scholarly journals Dynamic landscape and genetic regulation of RNA editing in schizophrenia

2018 ◽  
Author(s):  
Michael S. Breen ◽  
Amanda Dobbyn ◽  
Qin Li ◽  
Panos Roussos ◽  
Gabriel E. Hoffman ◽  
...  

ABSTRACTRNA editing is vital for neurodevelopment and the maintenance of normal neuronal function. We surveyed the global landscape and genetic regulation of RNA editing across several hundred schizophrenia and control postmortem brain samples from the CommonMind Consortium covering two regions, the dorsolateral prefrontal cortex (DLPFC) and anterior cingulate cortex. In schizophrenia, RNA editing sites encoding AMPA glutamate receptors and post-synaptic density genes were less edited, while more editing was detected in sites implicated in translational initiation. These sites replicate between brain regions, map to 3’UTRs, enrich for common sequence motifs and coincide for RNA binding proteins crucial for neurodevelopment. Importantly, these findings cross-validate in hundreds of non-overlapping DLPFC samples. Furthermore, ~30% of RNA editing sites associate with cis-regulatory variants (edQTLs). Fine-mapping edQTLs with schizophrenia GWAS loci revealed colocalization of 11 edQTLs with 6 GWAS loci. This supports a causal role of RNA editing in risk for schizophrenia. Our findings illustrate widespread altered RNA editing in schizophrenia and its genetic regulation, and shed light onto RNA editing-mediated mechanisms in schizophrenia neuropathology.

2004 ◽  
Vol 24 (14) ◽  
pp. 6241-6252 ◽  
Author(s):  
Kristina L. Carroll ◽  
Dennis A. Pradhan ◽  
Josh A. Granek ◽  
Neil D. Clarke ◽  
Jeffry L. Corden

ABSTRACT RNA polymerase II (Pol II) termination is triggered by sequences present in the nascent transcript. Termination of pre-mRNA transcription is coupled to recognition of cis-acting sequences that direct cleavage and polyadenylation of the pre-mRNA. Termination of nonpolyadenylated [non-poly(A)] Pol II transcripts in Saccharomyces cerevisiae requires the RNA-binding proteins Nrd1 and Nab3. We have used a mutational strategy to characterize non-poly(A) termination elements downstream of the SNR13 and SNR47 snoRNA genes. This approach detected two common RNA sequence motifs, GUA[AG] and UCUU. The first motif corresponds to the known Nrd1-binding site, which we have verified here by gel mobility shift assays. We also show that Nab3 protein binds specifically to RNA containing the UCUU motif. Taken together, our data suggest that Nrd1 and Nab3 binding sites play a significant role in defining non-poly(A) terminators. As is the case with poly(A) terminators, there is no strong consensus for non-poly(A) terminators, and the arrangement of Nrd1p and Nab3p binding sites varies considerably. In addition, the organization of these sequences is not strongly conserved among even closely related yeasts. This indicates a large degree of genetic variability. Despite this variability, we were able to use a computational model to show that the binding sites for Nrd1 and Nab3 can identify genes for which transcription termination is mediated by these proteins.


2020 ◽  
Author(s):  
Santana Royan ◽  
Bernard Gutmann ◽  
Catherine Colas des Francs-Small ◽  
Suvi Honkanen ◽  
Jason Schmidberger ◽  
...  

Abstract Targeted cytidine to uridine RNA editing is a widespread phenomenon throughout the land plant lineage. Members of the pentatricopeptide repeat (PPR) protein family act as the specificity factors in this process. These proteins consist of helix-turn-helix domains, each of which recognises a single RNA nucleotide following a well-elucidated code. A cytidine deaminase-like domain (present at the C-terminus of some PPR editing factors or provided in trans via protein-protein interactions) is the catalytic domain in the process. The huge expansion of the PPR superfamily in land plants provides the sequence variation required for design of novel consensus-based RNA-binding proteins. We used this approach to construct a synthetic RNA editing factor designed to target one of the two sites in the Arabidopsis chloroplast transcriptome naturally recognised by the RNA editing factor CHLOROPLAST BIOGENESIS 19 (CLB19). We show that this designed editing factor specifically recognises the target sequence in in vitro binding assays and can partially complement a clb19 mutant. The designed factor is specific for the target rpoA site and does not recognise or edit the other site recognised by CLB19 in the clpP1 transcript. We show that the designed editing factor can function equally specifically in the bacterium E. coli, and shows some activity even in the absence of the editing cofactors that are often required for natural editing factor activity in plants. This study serves as a successful pilot into the design and application of programmable RNA editing factors based on plant PPR proteins.


