scholarly journals SRSF3 and SRSF7 modulate 3′UTR length through suppression or activation of proximal polyadenylation sites and regulation of CFIm levels

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Oliver Daniel Schwich ◽  
Nicole Blümel ◽  
Mario Keller ◽  
Marius Wegener ◽  
Samarth Thonta Setty ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Mrna Export ◽  
Domain Architecture ◽  
Alternative Polyadenylation ◽  
Sr Proteins ◽  
Untranslated Regions ◽  
Dual Function ◽  
Independent Manner ◽  
Polyadenylation Sites ◽  
Selection Of

Abstract Background Alternative polyadenylation (APA) refers to the regulated selection of polyadenylation sites (PASs) in transcripts, which determines the length of their 3′ untranslated regions (3′UTRs). We have recently shown that SRSF3 and SRSF7, two closely related SR proteins, connect APA with mRNA export. The mechanism underlying APA regulation by SRSF3 and SRSF7 remained unknown. Results Here we combine iCLIP and 3′-end sequencing and find that SRSF3 and SRSF7 bind upstream of proximal PASs (pPASs), but they exert opposite effects on 3′UTR length. SRSF7 enhances pPAS usage in a concentration-dependent but splicing-independent manner by recruiting the cleavage factor FIP1, generating short 3′UTRs. Protein domains unique to SRSF7, which are absent from SRSF3, contribute to FIP1 recruitment. In contrast, SRSF3 promotes distal PAS (dPAS) usage and hence long 3′UTRs directly by counteracting SRSF7, but also indirectly by maintaining high levels of cleavage factor Im (CFIm) via alternative splicing. Upon SRSF3 depletion, CFIm levels decrease and 3′UTRs are shortened. The indirect SRSF3 targets are particularly sensitive to low CFIm levels, because here CFIm serves a dual function; it enhances dPAS and inhibits pPAS usage by binding immediately downstream and assembling unproductive cleavage complexes, which together promotes long 3′UTRs. Conclusions We demonstrate that SRSF3 and SRSF7 are direct modulators of pPAS usage and show how small differences in the domain architecture of SR proteins can confer opposite effects on pPAS regulation.

scholarly journals Animal-APAdb: a comprehensive animal alternative polyadenylation database

2020 ◽  
Vol 49 (D1) ◽  
pp. D47-D54
Author(s):  
Weiwei Jin ◽  
Qizhao Zhu ◽  
Yanbo Yang ◽  
Wenqian Yang ◽  
Dongyang Wang ◽  
...  
Keyword(s):  
Gene Expression Regulation ◽  
Alternative Polyadenylation ◽  
Untranslated Regions ◽  
Sequencing Data ◽  
Comprehensive Information ◽  
Transcriptional Regulatory Mechanism ◽  
Transcriptional Regulatory ◽  
Polyadenylation Sites ◽  
User Friendly ◽  
Polyadenylation Signals

Abstract Alternative polyadenylation (APA) is an important post-transcriptional regulatory mechanism that recognizes different polyadenylation signals on transcripts, resulting in transcripts with different lengths of 3′ untranslated regions and thereby influencing a series of biological processes. Recent studies have highlighted the important roles of APA in human. However, APA profiles in other animals have not been fully recognized, and there is no database that provides comprehensive APA information for other animals except human. Here, by using the RNA sequencing data collected from public databases, we systematically characterized the APA profiles in 9244 samples of 18 species. In total, we identified 342 952 APA events with a median of 17 020 per species using the DaPars2 algorithm, and 315 691 APA events with a median of 17 953 per species using the QAPA algorithm in these 18 species, respectively. In addition, we predicted the polyadenylation sites (PAS) and motifs near PAS of these species. We further developed Animal-APAdb, a user-friendly database (http://gong_lab.hzau.edu.cn/Animal-APAdb/) for data searching, browsing and downloading. With comprehensive information of APA events in different tissues of different species, Animal-APAdb may greatly facilitate the exploration of animal APA patterns and novel mechanisms, gene expression regulation and APA evolution across tissues and species.

