Role of GNRA Motif Mutations within Stem-Loop V of Internal Ribosome Entry Segment in Coxsackievirus B3 Molecular Attenuation

2008 ◽  
Vol 14 (4) ◽  
pp. 147-156 ◽  
Author(s):  
Manel Ben M’hadheb-Gharbi ◽  
Raïda El Hiar ◽  
Sylvie Paulous ◽  
Hela Jaïdane ◽  
Mahjoub Aouni ◽  
...  
Keyword(s):  
Coxsackievirus B3 ◽  
Stem Loop ◽  
Internal Ribosome Entry ◽  
Internal Ribosome Entry Segment

Effects of the Sabin-like mutations in domain V of the internal ribosome entry segment on translational efficiency of the Coxsackievirus B3

2006 ◽  
Vol 276 (4) ◽  
pp. 402-412 ◽  
Author(s):  
Manel Ben M’hadheb-Gharbi ◽  
Jawhar Gharbi ◽  
Sylvie Paulous ◽  
Michèle Brocard ◽  
Anastasia Komaromva ◽  
...  
Keyword(s):  
Coxsackievirus B3 ◽  
Translational Efficiency ◽  
Internal Ribosome Entry ◽  
Internal Ribosome Entry Segment ◽  
Domain V

scholarly journals Terminal uridyltransferase 7 regulates TLR4-triggered inflammation by controlling Regnase-1 mRNA uridylation and degradation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chia-Ching Lin ◽  
Yi-Ru Shen ◽  
Chi-Chih Chang ◽  
Xiang-Yi Guo ◽  
Yun-Yun Young ◽  
...  
Keyword(s):  
Posttranscriptional Regulation ◽  
Inflammatory Responses ◽  
Rna Stability ◽  
Innate Immune ◽  
Stem Loop ◽  
Stem Loop Structure ◽  
Tlr4 Activation ◽  
Harmful Effects ◽  
Different Levels

AbstractDifferent levels of regulatory mechanisms, including posttranscriptional regulation, are needed to elaborately regulate inflammatory responses to prevent harmful effects. Terminal uridyltransferase 7 (TUT7) controls RNA stability by adding uridines to its 3′ ends, but its function in innate immune response remains obscure. Here we reveal that TLR4 activation induces TUT7, which in turn selectively regulates the production of a subset of cytokines, including Interleukin 6 (IL-6). TUT7 regulates IL-6 expression by controlling ribonuclease Regnase-1 mRNA (encoded by Zc3h12a gene) stability. Mechanistically, TLR4 activation causes TUT7 to bind directly to the stem-loop structure on Zc3h12a 3′-UTR, thereby promotes Zc3h12a uridylation and degradation. Zc3h12a from LPS-treated TUT7-sufficient macrophages possesses increased oligo-uridylated ends with shorter poly(A) tails, whereas oligo-uridylated Zc3h12a is significantly reduced in Tut7-/- cells after TLR4 activation. Together, our findings reveal the functional role of TUT7 in sculpting TLR4-driven responses by modulating mRNA stability of a selected set of inflammatory mediators.

scholarly journals Identification and characterization of a sequence motif involved in nonsense-mediated mRNA decay.

1995 ◽  
Vol 15 (4) ◽  
pp. 2231-2244 ◽  
Author(s):  
S Zhang ◽  
M J Ruiz-Echevarria ◽  
Y Quan ◽  
S W Peltz
Keyword(s):  
Mrna Decay ◽  
Sequence Motif ◽  
Nonsense Mutations ◽  
Stem Loop ◽  
Cis Acting ◽  
Stem Loop Structure ◽  
Nonsense Codon ◽  
Nonsense Mediated Mrna Decay

In both prokaryotes and eukaryotes, nonsense mutations in a gene can enhance the decay rate or reduce the abundance of the mRNA transcribed from that gene, and we call this process nonsense-mediated mRNA decay. We have been investigating the cis-acting sequences involved in this decay pathway. Previous experiments have demonstrated that, in addition to a nonsense codon, specific sequences 3' of a nonsense mutation, which have been defined as downstream elements, are required for mRNA destabilization. The results presented here identify a sequence motif (TGYYGATGYYYYY, where Y stands for either T or C) that can predict regions in genes that, when positioned 3' of a nonsense codon, promote rapid decay of its mRNA. Sequences harboring two copies of the motif from five regions in the PGK1, ADE3, and HIS4 genes were able to function as downstream elements. In addition, four copies of this motif can function as an independent downstream element. The sequences flanking the motif played a more significant role in modulating its activity when fewer copies of the sequence motif were present. Our results indicate the sequences 5' of the motif can modulate its activity by maintaining a certain distance between the sequence motif and the termination codon. We also suggest that the sequences 3' of the motif modulate the activity of the downstream element by forming RNA secondary structures. Consistent with this view, a stem-loop structure positioned 3' of the sequence motif can enhance the activity of the downstream element. This sequence motif is one of the few elements that have been identified that can predict regions in genes that can be involved in mRNA turnover. The role of these sequences in mRNA decay is discussed.

sRNA STnc150 is involved in virulence regulation of Salmonella Typhimurium by targeting fimA mRNA

2021 ◽  
Vol 368 (18) ◽  
Author(s):  
Jing Li ◽  
Na Li ◽  
Chengcheng Ning ◽  
Yun Guo ◽  
Chunhui Ji ◽  
...  
Keyword(s):  
Salmonella Typhimurium ◽  
Target Genes ◽  
Reporter System ◽  
Stem Loop ◽  
Viral Loads ◽  
Virulence Regulation ◽  
Stem Loop Structure ◽  
Complementary Strain

ABSTRACT Small RNAs (sRNAs) are essential virulent regulators in Salmonella typhimurium (STM). To explore the role of sRNA STnc150 in regulating STM virulence, we constructed a STnc150 deletion strain (ΔSTnc150) and its complementary strain (ΔSTnc150/C). Then, we compared their characteristics to their original parent strain experimentally, identified the target genes of STnc150 and determined the expression levels of target genes. The results showed that the ΔSTnc150 strain exhibited delayed biofilm formation, enhanced adhesion to macrophages, significantly reduced LD50, increased liver and spleen viral loads and more vital pathological damaging ability than its parent and complementary strains. Further, bioinformatics combined with the bacterial dual plasmid reporter system confirmed that the bases 72–88 of STnc150 locating at the secondary stem-loop structure of the STnc150 are complementary with the bases 1–19 in the 5′-terminal of fimA mRNA of the type 1 fimbriae subunit. Western blot analysis showed that fimA protein level was increased in STnc150 strain compared with its parent and complementary strains. Together, this study suggested that STnc150 can down-regulate STM fimA expression at the translation level, which provided insights into the regulatory mechanisms of sRNAs in virulence of STM.

scholarly journals C-Myc 5′ untranslated region contains an internal ribosome entry segment

Oncogene ◽  
1998 ◽  
Vol 16 (3) ◽  
pp. 423-428 ◽  
Author(s):  
Mark Stoneley ◽  
Fiona EM Paulin ◽  
John PC Le Quesne ◽  
Stephen A Chappell ◽  
Anne E Willis
Keyword(s):  
Untranslated Region ◽  
Internal Ribosome Entry ◽  
Internal Ribosome Entry Segment
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