1993 ◽  
Vol 13 (9) ◽  
pp. 5323-5330 ◽  
Author(s):  
S A Amero ◽  
M J Matunis ◽  
E L Matunis ◽  
J W Hockensmith ◽  
G Raychaudhuri ◽  
...  

The protein on ecdysone puffs (PEP) is associated preferentially with active ecdysone-inducible puffs on Drosophila polytene chromosomes and contains sequence motifs characteristic of transcription factors and RNA-binding proteins (S. A. Amero, S. C. R. Elgin, and A. L. Beyer, Genes Dev. 5:188-200, 1991). PEP is associated with RNA in vivo, as demonstrated here by the sensitivity of PEP-specific chromosomal immunostaining in situ to RNase digestion and by the immunopurification of PEP in Drosophila cell extract with heterogeneous nuclear ribonucleoprotein (hnRNP) complexes. As revealed by sequential immunostaining, PEP is found on a subset of chromosomal sites bound by the HRB (heterogeneous nuclear RNA-binding) proteins, which are basic Drosophila hnRNPs. These observations lead us to suggest that a unique, PEP-containing hnRNP complex assembles preferentially on the transcripts of ecdysone-regulated genes in Drosophila melanogaster presumably to expedite the transcription and/or processing of these transcripts.


2020 ◽  
Vol 7 ◽  
Author(s):  
Saif N. Haify ◽  
Ruchira S. D. Mankoe ◽  
Valerie Boumeester ◽  
Esmay C. van der Toorn ◽  
Rob F. M. Verhagen ◽  
...  

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a rare neurodegenerative disorder caused by a 55–200 CGG repeat expansion in the 5′ untranslated region of the Fragile X Mental Retardation 1 (FMR1) gene. FXTAS is characterized by progressive cerebellar ataxia, Parkinsonism, intention tremors and cognitive decline. The main neuropathological hallmark of FXTAS is the presence of ubiquitin-positive intranuclear inclusions in neurons and astrocytes throughout the brain. The molecular pathology of FXTAS involves the presence of 2 to 8-fold elevated levels of FMR1 mRNA, and of a repeat-associated non-AUG (RAN) translated polyglycine peptide (FMRpolyG). Increased levels of FMR1 mRNA containing an expanded CGG repeat can result in cellular toxicity by an RNA gain-of-function mechanism. The increased levels of CGG repeat-expanded FMR1 transcripts may create RNA foci that sequester important cellular proteins, including RNA-binding proteins and FMRpolyG, in intranuclear inclusions. To date, it is unclear whether the FMRpolyG-positive intranuclear inclusions are a cause or a consequence of FXTAS disease pathology. In this report we studied the relation between the presence of neuronal intranuclear inclusions and behavioral deficits using an inducible mouse model for FXTAS. Neuronal intranuclear inclusions were observed 4 weeks after dox-induction. After 12 weeks, high numbers of FMRpolyG-positive intranuclear inclusions could be detected in the hippocampus and striatum, but no clear signs of behavioral deficits related to these specific brain regions were found. In conclusion, the observations in our inducible mouse model for FXTAS suggest a lack of correlation between the presence of intranuclear FMRpolyG-positive aggregates in brain regions and specific behavioral phenotypes.


Cell ◽  
2016 ◽  
Vol 165 (3) ◽  
pp. 742-753 ◽  
Author(s):  
Aoife C. McMahon ◽  
Reazur Rahman ◽  
Hua Jin ◽  
James L. Shen ◽  
Allegra Fieldsend ◽  
...  

