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Sample records for gene alternative splicing

  1. Functional and evolutionary analysis of alternatively spliced genes is consistent with an early eukaryotic origin of alternative splicing

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    Penny David

    2007-10-01

    Full Text Available Abstract Background Alternative splicing has been reported in various eukaryotic groups including plants, apicomplexans, diatoms, amoebae, animals and fungi. However, whether widespread alternative splicing has evolved independently in the different eukaryotic groups or was inherited from their last common ancestor, and may therefore predate multicellularity, is still unknown. To better understand the origin and evolution of alternative splicing and its usage in diverse organisms, we studied alternative splicing in 12 eukaryotic species, comparing rates of alternative splicing across genes of different functional classes, cellular locations, intron/exon structures and evolutionary origins. Results For each species, we find that genes from most functional categories are alternatively spliced. Ancient genes (shared between animals, fungi and plants show high levels of alternative splicing. Genes with products expressed in the nucleus or plasma membrane are generally more alternatively spliced while those expressed in extracellular location show less alternative splicing. We find a clear correspondence between incidence of alternative splicing and intron number per gene both within and between genomes. In general, we find several similarities in patterns of alternative splicing across these diverse eukaryotes. Conclusion Along with previous studies indicating intron-rich genes with weak intron boundary consensus and complex spliceosomes in ancestral organisms, our results suggest that at least a simple form of alternative splicing may already have been present in the unicellular ancestor of plants, fungi and animals. A role for alternative splicing in the evolution of multicellularity then would largely have arisen by co-opting the preexisting process.

  2. Resolving deconvolution ambiguity in gene alternative splicing

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    Hubbell Earl

    2009-08-01

    Full Text Available Abstract Background For many gene structures it is impossible to resolve intensity data uniquely to establish abundances of splice variants. This was empirically noted by Wang et al. in which it was called a "degeneracy problem". The ambiguity results from an ill-posed problem where additional information is needed in order to obtain an unique answer in splice variant deconvolution. Results In this paper, we analyze the situations under which the problem occurs and perform a rigorous mathematical study which gives necessary and sufficient conditions on how many and what type of constraints are needed to resolve all ambiguity. This analysis is generally applicable to matrix models of splice variants. We explore the proposal that probe sequence information may provide sufficient additional constraints to resolve real-world instances. However, probe behavior cannot be predicted with sufficient accuracy by any existing probe sequence model, and so we present a Bayesian framework for estimating variant abundances by incorporating the prediction uncertainty from the micro-model of probe responsiveness into the macro-model of probe intensities. Conclusion The matrix analysis of constraints provides a tool for detecting real-world instances in which additional constraints may be necessary to resolve splice variants. While purely mathematical constraints can be stated without error, real-world constraints may themselves be poorly resolved. Our Bayesian framework provides a generic solution to the problem of uniquely estimating transcript abundances given additional constraints that themselves may be uncertain, such as regression fit to probe sequence models. We demonstrate the efficacy of it by extensive simulations as well as various biological data.

  3. Functional and evolutionary analysis of alternatively spliced genes is consistent with an early eukaryotic origin of alternative splicing

    DEFF Research Database (Denmark)

    Irimia, Manuel; Rukov, Jakob Lewin; Penny, David

    2007-01-01

    , and may therefore predate multicellularity, is still unknown. To better understand the origin and evolution of alternative splicing and its usage in diverse organisms, we studied alternative splicing in 12 eukaryotic species, comparing rates of alternative splicing across genes of different functional......, we find several similarities in patterns of alternative splicing across these diverse eukaryotes. CONCLUSION: Along with previous studies indicating intron-rich genes with weak intron boundary consensus and complex spliceosomes in ancestral organisms, our results suggest that at least a simple form...... of alternative splicing may already have been present in the unicellular ancestor of plants, fungi and animals. A role for alternative splicing in the evolution of multicellularity then would largely have arisen by co-opting the preexisting process....

  4. Abnormalities in Alternative Splicing of Apoptotic Genes and Cardiovascular Diseases

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    Zodwa Dlamini

    2015-11-01

    Full Text Available Apoptosis is required for normal heart development in the embryo, but has also been shown to be an important factor in the occurrence of heart disease. Alternative splicing of apoptotic genes is currently emerging as a diagnostic and therapeutic target for heart disease. This review addresses the involvement of abnormalities in alternative splicing of apoptotic genes in cardiac disorders including cardiomyopathy, myocardial ischemia and heart failure. Many pro-apoptotic members of the Bcl-2 family have alternatively spliced isoforms that lack important active domains. These isoforms can play a negative regulatory role by binding to and inhibiting the pro-apoptotic forms. Alternative splicing is observed to be increased in various cardiovascular diseases with the level of alternate transcripts increasing elevated in diseased hearts compared to healthy subjects. In many cases these isoforms appear to be the underlying cause of the disease, while in others they may be induced in response to cardiovascular pathologies. Regardless of this, the detection of alternate splicing events in the heart can serve as useful diagnostic or prognostic tools, while those splicing events that seem to play a causative role in cardiovascular disease make attractive future drug targets.

  5. Insights into alternative splicing of sarcomeric genes in the heart

    NARCIS (Netherlands)

    Weeland, Cornelis J.; van den Hoogenhof, Maarten M.; Beqqali, Abdelaziz; Creemers, Esther E.

    2015-01-01

    Driven by rapidly evolving technologies in next-generation sequencing, alternative splicing has emerged as a crucial layer in gene expression, greatly expanding protein diversity and governing complex biological processes in the cardiomyocyte. At the core of cardiac contraction, the physical

  6. Intrasplicing coordinates alternative first exons with alternative splicing in the protein 4.1R gene

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    Conboy, John G.; Parra, Marilyn K.; Tan, Jeff S.; Mohandas, Narla; Conboy, John G.

    2008-11-07

    In the protein 4.1R gene, alternative first exons splice differentially to alternative 3' splice sites far downstream in exon 2'/2 (E2'/2). We describe a novel intrasplicing mechanism by which exon 1A (E1A) splices exclusively to the distal E2'/2 acceptor via two nested splicing reactions regulated by novel properties of exon 1B (E1B). E1B behaves as an exon in the first step, using its consensus 5' donor to splice to the proximal E2'/2 acceptor. A long region of downstream intron is excised, juxtaposing E1B with E2'/2 to generate a new composite acceptor containing the E1B branchpoint/pyrimidine tract and E2 distal 3' AG-dinucleotide. Next, the upstream E1A splices over E1B to this distal acceptor, excising the remaining intron plus E1B and E2' to form mature E1A/E2 product. We mapped branch points for both intrasplicing reactions and demonstrated that mutation of the E1B 5' splice site or branchpoint abrogates intrasplicing. In the 4.1R gene, intrasplicing ultimately determines N-terminal protein structure and function. More generally, intrasplicing represents a new mechanism whereby alternative promoters can be coordinated with downstream alternative splicing.

  7. Fast rate of evolution in alternatively spliced coding regions of mammalian genes

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    Nurtdinov Ramil N

    2006-04-01

    Full Text Available Abstract Background At least half of mammalian genes are alternatively spliced. Alternative isoforms are often genome-specific and it has been suggested that alternative splicing is one of the major mechanisms for generating protein diversity in the course of evolution. Another way of looking at alternative splicing is to consider sequence evolution of constitutive and alternative regions of protein-coding genes. Indeed, it turns out that constitutive and alternative regions evolve in different ways. Results A set of 3029 orthologous pairs of human and mouse alternatively spliced genes was considered. The rate of nonsynonymous substitutions (dN, the rate of synonymous substitutions (dS, and their ratio (ω = dN/dS appear to be significantly higher in alternatively spliced coding regions compared to constitutive regions. When N-terminal, internal and C-terminal alternatives are analysed separately, C-terminal alternatives appear to make the main contribution to the observed difference. The effects become even more pronounced in a subset of fast evolving genes. Conclusion These results provide evidence of weaker purifying selection and/or stronger positive selection in alternative regions and thus one more confirmation of accelerated evolution in alternative regions. This study corroborates the theory that alternative splicing serves as a testing ground for molecular evolution.

  8. The neurogenetics of alternative splicing.

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    Vuong, Celine K; Black, Douglas L; Zheng, Sika

    2016-05-01

    Alternative precursor-mRNA splicing is a key mechanism for regulating gene expression in mammals and is controlled by specialized RNA-binding proteins. The misregulation of splicing is implicated in multiple neurological disorders. We describe recent mouse genetic studies of alternative splicing that reveal its critical role in both neuronal development and the function of mature neurons. We discuss the challenges in understanding the extensive genetic programmes controlled by proteins that regulate splicing, both during development and in the adult brain.

  9. Alternative splice variants of the human PD-1 gene

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    Nielsen, Christian; Ohm-Laursen, Line; Barington, Torben

    2005-01-01

    PD-1 is an immunoregulatory receptor expressed on the surface of activated T cells, B cells, and monocytes. We describe four alternatively spliced PD-1 mRNA transcripts (PD-1Deltaex2, PD-1Deltaex3, PD-1Deltaex2,3, and PD-1Deltaex2,3,4) in addition to the full length isoform. PD-1Deltaex2 and PD-1...... and flPD-1 upon activation suggests an important interplay between the putative soluble PD-1 and flPD-1 possibly involved in maintenance of peripheral self-tolerance and prevention of autoimmunity....

  10. Alternative RNA splicing and cancer

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    Liu, Sali; Cheng, Chonghui

    2015-01-01

    Alternative splicing of pre-messenger RNA (mRNA) is a fundamental mechanism by which a gene can give rise to multiple distinct mRNA transcripts, yielding protein isoforms with different, even opposing, functions. With the recognition that alternative splicing occurs in nearly all human genes, its relationship with cancer-associated pathways has emerged as a rapidly growing field. In this review, we summarize recent findings that have implicated the critical role of alternative splicing in cancer and discuss current understandings of the mechanisms underlying dysregulated alternative splicing in cancer cells. PMID:23765697

  11. Alternative splicing and nonsense-mediated decay of circadian clock genes under environmental stress conditions in Arabidopsis.

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    Kwon, Young-Ju; Park, Mi-Jeong; Kim, Sang-Gyu; Baldwin, Ian T; Park, Chung-Mo

    2014-05-19

    The circadian clock enables living organisms to anticipate recurring daily and seasonal fluctuations in their growth habitats and synchronize their biology to the environmental cycle. The plant circadian clock consists of multiple transcription-translation feedback loops that are entrained by environmental signals, such as light and temperature. In recent years, alternative splicing emerges as an important molecular mechanism that modulates the clock function in plants. Several clock genes are known to undergo alternative splicing in response to changes in environmental conditions, suggesting that the clock function is intimately associated with environmental responses via the alternative splicing of the clock genes. However, the alternative splicing events of the clock genes have not been studied at the molecular level. We systematically examined whether major clock genes undergo alternative splicing under various environmental conditions in Arabidopsis. We also investigated the fates of the RNA splice variants of the clock genes. It was found that the clock genes, including EARLY FLOWERING 3 (ELF3) and ZEITLUPE (ZTL) that have not been studied in terms of alternative splicing, undergo extensive alternative splicing through diverse modes of splicing events, such as intron retention, exon skipping, and selection of alternative 5' splice site. Their alternative splicing patterns were differentially influenced by changes in photoperiod, temperature extremes, and salt stress. Notably, the RNA splice variants of TIMING OF CAB EXPRESSION 1 (TOC1) and ELF3 were degraded through the nonsense-mediated decay (NMD) pathway, whereas those of other clock genes were insensitive to NMD. Taken together, our observations demonstrate that the major clock genes examined undergo extensive alternative splicing under various environmental conditions, suggesting that alternative splicing is a molecular scheme that underlies the linkage between the clock and environmental stress

  12. Alternative splicing and nonsense-mediated decay of circadian clock genes under environmental stress conditions in Arabidopsis

    Science.gov (United States)

    2014-01-01

    Background The circadian clock enables living organisms to anticipate recurring daily and seasonal fluctuations in their growth habitats and synchronize their biology to the environmental cycle. The plant circadian clock consists of multiple transcription-translation feedback loops that are entrained by environmental signals, such as light and temperature. In recent years, alternative splicing emerges as an important molecular mechanism that modulates the clock function in plants. Several clock genes are known to undergo alternative splicing in response to changes in environmental conditions, suggesting that the clock function is intimately associated with environmental responses via the alternative splicing of the clock genes. However, the alternative splicing events of the clock genes have not been studied at the molecular level. Results We systematically examined whether major clock genes undergo alternative splicing under various environmental conditions in Arabidopsis. We also investigated the fates of the RNA splice variants of the clock genes. It was found that the clock genes, including EARLY FLOWERING 3 (ELF3) and ZEITLUPE (ZTL) that have not been studied in terms of alternative splicing, undergo extensive alternative splicing through diverse modes of splicing events, such as intron retention, exon skipping, and selection of alternative 5′ splice site. Their alternative splicing patterns were differentially influenced by changes in photoperiod, temperature extremes, and salt stress. Notably, the RNA splice variants of TIMING OF CAB EXPRESSION 1 (TOC1) and ELF3 were degraded through the nonsense-mediated decay (NMD) pathway, whereas those of other clock genes were insensitive to NMD. Conclusion Taken together, our observations demonstrate that the major clock genes examined undergo extensive alternative splicing under various environmental conditions, suggesting that alternative splicing is a molecular scheme that underlies the linkage between the clock

  13. Alternative splicing, a new target to block cellular gene expression by poliovirus 2A protease

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    Alvarez, Enrique; Castello, Alfredo; Carrasco, Luis; Izquierdo, Jose M.

    2011-01-01

    Highlights: → Novel role for poliovirus 2A protease as splicing modulator. → Poliovirus 2A protease inhibits the alternative splicing of pre-mRNAs. → Poliovirus 2A protease blocks the second catalytic step of splicing. -- Abstract: Viruses have developed multiple strategies to interfere with the gene expression of host cells at different stages to ensure their own survival. Here we report a new role for poliovirus 2A pro modulating the alternative splicing of pre-mRNAs. Expression of 2A pro potently inhibits splicing of reporter genes in HeLa cells. Low amounts of 2A pro abrogate Fas exon 6 skipping, whereas higher levels of protease fully abolish Fas and FGFR2 splicing. In vitro splicing of MINX mRNA using nuclear extracts is also strongly inhibited by 2A pro , leading to accumulation of the first exon and the lariat product containing the unspliced second exon. These findings reveal that the mechanism of action of 2A pro on splicing is to selectively block the second catalytic step.

