scholarly journals Structural basis for recognition of human 7SK long noncoding RNA by the La-related protein Larp7

2018 ◽  
Vol 115 (28) ◽  
pp. E6457-E6466 ◽  
Author(s):  
Catherine D. Eichhorn ◽  
Yuan Yang ◽  
Lucas Repeta ◽  
Juli Feigon

The La and the La-related protein (LARP) superfamily is a diverse class of RNA binding proteins involved in RNA processing, folding, and function. Larp7 binds to the abundant long noncoding 7SK RNA and is required for 7SK ribonucleoprotein (RNP) assembly and function. The 7SK RNP sequesters a pool of the positive transcription elongation factor b (P-TEFb) in an inactive state; on release, P-TEFb phosphorylates RNA Polymerase II to stimulate transcription elongation. Despite its essential role in transcription, limited structural information is available for the 7SK RNP, particularly for protein–RNA interactions. Larp7 contains an N-terminal La module that binds UUU-3′OH and a C-terminal atypical RNA recognition motif (xRRM) required for specific binding to 7SK and P-TEFb assembly. Deletion of the xRRM is linked to gastric cancer in humans. We report the 2.2-Å X-ray crystal structure of the human La-related protein group 7 (hLarp7) xRRM bound to the 7SK stem-loop 4, revealing a unique binding interface. Contributions of observed interactions to binding affinity were investigated by mutagenesis and isothermal titration calorimetry. NMR 13C spin relaxation data and comparison of free xRRM, RNA, and xRRM–RNA structures show that the xRRM is preordered to bind a flexible loop 4. Combining structures of the hLarp7 La module and the xRRM–7SK complex presented here, we propose a structural model for Larp7 binding to the 7SK 3′ end and mechanism for 7SK RNP assembly. This work provides insight into how this domain contributes to 7SK recognition and assembly of the core 7SK RNP.

2019 ◽  
Vol 20 (16) ◽  
pp. 3926 ◽  
Author(s):  
Xing Zhao ◽  
Yujie Cai ◽  
Jianzhen Xu

CircRNAs are a class of noncoding RNA species with a circular configuration that is formed by either typical spliceosome-mediated or lariat-type splicing. The expression of circRNAs is usually abnormal in many cancers. Several circRNAs have been demonstrated to play important roles in carcinogenesis. In this review, we will first provide an introduction of circRNAs biogenesis, especially the regulation of circRNA by RNA-binding proteins, then we will focus on the recent findings of circRNA molecular mechanisms and functions in cancer development. Finally, some open questions are also discussed.


2016 ◽  
Vol 72 (4) ◽  
pp. 497-511 ◽  
Author(s):  
Galina A. Stepanyuk ◽  
Pedro Serrano ◽  
Eigen Peralta ◽  
Carol L. Farr ◽  
Herbert L. Axelrod ◽  
...  

RNA-binding protein 39 (RBM39) is a splicing factor and a transcriptional co-activator of estrogen receptors and Jun/AP-1, and its function has been associated with malignant progression in a number of cancers. The C-terminal RRM domain of RBM39 belongs to the U2AF homology motif family (UHM), which mediate protein–protein interactions through a short tryptophan-containing peptide known as the UHM-ligand motif (ULM). Here, crystal and solution NMR structures of the RBM39-UHM domain, and the crystal structure of its complex with U2AF65-ULM, are reported. The RBM39–U2AF65 interaction was confirmed by co-immunoprecipitation from human cell extracts, by isothermal titration calorimetry and by NMR chemical shift perturbation experiments with the purified proteins. When compared with related complexes, such as U2AF35–U2AF65 and RBM39–SF3b155, the RBM39-UHM–U2AF65-ULM complex reveals both common and discriminating recognition elements in the UHM–ULM binding interface, providing a rationale for the known specificity of UHM–ULM interactions. This study therefore establishes a structural basis for specific UHM–ULM interactions by splicing factors such as U2AF35, U2AF65, RBM39 and SF3b155, and a platform for continued studies of intermolecular interactions governing disease-related alternative splicing in eukaryotic cells.


2020 ◽  
Vol 54 (1) ◽  
pp. 309-336
Author(s):  
Erin K. Borchardt ◽  
Nicole M. Martinez ◽  
Wendy V. Gilbert

Recent advances in pseudouridine detection reveal a complex pseudouridine landscape that includes messenger RNA and diverse classes of noncoding RNA in human cells. The known molecular functions of pseudouridine, which include stabilizing RNA conformations and destabilizing interactions with varied RNA-binding proteins, suggest that RNA pseudouridylation could have widespread effects on RNA metabolism and gene expression. Here, we emphasize how much remains to be learned about the RNA targets of human pseudouridine synthases, their basis for recognizing distinct RNA sequences, and the mechanisms responsible for regulated RNA pseudouridylation. We also examine the roles of noncoding RNA pseudouridylation in splicing and translation and point out the potential effects of mRNA pseudouridylation on protein production, including in the context of therapeutic mRNAs.


