scholarly journals Nuclear TARBP2 drives oncogenic dysregulation of RNA splicing and decay

2018 ◽  
Author(s):  
Lisa Fish ◽  
Hoang C.B. Nguyen ◽  
Steven Zhang ◽  
Myles Hochman ◽  
Brian D. Dill ◽  
...  

SUMMARYPost-transcriptional regulation of RNA stability is a key step in gene expression control. We describe a regulatory program, mediated by the double-stranded RNA binding protein TARBP2, that controls RNA stability in the nucleus. TARBP2 binding to pre-mRNAs results in increased intron retention, subsequently leading to targeted degradation of TARBP2-bound transcripts. This is mediated by TARBP2 recruitment of the m6A RNA methylation machinery to its target transcripts, where deposition of m6A marks influences the recruitment of splicing regulators, inhibiting efficient splicing. Interactions between TARBP2 and the nucleoprotein TPR then promote degradation of these TARBP2-bound transcripts by the nuclear exosome. Additionally, analysis of clinical gene expression datasets revealed a functional role for this TARBP2 pathway in lung cancer. Using xenograft mouse models, we find that TARBP2 impacts tumor growth in the lung, and that this function is dependent on TARBP2-mediated destabilization of ABCA3 and FOXN3. Finally, we establish the transcription factor ZNF143 as an upstream regulator of TARBP2 expression.RESEARCH HIGHLIGHTSThe RNA-binding protein TARBP2 controls the stability of its target transcripts in the nucleusNuclear TARBP2 recruits the methyltransferase complex to deposit m6A marks on its target transcriptsTARBP2 and m6A-mediated interactions with splicing and nuclear RNA surveillance complexes result in target transcript intron retention and decay.Increased TARBP2 expression is associated with lung cancer and promotes lung cancer growthin vivo.The transcription factor ZNF143 drives oncogenic TARBP2 upregulation in lung cancer.

2020 ◽  
Vol 48 (22) ◽  
pp. 12943-12956
Author(s):  
Jen-Hao Yang ◽  
Ming-Wen Chang ◽  
Poonam R Pandey ◽  
Dimitrios Tsitsipatis ◽  
Xiaoling Yang ◽  
...  

Abstract Long noncoding (lnc)RNAs potently regulate gene expression programs in physiology and disease. Here, we describe a key function for lncRNA OIP5-AS1 in myogenesis, the process whereby myoblasts differentiate into myotubes during muscle development and muscle regeneration after injury. In human myoblasts, OIP5-AS1 levels increased robustly early in myogenesis, and its loss attenuated myogenic differentiation and potently reduced the levels of the myogenic transcription factor MEF2C. This effect relied upon the partial complementarity of OIP5-AS1 with MEF2C mRNA and the presence of HuR, an RNA-binding protein (RBP) with affinity for both transcripts. Remarkably, HuR binding to MEF2C mRNA, which stabilized MEF2C mRNA and increased MEF2C abundance, was lost after OIP5-AS1 silencing, suggesting that OIP5-AS1 might serve as a scaffold to enhance HuR binding to MEF2C mRNA, in turn increasing MEF2C production. These results highlight a mechanism whereby a lncRNA promotes myogenesis by enhancing the interaction of an RBP and a myogenic mRNA.


2021 ◽  
Author(s):  
Kevin Tsai ◽  
Hal P. Bogerd ◽  
Edward M. Kennedy ◽  
Ann Emery ◽  
Ronald Swanstrom ◽  
...  

AbstractPrevious work in several laboratories has demonstrated that the epitranscriptomic addition of m6A to viral transcripts promotes the replication and pathogenicity of a wide range of DNA and RNA viruses, yet the underlying mechanisms responsible for this positive effect have remained unclear. It is known that m6A function is largely mediated by cellular m6A binding proteins or readers, yet how m6A readers regulate viral gene expression in general, and HIV-1 gene expression in particular, has been controversial. Here, we confirm that m6A addition indeed regulates HIV-1 RNA expression and demonstrate that this effect is in large part mediated by the the nuclear m6A reader YTHDC1 and the cytoplasmic m6A reader YTHDF2. Both YTHDC1 and YTHDF2 bind to multiple distinct and overlapping sites on the HIV-1 RNA genome, with YTHDC1 recruitment serving to regulate the alternative splicing of HIV-1 RNAs while YTHDF2 binding correlates with increased HIV-1 transcript stability.Author SummaryThis manuscript reports that the expression of mRNAs encoded by the pathogenic human retrovirus HIV-1 is regulated by the methylation of a small number of specific adenosine residues. These in turn recruit a nuclear RNA binding protein, called YTHDC1, which modulates the alternative splicing of HIV-1 transcripts, as well as a cytoplasmic RNA binding protein, called YTHDF2, which stabilizes viral mRNAs. The regulation of HIV-1 gene expression by adenosine methylation is therefore critical for the effective and ordered expression of HIV-1 mRNAs and could represent a novel target for antiviral development.