  14. Alternative splicing, a new target to block cellular gene expression by poliovirus 2A protease

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    Alvarez, Enrique, E-mail: ealvarez@cbm.uam.es [Centro de Biologia Molecular Severo Ochoa (CSIC-UAM), Nicolas Cabrera, 1 Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Castello, Alfredo; Carrasco, Luis; Izquierdo, Jose M. [Centro de Biologia Molecular Severo Ochoa (CSIC-UAM), Nicolas Cabrera, 1 Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain)

    2011-10-14

    Highlights: {yields} Novel role for poliovirus 2A protease as splicing modulator. {yields} Poliovirus 2A protease inhibits the alternative splicing of pre-mRNAs. {yields} Poliovirus 2A protease blocks the second catalytic step of splicing. -- Abstract: Viruses have developed multiple strategies to interfere with the gene expression of host cells at different stages to ensure their own survival. Here we report a new role for poliovirus 2A{sup pro} modulating the alternative splicing of pre-mRNAs. Expression of 2A{sup pro} potently inhibits splicing of reporter genes in HeLa cells. Low amounts of 2A{sup pro} abrogate Fas exon 6 skipping, whereas higher levels of protease fully abolish Fas and FGFR2 splicing. In vitro splicing of MINX mRNA using nuclear extracts is also strongly inhibited by 2A{sup pro}, leading to accumulation of the first exon and the lariat product containing the unspliced second exon. These findings reveal that the mechanism of action of 2A{sup pro} on splicing is to selectively block the second catalytic step.

  15. Alternative REST Splicing Underappreciated

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    Chen, Guo-Lin; Miller, Gregory

    2017-01-01

    As a major orchestrator of the cellular epigenome, the repressor element-1 silencing transcription factor (REST) can either repress or activate thousands of genes depending on cellular context, suggesting a highly context-dependent REST function tuned by environmental cues. While REST shows cell-type non-selective active transcription, an N-terminal REST4 isoform caused by alternative splicing - inclusion of an extra exon (N3c) which introduces a pre-mature stop codon - has been implicated in...

  16. Alternative splicing and differential gene expression in colon cancer detected by a whole genome exon array

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    Sugnet Charles

    2006-12-01

    Full Text Available Abstract Background Alternative splicing is a mechanism for increasing protein diversity by excluding or including exons during post-transcriptional processing. Alternatively spliced proteins are particularly relevant in oncology since they may contribute to the etiology of cancer, provide selective drug targets, or serve as a marker set for cancer diagnosis. While conventional identification of splice variants generally targets individual genes, we present here a new exon-centric array (GeneChip Human Exon 1.0 ST that allows genome-wide identification of differential splice variation, and concurrently provides a flexible and inclusive analysis of gene expression. Results We analyzed 20 paired tumor-normal colon cancer samples using a microarray designed to detect over one million putative exons that can be virtually assembled into potential gene-level transcripts according to various levels of prior supporting evidence. Analysis of high confidence (empirically supported transcripts identified 160 differentially expressed genes, with 42 genes occupying a network impacting cell proliferation and another twenty nine genes with unknown functions. A more speculative analysis, including transcripts based solely on computational prediction, produced another 160 differentially expressed genes, three-fourths of which have no previous annotation. We also present a comparison of gene signal estimations from the Exon 1.0 ST and the U133 Plus 2.0 arrays. Novel splicing events were predicted by experimental algorithms that compare the relative contribution of each exon to the cognate transcript intensity in each tissue. The resulting candidate splice variants were validated with RT-PCR. We found nine genes that were differentially spliced between colon tumors and normal colon tissues, several of which have not been previously implicated in cancer. Top scoring candidates from our analysis were also found to substantially overlap with EST-based bioinformatic

  17. A functional alternative splicing mutation in AIRE gene causes autoimmune polyendocrine syndrome type 1.

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    Junyu Zhang

    Full Text Available Autoimmune polyendocrine syndrome type 1 (APS-1 is a rare autosomal recessive disease defined by the presence of two of the three conditions: mucocutaneous candidiasis, hypoparathyroidism, and Addison's disease. Loss-of-function mutations of the autoimmune regulator (AIRE gene have been linked to APS-1. Here we report mutational analysis and functional characterization of an AIRE mutation in a consanguineous Chinese family with APS-1. All exons of the AIRE gene and adjacent exon-intron sequences were amplified by PCR and subsequently sequenced. We identified a homozygous missense AIRE mutation c.463G>A (p.Gly155Ser in two siblings with different clinical features of APS-1. In silico splice-site prediction and minigene analysis were carried out to study the potential pathological consequence. Minigene splicing analysis and subsequent cDNA sequencing revealed that the AIRE mutation potentially compromised the recognition of the splice donor of intron 3, causing alternative pre-mRNA splicing by intron 3 retention. Furthermore, the aberrant AIRE transcript was identified in a heterozygous carrier of the c.463G>A mutation. The aberrant intron 3-retaining transcript generated a truncated protein (p.G155fsX203 containing the first 154 AIRE amino acids and followed by 48 aberrant amino acids. Therefore, our study represents the first functional characterization of the alternatively spliced AIRE mutation that may explain the pathogenetic role in APS-1.

  18. Identification of new alternative splice events in the TCIRG1 gene in different human tissues

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    Smirnova, Anna S.; Morgun, Andrey; Shulzhenko, Natalia; Silva, Ismael D.C.G.; Gerbase-DeLima, Maria

    2005-01-01

    Two transcript variants (TV) of the T cell immune regulator gene 1 (TCIRG1) have already been characterized. TV1 encodes a subunit of the osteoclast vacuolar proton pump and TV2 encodes a T cell inhibitory receptor. Based on the search in dbEST, we validated by RT-PCR six new alternative splice events in TCIRG1 in most of the 28 human tissues studied. In addition, we observed that transcripts using the TV1 transcription start site and two splice forms previously described in a patient with infantile malignant osteopetrosis are also expressed in various tissues of healthy individuals. Studies of these nine splice forms in cytoplasmic RNA of peripheral blood mononuclear cells showed that at least six of them could be efficiently exported from the nucleus. Since various products with nearly ubiquitous tissue distribution are generated from TCIRG1, this gene may be involved in other processes besides immune response and bone resorption

  19. Differential HFE gene expression is regulated by alternative splicing in human tissues.

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    Martins, Rute; Silva, Bruno; Proença, Daniela; Faustino, Paula

    2011-03-03

    The pathophysiology of HFE-derived Hereditary Hemochromatosis and the function of HFE protein in iron homeostasis remain uncertain. Also, the role of alternative splicing in HFE gene expression regulation and the possible function of the corresponding protein isoforms are still unknown. The aim of this study was to gain insights into the physiological significance of these alternative HFE variants. Alternatively spliced HFE transcripts in diverse human tissues were identified by RT-PCR, cloning and sequencing. Total HFE transcripts, as well as two alternative splicing transcripts were quantified using a real-time PCR methodology. Intracellular localization, trafficking and protein association of GFP-tagged HFE protein variants were analysed in transiently transfected HepG2 cells by immunoprecipitation and immunofluorescence assays. Alternatively spliced HFE transcripts present both level- and tissue-specificity. Concerning the exon 2 skipping and intron 4 inclusion transcripts, the liver presents the lowest relative level, while duodenum presents one of the highest amounts. The protein resulting from exon 2 skipping transcript is unable to associate with β2M and TfR1 and reveals an ER retention. Conversely, the intron 4 inclusion transcript gives rise to a truncated, soluble protein (sHFE) that is mostly secreted by cells to the medium in association with β2M. HFE gene post-transcriptional regulation is clearly affected by a tissue-dependent alternative splicing mechanism. Among the corresponding proteins, a sHFE isoform stands out, which upon being secreted into the bloodstream, may act in remote tissues. It could be either an agonist or antagonist of the full length HFE, through hepcidin expression regulation in the liver or by controlling dietary iron absorption in the duodenum.

  20. Differential HFE gene expression is regulated by alternative splicing in human tissues.

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    Rute Martins

    Full Text Available BACKGROUND: The pathophysiology of HFE-derived Hereditary Hemochromatosis and the function of HFE protein in iron homeostasis remain uncertain. Also, the role of alternative splicing in HFE gene expression regulation and the possible function of the corresponding protein isoforms are still unknown. The aim of this study was to gain insights into the physiological significance of these alternative HFE variants. METHODOLOGY/PRINCIPAL FINDINGS: Alternatively spliced HFE transcripts in diverse human tissues were identified by RT-PCR, cloning and sequencing. Total HFE transcripts, as well as two alternative splicing transcripts were quantified using a real-time PCR methodology. Intracellular localization, trafficking and protein association of GFP-tagged HFE protein variants were analysed in transiently transfected HepG2 cells by immunoprecipitation and immunofluorescence assays. Alternatively spliced HFE transcripts present both level- and tissue-specificity. Concerning the exon 2 skipping and intron 4 inclusion transcripts, the liver presents the lowest relative level, while duodenum presents one of the highest amounts. The protein resulting from exon 2 skipping transcript is unable to associate with β2M and TfR1 and reveals an ER retention. Conversely, the intron 4 inclusion transcript gives rise to a truncated, soluble protein (sHFE that is mostly secreted by cells to the medium in association with β2M. CONCLUSIONS/SIGNIFICANCE: HFE gene post-transcriptional regulation is clearly affected by a tissue-dependent alternative splicing mechanism. Among the corresponding proteins, a sHFE isoform stands out, which upon being secreted into the bloodstream, may act in remote tissues. It could be either an agonist or antagonist of the full length HFE, through hepcidin expression regulation in the liver or by controlling dietary iron absorption in the duodenum.

  1. Aberrant alternative splicing is another hallmark of cancer.

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    Ladomery, Michael

    2013-01-01

    The vast majority of human genes are alternatively spliced. Not surprisingly, aberrant alternative splicing is increasingly linked to cancer. Splice isoforms often encode proteins that have distinct and even antagonistic properties. The abnormal expression of splice factors and splice factor kinases in cancer changes the alternative splicing of critically important pre-mRNAs. Aberrant alternative splicing should be added to the growing list of cancer hallmarks.

  2. Aberrant Alternative Splicing Is Another Hallmark of Cancer

    OpenAIRE

    Ladomery, Michael

    2013-01-01

    The vast majority of human genes are alternatively spliced. Not surprisingly, aberrant alternative splicing is increasingly linked to cancer. Splice isoforms often encode proteins that have distinct and even antagonistic properties. The abnormal expression of splice factors and splice factor kinases in cancer changes the alternative splicing of critically important pre-mRNAs. Aberrant alternative splicing should be added to the growing list of cancer hallmarks.

  3. Diverse alternative back-splicing and alternative splicing landscape of circular RNAs

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    Zhang, Xiao-Ou; Dong, Rui; Zhang, Yang; Zhang, Jia-Lin; Luo, Zheng; Zhang, Jun; Chen, Ling-Ling; Yang, Li

    2016-01-01

    Circular RNAs (circRNAs) derived from back-spliced exons have been widely identified as being co-expressed with their linear counterparts. A single gene locus can produce multiple circRNAs through alternative back-splice site selection and/or alternative splice site selection; however, a detailed map of alternative back-splicing/splicing in circRNAs is lacking. Here, with the upgraded CIRCexplorer2 pipeline, we systematically annotated different types of alternative back-splicing and alternative splicing events in circRNAs from various cell lines. Compared with their linear cognate RNAs, circRNAs exhibited distinct patterns of alternative back-splicing and alternative splicing. Alternative back-splice site selection was correlated with the competition of putative RNA pairs across introns that bracket alternative back-splice sites. In addition, all four basic types of alternative splicing that have been identified in the (linear) mRNA process were found within circRNAs, and many exons were predominantly spliced in circRNAs. Unexpectedly, thousands of previously unannotated exons were detected in circRNAs from the examined cell lines. Although these novel exons had similar splice site strength, they were much less conserved than known exons in sequences. Finally, both alternative back-splicing and circRNA-predominant alternative splicing were highly diverse among the examined cell lines. All of the identified alternative back-splicing and alternative splicing in circRNAs are available in the CIRCpedia database (http://www.picb.ac.cn/rnomics/circpedia). Collectively, the annotation of alternative back-splicing and alternative splicing in circRNAs provides a valuable resource for depicting the complexity of circRNA biogenesis and for studying the potential functions of circRNAs in different cells. PMID:27365365

  4. Human sex hormone-binding globulin gene expression- multiple promoters and complex alternative splicing

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    Rosner William

    2009-05-01

    Full Text Available Abstract Background Human sex hormone-binding globulin (SHBG regulates free sex steroid concentrations in plasma and modulates rapid, membrane based steroid signaling. SHBG is encoded by an eight exon-long transcript whose expression is regulated by a downstream promoter (PL. The SHBG gene was previously shown to express a second major transcript of unknown function, derived from an upstream promoter (PT, and two minor transcripts. Results We report that transcriptional expression of the human SHBG gene is far more complex than previously described. PL and PT direct the expression of at least six independent transcripts each, resulting from alternative splicing of exons 4, 5, 6, and/or 7. We mapped two transcriptional start sites downstream of PL and PT, and present evidence for a third SHBG gene promoter (PN within the neighboring FXR2 gene; PN regulates the expression of at least seven independent SHBG gene transcripts, each possessing a novel, 164-nt first exon (1N. Transcriptional expression patterns were generated for human prostate, breast, testis, liver, and brain, and the LNCaP, MCF-7, and HepG2 cell lines. Each expresses the SHBG transcript, albeit in varying abundance. Alternative splicing was more pronounced in the cancer cell lines. PL- PT- and PN-derived transcripts were most abundant in liver, testis, and prostate, respectively. Initial findings reveal the existence of a smaller immunoreactive SHBG species in LNCaP, MCF-7, and HepG2 cells. Conclusion These results extend our understanding of human SHBG gene transcription, and raise new and important questions regarding the role of novel alternatively spliced transcripts, their function in hormonally responsive tissues including the breast and prostate, and the role that aberrant SHBG gene expression may play in cancer.

