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Updated: Apr 14, 2026

Xenopus laevis as a Model to Identify Translation Impairment
Published on: September 27, 2015
A role for REP sequences in regulating translation
Wenxing Liang1, Kenneth E Rudd2, Murray P Deutscher2
1Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, FL 33101, USA; The Key Laboratory of Integrated Crop Pest Management of Shandong Province, College of Agronomy and Plant Protection, Qingdao Agricultural University, Qingdao 266109, China.
Abstract:
Repetitive extragenic palindromic (REP) sequences are highly structured elements found downstream of ∼500 genes in Escherichia coli that result in extensive stem-loop structures in their mRNAs. However, their physiological role has remained elusive. Here, we show that REP sequences can downregulate translation, but only if they are within 15 nt of a termination codon; a spacing of 16 nt has no effect, suggesting that the REP element acts to stall ribosome movement. Ribosome stalling leads to cleavage of the mRNA and induction of the trans-translation process. Using nrdAB as a model, we find that its regulation can be partially reversed by overexpression of RNA helicases and can be fully overcome upon UV stress, emphasizing the importance of this regulatory process. Since 50% of REP-associated genes have these elements within the critical 15 nt, these findings identify a regulatory mechanism with the potential to affect translation from a large number of genes.
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