Complexity and species variation of the kidney-type glutaminase gene

2002 ◽  
Vol 9 (3) ◽  
pp. 157-166 ◽  
Author(s):  
L. David Porter ◽  
Hend Ibrahim ◽  
Lynn Taylor ◽  
Norman P. Curthoys
Keyword(s):  
Rat Kidney ◽  
Alternative Polyadenylation ◽  
Rnase H ◽  
Untranslated Regions ◽  
Species Variation ◽  
Pcr Cloning ◽  
Mrna Stabilization ◽  
Ph Response ◽  
Untranslated Sequence ◽  
Polyadenylation Sites

Increased expression of rat kidney-type glutaminase (KGA) during metabolic acidosis results from selective mRNA stabilization. This process is mediated by an 8-base AU-sequence that functions as a pH-response element (pHRE). LLC-PK1-FBPase+ cells, a pH-responsive porcine kidney cell line, express four distinct GA mRNAs. RNase H mapping indicated that three of the GA mRNAs are generated by use of alternative polyadenylation sites and are homologs of the rat KGA mRNA, while the fourth contains a different COOH-terminal coding and 3′-untranslated sequence. PCR cloning and sequencing established that the latter GA mRNA is the homolog of the human GAC mRNA. A rat GAC cDNA was also cloned from a rat kidney library. The 3′-untranslated regions of the GAC mRNAs, but not the porcine or human KGA mRNAs, contain identifiable pHREs. The human KGA gene spans 82 kb and is composed of 19 exons. The unique sequence from the hGAC cDNA is contained in a single exon. Thus in humans, alternative splicing of the initial transcript could produce two GA mRNAs, only one of which may be increased during acidosis.

scholarly journals The RNA-Binding Protein HuD Regulates Alternative Splicing and Alternative Polyadenylation in the Mouse Neocortex

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2836
Author(s):  
Rebecca M. Sena ◽  
Jeffery L. Twiss ◽  
Amy S. Gardiner ◽  
Michela Dell’Orco ◽  
David N. Linsenbardt ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Alternative Polyadenylation ◽  
Untranslated Regions ◽  
Sequencing Data ◽  
Hu Proteins ◽  
Nuclear Events ◽  
Neuronal Functions ◽  
Polyadenylation Signals

The neuronal Hu/ELAV-like proteins HuB, HuC and HuD are a class of RNA-binding proteins that are crucial for proper development and maintenance of the nervous system. These proteins bind to AU-rich elements (AREs) in the untranslated regions (3′-UTRs) of target mRNAs regulating mRNA stability, transport and translation. In addition to these cytoplasmic functions, Hu proteins have been implicated in alternative splicing and alternative polyadenylation in the nucleus. The purpose of this study was to identify transcriptome-wide effects of HuD deletion on both of these nuclear events using RNA sequencing data obtained from the neocortex of Elavl4–/– (HuD KO) mice. HuD KO affected alternative splicing of 310 genes, including 17 validated HuD targets such as Cbx3, Cspp1, Snap25 and Gria2. In addition, deletion of HuD affected polyadenylation of 53 genes, with the majority of significantly altered mRNAs shifting towards usage of proximal polyadenylation signals (PAS), resulting in shorter 3′-UTRs. None of these genes overlapped with those showing alternative splicing events. Overall, HuD KO had a greater effect on alternative splicing than polyadenylation, with many of the affected genes implicated in several neuronal functions and neuropsychiatric disorders.

scholarly journals ALTERNATIVELY POLYADENYLATED CALPASTATIN TRANSCRIPTS IN BOVINE MUSCLES

2020 ◽  
Vol 31 (1) ◽  
pp. 45-51
Author(s):  
M.F. Casale ◽  
C. Silvestro ◽  
P.M. Corva ◽  
L.A. Soria
Keyword(s):  
Alternative Splicing ◽  
Beef Cattle ◽  
Relative Abundance ◽  
Alternative Polyadenylation ◽  
Triceps Brachii ◽  
Beef Tenderness ◽  
Alternatively Spliced ◽  
Polyadenylation Sites ◽  
Race Pcr ◽  
Definition Of

Calpastatin activity has a key role in the tenderization process that occurs during postmortem storage of meat under refrigerated conditioning. The regulation of calpastatin (CAST) expression is highly complex, the gene has four putative promoters and at least three different polyadenylation sites, and it is also alternatively spliced. We investigated the presence of alternative polyadenylation (APA) isoforms of CAST transcripts in three muscles (infraspinatus, triceps brachii and semitendinosus) of two bovine breeds (Angus and Brahman). The 3´ RACE-PCR was used to specifically amplify the different APA sites. The amplified fragments were cloned and sequenced. Sequencing confirmed the existence of three expected polyadenylation sites corresponding to short, medium and long polyadenylated transcripts. Also, transcripts with a novel APA site were found in the three muscles of both breeds. Because the same APAs isoforms were found between muscles and breeds, we could hypothesize a possible contribution to the relative abundance of different isoforms, probably in coordination with promoter preference and alternative splicing. This knowledge would be useful in the design of future experiments to analyze differential expression of CAST isoforms and their contribution to the definition of beef tenderness. Key words: Beef cattle; Alternative polyadenylation; 3´ RACE-PCR.

