scholarly journals miR-503 represses CUG-binding protein 1 translation by recruiting CUGBP1 mRNA to processing bodies

2012 ◽  
Vol 23 (1) ◽  
pp. 151-162 ◽  
Author(s):  
Yu-Hong Cui ◽  
Lan Xiao ◽  
Jaladanki N. Rao ◽  
Tongtong Zou ◽  
Lan Liu ◽  
...  
Keyword(s):  
Rna Binding ◽  
De Novo ◽  
Rna Binding Proteins ◽  
Binding Protein ◽  
Mrna Levels ◽  
Intestinal Epithelial ◽  
Coding Region ◽  
Processing Bodies ◽  
Target Mrnas ◽  
Repressive Effect

microRNAs (miRNAs) and RNA-binding proteins (RBPs) jointly regulate gene expression at the posttranscriptional level and are involved in many aspects of cellular functions. The RBP CUG-binding protein 1 (CUGBP1) destabilizes and represses the translation of several target mRNAs, but the exact mechanism that regulates CUGBP1 abundance remains elusive. In this paper, we show that miR-503, computationally predicted to associate with three sites of the CUGBP1 mRNA, represses CUGBP1 expression. Overexpression of an miR-503 precursor (pre-miR-503) reduced the de novo synthesis of CUGBP1 protein, whereas inhibiting miR-503 by using an antisense RNA (antagomir) enhanced CUGBP1 biosynthesis and elevated its abundance; neither intervention changed total CUGBP1 mRNA levels. Studies using heterologous reporter constructs revealed a greater repressive effect of miR-503 through the CUGBP1 coding region sites than through the single CUGBP1 3′-untranslated region target site. CUGBP1 mRNA levels in processing bodies (P-bodies) increased in cells transfected with pre-miR-503, while silencing P-body resident proteins Ago2, RCK, or LSm4 decreased miR-503–mediated repression of CUGBP1 expression. Decreasing the levels of cellular polyamines reduced endogenous miR-503 levels and promoted CUGBP1 expression, an effect that was prevented by ectopic miR-503 overexpression. Repression of CUGBP1 by miR-503 in turn altered the expression of CUGBP1 target mRNAs and thus increased the sensitivity of intestinal epithelial cells to apoptosis. These findings identify miR-503 as both a novel regulator of CUGBP1 expression and a modulator of intestinal epithelial homoeostasis.

scholarly journals Competition between RNA-binding proteins CELF1 and HuR modulates MYC translation and intestinal epithelium renewal

2015 ◽  
Vol 26 (10) ◽  
pp. 1797-1810 ◽  
Author(s):  
Lan Liu ◽  
Miao Ouyang ◽  
Jaladanki N. Rao ◽  
Tongtong Zou ◽  
Lan Xiao ◽  
...  
Keyword(s):  
Intestinal Epithelium ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Binding Protein ◽  
The Body ◽  
Small Intestinal Mucosa ◽  
Mrna Levels ◽  
Intestinal Epithelial ◽  
Mucosal Growth ◽  
The Stability

The mammalian intestinal epithelium is one of the most rapidly self-renewing tissues in the body, and its integrity is preserved through strict regulation. The RNA-binding protein (RBP) ELAV-like family member 1 (CELF1), also referred to as CUG-binding protein 1 (CUGBP1), regulates the stability and translation of target mRNAs and is implicated in many aspects of cellular physiology. We show that CELF1 competes with the RBP HuR to modulate MYC translation and regulates intestinal epithelial homeostasis. Growth inhibition of the small intestinal mucosa by fasting in mice was associated with increased CELF1/ Myc mRNA association and decreased MYC expression. At the molecular level, CELF1 was found to bind the 3′-untranslated region (UTR) of Myc mRNA and repressed MYC translation without affecting total Myc mRNA levels. HuR interacted with the same Myc 3′-UTR element, and increasing the levels of HuR decreased CELF1 binding to Myc mRNA. In contrast, increasing the concentrations of CELF1 inhibited formation of the [HuR/ Myc mRNA] complex. Depletion of cellular polyamines also increased CELF1 and enhanced CELF1 association with Myc mRNA, thus suppressing MYC translation. Moreover, ectopic CELF1 overexpression caused G1-phase growth arrest, whereas CELF1 silencing promoted cell proliferation. These results indicate that CELF1 represses MYC translation by decreasing Myc mRNA association with HuR and provide new insight into the molecular functions of RBPs in the regulation of intestinal mucosal growth.