  5. Genomic organization and the tissue distribution of alternatively spliced isoforms of the mouse Spatial gene

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    Mattei Marie-Geneviève

    2004-07-01

    Full Text Available Abstract Background The stromal component of the thymic microenvironment is critical for T lymphocyte generation. Thymocyte differentiation involves a cascade of coordinated stromal genes controlling thymocyte survival, lineage commitment and selection. The "Stromal Protein Associated with Thymii And Lymph-node" (Spatial gene encodes a putative transcription factor which may be involved in T-cell development. In the testis, the Spatial gene is also expressed by round spermatids during spermatogenesis. Results The Spatial gene maps to the B3-B4 region of murine chromosome 10 corresponding to the human syntenic region 10q22.1. The mouse Spatial genomic DNA is organised into 10 exons and is alternatively spliced to generate two short isoforms (Spatial-α and -γ and two other long isoforms (Spatial-δ and -ε comprising 5 additional exons on the 3' site. Here, we report the cloning of a new short isoform, Spatial-β, which differs from other isoforms by an additional alternative exon of 69 bases. This new exon encodes an interesting proline-rich signature that could confer to the 34 kDa Spatial-β protein a particular function. By quantitative TaqMan RT-PCR, we have shown that the short isoforms are highly expressed in the thymus while the long isoforms are highly expressed in the testis. We further examined the inter-species conservation of Spatial between several mammals and identified that the protein which is rich in proline and positive amino acids, is highly conserved. Conclusions The Spatial gene generates at least five alternative spliced variants: three short isoforms (Spatial-α, -β and -γ highly expressed in the thymus and two long isoforms (Spatial-δ and -ε highly expressed in the testis. These alternative spliced variants could have a tissue specific function.

  6. Alternative Splicing in Adhesion- and Motility-Related Genes in Breast Cancer

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    Rosanna Aversa

    2016-01-01

    Full Text Available Breast cancer is the most common tumor and the second leading cause of cancer death among woman, mainly caused by the metastatic spread. Tumor invasiveness is due to an altered expression of adhesion molecules. Among them, semaphorins are of peculiar interest. Cancer cells can manipulate alternative splicing patterns to modulate the expression of adhesion- and motility-related molecules, also at the isoform level. In this study, combining RNA-Sequencing on MCF-7 to targeted experimental validations—in human breast cell lines and breast tumor biopsies—we identified 12 new alternative splicing transcripts in genes encoding adhesion- and motility-related molecules, including semaphorins, their receptors and co-receptors. Among them, a new SEMA3F transcript is expressed in all breast cell lines and breast cancer biopsies, and is translated into a new semaphorin 3F isoform. In silico analysis predicted that most of the new putative proteins lack functional domains, potentially missing some functions and acquiring new ones. Our findings better describe the extent of alternative splicing in breast cancer and highlight the need to further investigate adhesion- and motility-related molecules to gain insights into breast cancer progression.

  7. Verification of predicted alternatively spliced Wnt genes reveals two new splice variants (CTNNB1 and LRP5 and altered Axin-1 expression during tumour progression

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    Reich Jens G

    2006-06-01

    Full Text Available Abstract Background Splicing processes might play a major role in carcinogenesis and tumour progression. The Wnt pathway is of crucial relevance for cancer progression. Therefore we focussed on the Wnt/β-catenin signalling pathway in order to validate the expression of sequences predicted as alternatively spliced by bioinformatic methods. Splice variants of its key molecules were selected, which may be critical components for the understanding of colorectal tumour progression and may have the potential to act as biological markers. For some of the Wnt pathway genes the existence of splice variants was either proposed (e.g. β-Catenin and CTNNB1 or described only in non-colon tissues (e.g. GSK3β or hitherto not published (e.g. LRP5. Results Both splice variants – normal and alternative form – of all selected Wnt pathway components were found to be expressed in cell lines as well as in samples derived from tumour, normal and healthy tissues. All splice positions corresponded totally with the bioinformatical prediction as shown by sequencing. Two hitherto not described alternative splice forms (CTNNB1 and LRP5 were detected. Although the underlying EST data used for the bioinformatic analysis suggested a tumour-specific expression neither a qualitative nor a significant quantitative difference between the expression in tumour and healthy tissues was detected. Axin-1 expression was reduced in later stages and in samples from carcinomas forming distant metastases. Conclusion We were first to describe that splice forms of crucial genes of the Wnt-pathway are expressed in human colorectal tissue. Newly described splicefoms were found for β-Catenin, LRP5, GSK3β, Axin-1 and CtBP1. However, the predicted cancer specificity suggested by the origin of the underlying ESTs was neither qualitatively nor significant quantitatively confirmed. That let us to conclude that EST sequence data can give adequate hints for the existence of alternative splicing

  8. Acute hypoxia stress induced abundant differential expression genes and alternative splicing events in heart of tilapia.

    Science.gov (United States)

    Xia, Jun Hong; Li, Hong Lian; Li, Bi Jun; Gu, Xiao Hui; Lin, Hao Ran

    2018-01-10

    Hypoxia is one of the critical environmental stressors for fish in aquatic environments. Although accumulating evidences indicate that gene expression is regulated by hypoxia stress in fish, how genes undergoing differential gene expression and/or alternative splicing (AS) in response to hypoxia stress in heart are not well understood. Using RNA-seq, we surveyed and detected 289 differential expressed genes (DEG) and 103 genes that undergo differential usage of exons and splice junctions events (DUES) in heart of a hypoxia tolerant fish, Nile tilapia, Oreochromis niloticus following 12h hypoxic treatment. The spatio-temporal expression analysis validated the significant association of differential exon usages in two randomly selected DUES genes (fam162a and ndrg2) in 5 tissues (heart, liver, brain, gill and spleen) sampled at three time points (6h, 12h, and 24h) under acute hypoxia treatment. Functional analysis significantly associated the differential expressed genes with the categories related to energy conservation, protein synthesis and immune response. Different enrichment categories were found between the DEG and DUES dataset. The Isomerase activity, Oxidoreductase activity, Glycolysis and Oxidative stress process were significantly enriched for the DEG gene dataset, but the Structural constituent of ribosome and Structural molecule activity, Ribosomal protein and RNA binding protein were significantly enriched only for the DUES genes. Our comparative transcriptomic analysis reveals abundant stress responsive genes and their differential regulation function in the heart tissues of Nile tilapia under acute hypoxia stress. Our findings will facilitate future investigation on transcriptome complexity and AS regulation during hypoxia stress in fish. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. 4β-Hydroxywithanolide E Modulates Alternative Splicing of Apoptotic Genes in Human Hepatocellular Carcinoma Huh-7 Cells.

    Science.gov (United States)

    Lee, Chien-Chin; Chang, Wen-Hsin; Chang, Ya-Sian; Liu, Ting-Yuan; Chen, Yu-Chia; Wu, Yang-Chang; Chang, Jan-Gowth

    2017-08-04

    Alternative splicing is a mechanism for increasing protein diversity from a limited number of genes. Studies have demonstrated that aberrant regulation in the alternative splicing of apoptotic gene transcripts may contribute to the development of cancer. In this study, we isolated 4β-Hydroxywithanolide E (4bHWE) from the traditional herb Physalis peruviana and investigated its biological effect in cancer cells. The results demonstrated that 4bHWE modulates the alternative splicing of various apoptotic genes, including HIPK3, SMAC/DIABLO, and SURVIVIN. We also discovered that the levels of SRSF1 phospho-isoform were decreased and the levels of H3K36me3 were increased in 4bHWE treatment. Knockdown experiments revealed that the splicing site selection of SMAC/DIABLO could be mediated by changes in the level of H3K36me3 in 4bHWE-treated cells. Furthermore, we extended our study to apoptosis-associated molecules, and detected increased levels of poly ADP-ribose polymerase cleavage and the active form of CASPASE-3 in 4bHWE-induced apoptosis. In vivo experiments indicated that the treatment of tumor-bearing mice with 4bHWE resulted in a marked decrease in tumor size. This study is the first to demonstrate that 4bHWE affects alternative splicing by modulating splicing factors and histone modifications, and provides a novel view of the antitumor mechanism of 4bHWE.

  10. Abnormalities in alternative splicing of angiogenesis-related genes and their role in HIV-related cancers

    Directory of Open Access Journals (Sweden)

    Mthembu NN

    2017-03-01

    Full Text Available Nonkululeko N Mthembu,1 Zukile Mbita,2 Rodney Hull,1 Zodwa Dlamini1 1Research, Innovation and Engagements, Mangosuthu University of Technology, Durban, 2Department of Biochemistry, Microbiology and Biotechnology, University of Limpopo, Sovenga, South Africa Abstract: Alternative splicing of mRNA leads to an increase in proteome biodiversity by allowing the generation of multiple mRNAs, coding for multiple protein isoforms of various structural and functional properties from a single primary pre-mRNA transcript. The protein isoforms produced are tightly regulated in normal development but are mostly deregulated in various cancers. In HIV-infected individuals with AIDS, there is an increase in aberrant alternative splicing, resulting in an increase in HIV/AIDS-related cancers, such as Kaposi’s sarcoma, non-Hodgkin’s lymphoma, and cervical cancer. This aberrant splicing leads to abnormal production of protein and is caused by mutations in cis-acting elements or trans-acting factors in angiogenesis-related genes. Restoring the normal regulation of alternative splicing of angiogenic genes would alter the expression of protein isoforms and may confer normal cell physiology in patients with these cancers. This review highlights the abnormalities in alternative splicing of angiogenesis-related genes and their implication in HIV/AIDS-related cancers. This allows us to gain an insight into the pathogenesis of HIV/AIDS-related cancer and in turn elucidate the therapeutic potential of alternatively spliced genes in HIV/AIDS-related malignancies. Keywords: vascular endothelial growth factor, oncogenic viruses, hypoxia induced factor 1, Kaposi’s sarcoma, non-Hodgkin’s lymphoma, therapies targeting alternative splicing

  11. A dual-specificity isoform of the protein kinase inhibitor PKI produced by alternate gene splicing.

    Science.gov (United States)

    Kumar, Priyadarsini; Walsh, Donal A

    2002-03-15

    We have previously shown that the protein kinase inhibitor beta (PKIbeta) form of the cAMP-dependent protein kinase inhibitor exists in multiple isoforms, some of which are specific inhibitors of the cAMP-dependent protein kinase, whereas others also inhibit the cGMP-dependent enzyme [Kumar, Van Patten and Walsh (1997), J. Biol. Chem. 272, 20011-20020]. We have now demonstrated that the switch from a cAMP-dependent protein kinase (PKA)-specific inhibitor to one with dual specificity arises as a consequence of alternate gene splicing. We have confirmed using bacterially produced pure protein that a single inhibitor species has dual specificity for both PKA and cGMP-dependent protein kinase (PKG), inhibiting each with very high and closely similar inhibitory potencies. The gene splicing converted a protein with 70 amino acids into one of 109 amino acids, and did not change the inhibitory potency to PKA, but changed it from a protein that had no detectable PKG inhibitory activity to one that now inhibited PKG in the nanomolar range.

  12. Alternative Splicing Control of Abiotic Stress Responses.

    Science.gov (United States)

    Laloum, Tom; Martín, Guiomar; Duque, Paula

    2018-02-01

    Alternative splicing, which generates multiple transcripts from the same gene, is an important modulator of gene expression that can increase proteome diversity and regulate mRNA levels. In plants, this post-transcriptional mechanism is markedly induced in response to environmental stress, and recent studies have identified alternative splicing events that allow rapid adjustment of the abundance and function of key stress-response components. In agreement, plant mutants defective in splicing factors are severely impaired in their response to abiotic stress. Notably, mounting evidence indicates that alternative splicing regulates stress responses largely by targeting the abscisic acid (ABA) pathway. We review here current understanding of post-transcriptional control of plant stress tolerance via alternative splicing and discuss research challenges for the near future. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Differential gene expression and alternative splicing between diploid and tetraploid watermelon.

    Science.gov (United States)

    Saminathan, Thangasamy; Nimmakayala, Padma; Manohar, Sumanth; Malkaram, Sridhar; Almeida, Aldo; Cantrell, Robert; Tomason, Yan; Abburi, Lavanya; Rahman, Mohammad A; Vajja, Venkata G; Khachane, Amit; Kumar, Brajendra; Rajasimha, Harsha K; Levi, Amnon; Wehner, Todd; Reddy, Umesh K

    2015-03-01

    The exploitation of synthetic polyploids for producing seedless fruits is well known in watermelon. Tetraploid progenitors of triploid watermelon plants, compared with their diploid counterparts, exhibit wide phenotypic differences. Although many factors modulate alternative splicing (AS) in plants, the effects of autopolyploidization on AS are still unknown. In this study, we used tissues of leaf, stem, and fruit of diploid and tetraploid sweet watermelon to understand changes in gene expression and the occurrence of AS. RNA-sequencing analysis was performed along with reverse transcription quantitative PCR and rapid amplification of cDNA ends (RACE)-PCR to demonstrate changes in expression and splicing. All vegetative tissues except fruit showed an increased level of AS in the tetraploid watermelon throughout the growth period. The ploidy levels of diploids and the tetraploid were confirmed using a ploidy analyser. We identified 5362 and 1288 genes that were up- and downregulated, respectively, in tetraploid as compared with diploid plants. We further confirmed that 22 genes underwent AS events across tissues, indicating possibilities of generating different protein isoforms with altered functions of important transcription factors and transporters. Arginine biosynthesis, chlorophyllide synthesis, GDP mannose biosynthesis, trehalose biosynthesis, and starch and sucrose degradation pathways were upregulated in autotetraploids. Phloem protein 2, chloroplastic PGR5-like protein, zinc-finger protein, fructokinase-like 2, MYB transcription factor, and nodulin MtN21 showed AS in fruit tissues. These results should help in developing high-quality seedless watermelon and provide additional transcriptomic information related to other cucurbits. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  14. Functions, structure, and read-through alternative splicing of feline APOBEC3 genes

    Science.gov (United States)

    Münk, Carsten; Beck, Thomas; Zielonka, Jörg; Hotz-Wagenblatt, Agnes; Chareza, Sarah; Battenberg, Marion; Thielebein, Jens; Cichutek, Klaus; Bravo, Ignacio G; O'Brien, Stephen J; Lochelt, Martin; Yuhki, Naoya