Antioxidants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 552
Author(s):  
Jasmine Harley ◽  
Benjamin E. Clarke ◽  
Rickie Patani

RNA binding proteins fulfil a wide number of roles in gene expression. Multiple mechanisms of RNA binding protein dysregulation have been implicated in the pathomechanisms of several neurodegenerative diseases including amyotrophic lateral sclerosis (ALS). Oxidative stress and mitochondrial dysfunction also play important roles in these diseases. In this review, we highlight the mechanistic interplay between RNA binding protein dysregulation, oxidative stress and mitochondrial dysfunction in ALS. We also discuss different potential therapeutic strategies targeting these pathways.


Biology ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 361
Author(s):  
Myeongwoo Jung ◽  
Eun-Kyung Lee

HuD (also known as ELAVL4) is an RNA–binding protein belonging to the human antigen (Hu) family that regulates stability, translation, splicing, and adenylation of target mRNAs. Unlike ubiquitously distributed HuR, HuD is only expressed in certain types of tissues, mainly in neuronal systems. Numerous studies have shown that HuD plays essential roles in neuronal development, differentiation, neurogenesis, dendritic maturation, neural plasticity, and synaptic transmission by regulating the metabolism of target mRNAs. However, growing evidence suggests that HuD also functions as a pivotal regulator of gene expression in non–neuronal systems and its malfunction is implicated in disease pathogenesis. Comprehensive knowledge of HuD expression, abundance, molecular targets, and regulatory mechanisms will broaden our understanding of its role as a versatile regulator of gene expression, thus enabling novel treatments for diseases with aberrant HuD expression. This review focuses on recent advances investigating the emerging role of HuD, its molecular mechanisms of target gene regulation, and its disease relevance in both neuronal and non–neuronal systems.


2018 ◽  
Vol 154 (6) ◽  
pp. S-585
Author(s):  
Sarah F. Andres ◽  
Kathy N. Williams ◽  
Kathryn E. Hamilton ◽  
Rei Mizuno ◽  
Jeff Headd ◽  
...  

2020 ◽  
Vol 295 (42) ◽  
pp. 14291-14304
Author(s):  
Kathrin Bajak ◽  
Kevin Leiss ◽  
Christine Clayton ◽  
Esteban Erben

In Trypanosoma brucei and related kinetoplastids, gene expression regulation occurs mostly posttranscriptionally. Consequently, RNA-binding proteins play a critical role in the regulation of mRNA and protein abundance. Yet, the roles of many RNA-binding proteins are not understood. Our previous research identified the RNA-binding protein ZC3H5 as possibly involved in gene repression, but its role in controlling gene expression was unknown. We here show that ZC3H5 is an essential cytoplasmic RNA-binding protein. RNAi targeting ZC3H5 causes accumulation of precytokinetic cells followed by rapid cell death. Affinity purification and pairwise yeast two-hybrid analysis suggest that ZC3H5 forms a complex with three other proteins, encoded by genes Tb927.11.4900, Tb927.8.1500, and Tb927.7.3040. RNA immunoprecipitation revealed that ZC3H5 is preferentially associated with poorly translated, low-stability mRNAs, the 5′-untranslated regions and coding regions of which are enriched in the motif (U/A)UAG(U/A). As previously found in high-throughput analyses, artificial tethering of ZC3H5 to a reporter mRNA or other complex components repressed reporter expression. However, depletion of ZC3H5 in vivo caused only very minor decreases in a few targets, marked increases in the abundances of very stable mRNAs, an increase in monosomes at the expense of large polysomes, and appearance of “halfmer” disomes containing two 80S subunits and one 40S subunit. We speculate that the ZC3H5 complex might be implicated in quality control during the translation of suboptimal open reading frames.


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