2020 ◽  
Author(s):  
Oliver Binas ◽  
Jan-Niklas Tants ◽  
Stephen A Peter ◽  
Robert Janowski ◽  
Elena Davydova ◽  
...  

Abstract Adenylate/uridylate-rich elements (AREs) are the most common cis-regulatory elements in the 3′-untranslated region (UTR) of mRNAs, where they fine-tune turnover by mediating mRNA decay. They increase plasticity and efficacy of mRNA regulation and are recognized by several ARE-specific RNA-binding proteins (RBPs). Typically, AREs are short linear motifs with a high content of complementary A and U nucleotides and often occur in multiple copies. Although thermodynamically rather unstable, the high AU-content might enable transient secondary structure formation and modify mRNA regulation by RBPs. We have recently suggested that the immunoregulatory RBP Roquin recognizes folded AREs as constitutive decay elements (CDEs), resulting in shape-specific ARE-mediated mRNA degradation. However, the structural evidence for a CDE-like recognition of AREs by Roquin is still lacking. We here present structures of CDE-like folded AREs, both in their free and protein-bound form. Moreover, the AREs in the UCP3 3′-UTR are additionally bound by the canonical ARE-binding protein AUF1 in their linear form, adopting an alternative binding-interface compared to the recognition of their CDE structure by Roquin. Strikingly, our findings thus suggest that AREs can be recognized in multiple ways, allowing control over mRNA regulation by adapting distinct conformational states, thus providing differential accessibility to regulatory RBPs.


Blood ◽  
2019 ◽  
Vol 133 (22) ◽  
pp. 2365-2373 ◽  
Author(s):  
Daniel J. Hodson ◽  
Michael Screen ◽  
Martin Turner

Abstract RNA-binding proteins (RBPs) regulate fundamental processes, such as differentiation and self-renewal, by enabling the dynamic control of protein abundance or isoforms or through the regulation of noncoding RNA. RBPs are increasingly appreciated as being essential for normal hematopoiesis, and they are understood to play fundamental roles in hematological malignancies by acting as oncogenes or tumor suppressors. Alternative splicing has been shown to play roles in the development of specific hematopoietic lineages, and sequence-specific mutations in RBPs lead to dysregulated splicing in myeloid and lymphoid leukemias. RBPs that regulate translation contribute to the development and function of hematological lineages, act as nodes for the action of multiple signaling pathways, and contribute to hematological malignancies. These insights broaden our mechanistic understanding of the molecular regulation of hematopoiesis and offer opportunities to develop disease biomarkers and new therapeutic modalities.


2019 ◽  
Vol 19 (4) ◽  
pp. 255-263 ◽  
Author(s):  
Yuangang Wu ◽  
Xiaoxi Lu ◽  
Bin Shen ◽  
Yi Zeng

Background: Osteoarthritis (OA) is a disease characterized by progressive degeneration, joint hyperplasia, narrowing of joint spaces, and extracellular matrix metabolism. Recent studies have shown that the pathogenesis of OA may be related to non-coding RNA, and its pathological mechanism may be an effective way to reduce OA. Objective: The purpose of this review was to investigate the recent progress of miRNA, long noncoding RNA (lncRNA) and circular RNA (circRNA) in gene therapy of OA, discussing the effects of this RNA on gene expression, inflammatory reaction, apoptosis and extracellular matrix in OA. Methods: The following electronic databases were searched, including PubMed, EMBASE, Web of Science, and the Cochrane Library, for published studies involving the miRNA, lncRNA, and circRNA in OA. The outcomes included the gene expression, inflammatory reaction, apoptosis, and extracellular matrix. Results and Discussion: With the development of technology, miRNA, lncRNA, and circRNA have been found in many diseases. More importantly, recent studies have found that RNA interacts with RNA-binding proteins to regulate gene transcription and protein translation, and is involved in various pathological processes of OA, thus becoming a potential therapy for OA. Conclusion: In this paper, we briefly introduced the role of miRNA, lncRNA, and circRNA in the occurrence and development of OA and as a new target for gene therapy.