    2008-01-01

    Background Over the past years a variety of host restriction genes have been identified in human and mammals that modulate retrovirus infectivity, replication, assembly, and/or cross-species transmission. Among these host-encoded restriction factors, the APOBEC3 (A3; apolipoprotein B mRNA-editing catalytic polypeptide 3) proteins are potent inhibitors of retroviruses and retrotransposons. While primates encode seven of these genes (A3A to A3H), rodents carry only a single A3 gene. Results Here we identified and characterized several A3 genes in the genome of domestic cat (Felis catus) by analyzing the genomic A3 locus. The cat genome presents one A3H gene and three very similar A3C genes (a-c), probably generated after two consecutive gene duplications. In addition to these four one-domain A3 proteins, a fifth A3, designated A3CH, is expressed by read-through alternative splicing. Specific feline A3 proteins selectively inactivated only defined genera of feline retroviruses: Bet-deficient feline foamy virus was mainly inactivated by feA3Ca, feA3Cb, and feA3Cc, while feA3H and feA3CH were only weakly active. The infectivity of Vif-deficient feline immunodeficiency virus and feline leukemia virus was reduced only by feA3H and feA3CH, but not by any of the feA3Cs. Within Felidae, A3C sequences show significant adaptive selection, but unexpectedly, the A3H sequences present more sites that are under purifying selection. Conclusion Our data support a complex evolutionary history of expansion, divergence, selection and individual extinction of antiviral A3 genes that parallels the early evolution of Placentalia, becoming more intricate in taxa in which the arms race between host and retroviruses is harsher. PMID:18315870

  15. Depolarization-mediated regulation of alternative splicing

    Directory of Open Access Journals (Sweden)

    Alok eSharma

    2011-12-01

    Full Text Available Alternative splicing in eukaryotes plays an important role in regulating gene expression by selectively including alternative exons. A wealth of information has been accumulated that explains how alternative exons are selected in a developmental stage- or tissue-specific fashion. However, our knowledge of how cells respond to environmental changes to alter alternative splicing is very limited. For example, although a number of alternative exons have been shown to be regulated by calcium level alterations, the underlying mechanisms are not well understood. As calcium signaling in neurons plays a crucial role in essential neuronal functions such as learning and memory formation, it is important to understand how this process is regulated at every level in gene expression. The significance of the dynamic control of alternative splicing in response to changes of calcium levels has been largely unappreciated. In this communication, we will summarize the recent advances in calcium signaling-mediated alternative splicing that have provided some insights into the important regulatory mechanisms. In addition to describing the cis-acting RNA elements on the pre-mRNA molecules that respond to changes of intracellular calcium levels, we will summarize how splicing regulators change and affect alternative splicing in this process. We will also discuss a novel mode of calcium-mediated splicing regulation at the level of chromatin structure and transcription.

  16. HOLLYWOOD: a comparative relational database of alternative splicing.

    Science.gov (United States)

    Holste, Dirk; Huo, George; Tung, Vivian; Burge, Christopher B

    2006-01-01

    RNA splicing is an essential step in gene expression, and is often variable, giving rise to multiple alternatively spliced mRNA and protein isoforms from a single gene locus. The design of effective databases to support experimental and computational investigations of alternative splicing (AS) is a significant challenge. In an effort to integrate accurate exon and splice site annotation with current knowledge about splicing regulatory elements and predicted AS events, and to link information about the splicing of orthologous genes in different species, we have developed the Hollywood system. This database was built upon genomic annotation of splicing patterns of known genes derived from spliced alignment of complementary DNAs (cDNAs) and expressed sequence tags, and links features such as splice site sequence and strength, exonic splicing enhancers and silencers, conserved and non-conserved patterns of splicing, and cDNA library information for inferred alternative exons. Hollywood was implemented as a relational database and currently contains comprehensive information for human and mouse. It is accompanied by a web query tool that allows searches for sets of exons with specific splicing characteristics or splicing regulatory element composition, or gives a graphical or sequence-level summary of splicing patterns for a specific gene. A streamlined graphical representation of gene splicing patterns is provided, and these patterns can alternatively be layered onto existing information in the UCSC Genome Browser. The database is accessible at http://hollywood.mit.edu.

  17. Molecular cloning and functional characterization of a mouse gene upregulated by lipopolysaccharide treatment reveals alternative splicing

    Energy Technology Data Exchange (ETDEWEB)

    Du, Kejun; Chen, Yaoming; Dai, Zongming; Bi, Yuan; Cai, Tongjian [Department of Occupational and Environmental Health, Fourth Military Medical University, Xi' an 710032, Shaanxi Province (China); Hou, Lichao [Department of Anesthesiology, Xijing Hospital, Fourth Military Medical University, Xi' an 710032, Shaanxi Province (China); Chai, Yubo; Song, Qinghe; Chen, Sumin [Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi' an 710032, Shaanxi Province (China); Luo, Wenjing, E-mail: luowenj@fmmu.edu.cn [Department of Occupational and Environmental Health, Fourth Military Medical University, Xi' an 710032, Shaanxi Province (China); Chen, Jingyuan, E-mail: jy_chen@fmmu.edu.cn [Department of Occupational and Environmental Health, Fourth Military Medical University, Xi' an 710032, Shaanxi Province (China)

    2010-01-01

    Treatment of mouse cells with lipopolysaccharide (LPS) potently initiates an inflammatory response, but the underlying mechanisms are unclear. We therefore sought to characterize cDNA sequences of a new mouse LPS-responsive gene, and to evaluate the effects of MLrg. Full-length cDNAs were obtained from LPS-treated NIH3T3 cells. We report that the MLrg gene produces two alternative splice products (GenBank Accession Nos. (DQ316984) and (DQ320011)), respectively, encoding MLrgW and MLrgS polypeptides. Both proteins contain zinc finger and leucine zipper domains and are thus potential regulators of transcription. Expression of MLrgW and MLrgS were robustly upregulated following LPS treatment, and the proteins were localized predominantly in the nuclear membrane and cytoplasm. In stable transfectants over-expressing MLrgW the proportion of cells in G1 phase was significantly reduced, while in cells over-expressing MLrgS the proportion of cells in G2 was significantly increased; both proteins are thus potential regulators of cell cycle progression. Upregulation of MLrgW and MLrgS may be an important component of the LPS inflammatory pathway and of the host response to infection with GNB.

  18. TUMOR-SPECIFIC EXPRESSION AND ALTERNATIVE SPLICING OF THE COL6A3 GENE IN PANCREATIC CANCER

    Science.gov (United States)

    Arafat, Hwyda; Lazar, Melissa; Salem, Khalifa; Chipitsyna, Galina; Gong, Qiaoke; Pan, Te-Cheng; Zhang, Rui-Zhu; Yeo, Charles J.; Chu, Mon-Li

    2011-01-01

    Introduction Pancreatic ductal adenocarcinoma (PDA) is a highly lethal disease in which a prominent desmoplastic reaction is a defining characteristic. Fibrillar collagens, such as collagen I and to a lesser extent, collagen III and V comprise the majority of this stromal fibrosis. Type VI collagen (COL6) forms a microfibrillar network associated with type I collagen fibrils. The expression of COL6 has been linked to inflammation and survival. Importantly, tumor-specific alternative splicing in COL6A3 has been identified in several cancers by genome exon arrays. We evaluated the expression and localization of COL6A3 in PDA and premalignant lesions and explored the presence of alternative splicing events. Methods We analyzed paired PDA-normal (n=18), IPMN (n=5), pancreatic cystadenoma (n=5), and eight PDA cell lines with RT-PCR, using unique primers that identify total COL6A3 gene and alternative splicing sites in several of its exons. Western blot analysis and immunohistochemistry were used to analyze the expression levels and localization of COL6A3 protein in the different lesions, and in two animal models of PDA. Results COL6A3 protein levels were significantly upregulated in 77% of the paired PDA-adjacent tissue examined. COL6A3 was mainly present in the desmoplastic stroma of PDA, with high deposition around the malignant ducts and in between the sites of stromal fatty infiltration. Analysis of the COL6A3 splice variants showed tumor-specific consistent inclusion of exons 3 and 6 in 17 of the 18 (94%) paired PDA-adjacent tissues. Inclusion of exon 4 was exclusively tumor-specific, with barely detectable expression in the adjacent tissues. IPMN and pancreatic cystadenomas showed no expression of any of the examined exons. Total COL6A3 mRNA and exon 6 were identified in six PDA cell lines, but only two cell lines (MIA PACA-2 and ASPC-1) expressed exons 3 and 4. In both the xenograft and transgenic models of PDA, COL6A3 immunoreactivity was present in the stroma

  19. Organization and alternative splicing of the Caenorhabditis elegans cAMP-dependent protein kinase catalytic-subunit gene (kin-1).

    Science.gov (United States)

    Tabish, M; Clegg, R A; Rees, H H; Fisher, M J

    1999-04-01

    The cAMP-dependent protein kinase (protein kinase A, PK-A) is multifunctional in nature, with key roles in the control of diverse aspects of eukaryotic cellular activity. In the case of the free-living nematode, Caenorhabditis elegans, a gene encoding the PK-A catalytic subunit has been identified and two isoforms of this subunit, arising from a C-terminal alternative-splicing event, have been characterized [Gross, Bagchi, Lu and Rubin (1990) J. Biol. Chem. 265, 6896-6907]. Here we report the occurrence of N-terminal alternative-splicing events that, in addition to generating a multiplicity of non-myristoylatable isoforms, also generate the myristoylated variant(s) of the catalytic subunit that we have recently characterized [Aspbury, Fisher, Rees and Clegg (1997) Biochem. Biophys. Res. Commun. 238, 523-527]. The gene spans more than 36 kb and is divided into a total of 13 exons. Each of the mature transcripts contains only 7 exons. In addition to the already characterized exon 1, the 5'-untranslated region and first intron actually contain 5 other exons, any one of which may be alternatively spliced on to exon 2 at the 5' end of the pre-mRNA. This N-terminal alternative splicing occurs in combination with either of the already characterized C-terminal alternative exons. Thus, C. elegans expresses at least 12 different isoforms of the catalytic subunit of PK-A. The significance of this unprecedented structural diversity in the family of PK-A catalytic subunits is discussed.

  20. Cloning and characterization of the mouse Mcoln1 gene reveals an alternatively spliced transcript not seen in humans

    Directory of Open Access Journals (Sweden)

    Stahl Stefanie

    2002-02-01

    Full Text Available Abstract Background Mucolipidosis type IV (MLIV is an autosomal recessive lysosomal storage disorder characterized by severe neurologic and ophthalmologic abnormalities. Recently the MLIV gene, MCOLN1, has been identified as a new member of the transient receptor potential (TRP cation channel superfamily. Here we report the cloning and characterization of the mouse homologue, Mcoln1, and report a novel splice variant that is not seen in humans. Results The human and mouse genes display a high degree of synteny. Mcoln1 shows 91% amino acid and 86% nucleotide identity to MCOLN1. Also, Mcoln1 maps to chromosome 8 and contains an open reading frame of 580 amino acids, with a transcript length of approximately 2 kb encoded by 14 exons, similar to its human counterpart. The transcript that results from murine specific alternative splicing encodes a 611 amino acid protein that differs at the c-terminus. Conclusions Mcoln1 is highly similar to MCOLN1, especially in the transmembrane domains and ion pore region. Also, the late endosomal/lysosomal targeting signal is conserved, supporting the hypothesis that the protein is localized to these vesicle membranes. To date, there are very few reports describing species-specific splice variants. While identification of Mcoln1 is crucial to the development of mouse models for MLIV, the fact that there are two transcripts in mice suggests an additional or alternate function of the gene that may complicate phenotypic assessment.

  1. Alternative splicing in cancers: From aberrant regulation to new therapeutics.

    Science.gov (United States)

    Song, Xiaowei; Zeng, Zhenyu; Wei, Huanhuan; Wang, Zefeng

    2018-03-01

    Alternative splicing is one of the most common mechanisms for gene regulation in humans, and plays a vital role to increase the complexity of functional proteins. In this article, we seek to provide a general review on the relationships between alternative splicing and tumorigenesis. We briefly introduce the basic rules for regulation of alternative splicing, and discuss recent advances on dynamic regulation of alternative splicing in cancers by highlighting the roles of a variety of RNA splicing factors in tumorigenesis. We further discuss several important questions regarding the splicing of long noncoding RNAs and back-splicing of circular RNAs in cancers. Finally, we discuss the current technologies that can be used to manipulate alternative splicing and serve as potential cancer treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Alternative splicing, gene localization, and binding of SH2-B to the insulin receptor kinase domain

    OpenAIRE

    Nelms, Keats; O'Neill, Thomas J.; Li, Shiqing; Hubbard, Stevan R.; Gustafson, Thomas A.; Paul, William E.

    1999-01-01

    . The SH2-B protein is an SH2-domain-containing molecule that interacts with a number of phosphorylated kinase and receptor molecules including the insulin receptor. Two isoforms of the SH2-B have been identified and have been proposed to arise through alternate splicing. Here we have identified a third isoform of the SH2-B protein, SH2-Bγ, that interacts specifically with the insulin receptor. This interaction required phosphorylation of residue Y1146 in the triple tyrosine motif within the ...