scholarly journals Competitive binding of CUGBP1 and HuR to occludin mRNA controls its translation and modulates epithelial barrier function

2013 ◽  
Vol 24 (2) ◽  
pp. 85-99 ◽  
Author(s):  
Ting-Xi Yu ◽  
Jaladanki N. Rao ◽  
Tongtong Zou ◽  
Lan Liu ◽  
Lan Xiao ◽  
...  
Keyword(s):  
Barrier Function ◽  
Untranslated Region ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Cell Monolayer ◽  
Intestinal Epithelial ◽  
Processing Bodies ◽  
Epithelial Barrier Function ◽  
P Bodies ◽  
The Stability

RNA-binding proteins CUG-binding protein 1 (CUGBP1) and HuR are highly expressed in epithelial tissues and modulate the stability and translation of target mRNAs. Here we present evidence that CUGBP1 and HuR jointly regulate the translation of occludin and play a crucial role in the maintenance of tight junction (TJ) integrity in the intestinal epithelial cell monolayer. CUGBP1 and HuR competed for association with the same occludin 3′-untranslated region element and regulated occludin translation competitively and in opposite directions. CUGBP1 overexpression decreased HuR binding to occludin mRNA, repressed occludin translation, and compromised the TJ barrier function, whereas HuR overexpression inhibited CUGBP1 association with occludin mRNA and promoted occludin translation, thereby enhancing the barrier integrity. Repression of occludin translation by CUGBP1 was due to the colocalization of CUGBP1 and tagged occludin RNA in processing bodies (P-bodies), and this colocalization was prevented by HuR overexpression. These findings indicate that CUGBP1 represses occludin translation by increasing occludin mRNA recruitment to P-bodies, whereas HuR promotes occludin translation by blocking occludin mRNA translocation to P-bodies via the displacement of CUGBP1.

scholarly journals Depletion of the Trypanosome Pumilio Domain Protein PUF2 or of Some Other Essential Proteins Causes Transcriptome Changes Related to Coding Region Length

2014 ◽  
Vol 13 (5) ◽  
pp. 664-674 ◽  
Author(s):  
Bhaskar Anand Jha ◽  
Abeer Fadda ◽  
Clementine Merce ◽  
Elisha Mugo ◽  
Dorothea Droll ◽  
...  
Keyword(s):  
Rna Binding ◽  
Rna Binding Proteins ◽  
Mrna Translation ◽  
Open Reading Frames ◽  
Mrna Levels ◽  
Coding Region ◽  
Content Type ◽  
Puf Proteins ◽  
Reading Frames

ABSTRACT Pumilio domain RNA-binding proteins are known mainly as posttranscriptional repressors of gene expression that reduce mRNA translation and stability. Trypanosoma brucei has 11 PUF proteins. We show here that PUF2 is in the cytosol, with roughly the same number of molecules per cell as there are mRNAs. Although PUF2 exhibits a low level of in vivo RNA binding, it is not associated with polysomes. PUF2 also decreased reporter mRNA levels in a tethering assay, consistent with a repressive role. Depletion of PUF2 inhibited growth of bloodstream-form trypanosomes, causing selective loss of mRNAs with long open reading frames and increases in mRNAs with shorter open reading frames. Reexamination of published RNASeq data revealed the same trend in cells depleted of some other proteins. We speculate that these length effects could be caused by inhibition of the elongation phase of transcription or by an influence of translation status or polysomal conformation on mRNA decay.

scholarly journals Translational Control of Cytochrome c by RNA-Binding Proteins TIA-1 and HuR