2021 ◽  
Vol 15 ◽  
Author(s):  
Lichao Zhang ◽  
Zihong Huang ◽  
Liang Kong

Background: RNA-binding proteins establish posttranscriptional gene regulation by coordinating the maturation, editing, transport, stability, and translation of cellular RNAs. The immunoprecipitation experiments could identify interaction between RNA and proteins, but they are limited due to the experimental environment and material. Therefore, it is essential to construct computational models to identify the function sites. Objective: Although some computational methods have been proposed to predict RNA binding sites, the accuracy could be further improved. Moreover, it is necessary to construct a dataset with more samples to design a reliable model. Here we present a computational model based on multi-information sources to identify RNA binding sites. Method: We construct an accurate computational model named CSBPI_Site, based on xtreme gradient boosting. The specifically designed 15-dimensional feature vector captures four types of information (chemical shift, chemical bond, chemical properties and position information). Results: The satisfied accuracy of 0.86 and AUC of 0.89 were obtained by leave-one-out cross validation. Meanwhile, the accuracies were slightly different (range from 0.83 to 0.85) among three classifiers algorithm, which showed the novel features are stable and fit to multiple classifiers. These results showed that the proposed method is effective and robust for noncoding RNA binding sites identification. Conclusion: Our method based on multi-information sources is effective to represent the binding sites information among ncRNAs. The satisfied prediction results of Diels-Alder riboz-yme based on CSBPI_Site indicates that our model is valuable to identify the function site.


2014 ◽  
Vol 42 (15) ◽  
pp. 10185-10195 ◽  
Author(s):  
Constanze Schelhorn ◽  
James M.B. Gordon ◽  
Lidia Ruiz ◽  
Javier Alguacil ◽  
Enrique Pedroso ◽  
...  

Abstract Cytoplasmic polyadenylation is regulated by the interaction of the cytoplasmic polyadenylation element binding proteins (CPEB) with cytoplasmic polyadenylation element (CPE) containing mRNAs. The CPEB family comprises four paralogs, CPEB1–4, each composed of a variable N-terminal region, two RNA recognition motif (RRM) and a C-terminal ZZ-domain. We have characterized the RRM domains of CPEB4 and their binding properties using a combination of biochemical, biophysical and NMR techniques. Isothermal titration calorimetry, NMR and electrophoretic mobility shift assay experiments demonstrate that both the RRM domains are required for an optimal CPE interaction and the presence of either one or two adenosines in the two most commonly used consensus CPE motifs has little effect on the affinity of the interaction. Both the single RRM1 and the tandem RRM1–RRM2 have the ability to dimerize, although representing a minor population. Self-association does not affect the proteins’ ability to interact with RNA as demonstrated by ion mobility–mass spectrometry. Chemical shift effects measured by NMR of the apo forms of the RRM1–RRM2 samples indicate that the two domains are orientated toward each other. NMR titration experiments show that residues on the β-sheet surface on RRM1 and at the C-terminus of RRM2 are affected upon RNA binding. We propose a model of the CPEB4 RRM1–RRM2–CPE complex that illustrates the experimental data.


1991 ◽  
Vol 11 (2) ◽  
pp. 894-905
Author(s):  
R A Voelker ◽  
W Gibson ◽  
J P Graves ◽  
J F Sterling ◽  
M T Eisenberg

The nucleotide sequence of the Drosophila melanogaster suppressor of sable [su(s)] gene has been determined. Comparison of genomic and cDNA sequences indicates that an approximately 7,860-nucleotide primary transcript is processed into an approximately 5-kb message, expressed during all stages of the life cycle, that contains an open reading frame capable of encoding a 1,322-amino-acid protein of approximately 150 kDa. The putative protein contains an RNA recognition motif-like region and a highly charged arginine-, lysine-, serine-, aspartic or glutamic acid-rich region that is similar to a region contained in several RNA-processing proteins. In vitro translation of in vitro-transcribed RNA from a complete cDNA yields a product whose size agrees with the size predicted by the open reading frame. Antisera against su(s) fusion proteins recognize the in vitro-translated protein and detect a protein of identical size in the nuclear fractions from tissue culture cells and embryos. The protein is also present in smaller amounts in cytoplasmic fractions of embryos. That the su(s) protein has regions similar in structure to RNA-processing protein is consistent with its known role in affecting the transcript levels of those alleles that it suppresses.


Author(s):  
Xinyun Chen ◽  
Jianwen Yin ◽  
Dayan Cao ◽  
Deyong Xiao ◽  
Zhongjun Zhou ◽  
...  

RNA binding proteins (RBPs) have a broad biological and physiological function and are critical in regulating pre-mRNA posttranscriptional processing, intracellular migration, and mRNA stability. QKI, also known as Quaking, is a member of the signal transduction and activation of RNA (STAR) family, which also belongs to the heterogeneous nuclear ribonucleoprotein K- (hnRNP K-) homology domain protein family. There are three major alternatively spliced isoforms, QKI-5, QKI-6, and QKI-7, differing in carboxy-terminal domains. They share a common RNA binding property, but each isoform can regulate pre-mRNA splicing, transportation or stability differently in a unique cell type-specific manner. Previously, QKI has been known for its important role in contributing to neurological disorders. A series of recent work has further demonstrated that QKI has important roles in much broader biological systems, such as cardiovascular development, monocyte to macrophage differentiation, bone metabolism, and cancer progression. In this mini-review, we will focus on discussing the emerging roles of QKI in regulating cardiac and vascular development and function and its potential link to cardiovascular pathophysiology.


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