  3. SplicingTypesAnno: annotating and quantifying alternative splicing events for RNA-Seq data.

    Science.gov (United States)

    Sun, Xiaoyong; Zuo, Fenghua; Ru, Yuanbin; Guo, Jiqiang; Yan, Xiaoyan; Sablok, Gaurav

    2015-04-01

    Alternative splicing plays a key role in the regulation of the central dogma. Four major types of alternative splicing have been classified as intron retention, exon skipping, alternative 5 splice sites or alternative donor sites, and alternative 3 splice sites or alternative acceptor sites. A few algorithms have been developed to detect splice junctions from RNA-Seq reads. However, there are few tools targeting at the major alternative splicing types at the exon/intron level. This type of analysis may reveal subtle, yet important events of alternative splicing, and thus help gain deeper understanding of the mechanism of alternative splicing. This paper describes a user-friendly R package, extracting, annotating and analyzing alternative splicing types for sequence alignment files from RNA-Seq. SplicingTypesAnno can: (1) provide annotation for major alternative splicing at exon/intron level. By comparing the annotation from GTF/GFF file, it identifies the novel alternative splicing sites; (2) offer a convenient two-level analysis: genome-scale annotation for users with high performance computing environment, and gene-scale annotation for users with personal computers; (3) generate a user-friendly web report and additional BED files for IGV visualization. SplicingTypesAnno is a user-friendly R package for extracting, annotating and analyzing alternative splicing types at exon/intron level for sequence alignment files from RNA-Seq. It is publically available at https://sourceforge.net/projects/splicingtypes/files/ or http://genome.sdau.edu.cn/research/software/SplicingTypesAnno.html. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  4. The implications of alternative splicing in the ENCODE protein complement

    DEFF Research Database (Denmark)

    Tress, Michael L.; Martelli, Pier Luigi; Frankish, Adam

    2007-01-01

    suggested as one explanation for the discrepancy between the number of human genes and functional complexity. Here, we carry out a detailed study of the alternatively spliced gene products annotated in the ENCODE pilot project. We find that alternative splicing in human genes is more frequent than has...

  5. Alternative RNA splicing and gastric cancer.

    Science.gov (United States)

    Li, Ying; Yuan, Yuan

    2017-07-01

    Alternative splicing (AS) linked to diseases, especially to tumors. Recently, more and more studies focused on the relationship between AS and gastric cancer (GC). This review surveyed the hot topic from four aspects: First, the common types of AS in cancer, including exon skipping, intron retention, mutually exclusive exon, alternative 5 ' or 3' splice site, alternative first or last exon and alternative 3' untranslated regions. Second, basic mechanisms of AS and its relationship with cancer. RNA splicing in eukaryotes follows the GT-AG rule by both cis-elements and trans-acting factors regulatory. Through RNA splicing, different proteins with different forms and functions can be produced and may be associated with carcinogenesis. Third, AS types of GC-related genes and their splicing variants. In this paper, we listed 10 common genes with AS and illustrated its possible molecular mechanisms owing to genetic variation (mutation and /or polymorphism). Fourth, the splicing variants of GC-associated genes and gastric carcinogenesis, invasion and metastasis. Many studies have found that the different splicing variants of the same gene are differentially expressed in GC and its precancerous diseases, suggesting AS has important implications in GC development. Taking together, this review highlighted the role of AS and splicing variants in the process of GC. We hope that this is not only beneficial to advances in the study field of GC, but also can provide valuable information to other similar tumor research.Although we already know some gene splicing and splicing variants play an important role in the development of GC, but many phenomena and mechanisms are still unknown. For example, how the tumor microenvironment and signal transduction pathway effect the forming and function of AS? Unfortunately, this review did not cover the contents because the current study is limited. It is no doubt that clarifying the phenomena and mechanisms of these unknown may help to reveal

  6. Widespread alternative and aberrant splicing revealed by lariat sequencing

    Science.gov (United States)

    Stepankiw, Nicholas; Raghavan, Madhura; Fogarty, Elizabeth A.; Grimson, Andrew; Pleiss, Jeffrey A.

    2015-01-01

    Alternative splicing is an important and ancient feature of eukaryotic gene structure, the existence of which has likely facilitated eukaryotic proteome expansions. Here, we have used intron lariat sequencing to generate a comprehensive profile of splicing events in Schizosaccharomyces pombe, amongst the simplest organisms that possess mammalian-like splice site degeneracy. We reveal an unprecedented level of alternative splicing, including alternative splice site selection for over half of all annotated introns, hundreds of novel exon-skipping events, and thousands of novel introns. Moreover, the frequency of these events is far higher than previous estimates, with alternative splice sites on average activated at ∼3% the rate of canonical sites. Although a subset of alternative sites are conserved in related species, implying functional potential, the majority are not detectably conserved. Interestingly, the rate of aberrant splicing is inversely related to expression level, with lowly expressed genes more prone to erroneous splicing. Although we validate many events with RNAseq, the proportion of alternative splicing discovered with lariat sequencing is far greater, a difference we attribute to preferential decay of aberrantly spliced transcripts. Together, these data suggest the spliceosome possesses far lower fidelity than previously appreciated, highlighting the potential contributions of alternative splicing in generating novel gene structures. PMID:26261211

  7. Vitamin D and alternative splicing of RNA.

    Science.gov (United States)

    Zhou, Rui; Chun, Rene F; Lisse, Thomas S; Garcia, Alejandro J; Xu, Jianzhong; Adams, John S; Hewison, Martin

    2015-04-01

    The active form of vitamin D (1α,25-dihydroxyvitamin D, 1,25(OH)2D) exerts its genomic effects via binding to a nuclear high-affinity vitamin D receptor (VDR). Recent deep sequencing analysis of VDR binding locations across the complete genome has significantly expanded our understanding of the actions of vitamin D and VDR on gene transcription. However, these studies have also promoted appreciation of the extra-transcriptional impact of vitamin D on gene expression. It is now clear that vitamin D interacts with the epigenome via effects on DNA methylation, histone acetylation, and microRNA generation to maintain normal biological functions. There is also increasing evidence that vitamin D can influence pre-mRNA constitutive splicing and alternative splicing, although the mechanism for this remains unclear. Pre-mRNA splicing has long been thought to be a post-transcription RNA processing event, but current data indicate that this occurs co-transcriptionally. Several steroid hormones have been recognized to coordinately control gene transcription and pre-mRNA splicing through the recruitment of nuclear receptor co-regulators that can both control gene transcription and splicing. The current review will discuss this concept with specific reference to vitamin D, and the potential role of heterogeneous nuclear ribonucleoprotein C (hnRNPC), a nuclear factor with an established function in RNA splicing. hnRNPC, has been shown to be involved in the VDR transcriptional complex as a vitamin D-response element-binding protein (VDRE-BP), and may act as a coupling factor linking VDR-directed gene transcription with RNA splicing. In this way hnRNPC may provide an additional mechanism for the fine-tuning of vitamin D-regulated target gene expression. This article is part of a Special Issue entitled '17th Vitamin D Workshop'. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Genetics of alternative splicing evolution during sunflower domestication.

    Science.gov (United States)

    Smith, Chris C R; Tittes, Silas; Mendieta, J Paul; Collier-Zans, Erin; Rowe, Heather C; Rieseberg, Loren H; Kane, Nolan C

    2018-06-11

    Alternative splicing enables organisms to produce the diversity of proteins necessary for multicellular life by using relatively few protein-coding genes. Although differences in splicing have been identified among divergent taxa, the shorter-term evolution of splicing is understudied. The origins of novel splice forms, and the contributions of alternative splicing to major evolutionary transitions, are largely unknown. This study used transcriptomes of wild and domesticated sunflowers to examine splice differentiation and regulation during domestication. We identified substantial splicing divergence between wild and domesticated sunflowers, mainly in the form of intron retention. Transcripts with divergent splicing were enriched for seed-development functions, suggesting that artificial selection impacted splicing patterns. Mapping of quantitative trait loci (QTLs) associated with 144 differential splicing cases revealed primarily trans -acting variation affecting splicing patterns. A large proportion of identified QTLs contain known spliceosome proteins and are associated with splicing variation in multiple genes. Examining a broader set of wild and domesticated sunflower genotypes revealed that most differential splicing patterns in domesticated sunflowers likely arose from standing variation in wild Helianthus annuus and gained frequency during the domestication process. However, several domesticate-associated splicing patterns appear to be introgressed from other Helianthus species. These results suggest that sunflower domestication involved selection on pleiotropic regulatory alleles. More generally, our findings indicate that substantial differences in isoform abundances arose rapidly during a recent evolutionary transition and appear to contribute to adaptation and population divergence.

  9. A study of alternative splicing in the pig

    Directory of Open Access Journals (Sweden)

    Jørgensen Claus B

    2010-05-01

    Full Text Available Abstract Background Since at least half of the genes in mammalian genomes are subjected to alternative splicing, alternative pre-mRNA splicing plays an important contribution to the complexity of the mammalian proteome. Expressed sequence tags (ESTs provide evidence of a great number of possible alternative isoforms. With the EST resource for the domestic pig now containing more than one million porcine ESTs, it is possible to identify alternative splice forms of the individual transcripts in this species from the EST data with some confidence. Results The pig EST data generated by the Sino-Danish Pig Genome project has been assembled with publicly available ESTs and made available in the PigEST database. Using the Distiller package 2,515 EST clusters with candidate alternative isoforms were identified in the EST data with high confidence. In agreement with general observations in human and mouse, we find putative splice variants in about 30% of the contigs with more than 50 ESTs. Based on the criteria that a minimum of two EST sequences confirmed each splice event, a list of 100 genes with the most distinct tissue-specific alternative splice events was generated from the list of candidates. To confirm the tissue specificity of the splice events, 10 genes with functional annotation were randomly selected from which 16 individual splice events were chosen for experimental verification by quantitative PCR (qPCR. Six genes were shown to have tissue specific alternatively spliced transcripts with expression patterns matching those of the EST data. The remaining four genes had tissue-restricted expression of alternative spliced transcripts. Five out of the 16 splice events that were experimentally verified were found to be putative pig specific. Conclusions In accordance with human and rodent studies we estimate that approximately 30% of the porcine genes undergo alternative splicing. We found a good correlation between EST predicted tissue

  10. Quantitative regulation of alternative splicing in evolution and development

    DEFF Research Database (Denmark)

    Irimia, Manuel; Rukov, Jakob L; Roy, Scott W

    2009-01-01

    Alternative splicing (AS) is a widespread mechanism with an important role in increasing transcriptome and proteome diversity by generating multiple different products from the same gene. Evolutionary studies of AS have focused primarily on the conservation of alternatively spliced sequences or o...

  11. Allelic variation, alternative splicing and expression analysis of Psy1 gene in Hordeum chilense Roem. et Schult.

    Directory of Open Access Journals (Sweden)

    Cristina Rodríguez-Suárez

    Full Text Available BACKGROUND: The wild barley Hordeum chilense Roem. et Schult. is a valuable source of genes for increasing carotenoid content in wheat. Tritordeums, the amphiploids derived from durum or common wheat and H. chilense, systematically show higher values of yellow pigment colour and carotenoid content than durum wheat. Phytoene synthase 1 gene (Psy1 is considered a key step limiting the carotenoid biosynthesis, and the correlation of Psy1 transcripts accumulation and endosperm carotenoid content has been demonstrated in the main grass species. METHODOLOGY/PRINCIPAL FINDINGS: We analyze the variability of Psy1 alleles in three lines of H. chilense (H1, H7 and H16 representing the three ecotypes described in this species. Moreover, we analyze Psy1 expression in leaves and in two seed developing stages of H1 and H7, showing mRNA accumulation patterns similar to those of wheat. Finally, we identify thirty-six different transcripts forms originated by alternative splicing of the 5' UTR and/or exons 1 to 5 of Psy1 gene. Transcripts function is tested in a heterologous complementation assay, revealing that from the sixteen different predicted proteins only four types (those of 432, 370, 364 and 271 amino acids, are functional in the bacterial system. CONCLUSIONS/SIGNIFICANCE: The large number of transcripts originated by alternative splicing of Psy1, and the coexistence of functional and non functional forms, suggest a fine regulation of PSY activity in H. chilense. This work is the first analysis of H. chilense Psy1 gene and the results reported here are the bases for its potential use in carotenoid enhancement in durum wheat.

  12. Transcriptomic insights into the alternative splicing-mediated adaptation of the entomopathogenic fungus Beauveria bassiana to host niches: autophagy-related gene 8 as an example.

    Science.gov (United States)

    Dong, Wei-Xia; Ding, Jin-Li; Gao, Yang; Peng, Yue-Jin; Feng, Ming-Guang; Ying, Sheng-Hua

    2017-10-01

    Alternative splicing (AS) regulates various biological processes in fungi by extending the cellular proteome. However, comprehensive studies investigating AS in entomopathogenic fungi are lacking. Based on transcriptome data obtained via dual RNA-seq, the first overview of AS events was developed for Beauveria bassiana growing in an insect haemocoel. The AS was demonstrated for 556 of 8840 expressed genes, accounting for 5.4% of the total genes in B. bassiana. Intron retention was the most abundant type of AS, accounting for 87.1% of all splicing events and exon skipping events were rare, only accounting for 2.0% of all events. Functional distribution analysis indicated an association between alternatively spliced genes and several physiological processes. Notably, B. bassiana autophagy-related gene 8 (BbATG8), an indispensable gene for autophagy, was spliced at an alternative 5' splice site to generate two transcripts (BbATG8-α and BbATG8-β). The BbATG8-α transcript was necessary for fungal autophagy and oxidation tolerance, while the BbATG8-β transcript was not. These two transcripts differentially contributed to the formation of conidia or blastospores as well as fungal virulence. Thus, AS acts as a powerful post-transcriptional regulatory strategy in insect mycopathogens and significantly mediates fungal transcriptional adaption to host niches. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  13. Alternative Splicing as a Target for Cancer Treatment.

    Science.gov (United States)

    Martinez-Montiel, Nancy; Rosas-Murrieta, Nora Hilda; Anaya Ruiz, Maricruz; Monjaraz-Guzman, Eduardo; Martinez-Contreras, Rebeca

    2018-02-11

    Alternative splicing is a key mechanism determinant for gene expression in metazoan. During alternative splicing, non-coding sequences are removed to generate different mature messenger RNAs due to a combination of sequence elements and cellular factors that contribute to splicing regulation. A different combination of splicing sites, exonic or intronic sequences, mutually exclusive exons or retained introns could be selected during alternative splicing to generate different mature mRNAs that could in turn produce distinct protein products. Alternative splicing is the main source of protein diversity responsible for 90% of human gene expression, and it has recently become a hallmark for cancer with a full potential as a prognostic and therapeutic tool. Currently, more than 15,000 alternative splicing events have been associated to different aspects of cancer biology, including cell proliferation and invasion, apoptosis resistance and susceptibility to different chemotherapeutic drugs. Here, we present well established and newly discovered splicing events that occur in different cancer-related genes, their modification by several approaches and the current status of key tools developed to target alternative splicing with diagnostic and therapeutic purposes.