2006 ◽  
Vol 26 (8) ◽  
pp. 3295-3307 ◽  
Author(s):  
Tomoko Kawai ◽  
Ashish Lal ◽  
Xiaoling Yang ◽  
Stefanie Galban ◽  
Krystyna Mazan-Mamczarz ◽  
...  
Keyword(s):  
Er Stress ◽  
Translational Control ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Expression Patterns ◽  
Mrna Levels ◽  
Coding Region ◽  
Translation Rate ◽  
Translational Repressor

ABSTRACT Stresses affecting the endoplasmic reticulum (ER) globally modulate gene expression patterns by altering posttranscriptional processes such as translation. Here, we use tunicamycin (Tn) to investigate ER stress-triggered changes in the translation of cytochrome c, a pivotal regulator of apoptosis. We identified two RNA-binding proteins that associate with its ∼900-bp-long, adenine- and uridine-rich 3′ untranslated region (UTR): HuR, which displayed affinity for several regions of the cytochrome c 3′UTR, and T-cell-restricted intracellular antigen 1 (TIA-1), which preferentially bound the segment proximal to the coding region. HuR did not appear to influence the cytochrome c mRNA levels but instead promoted cytochrome c translation, as HuR silencing greatly diminished the levels of nascent cytochrome c protein. By contrast, TIA-1 functioned as a translational repressor of cytochrome c, with interventions to silence TIA-1 dramatically increasing cytochrome c translation. Following treatment with Tn, HuR binding to cytochrome c mRNA decreased, and both the presence of cytochrome c mRNA within actively translating polysomes and the rate of cytochrome c translation declined. Taken together, our data suggest that the translation rate of cytochrome c is determined by the opposing influences of HuR and TIA-1 upon the cytochrome c mRNA. Under unstressed conditions, cytochrome c mRNA is actively translated, but in response to ER stress agents, both HuR and TIA-1 contribute to lowering its biosynthesis rate. We propose that HuR and TIA-1 function coordinately to maintain precise levels of cytochrome c production under unstimulated conditions and to modify cytochrome c translation when damaged cells are faced with molecular decisions to follow a prosurvival or a prodeath path.

scholarly journals The c-myc coding region determinant-binding protein: a member of a family of KH domain RNA-binding proteins

1998 ◽  
Vol 26 (22) ◽  
pp. 5036-5044 ◽  
Author(s):  
G. A. R. Doyle ◽  
P. F. Leeds ◽  
A. J. Fleisig ◽  
J. Ross ◽  
N. A. Betz ◽  
...  
Keyword(s):  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Binding Protein ◽  
Protein A ◽  
Coding Region ◽  
Kh Domain

scholarly journals Jnk2 deletion disrupts intestinal mucosal homeostasis and maturation by differentially modulating RNA-binding proteins HuR and CUGBP1

2014 ◽  
Vol 306 (12) ◽  
pp. C1167-C1175 ◽  
Author(s):  
Hee Kyoung Chung ◽  
Jaladanki N. Rao ◽  
Tongtong Zou ◽  
Lan Liu ◽  
Lan Xiao ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Intestinal Epithelium ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Binding Protein ◽  
Intestinal Epithelial ◽  
Targeted Gene Deletion ◽  
Epithelial Homeostasis

Homeostasis and maturation of the mammalian intestinal epithelium are preserved through strict regulation of cell proliferation, apoptosis, and differentiation, but the exact mechanism underlying this process remains largely unknown. c-Jun NH2-terminal kinase 2 (JNK2) is highly expressed in the intestinal mucosa, and its activation plays an important role in proliferation and also mediates apoptosis in cultured intestinal epithelial cells (IECs). Here, we investigated the in vivo function of JNK2 in the regulation of intestinal epithelial homeostasis and maturation by using a targeted gene deletion approach. Targeted deletion of the jnk2 gene increased cell proliferation within the crypts in the small intestine and disrupted mucosal maturation as indicated by decreases in the height of villi and the villus-to-crypt ratio. JNK2 deletion also decreased susceptibility of the intestinal epithelium to apoptosis. JNK2-deficient intestinal epithelium was associated with an increase in the level of the RNA-binding protein HuR and with a decrease in the abundance of CUG-binding protein 1 (CUGBP1). In studies in vitro, JNK2 silencing protected intestinal epithelial cell-6 (IEC-6) cells against apoptosis and this protection was prevented by inhibiting HuR. Ectopic overexpression of CUGBP1 repressed IEC-6 cell proliferation, whereas CUGBP1 silencing enhanced cell growth. These results indicate that JNK2 is essential for maintenance of normal intestinal epithelial homeostasis and maturation under biological conditions by differentially modulating HuR and CUGBP1.

