to enhance recognition of these proteins by ClpXP, demonstrating that SSPB is a specificity-enhancing factor for Clp XP that controls substrate choice.
Quality control of the elongation step of protein synthesis by tmRNP.
Trans-translation is a quality-control process, activated upon premature termination of protein elongation, which recycles stalled ribosomes and degrades incomplete polypeptides through transfer-messenger RNA, a small stable RNA molecule encoded by the SsrA gene found in bacteria, chloroplasts and mitochondria.


C-terminal Extension of Truncated Recombinant Proteins in Escherichia coli with a 10Sa RNA Decapeptide(*)
Peptide mapping, electrospray ionization-mass spectrometry, and automated N- and C-terminal sequencing identified a peptide (“tag” peptide), encoded by a small metabolically stable RNA of E. coli attached to truncated C termini of the recombinant protein.
A persistent untranslated sequence within bacteriophage T4 DNA topoisomerase gene 60.
A mechanism is proposed in which folding of the untranslated region brings together codons separated by the interruption so that the elongating ribosome may skip the 50 nucleotides during translation.
Carboxy-terminal determinants of intracellular protein degradation.
The data suggest that the degradation of amino- terminal domain variants with nonpolar carboxy-terminal residues involves proteolytic components distinct from those known to be important for the turnover of unfolded proteins in E. coli.
A tRNA-like structure is present in 10Sa RNA, a small stable RNA from Escherichia coli.
Primer-extension analysis of 10Sa RNA extracted from a bacterial mutant with temperature-sensitive RNase P function revealed that the precursor to 10SaRNA (pre-10Sa RNA) is folded into a pre-tRNA-like structure in vivo such that it can be cleaved byRNase P to generate the 5' end of the mature 10 Sa RNA.
Roles of RNase E, RNase II and PNPase in the degradation of the rpsO transcripts of Escherichia coli: stabilizing function of RNase II and evidence for efficient degradation in an ams pnp rnb mutant.
Rapid degradation of the rpsO mRNA is observed after inactivation of RNase II even in a strain deficient for RNase E and polynucleotide phosphorylase.
The N-end rule in Escherichia coli: cloning and analysis of the leucyl, phenylalanyl-tRNA-protein transferase gene aat
The cloning and analysis of aat, the Escherichia coli gene that encodes leucyl, phenylalanyl-tRNA-protein transferase (L/F-transferase), a component of the bacterial N-end rule pathway, are reported, suggesting the specificity of L/F -transferase in vivo may be greater than that in vitro.
Tsp: a tail-specific protease that selectively degrades proteins with nonpolar C termini.
  • K. Silber, K. Keiler, R. Sauer
  • Biology, Chemistry
    Proceedings of the National Academy of Sciences of the United States of America
  • 1992
The deduced protein sequence of Tsp shows no significant homology to known protease sequences but does show sequence similarity to the human and bovine interphotoreceptor retinoid-binding proteins, which bind hydrophobic ligands.
Regulation by proteolysis: energy-dependent proteases and their targets.
A number of critical regulatory proteins in both prokaryotic and eukaryotic cells are subject to rapid, energy-dependent proteolysis, providing a mechanism by which the availability of a protein can be limited both temporally and spatially.