  14. Alternative splicing of DENND1A, a PCOS candidate gene, generates variant 2.

    Science.gov (United States)

    Tee, Meng Kian; Speek, Mart; Legeza, Balázs; Modi, Bhavi; Teves, Maria Eugenia; McAllister, Janette M; Strauss, Jerome F; Miller, Walter L

    2016-10-15

    Polycystic ovary syndrome (PCOS) is a common endocrinopathy characterized by hyperandrogenism and metabolic disorders. The excess androgens may be of both ovarian and adrenal origin. PCOS has a strong genetic component, and genome-wide association studies have identified several candidate genes, notably DENND1A, which encodes connecdenn 1, involved in trafficking of endosomes. DENND1A encodes two principal variants, V1 (1009 amino acids) and V2 (559 amino acids). The androgen-producing ovarian theca cells of PCOS women over-express V2. Knockdown of V2 in these cells reduces androgen production, and overexpression of V2 in normal theca cells confers upon them a PCOS phenotype of increased androgen synthesis. We report that human adrenal NCI-H295A cells express V1 and V2 mRNA and that the V2 isoform is produced by exonization of sequences in intron 20, which generates a unique exon 20A, encoding the C-terminus of V2. As in human theca cells from normal women, forced expression of V2 in NCI-H295A cells resulted in increased abundance of CYP17A1 and CYP11A1 mRNAs. We also found genetic variation in the intronic region 330 bp upstream from exon 20A, which could have the potential to drive the selective expression of V2. There was no clear association with these variants with PCOS when we analyzed genomc DNA from normal women and women with PCOS. Using minigene expression vectors in NCI-H295A cells, this variable region did not consistently favor splicing of the V2 transcript. These findings suggest increased V2 expression in PCOS theca cells is not the result of genomic sequence variation in intron 20. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. Alternative splicing: a novel mechanism of regulation identified in the chorismate mutase gene of the potato cyst nematode Globodera rostochiensis.

    Science.gov (United States)

    Lu, Shun-Wen; Tian, Duanhua; Borchardt-Wier, Harmony B; Wang, Xiaohong

    2008-11-01

    Chorismate mutase (CM) secreted from the stylet of plant-parasitic nematodes plays an important role in plant parasitism. We isolated and characterized a new nematode CM gene (Gr-cm-1) from the potato cyst nematode, Globodera rostochiensis. The Gr-cm-1 gene was found to exist in the nematode genome as a single-copy gene that has two different alleles, Gr-cm-1A and Gr-cm-1B, both of which could give rise to two different mRNA transcripts of Gr-cm-1 and Gr-cm-1-IRII. In situ mRNA hybridization showed that the Gr-cm-1 gene was exclusively expressed within the subventral oesophageal gland cells of the nematode. Gr-cm-1 was demonstrated to encode a functional CM (GR-CM-1) potentially having a dimeric structure as the secreted bacterial *AroQ CMs. Gr-cm-1-IRII, generated by retention of intron 2 of the Gr-cm-1 pre-mRNA through alternative splicing (AS), would encode a truncated protein (GR-CM-1t) lacking the CM domain with no CM activity. The quantitative real-time reverse transcription-PCR assay revealed that splicing of the Gr-cm-1 gene was developmentally regulated; Gr-cm-1 was up-regulated whereas Gr-cm-1-IRII was down-regulated in early nematode parasitic stages compared to the preparasitic juvenile stage. Low-temperature SDS-PAGE analysis revealed that GR-CM-1 could form homodimers when expressed in Escherichia coli and the dimerization domain was retained in the truncated GR-CM-1t protein. The specific interaction between the two proteins was demonstrated in yeast. Our data suggested that the novel splice variant might function as a dominant negative isoform through heterodimerization with the full-length GR-CM-1 protein and that AS may represent an important mechanism for regulating CM activity during nematode parasitism.

  16. The hnRNP 2H9 gene, which is involved in the splicing reaction, is a multiply spliced gene

    DEFF Research Database (Denmark)

    Honoré, B

    2000-01-01

    The hnRNP 2H9 gene products are involved in the splicing process and participate in early heat shock-induced splicing arrest. By combining low/high stringency hybridisation, database search, Northern and Western blotting it is shown that the gene is alternatively spliced into at least six...

  17. MeCP2 regulates Tet1-catalyzed demethylation, CTCF binding, and learning-dependent alternative splicing of the BDNF gene in Turtle

    Science.gov (United States)

    Zheng, Zhaoqing; Ambigapathy, Ganesh; Keifer, Joyce

    2017-01-01

    MECP2 mutations underlying Rett syndrome cause widespread misregulation of gene expression. Functions for MeCP2 other than transcriptional are not well understood. In an ex vivo brain preparation from the pond turtle Trachemys scripta elegans, an intraexonic splicing event in the brain-derived neurotrophic factor (BDNF) gene generates a truncated mRNA transcript in naïve brain that is suppressed upon classical conditioning. MeCP2 and its partners, splicing factor Y-box binding protein 1 (YB-1) and methylcytosine dioxygenase 1 (Tet1), bind to BDNF chromatin in naïve but dissociate during conditioning; the dissociation correlating with decreased DNA methylation. Surprisingly, conditioning results in new occupancy of BDNF chromatin by DNA insulator protein CCCTC-binding factor (CTCF), which is associated with suppression of splicing in conditioning. Knockdown of MeCP2 shows it is instrumental for splicing and inhibits Tet1 and CTCF binding thereby negatively impacting DNA methylation and conditioning-dependent splicing regulation. Thus, mutations in MECP2 can have secondary effects on DNA methylation and alternative splicing. DOI: http://dx.doi.org/10.7554/eLife.25384.001 PMID:28594324

  18. Validation and Interrogation of Differentially Expressed and Alternately Spliced Genes in African American Prostate Cancer

    Science.gov (United States)

    2017-10-01

    receptor (AR) and epidermal growth factor receptor (EGFR) pathways in AA versus white prostate cancer . Thus, there is an urgent need to develop a novel...androgen receptor signaling and aggressive prostate cancer . AACR Conference on The Science of Cancer Health Disparities in Racial/Ethnic Minorities and...Freedman and S. R. Patierno. Race-related differential splicing of the insulin receptor : A novel target underlying prostate cancer disparities. AACR

  19. Revised genomic structure of the human ghrelin gene and identification of novel exons, alternative splice variants and natural antisense transcripts

    Directory of Open Access Journals (Sweden)

    Herington Adrian C

    2007-08-01

    Full Text Available Abstract Background Ghrelin is a multifunctional peptide hormone expressed in a range of normal tissues and pathologies. It has been reported that the human ghrelin gene consists of five exons which span 5 kb of genomic DNA on chromosome 3 and includes a 20 bp non-coding first exon (20 bp exon 0. The availability of bioinformatic tools enabling comparative analysis and the finalisation of the human genome prompted us to re-examine the genomic structure of the ghrelin locus. Results We have demonstrated the presence of an additional novel exon (exon -1 and 5' extensions to exon 0 and 1 using comparative in silico analysis and have demonstrated their existence experimentally using RT-PCR and 5' RACE. A revised exon-intron structure demonstrates that the human ghrelin gene spans 7.2 kb and consists of six rather than five exons. Several ghrelin gene-derived splice forms were detected in a range of human tissues and cell lines. We have demonstrated ghrelin gene-derived mRNA transcripts that do not code for ghrelin, but instead may encode the C-terminal region of full-length preproghrelin (C-ghrelin, which contains the coding region for obestatin and a transcript encoding obestatin-only. Splice variants that differed in their 5' untranslated regions were also found, suggesting a role of these regions in the post-transcriptional regulation of preproghrelin translation. Finally, several natural antisense transcripts, termed ghrelinOS (ghrelin opposite strand transcripts, were demonstrated via orientation-specific RT-PCR, 5' RACE and in silico analysis of ESTs and cloned amplicons. Conclusion The sense and antisense alternative transcripts demonstrated in this study may function as non-coding regulatory RNA, or code for novel protein isoforms. This is the first demonstration of putative obestatin and C-ghrelin specific transcripts and these findings suggest that these ghrelin gene-derived peptides may also be produced independently of preproghrelin

  20. Alternative Splicing Profile and Sex-Preferential Gene Expression in the Female and Male Pacific Abalone Haliotis discus hannai.

    Science.gov (United States)

    Kim, Mi Ae; Rhee, Jae-Sung; Kim, Tae Ha; Lee, Jung Sick; Choi, Ah-Young; Choi, Beom-Soon; Choi, Ik-Young; Sohn, Young Chang

    2017-03-09

    In order to characterize the female or male transcriptome of the Pacific abalone and further increase genomic resources, we sequenced the mRNA of full-length complementary DNA (cDNA) libraries derived from pooled tissues of female and male Haliotis discus hannai by employing the Iso-Seq protocol of the PacBio RSII platform. We successfully assembled whole full-length cDNA sequences and constructed a transcriptome database that included isoform information. After clustering, a total of 15,110 and 12,145 genes that coded for proteins were identified in female and male abalones, respectively. A total of 13,057 putative orthologs were retained from each transcriptome in abalones. Overall Gene Ontology terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways analyzed in each database showed a similar composition between sexes. In addition, a total of 519 and 391 isoforms were genome-widely identified with at least two isoforms from female and male transcriptome databases. We found that the number of isoforms and their alternatively spliced patterns are variable and sex-dependent. This information represents the first significant contribution to sex-preferential genomic resources of the Pacific abalone. The availability of whole female and male transcriptome database and their isoform information will be useful to improve our understanding of molecular responses and also for the analysis of population dynamics in the Pacific abalone.

  1. Alternative Splicing Profile and Sex-Preferential Gene Expression in the Female and Male Pacific Abalone Haliotis discus hannai

    Directory of Open Access Journals (Sweden)

    Mi Ae Kim

    2017-03-01

    Full Text Available In order to characterize the female or male transcriptome of the Pacific abalone and further increase genomic resources, we sequenced the mRNA of full-length complementary DNA (cDNA libraries derived from pooled tissues of female and male Haliotis discus hannai by employing the Iso-Seq protocol of the PacBio RSII platform. We successfully assembled whole full-length cDNA sequences and constructed a transcriptome database that included isoform information. After clustering, a total of 15,110 and 12,145 genes that coded for proteins were identified in female and male abalones, respectively. A total of 13,057 putative orthologs were retained from each transcriptome in abalones. Overall Gene Ontology terms and Kyoto Encyclopedia of Genes and Genomes (KEGG pathways analyzed in each database showed a similar composition between sexes. In addition, a total of 519 and 391 isoforms were genome-widely identified with at least two isoforms from female and male transcriptome databases. We found that the number of isoforms and their alternatively spliced patterns are variable and sex-dependent. This information represents the first significant contribution to sex-preferential genomic resources of the Pacific abalone. The availability of whole female and male transcriptome database and their isoform information will be useful to improve our understanding of molecular responses and also for the analysis of population dynamics in the Pacific abalone.

  2. Alternative splicing studies of the reactive oxygen species gene network in Populus reveal two isoforms of high-isoelectric-point superoxide dismutase.

    Science.gov (United States)

    Srivastava, Vaibhav; Srivastava, Manoj Kumar; Chibani, Kamel; Nilsson, Robert; Rouhier, Nicolas; Melzer, Michael; Wingsle, Gunnar

    2009-04-01

    Recent evidence has shown that alternative splicing (AS) is widely involved in the regulation of gene expression, substantially extending the diversity of numerous proteins. In this study, a subset of expressed sequence tags representing members of the reactive oxygen species gene network was selected from the PopulusDB database to investigate AS mechanisms in Populus. Examples of all known types of AS were detected, but intron retention was the most common. Interestingly, the closest Arabidopsis (Arabidopsis thaliana) homologs of half of the AS genes identified in Populus are not reportedly alternatively spliced. Two genes encoding the protein of most interest in our study (high-isoelectric-point superoxide dismutase [hipI-SOD]) have been found in black cottonwood (Populus trichocarpa), designated PthipI-SODC1 and PthipI-SODC2. Analysis of the expressed sequence tag libraries has indicated the presence of two transcripts of PthipI-SODC1 (hipI-SODC1b and hipI-SODC1s). Alignment of these sequences with the PthipI-SODC1 gene showed that hipI-SODC1b was 69 bp longer than hipI-SODC1s due to an AS event involving the use of an alternative donor splice site in the sixth intron. Transcript analysis showed that the splice variant hipI-SODC1b was differentially expressed, being clearly expressed in cambial and xylem, but not phloem, regions. In addition, immunolocalization and mass spectrometric data confirmed the presence of hipI-SOD proteins in vascular tissue. The functionalities of the spliced gene products were assessed by expressing recombinant hipI-SOD proteins and in vitro SOD activity assays.