scholarly journals RNA-Binding Proteins HuR and PTB Promote the Translation of Hypoxia-Inducible Factor 1α

2007 ◽  
Vol 28 (1) ◽  
pp. 93-107 ◽  
Author(s):  
Stefanie Galbán ◽  
Yuki Kuwano ◽  
Rudolf Pullmann ◽  
Jennifer L. Martindale ◽  
Hyeon Ho Kim ◽  
...  
Keyword(s):  
Binding Proteins ◽  
Rna Binding ◽  
De Novo ◽  
Rna Binding Proteins ◽  
Hypoxia Inducible Factor ◽  
Mrna Levels ◽  
Entry Site ◽  
Hypoxia Inducible Factor 1Α ◽  
Ribonucleoprotein Complexes ◽  
Polypyrimidine Tract Binding Protein

ABSTRACT The levels of hypoxia-inducible factor 1α (HIF-1α) are tightly controlled. Here, we investigated the posttranscriptional regulation of HIF-1α expression in human cervical carcinoma HeLa cells responding to the hypoxia mimetic CoCl2. Undetectable in untreated cells, HIF-1α levels increased dramatically in CoCl2-treated cells, while HIF-1α mRNA levels were unchanged. HIF-1α translation was potently elevated by CoCl2 treatment, as determined by de novo translation analysis and by monitoring the polysomal association of HIF-1α mRNA. An internal ribosome entry site in the HIF-1α 5′ untranslated region (UTR) was found to enhance translation constitutively, but it did not further induce translation in response to CoCl2 treatment. Instead, we postulated that RNA-binding proteins HuR and PTB, previously shown to bind HIF-1α mRNA, participated in its translational upregulation after CoCl2 treatment. Indeed, both RNA-binding proteins were found to bind HIF-1α mRNA in a CoCl2-inducible manner as assessed by immunoprecipitation of endogenous ribonucleoprotein complexes. Using a chimeric reporter, polypyrimidine tract-binding protein (PTB) was found to bind the HIF-1α 3′UTR, while HuR associated principally with the 5′UTR. Lowering PTB expression or HuR expression using RNA interference reduced HIF-1α translation and expression levels but not HIF-1α mRNA abundance. Conversely, HIF-1α expression and translation in response to CoCl2 were markedly elevated after HuR overexpression. We propose that HuR and PTB jointly upregulate HIF-1α translation in response to CoCl2.

scholarly journals Post-transcriptional regulation of Wnt co-receptor LRP6 and RNA-binding protein HuR by miR-29b in intestinal epithelial cells

2016 ◽  
Vol 473 (11) ◽  
pp. 1641-1649 ◽  
Author(s):  
Yanwu Li ◽  
Gang Chen ◽  
Jun-Yao Wang ◽  
Tongtong Zou ◽  
Lan Liu ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Rna Binding ◽  
Intestinal Epithelial Cells ◽  
Binding Protein ◽  
Low Density Lipoprotein ◽  
Rna Binding Protein ◽  
Density Lipoprotein ◽  
Transcriptional Level ◽  
Intestinal Epithelial ◽  
Repressive Effect