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Tracey W. Chan ◽  
Ting Fu ◽  
Jae Hoon Bahn ◽  
Hyun-Ik Jun ◽  
Jae-Hyung Lee ◽  
...  

Abstract Background RNA editing generates modifications to the RNA sequences, thereby increasing protein diversity and shaping various layers of gene regulation. Recent studies have revealed global shifts in editing levels across many cancer types, as well as a few specific mechanisms implicating individual sites in tumorigenesis or metastasis. However, most tumor-associated sites, predominantly in noncoding regions, have unknown functional relevance. Results Here, we carry out integrative analysis of RNA editing profiles between epithelial and mesenchymal tumors, since epithelial-mesenchymal transition is a key paradigm for metastasis. We identify distinct editing patterns between epithelial and mesenchymal tumors in seven cancer types using TCGA data, an observation further supported by single-cell RNA sequencing data and ADAR perturbation experiments in cell culture. Through computational analyses and experimental validations, we show that differential editing sites between epithelial and mesenchymal phenotypes function by regulating mRNA abundance of their respective genes. Our analysis of RNA-binding proteins reveals ILF3 as a potential regulator of this process, supported by experimental validations. Consistent with the known roles of ILF3 in immune response, epithelial-mesenchymal differential editing sites are enriched in genes involved in immune and viral processes. The strongest target of editing-dependent ILF3 regulation is the transcript encoding PKR, a crucial player in immune and viral response. Conclusions Our study reports widespread differences in RNA editing between epithelial and mesenchymal tumors and a novel mechanism of editing-dependent regulation of mRNA abundance. It reveals the broad impact of RNA editing in cancer and its relevance to cancer-related immune pathways.


2018 ◽  
Author(s):  
Peter K. Koo ◽  
Praveen Anand ◽  
Steffan B. Paul ◽  
Sean R. Eddy

AbstractTo infer the sequence and RNA structure specificities of RNA-binding proteins (RBPs) from experiments that enrich for bound sequences, we introduce a convolutional residual network which we call ResidualBind. ResidualBind significantly outperforms previous methods on experimental data from many RBP families. We interrogate ResidualBind to identify what features it has learned from high-affinity sequences with saliency analysis along with 1st-order and 2nd-orderin silicomutagenesis. We show that in addition to sequence motifs, ResidualBind learns a model that includes the number of motifs, their spacing, and both positive and negative effects of RNA structure context. Strikingly, ResidualBind learns RNA structure context, including detailed base-pairing relationships, directly from sequence data, which we confirm on synthetic data. ResidualBind is a powerful, flexible, and interpretable model that can uncovercis-recognition preferences across a broad spectrum of RBPs.


2021 ◽  
Author(s):  
Kalia Bernath-Levin ◽  
Jason Schmidberger ◽  
Suvi Honkanen ◽  
Bernard Gutmann ◽  
Yueming Kelly Sun ◽  
...  

ABSTRACT Pentatricopeptide repeat (PPR) proteins are RNA-binding proteins that are attractive tools for RNA processing in synthetic biology applications given their modular structure and ease of design. Several distinct types of motifs have been described from natural PPR proteins, but almost all work so far with synthetic PPR proteins has focused on the most widespread P-type motifs. We have investigated synthetic PPR proteins based on tandem repeats of the more compact S-type PPR motif found in plant organellar RNA editing factors, and particularly prevalent in the lycophyte Selaginella. With the aid of a novel plate-based screening method we show that synthetic S-type PPR proteins are easy to design, bind with high affinity and specificity, and are functional in a wide range of pH, salt and temperature conditions. We find that they outperform a synthetic P-type PPR scaffold in many situations. We designed an S-type editing factor to edit an RNA target in E. coli and demonstrate that it edits effectively without requiring any additional cofactors to be added to the system. These qualities make S-type PPR scaffolds ideal for developing new RNA processing tools.


Sign in / Sign up

Export Citation Format

Share Document