  3. Alternative Splicing Studies of the Reactive Oxygen Species Gene Network in Populus Reveal Two Isoforms of High-Isoelectric-Point Superoxide Dismutase1[C][W

    Science.gov (United States)

    Srivastava, Vaibhav; Srivastava, Manoj Kumar; Chibani, Kamel; Nilsson, Robert; Rouhier, Nicolas; Melzer, Michael; Wingsle, Gunnar

    2009-01-01

    Recent evidence has shown that alternative splicing (AS) is widely involved in the regulation of gene expression, substantially extending the diversity of numerous proteins. In this study, a subset of expressed sequence tags representing members of the reactive oxygen species gene network was selected from the PopulusDB database to investigate AS mechanisms in Populus. Examples of all known types of AS were detected, but intron retention was the most common. Interestingly, the closest Arabidopsis (Arabidopsis thaliana) homologs of half of the AS genes identified in Populus are not reportedly alternatively spliced. Two genes encoding the protein of most interest in our study (high-isoelectric-point superoxide dismutase [hipI-SOD]) have been found in black cottonwood (Populus trichocarpa), designated PthipI-SODC1 and PthipI-SODC2. Analysis of the expressed sequence tag libraries has indicated the presence of two transcripts of PthipI-SODC1 (hipI-SODC1b and hipI-SODC1s). Alignment of these sequences with the PthipI-SODC1 gene showed that hipI-SODC1b was 69 bp longer than hipI-SODC1s due to an AS event involving the use of an alternative donor splice site in the sixth intron. Transcript analysis showed that the splice variant hipI-SODC1b was differentially expressed, being clearly expressed in cambial and xylem, but not phloem, regions. In addition, immunolocalization and mass spectrometric data confirmed the presence of hipI-SOD proteins in vascular tissue. The functionalities of the spliced gene products were assessed by expressing recombinant hipI-SOD proteins and in vitro SOD activity assays. PMID:19176719

  4. Alternative Splicing in Neurogenesis and Brain Development.

    Science.gov (United States)

    Su, Chun-Hao; D, Dhananjaya; Tarn, Woan-Yuh

    2018-01-01

    Alternative splicing of precursor mRNA is an important mechanism that increases transcriptomic and proteomic diversity and also post-transcriptionally regulates mRNA levels. Alternative splicing occurs at high frequency in brain tissues and contributes to every step of nervous system development, including cell-fate decisions, neuronal migration, axon guidance, and synaptogenesis. Genetic manipulation and RNA sequencing have provided insights into the molecular mechanisms underlying the effects of alternative splicing in stem cell self-renewal and neuronal fate specification. Timely expression and perhaps post-translational modification of neuron-specific splicing regulators play important roles in neuronal development. Alternative splicing of many key transcription regulators or epigenetic factors reprograms the transcriptome and hence contributes to stem cell fate determination. During neuronal differentiation, alternative splicing also modulates signaling activity, centriolar dynamics, and metabolic pathways. Moreover, alternative splicing impacts cortical lamination and neuronal development and function. In this review, we focus on recent progress toward understanding the contributions of alternative splicing to neurogenesis and brain development, which has shed light on how splicing defects may cause brain disorders and diseases.

  5. Alternative Splicing in Neurogenesis and Brain Development

    Directory of Open Access Journals (Sweden)

    Chun-Hao Su

    2018-02-01

    Full Text Available Alternative splicing of precursor mRNA is an important mechanism that increases transcriptomic and proteomic diversity and also post-transcriptionally regulates mRNA levels. Alternative splicing occurs at high frequency in brain tissues and contributes to every step of nervous system development, including cell-fate decisions, neuronal migration, axon guidance, and synaptogenesis. Genetic manipulation and RNA sequencing have provided insights into the molecular mechanisms underlying the effects of alternative splicing in stem cell self-renewal and neuronal fate specification. Timely expression and perhaps post-translational modification of neuron-specific splicing regulators play important roles in neuronal development. Alternative splicing of many key transcription regulators or epigenetic factors reprograms the transcriptome and hence contributes to stem cell fate determination. During neuronal differentiation, alternative splicing also modulates signaling activity, centriolar dynamics, and metabolic pathways. Moreover, alternative splicing impacts cortical lamination and neuronal development and function. In this review, we focus on recent progress toward understanding the contributions of alternative splicing to neurogenesis and brain development, which has shed light on how splicing defects may cause brain disorders and diseases.

  6. Global identification of the full-length transcripts and alternative splicing related to phenolic acid biosynthetic genes in Salvia miltiorrhiza

    Directory of Open Access Journals (Sweden)

    Zhichao eXu

    2016-02-01

    Full Text Available Salvianolic acids are among the main bioactive components in Salvia miltiorrhiza, and their biosynthesis has attracted widespread interest. However, previous studies on the biosynthesis of phenolic acids using next-generation sequencing platforms are limited with regard to the assembly of full-length transcripts. Based on hybrid-seq (next-generation and single molecular real-time sequencing of the S. miltiorrhiza root transcriptome, we experimentally identified 15 full-length transcripts and 4 alternative splicing events of enzyme-coding genes involved in the biosynthesis of rosmarinic acid. Moreover, we herein demonstrate that lithospermic acid B accumulates in the phloem and xylem of roots, in agreement with the expression patterns of the identified key genes related to rosmarinic acid biosynthesis. According to co-expression patterns, we predicted that 6 candidate cytochrome P450s and 5 candidate laccases participate in the salvianolic acid pathway. Our results provide a valuable resource for further investigation into the synthetic biology of phenolic acids in S. miltiorrhiza.

  7. Evidence for the possible biological significance of the igf-1 gene alternative splicing in prostate cancer

    Directory of Open Access Journals (Sweden)

    Anastassios ePhilippou

    2013-03-01

    Full Text Available Insulin-like growth factor I (IGF-I has been implicated in the pathogenesis of prostate cancer (PCa, since it plays a key role in cell proliferation, differentiation and apoptosis. The IGF-I actions are mediated mainly via its binding to the type I IGF receptor (IGF-IR, however IGF-I signaling via insulin receptor (IR and hybrid IGF-I/IR is also evident. Different IGF-I mRNA splice variants, namely IGF-IEa, IGF-IEb and IGF-IEc, are expressed in human cells and tissues. These transcripts encode several IGF-I precursor proteins which contain the same bioactive product (mature IGF-I, however, they differ by the length of their signal peptides on the amino-terminal end and the structure of the extension peptides (E-peptides on the carboxy-terminal end. There is an increasing interest in the possible different role of the IGF-I transcripts and their respective non-(matureIGF-I products in the regulation of distinct biological activities. Moreover, there is strong evidence of a differential expression profile of the IGF-I splice variants in normal vs. PCa tissues and PCa cells, implying that the expression pattern of the various IGF-I transcripts and their respective protein products may possess different functions in cancer biology. Herein, the evidence that the IGF-IEc transcript regulates PCa growth via Ec-peptide specific and IGF-IR/IR-independent signaling is discussed.

  8. Tools to covisualize and coanalyze proteomic data with genomes and transcriptomes: validation of genes and alternative mRNA splicing.

    Science.gov (United States)

    Pang, Chi Nam Ignatius; Tay, Aidan P; Aya, Carlos; Twine, Natalie A; Harkness, Linda; Hart-Smith, Gene; Chia, Samantha Z; Chen, Zhiliang; Deshpande, Nandan P; Kaakoush, Nadeem O; Mitchell, Hazel M; Kassem, Moustapha; Wilkins, Marc R

    2014-01-03

    Direct links between proteomic and genomic/transcriptomic data are not frequently made, partly because of lack of appropriate bioinformatics tools. To help address this, we have developed the PG Nexus pipeline. The PG Nexus allows users to covisualize peptides in the context of genomes or genomic contigs, along with RNA-seq reads. This is done in the Integrated Genome Viewer (IGV). A Results Analyzer reports the precise base position where LC-MS/MS-derived peptides cover genes or gene isoforms, on the chromosomes or contigs where this occurs. In prokaryotes, the PG Nexus pipeline facilitates the validation of genes, where annotation or gene prediction is available, or the discovery of genes using a "virtual protein"-based unbiased approach. We illustrate this with a comprehensive proteogenomics analysis of two strains of Campylobacter concisus . For higher eukaryotes, the PG Nexus facilitates gene validation and supports the identification of mRNA splice junction boundaries and splice variants that are protein-coding. This is illustrated with an analysis of splice junctions covered by human phosphopeptides, and other examples of relevance to the Chromosome-Centric Human Proteome Project. The PG Nexus is open-source and available from https://github.com/IntersectAustralia/ap11_Samifier. It has been integrated into Galaxy and made available in the Galaxy tool shed.

  9. Tissue-specific alternative splicing and expression of ATP1B2 gene

    African Journals Online (AJOL)

    user6

    2012-05-15

    May 15, 2012 ... retention; these isoforms were found in liver, kidney, muscle and breast tissues. ... lower levels than the complete ATP1B2 gene transcript in all the ... temperature. ... growth, differentiation, and disease (Zhou et al., 2002;.

  10. Two alternatively spliced GPR39 transcripts in seabream: molecular cloning, genomic organization, and regulation of gene expression by metabolic signals.

    Science.gov (United States)

    Zhang, Yong; Liu, Yun; Huang, Xigui; Liu, Xiaochun; Jiao, Baowei; Meng, Zining; Zhu, Pei; Li, Shuisheng; Lin, Haoran; Cheng, Christopher H K

    2008-12-01

    Two GPR39 transcripts, designated as sbGPR39-1a and sbGPR39-1b, were identified in black seabream (Acanthopagrus schlegeli). The deduced amino acid (aa) sequence of sbGPR39-1a contains 423 residues with seven putative transmembrane (TM) domains. On the other hand, sbGPR39-1b contains 284 aa residues with only five putative TM domains. Northern blot analysis confirmed the presence of two GPR39 transcripts in the seabream intestine, stomach, and liver. Apart from seabream, the presence of two GPR39 transcripts was also found to exist in a number of teleosts (zebrafish and pufferfish) and mammals (human and mouse). Analysis of the GPR39 gene structure in different species suggests that the two GPR39 transcripts are generated by alternative splicing. When the seabream receptors were expressed in cultured HEK293 cells, Zn(2)(+) could trigger sbGPR39-1a signaling through the serum response element pathway, but no such functionality could be detected for the sbGPR39-1b receptor. The two receptors were found to be differentially expressed in seabream tissues. sbGPR39-1a is predominantly expressed in the gastrointestinal tract. On the other hand, sbGPR39-1b is widely expressed in most central and peripheral tissues except muscle and ovary. The expression of sbGPR39-1a in the intestine and the expression of sbGPR39-1b in the hypothalamus were decreased significantly during food deprivation in seabream. On the contrary, the expression of the GH secretagogue receptors (sbGHSR-1a and sbGHSR-1b) was significantly increased in the hypothalamus of the food-deprived seabream. The reciprocal regulatory patterns of expression of these two genes suggest that both of them are involved in controlling the physiological response of the organism during starvation.

  11. Characterization of the interferon genes in homozygous rainbow trout reveals two novel genes, alternate splicing and differential regulation of duplicated genes

    Science.gov (United States)

    Purcell, M.K.; Laing, K.J.; Woodson, J.C.; Thorgaard, G.H.; Hansen, J.D.

    2009-01-01

    The genes encoding the type I and type II interferons (IFNs) have previously been identified in rainbow trout and their proteins partially characterized. These previous studies reported a single type II IFN (rtIFN-??) and three rainbow trout type I IFN genes that are classified into either group I (rtIFN1, rtIFN2) or group II (rtIFN3). In this present study, we report the identification of a novel IFN-?? gene (rtIFN-??2) and a novel type I group II IFN (rtIFN4) in homozygous rainbow trout and predict that additional IFN genes or pseudogenes exist in the rainbow trout genome. Additionally, we provide evidence that short and long forms of rtIFN1 are actively and differentially transcribed in homozygous trout, and likely arose due to alternate splicing of the first exon. Quantitative reverse transcriptase PCR (qRT-PCR) assays were developed to systematically profile all of the rainbow trout IFN transcripts, with high specificity at an individual gene level, in na??ve fish and after stimulation with virus or viral-related molecules. Cloned PCR products were used to ensure the specificity of the qRT-PCR assays and as absolute standards to assess transcript abundance of each gene. All IFN genes were modulated in response to Infectious hematopoietic necrosis virus (IHNV), a DNA vaccine based on the IHNV glycoprotein, and poly I:C. The most inducible of the type I IFN genes, by all stimuli tested, were rtIFN3 and the short transcript form of rtIFN1. Gene expression of rtIFN-??1 and rtIFN-??2 was highly up-regulated by IHNV infection and DNA vaccination but rtIFN-??2 was induced to a greater magnitude. The specificity of the qRT-PCR assays reported here will be useful for future studies aimed at identifying which cells produce IFNs at early time points after infection. ?? 2008 Elsevier Ltd.

  12. Epigenetic Machinery Regulates Alternative Splicing of Androgen Receptor (AR) Gene in Castration-Resistant Prostate Cancer (CRPC)

    Science.gov (United States)

    2017-09-01

    Splicing of Androgen Receptor (AR) Gene in Castration-Resistant Prostate Cancer (CRPC) 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Jer...Epigenetic regulation of androgen receptor signaling in prostate cancer . Epigenetics. 5, 100-104. 2. Duan LL, Rai G , Roggero C, Zhang Q-J, Wei Q... Prostate Cancer (CRPC) PRINCIPAL INVESTIGATOR: Hsieh, Jer-Tsong CONTRACTING ORGANIZATION: University of Texas Southwestern Medical Center

  13. Tissue-specific alternative splicing and expression of ATP1B2 gene ...

    African Journals Online (AJOL)

    After heat-stress, the expression levels of the different transcripts were lower in different tissues; however, the expression of the ATP1B2-complete transcript increased in heart and lung tissues. The results of this research provide some useful information for further studies into the function of the bovine ATP1B2 gene.

  14. Epigenetic Machinery Regulates Alternative Splicing of Androgen Receptor (AR) Gene in Castration Resistant Prostate Cancer

    Science.gov (United States)

    2017-09-01

    resistant prostate cancer PRINCIPAL INVESTIGATOR: Zhi-Ping Liu CONTRACTING ORGANIZATION: UT Southwestern Medical Center Dallas, TX 75390 REPORT DATE...NUMBER gene in castration-resistant prostate cancer 5b. GRANT NUMBER W81XWH-16-1-0531 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Zhi-Ping Liu 5d...NOTES 14. ABSTRACT Androgen deprivation therapy (ADT) is the primary treatment for metastatic prostate cancer (PCa) since PCa depends on androgen for

  15. Dissecting an alternative splicing analysis workflow for GeneChip® Exon 1.0 ST Affymetrix arrays

    Directory of Open Access Journals (Sweden)

    Calogero Raffaele A

    2008-11-01

    Full Text Available Abstract Background A new microarray platform (GeneChip® Exon 1.0 ST has recently been developed by Affymetrix http://www.affymetrix.com. This microarray platform changes the conventional view of transcript analysis since it allows the evaluation of the expression level of a transcript by querying each exon component. The Exon 1.0 ST platform does however raise some issues regarding the approaches to be used in identifying genome-wide alternative splicing events (ASEs. In this study an exon-level data analysis workflow is dissected in order to detect limit and strength of each step, thus modifying the overall workflow and thereby optimizing the detection of ASEs. Results This study was carried out using a semi-synthetic exon-skipping benchmark experiment embedding a total of 268 exon skipping events. Our results point out that summarization methods (RMA, PLIER do not affect the efficacy of statistical tools in detecting ASEs. However, data pre-filtering is mandatory if the detected number of false ASEs are to be reduced. MiDAS and Rank Product methods efficiently detect true ASEs but they suffer from the lack of multiple test error correction. The intersection of MiDAS and Rank Product results efficiently moderates the detection of false ASEs. Conclusion To optimize the detection of ASEs we propose the following workflow: i data pre-filtering, ii statistical selection of ASEs using both MiDAS and Rank Product, iii intersection of results derived from the two statistical analyses in order to moderate family-wise errors (FWER.

