Conserved GU-Rich Elements Mediate mRNA Decay by Binding to CUG-Binding Protein 1

Abstract

We used computational algorithms to find conserved sequences in the 3' untranslated region (UTR) of transcripts that exhibited rapid decay in primary human T cells and found that the consensus sequence UGUUUGUUUGU, which we have termed a GU-rich element (GRE), was enriched in short-lived transcripts. Using a tet-off reporter system, we showed that insertion of GRE-containing sequences from c-jun, jun B, or TNF receptor 1B, but not mutated GRE sequences, into the 3'UTR of a beta-globin transcript conferred instability on the otherwise stable beta-globin transcript. CUG-binding protein 1 (CUGBP1) was identified as the major GRE-binding activity in cytoplasmic extracts from primary human T cells based on supershift and immunoprecipitation assays. siRNA-mediated knockdown of CUGBP1 in HeLa cells caused stabilization of GRE-containing transcripts, suggesting that CUGBP1 is a mediator of GRE-dependent mRNA decay. Overall, our results suggest that the GRE mediates coordinated mRNA decay by binding to CUGBP1.

Regulation of CUG-binding Protein 1 (CUGBP1) Binding to Target Transcripts upon T Cell Activation

“…Cells were then incubated for 6 h in 15-cm dishes (5 ϫ 10 7 cells/dish) with medium alone or with a combination of immobilized monoclonal antibodies (1 g/ml) directed against the CD3 component of the TCR complex (R&D Systems) and the CD28 co-stimulatory molecule (R&D Systems) as described previously (12).…”

“…AREs are conserved sequence elements found in the 3Ј-untranslated region (UTR) of transcripts encoding numerous cytokine transcripts and other inflammatory mediators, and AREs function to coordinately regulate mRNA decay during immune responses by interacting with cytoplasmic ARE-binding proteins (10,11). Another recently described posttranscriptional regulatory network involves the RNA-binding protein CUG-binding protein 1 (CUGBP1), also referred to as CUGBP-and ELAV-like family member 1 (CELF1), which binds to a GU-rich element (GRE) residing in the 3Ј-UTR of target transcripts and mediates coordinate degradation of GRE-containing transcripts (12). The GRE was originally identified as a sequence that was highly enriched in the 3Ј-UTR of transcripts that decayed rapidly in primary human T cells and was shown to function as a regulator of mRNA decay (12).…”

“…Another recently described posttranscriptional regulatory network involves the RNA-binding protein CUG-binding protein 1 (CUGBP1), also referred to as CUGBP-and ELAV-like family member 1 (CELF1), which binds to a GU-rich element (GRE) residing in the 3Ј-UTR of target transcripts and mediates coordinate degradation of GRE-containing transcripts (12). The GRE was originally identified as a sequence that was highly enriched in the 3Ј-UTR of transcripts that decayed rapidly in primary human T cells and was shown to function as a regulator of mRNA decay (12). Based on a bioinformatic analysis of mRNA targets of CUGBP1 in HeLa cells, the GRE was defined to be the consensus sequence UGU(G/U)UGU(G/U)UGU (13).…”

The system with zwitterionic lactose-based surfactant for complexation and delivery of small interfering ribonucleic acid—A structural and spectroscopic study

“…The main problem of this strategy is low stability of siRNA and lack of efficient delivery systems of these reagents. 12,13 The complex proposed in our study should effectively bind and stabilise siRNA for transfection and should show low toxicity for a variety of cells. For the lactose based surfactants chosen (LA12), the bonding of lactose moiety with the hydrophobic fragment via an amine group ensures effective proton bonding in acidic environment, which means that they can act as cationic surfactants.…”

“…The sequence studied is responsible for silencing the gene that can be important in therapy of myotonic dystrophy type 1 (DM1). [11][12][13] DM1 is the most frequent form of muscular dystrophy in adults. 14 It is an autosomal-dominant hereditary disease which can affect many tissues and produce diverse symptoms, including muscle hyperactivity (myotonia), progressive myasthenia, heart conduction defects, cardiomyopathy, insulin resistance, or neuropsychological disturbances.…”