Ribosome stalling during translation elongation induces cleavage of mRNA being translated in Escherichia coli.
Recently, it has been found that ribosome pausing at stop codons caused by certain nascent peptides induces cleavage of mRNA in Escherichia coli cells (1, 2). The question we addressed in the present study is whether mRNA cleavage occurs when translation elongation is prevented. We focused on a specific peptide sequence (AS17), derived from SecM, that is known to cause elongation arrest. When the crp-crr fusion gene encoding CRP-AS17-IIA(Glc) was expressed, cAMP receptor protein (CRP) proteins truncated around the arrest sequence were efficiently produced, and they were tagged by the transfer-messenger RNA (tmRNA) system. Northern blot analysis revealed that both truncated upstream crp and downstream crr mRNAs were generated along with reduced amounts of the full-length crp-crr mRNA. The truncated crp mRNA dramatically decreased in the presence of tmRNA due to rapid degradation. The 3' ends of truncated crp mRNA correspond well to the C termini of the truncated CRP proteins. We conclude that ribosome stalling by the arrest sequence induces mRNA cleavage near the arrest point, resulting in nonstop mRNAs that are recognized by tmRNA. We propose that the mRNA cleavage induced by ribosome stalling acts in concert with the tmRNA system as a way to ensure quality control of protein synthesis and possibly to regulate the expression of certain genes.
Sunohara
Takafumi
T
Division of Biological Science, Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8602, Japan.
Jojima
Kaoru
K
Tagami
Hideaki
H
Inada
Toshifumi
T
Aiba
Hiroji
H
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000378:metabolism; D001483:Base Sequence; D015152:Blotting, Northern; D015153:Blotting, Western; D002455:Cell Division; D003062:Codon; D018388:Codon, Terminator; D000242:Cyclic AMP / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism*; D013058:Mass Spectrometry; D026901:Membrane Transport Proteins / Q000378:metabolism; D008954:Models, Biological; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry; D010957:Plasmids / Q000378:metabolism; D014176:Protein Biosynthesis; D017434:Protein Structure, Tertiary; D012313:RNA / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012270:Ribosomes / Q000737:chemistry / Q000378:metabolism*; D000069816:SEC Translocation Channels; D000081416:SecA Proteins
D001426:Bacterial Proteins; D003062:Codon; D018388:Codon, Terminator; D026901:Membrane Transport Proteins; D010455:Peptides; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D000069816:SEC Translocation Channels; D012313:RNA; D000242:Cyclic AMP; D000251:Adenosine Triphosphatases; D000081416:SecA Proteins