MicroRNAs (miRNAs) control gene expression by binding to their target mRNAs for degradation and/or translation repression and are implicated in many aspects of cellular physiology. Our previous study shows that miR-29b acts as a biological repressor of intestinal mucosal growth, but its exact downstream targets remain largely unknown. In the present study, we found that mRNAs, encoding Wnt co-receptor LRP6 (low-density lipoprotein-receptor-related protein 6) and RNA-binding protein (RBP) HuR, are novel targets of miR-29b in intestinal epithelial cells (IECs) and that expression of LRP6 and HuR is tightly regulated by miR-29b at the post-transcriptional level. miR-29b interacted with both Lrp6 and HuR mRNAs via their 3′-UTRs and inhibited LRP6 and HuR expression by destabilizing Lrp6 and HuR mRNAs and repressing their translation. Studies using heterologous reporter constructs revealed a greater repressive effect of miR-29b through a single binding site in the Lrp6 or HuR 3′-UTR, whereas deletion mutation of this site prevented miR-29b-induced repression of LRP6 and HuR expression. Repression of HuR by miR-29b in turn also contributed to miR-29b-induced LRP6 inhibition, since ectopic overexpression of HuR in cells overexpressing miR-29b restored LRP6 expression to near normal levels. Taken together, our results suggest that miR-29b inhibits expression of LRP6 and HuR post-transcriptionally, thus playing a role in the regulation of IEC proliferation and intestinal epithelial homoeostasis.

scholarly journals Fission Yeast Puf2, a Pumilio and FBF Family RNA-Binding Protein, Links Stress Granules to Processing Bodies

2020 ◽  
Vol 40 (9) ◽  
Author(s):  
Wan-Yi Hsiao ◽  
Yi-Ting Wang ◽  
Shao-Win Wang
Keyword(s):  
Fission Yeast ◽  
Rna Binding ◽  
Fluorescent Protein ◽  
Rna Binding Proteins ◽  
Binding Protein ◽  
Intrinsically Disordered Protein ◽  
Stress Granules ◽  
Low Complexity ◽  
Processing Bodies ◽  
Intrinsically Disordered

ABSTRACT Stress granules (SGs) are cytoplasmic aggregates formed upon stress when untranslated messenger ribonucleoproteins accumulate in the cells. In a green fluorescent protein library screening of the fission yeast SG proteins, Puf2 of the PUF family of RNA-binding proteins was identified that is required for SG formation after deprivation of glucose. Accordingly, the puf2 mutant is defective in recovery from glucose starvation with a much longer lag to reenter the cell cycle. In keeping with these results, Puf2 contains several low-complexity and intrinsically disordered protein regions with a tendency to form aggregates and, when overexpressed, it represses translation to induce aggregation of poly(A) binding protein Pabp, the signature constituent of SGs. Intriguingly, overexpression of Puf2 also enhances the structure of processing bodies (PBs), another type of cytoplasmic RNA granule, a complex of factors involved in mRNA degradation. In this study, we demonstrate a function of the fission yeast PB in SG formation and show Puf2 may provide a link between these two structures.

scholarly journals Post-transcriptionally impaired de novo mutations contribute to the genetic etiology of four neuropsychiatric disorders

2017 ◽  
Author(s):  
Fengbiao Mao ◽  
Lu Wang ◽  
Xiaolu Zhao ◽  
Zhongshan Li ◽  
Luoyuan Xiao ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Rna Binding ◽  
De Novo ◽  
Rna Binding Proteins ◽  
Genetic Disorders ◽  
Interaction Network ◽  
Neuropsychiatric Disorders ◽  
Protein Protein Interactions ◽  
De Novo Mutations ◽  
Coding Region

AbstractWhile deleterious de novo mutations (DNMs) in coding region conferring risk in neuropsychiatric disorders have been revealed by next-generation sequencing, the role of DNMs involved in post-transcriptional regulation in pathogenesis of these disorders remains to be elucidated. Here, we identified 1,736 post-transcriptionally impaired DNMs (piDNMs), and prioritized 1,482 candidate genes in four neuropsychiatric disorders from 7,748 families. Our results revealed higher prevalence of piDNMs in the probands than in controls (P = 8.19×10−17), and piDNM-harboring genes were enriched for epigenetic modifications and neuronal or synaptic functions. Moreover, we identified 86 piDNM-containing genes forming convergent co-expression modules and intensive protein-protein interactions in at least two neuropsychiatric disorders. These cross-disorder genes carrying piDNMs could form interaction network centered on RNA binding proteins, suggesting a shared post-transcriptional etiology underlying these disorders. Our findings illustrate the significant contribution of piDNMs to four neuropsychiatric disorders, and lay emphasis on combining functional and network-based evidences to identify regulatory causes of genetic disorders.

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