scholarly journals Interactions between RNA m6A modification, alternative splicing, and poly(A) tail revealed by MePAIso-seq2

2021 ◽  
Author(s):  
Yusheng Liu ◽  
Yiwei Zhang ◽  
Falong Lu ◽  
Jiaqiang Wang
Keyword(s):  
Alternative Splicing ◽  
Embryonic Stem ◽  
Alternative Polyadenylation ◽  
Tail Length ◽  
Mouse Cell ◽  
Full Length ◽  
New Method ◽  
Rna Immunoprecipitation ◽  
Polyadenylation Sites ◽  
End Capping

RNA post-transcriptional regulation involves 5-end capping, 3-poly(A) tailing (including polyadenylation sites, tail length, and non-A residues), alternative splicing, and chemical modifications including N6-methyladenosine (m6A). Studying the interplay of m6A, alternative splicing, alternative polyadenylation sites, poly(A) tail length, and non-A residues in poly(A) tails requires monitoring them simultaneously on one transcript, however strategies to achieve this are lacking. Therefore, we developed a new method, combining m6A-specific methylated RNA immunoprecipitation and the PacBio-based, tail-included, full-length RNA sequencing approach PAIso-seq2, which we have named m6A and poly(A) inclusive RNA isoform sequencing 2 (MePAIso-seq2). Using MePAIso-seq2, we revealed that m6A promotes and inhibits a similar number of alternative splicing events in mouse cell lines, showing that m6A does affect alternative splicing. In contrast, no correlation was detected between m6A and alternative polyadenylation sites choice. Surprisingly, we found that m6A-modified RNAs possess longer poly(A) tails and a lower proportion of poly(A) tails containing non-A residues, especially in mouse embryonic stem cells. Together, we developed a new method to detect full-length m6A-modified RNAs to comprehensively study the relationships between m6A, alternative splicing, and poly(A) tailing, laying a foundation for further exploration of the functional coordination of different RNA post-transcriptional modifications.

scholarly journals The landscape of alternative polyadenylation in single cells of the developing mouse embryo

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Vikram Agarwal ◽  
Sereno Lopez-Darwin ◽  
David R. Kelley ◽  
Jay Shendure
Keyword(s):  
Rna Binding ◽  
Developmental Stages ◽  
Single Cells ◽  
Neuronal Cell ◽  
Alternative Polyadenylation ◽  
Cell Types ◽  
Untranslated Regions ◽  
Mammalian Development ◽  
Translation Rate ◽  
Dynamic Landscape

Abstract3′ untranslated regions (3′ UTRs) post-transcriptionally regulate mRNA stability, localization, and translation rate. While 3′-UTR isoforms have been globally quantified in limited cell types using bulk measurements, their differential usage among cell types during mammalian development remains poorly characterized. In this study, we examine a dataset comprising ~2 million nuclei spanning E9.5–E13.5 of mouse embryonic development to quantify transcriptome-wide changes in alternative polyadenylation (APA). We observe a global lengthening of 3′ UTRs across embryonic stages in all cell types, although we detect shorter 3′ UTRs in hematopoietic lineages and longer 3′ UTRs in neuronal cell types within each stage. An analysis of RNA-binding protein (RBP) dynamics identifies ELAV-like family members, which are concomitantly induced in neuronal lineages and developmental stages experiencing 3′-UTR lengthening, as putative regulators of APA. By measuring 3′-UTR isoforms in an expansive single cell dataset, our work provides a transcriptome-wide and organism-wide map of the dynamic landscape of alternative polyadenylation during mammalian organogenesis.

scholarly journals Aptardi predicts polyadenylation sites in sample-specific transcriptomes using high-throughput RNA sequencing and DNA sequence

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ryan Lusk ◽  
Evan Stene ◽  
Farnoush Banaei-Kashani ◽  
Boris Tabakoff ◽  
Katerina Kechris ◽  
...  
Keyword(s):  
Rna Sequencing ◽  
Dna Sequence ◽  
Mammalian Species ◽  
Alternative Polyadenylation ◽  
Sequence Information ◽  
Rna Seq ◽  
Average Precision ◽  
Polyadenylation Sites ◽  
Dna Nucleotide Sequence

AbstractAnnotation of polyadenylation sites from short-read RNA sequencing alone is a challenging computational task. Other algorithms rooted in DNA sequence predict potential polyadenylation sites; however, in vivo expression of a particular site varies based on a myriad of conditions. Here, we introduce aptardi (alternative polyadenylation transcriptome analysis from RNA-Seq data and DNA sequence information), which leverages both DNA sequence and RNA sequencing in a machine learning paradigm to predict expressed polyadenylation sites. Specifically, as input aptardi takes DNA nucleotide sequence, genome-aligned RNA-Seq data, and an initial transcriptome. The program evaluates these initial transcripts to identify expressed polyadenylation sites in the biological sample and refines transcript 3′-ends accordingly. The average precision of the aptardi model is twice that of a standard transcriptome assembler. In particular, the recall of the aptardi model (the proportion of true polyadenylation sites detected by the algorithm) is improved by over three-fold. Also, the model—trained using the Human Brain Reference RNA commercial standard—performs well when applied to RNA-sequencing samples from different tissues and different mammalian species. Finally, aptardi’s input is simple to compile and its output is easily amenable to downstream analyses such as quantitation and differential expression.

scholarly journals Functional properties of p54, a novel SR protein active in constitutive and alternative splicing.

1996 ◽  
Vol 16 (10) ◽  
pp. 5400-5408 ◽  
Author(s):  
W J Zhang ◽  
J Y Wu
Keyword(s):  
Alternative Splicing ◽  
Splice Site ◽  
Sr Proteins ◽  
Dependent Manner ◽  
Sr Protein ◽  
Protein Protein Interaction ◽  
Small Nuclear Ribonucleoprotein ◽  
S100 Extract ◽  
U2 Auxiliary Factor ◽  
Auxiliary Factor

The p54 protein was previously identified by its reactivity with an autoantiserum. We report here that p54 is a new member of the SR family of splicing factors, as judged from its structural, antigenic, and functional characteristics. Consistent with its identification as an SR protein, p54 can function as a constitutive splicing factor in complementing splicing-deficient HeLa cell S100 extract. However, p54 also shows properties distinct from those of other SR family members, p54 can directly interact with the 65-kDa subunit of U2 auxiliary factor (U2AF65), a protein associated with the 3' splice site. In addition, p54 interacts with other SR proteins but does not interact with the U1 small nuclear ribonucleoprotein U1-70K or the 35-kDa subunit of U2 auxiliary factor (U2AF35). This protein-protein interaction profile is different from those of prototypical SR proteins SC35 and ASF/SF2, both of which interact with U1-70K and U2AF35 but not with U2AF65. p54 promotes the use of the distal 5' splice site in E1A pre-mRNA alternative splicing, while the same site is suppressed by ASF/SF2 and SC35. These findings and the differential tissue distribution of p54 suggest that this novel SR protein may participate in regulation of alternative splicing in a tissue- and substrate-dependent manner.

Calcitonin/calcitonin gene-related peptide transcription unit: tissue-specific expression involves selective use of alternative polyadenylation sites

1984 ◽  
Vol 4 (10) ◽  
pp. 2151-2160
Author(s):  
S G Amara ◽  
R M Evans ◽  
M G Rosenfeld
Keyword(s):  
Regulation Of Gene Expression ◽  
Alternative Polyadenylation ◽  
Calcitonin Gene Related Peptide ◽  
Transcription Unit ◽  
Specific Expression ◽  
Tissue Specific ◽  
Related Peptide ◽  
Calcitonin Gene ◽  
Polyadenylation Sites ◽  
Specific Regulation

Different 3' coding exons in the rat calcitonin gene are used to generate distinct mRNAs encoding either the hormone calcitonin in thyroidal C-cells or a new neuropeptide referred to as calcitonin gene-related peptide in neuronal tissue, indicating the RNA processing regulation is one strategy used in tissue-specific regulation of gene expression in the brain. Although the two mRNAs use the same transcriptional initiation site and have identical 5' terminal sequences, their 3' termini are distinct. The polyadenylation sites for calcitonin and calcitonin gene-related peptide mRNAs are located at the end of the exons 4 and 6, respectively. Termination of transcription after the calcitonin exon does not dictate the production of calcitonin mRNA, because transcription proceeds through both calcitonin and calcitonin gene-related peptide exons irrespective of which mRNA is ultimately produced. In isolated nuclei, both polyadenylation sites appear to be utilized; however, the proximal (calcitonin) site is preferentially used in nuclei from tissues producing calcitonin mRNA. These data suggest that the mechanism dictating production of each mRNA involves the selective use of alternative polyadenylation sites.

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