  16. Revealing the Determinants of Widespread Alternative Splicing Perturbation in Cancer

    Directory of Open Access Journals (Sweden)

    Yongsheng Li

    2017-10-01

    Full Text Available It is increasingly appreciated that alternative splicing plays a key role in generating functional specificity and diversity in cancer. However, the mechanisms by which cancer mutations perturb splicing remain unknown. Here, we developed a network-based strategy, DrAS-Net, to investigate more than 2.5 million variants across cancer types and link somatic mutations with cancer-specific splicing events. We identified more than 40,000 driver variant candidates and their 80,000 putative splicing targets deregulated in 33 cancer types and inferred their functional impact. Strikingly, tumors with splicing perturbations show reduced expression of immune system-related genes and increased expression of cell proliferation markers. Tumors harboring different mutations in the same gene often exhibit distinct splicing perturbations. Further stratification of 10,000 patients based on their mutation-splicing relationships identifies subtypes with distinct clinical features, including survival rates. Our work reveals how single-nucleotide changes can alter the repertoires of splicing isoforms, providing insights into oncogenic mechanisms for precision medicine.

  17. The fitness cost of mis-splicing is the main determinant of alternative splicing patterns.

    Science.gov (United States)

    Saudemont, Baptiste; Popa, Alexandra; Parmley, Joanna L; Rocher, Vincent; Blugeon, Corinne; Necsulea, Anamaria; Meyer, Eric; Duret, Laurent

    2017-10-30

    Most eukaryotic genes are subject to alternative splicing (AS), which may contribute to the production of protein variants or to the regulation of gene expression via nonsense-mediated messenger RNA (mRNA) decay (NMD). However, a fraction of splice variants might correspond to spurious transcripts and the question of the relative proportion of splicing errors to functional splice variants remains highly debated. We propose a test to quantify the fraction of AS events corresponding to errors. This test is based on the fact that the fitness cost of splicing errors increases with the number of introns in a gene and with expression level. We analyzed the transcriptome of the intron-rich eukaryote Paramecium tetraurelia. We show that in both normal and in NMD-deficient cells, AS rates strongly decrease with increasing expression level and with increasing number of introns. This relationship is observed for AS events that are detectable by NMD as well as for those that are not, which invalidates the hypothesis of a link with the regulation of gene expression. Our results show that in genes with a median expression level, 92-98% of observed splice variants correspond to errors. We observed the same patterns in human transcriptomes and we further show that AS rates correlate with the fitness cost of splicing errors. These observations indicate that genes under weaker selective pressure accumulate more maladaptive substitutions and are more prone to splicing errors. Thus, to a large extent, patterns of gene expression variants simply reflect the balance between selection, mutation, and drift.

  18. Diversification of the muscle proteome through alternative splicing.

    Science.gov (United States)

    Nakka, Kiran; Ghigna, Claudia; Gabellini, Davide; Dilworth, F Jeffrey

    2018-03-06

    Skeletal muscles express a highly specialized proteome that allows the metabolism of energy sources to mediate myofiber contraction. This muscle-specific proteome is partially derived through the muscle-specific transcription of a subset of genes. Surprisingly, RNA sequencing technologies have also revealed a significant role for muscle-specific alternative splicing in generating protein isoforms that give specialized function to the muscle proteome. In this review, we discuss the current knowledge with respect to the mechanisms that allow pre-mRNA transcripts to undergo muscle-specific alternative splicing while identifying some of the key trans-acting splicing factors essential to the process. The importance of specific splicing events to specialized muscle function is presented along with examples in which dysregulated splicing contributes to myopathies. Though there is now an appreciation that alternative splicing is a major contributor to proteome diversification, the emergence of improved "targeted" proteomic methodologies for detection of specific protein isoforms will soon allow us to better appreciate the extent to which alternative splicing modifies the activity of proteins (and their ability to interact with other proteins) in the skeletal muscle. In addition, we highlight a continued need to better explore the signaling pathways that contribute to the temporal control of trans-acting splicing factor activity to ensure specific protein isoforms are expressed in the proper cellular context. An understanding of the signal-dependent and signal-independent events driving muscle-specific alternative splicing has the potential to provide us with novel therapeutic strategies to treat different myopathies.

  19. fruitless alternative splicing and sex behaviour in insects

    Indian Academy of Sciences (India)

    In Drosophila melanogaster, male courtship requires proteins encoded by the fruitless (fru) gene that are produced in different sex-specific isoforms via alternative splicing. Drosophila mutant flies with loss-of-function alleles of the fru gene exhibit blocked male courtship behaviour. However, various individual steps in the ...

  20. The determinants of alternative RNA splicing in human cells.

    Science.gov (United States)

    Ramanouskaya, Tatsiana V; Grinev, Vasily V

    2017-12-01

    Alternative splicing represents an important level of the regulation of gene function in eukaryotic organisms. It plays a critical role in virtually every biological process within an organism, including regulation of cell division and cell death, differentiation of tissues in the embryo and the adult organism, as well as in cellular response to diverse environmental factors. In turn, studies of the last decade have shown that alternative splicing itself is controlled by different mechanisms. Unfortunately, there is no clear understanding of how these diverse mechanisms, or determinants, regulate and constrain the set of alternative RNA species produced from any particular gene in every cell of the human body. Here, we provide a consolidated overview of alternative splicing determinants including RNA-protein interactions, epigenetic regulation via chromatin remodeling, coupling of transcription-to-alternative splicing, effect of secondary structures in pre-RNA, and function of the RNA quality control systems. We also extensively and critically discuss some mechanistic insights on coordinated inclusion/exclusion of exons during the formation of mature RNA molecules. We conclude that the final structure of RNA is pre-determined by a complex interplay between cis- and trans-acting factors. Altogether, currently available empirical data significantly expand our understanding of the functioning of the alternative splicing machinery of cells in normal and pathological conditions. On the other hand, there are still many blind spots that require further deep investigations.

  1. Systematic profiling of alternative splicing signature reveals prognostic predictor for ovarian cancer.

    Science.gov (United States)

    Zhu, Junyong; Chen, Zuhua; Yong, Lei

    2018-02-01

    The majority of genes are alternatively spliced and growing evidence suggests that alternative splicing is modified in cancer and is associated with cancer progression. Systematic analysis of alternative splicing signature in ovarian cancer is lacking and greatly needed. We profiled genome-wide alternative splicing events in 408 ovarian serous cystadenocarcinoma (OV) patients in TCGA. Seven types of alternative splicing events were curated and prognostic analyses were performed with predictive models and splicing network built for OV patients. Among 48,049 mRNA splicing events in 10,582 genes, we detected 2,611 alternative splicing events in 2,036 genes which were significant associated with overall survival of OV patients. Exon skip events were the most powerful prognostic factors among the seven types. The area under the curve of the receiver-operator characteristic curve for prognostic predictor, which was built with top significant alternative splicing events, was 0.937 at 2,000 days of overall survival, indicating powerful efficiency in distinguishing patient outcome. Interestingly, splicing correlation network suggested obvious trends in the role of splicing factors in OV. In summary, we built powerful prognostic predictors for OV patients and uncovered interesting splicing networks which could be underlying mechanisms. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Variation in alternative splicing across human tissues

    OpenAIRE

    Yeo, Gene; Holste, Dirk; Kreiman, Gabriel; Burge, Christopher B

    2004-01-01

    Background: Alternative pre-mRNA splicing (AS) is widely used by higher eukaryotes to generate different protein isoforms in specific cell or tissue types. To compare AS events across human tissues, we analyzed the splicing patterns of genomically aligned expressed sequence tags (ESTs) derived from libraries of cDNAs from different tissues. Results: Controlling for differences in EST coverage among tissues, we found that the brain and testis had the highest levels of exon skipping. The most p...

  3. Aberrant and alternative splicing in skeletal system disease.

    Science.gov (United States)

    Fan, Xin; Tang, Liling

    2013-10-01

    The main function of skeletal system is to support the body and help movement. A variety of factors can lead to skeletal system disease, including age, exercise, and of course genetic makeup and expression. Pre-mRNA splicing plays a crucial role in gene expression, by creating multiple protein variants with different biological functions. The recent studies show that several skeletal system diseases are related to pre-mRNA splicing. This review focuses on the relationship between pre-mRNA splicing and skeletal system disease. On the one hand, splice site mutation that leads to aberrant splicing often causes genetic skeletal system disease, like COL1A1, SEDL and LRP5. On the other hand, alternative splicing without genomic mutation may generate some marker protein isoforms, for example, FN, VEGF and CD44. Therefore, understanding the relationship between pre-mRNA splicing and skeletal system disease will aid in uncovering the mechanism of disease and contribute to the future development of gene therapy. © 2013 Elsevier B.V. All rights reserved.

  4. Investigation of tissue-specific human orthologous alternative splice events in pig

    DEFF Research Database (Denmark)

    Hillig, Ann-Britt Nygaard; Jørgensen, Claus Bøttcher; Salicio, Susanna Cirera

    2010-01-01

    Alternative splicing of pre-mRNA can contribute to differences between tissues or cells either by regulating gene expression or creating proteins with various functions encoded by one gene. The number of investigated alternative splice events in pig has so far been limited. In this study we have ...... in preservation of open reading frame are indicative of a functional significance of the splice variants of the gene....

  5. Interplay between estrogen receptor and AKT in estradiol-induced alternative splicing.

    Science.gov (United States)

    Bhat-Nakshatri, Poornima; Song, Eun-Kyung; Collins, Nikail R; Uversky, Vladimir N; Dunker, A Keith; O'Malley, Bert W; Geistlinger, Tim R; Carroll, Jason S; Brown, Myles; Nakshatri, Harikrishna

    2013-06-11

    Alternative splicing is critical for generating complex proteomes in response to extracellular signals. Nuclear receptors including estrogen receptor alpha (ERα) and their ligands promote alternative splicing. The endogenous targets of ERα:estradiol (E2)-mediated alternative splicing and the influence of extracellular kinases that phosphorylate ERα on E2-induced splicing are unknown. MCF-7 and its anti-estrogen derivatives were used for the majority of the assays. CD44 mini gene was used to measure the effect of E2 and AKT on alternative splicing. ExonHit array analysis was performed to identify E2 and AKT-regulated endogenous alternatively spliced apoptosis-related genes. Quantitative reverse transcription polymerase chain reaction was performed to verify alternative splicing. ERα binding to alternatively spliced genes was verified by chromatin immunoprecipitation assay. Bromodeoxyuridine incorporation-ELISA and Annexin V labeling assays were done to measure cell proliferation and apoptosis, respectively. We identified the targets of E2-induced alternative splicing and deconstructed some of the mechanisms surrounding E2-induced splicing by combining splice array with ERα cistrome and gene expression array. E2-induced alternatively spliced genes fall into at least two subgroups: coupled to E2-regulated transcription and ERα binding to the gene without an effect on rate of transcription. Further, AKT, which phosphorylates both ERα and splicing factors, influenced ERα:E2 dependent splicing in a gene-specific manner. Genes that are alternatively spliced include FAS/CD95, FGFR2, and AXIN-1. E2 increased the expression of FGFR2 C1 isoform but reduced C3 isoform at mRNA level. E2-induced alternative splicing of FAS and FGFR2 in MCF-7 cells correlated with resistance to FAS activation-induced apoptosis and response to keratinocyte growth factor (KGF), respectively. Resistance of MCF-7 breast cancer cells to the anti-estrogen tamoxifen was associated with ER

  6. Alternative-splicing in the exon-10 region of GABA(A receptor beta(2 subunit gene: relationships between novel isoforms and psychotic disorders.

    Directory of Open Access Journals (Sweden)

    Cunyou Zhao

    Full Text Available BACKGROUND: Non-coding single nucleotide polymorphisms (SNPs in GABRB2, the gene for beta(2-subunit of gamma-aminobutyric acid type A (GABA(A receptor, have been associated with schizophrenia (SCZ and quantitatively correlated to mRNA expression and alternative splicing. METHODS AND FINDINGS: Expression of the Exon 10 region of GABRB2 from minigene constructs revealed this region to be an "alternative splicing hotspot" that readily gave rise to differently spliced isoforms depending on intron sequences. This led to a search in human brain cDNA libraries, and the discovery of two novel isoforms, beta(2S1 and beta(2S2, bearing variations in the neighborhood of Exon-10. Quantitative real-time PCR analysis of postmortem brain samples showed increased beta(2S1 expression and decreased beta(2S2 expression in both SCZ and bipolar disorder (BPD compared to controls. Disease-control differences were significantly correlated with SNP rs187269 in BPD males for both beta(2S1 and beta(2S2 expressions, and significantly correlated with SNPs rs2546620 and rs187269 in SCZ males for beta(2S2 expression. Moreover, site-directed mutagenesis indicated that Thr(365, a potential phosphorylation site in Exon-10, played a key role in determining the time profile of the ATP-dependent electrophysiological current run-down. CONCLUSION: This study therefore provided experimental evidence for the importance of non-coding sequences in the Exon-10 region in GABRB2 with respect to beta(2-subunit splicing diversity and the etiologies of SCZ and BPD.

  7. Core clock, SUB1, and ABAR genes mediate flooding and drought responses via alternative splicing in soybean.

    Science.gov (United States)

    Syed, Naeem H; Prince, Silvas J; Mutava, Raymond N; Patil, Gunvant; Li, Song; Chen, Wei; Babu, Valliyodan; Joshi, Trupti; Khan, Saad; Nguyen, Henry T

    2015-12-01

    Circadian clocks are a great evolutionary innovation and provide competitive advantage during the day/night cycle and under changing environmental conditions. The circadian clock mediates expression of a large proportion of genes in plants, achieving a harmonious relationship between energy metabolism, photosynthesis, and biotic and abiotic stress responses. Here it is shown that multiple paralogues of clock genes are present in soybean (Glycine max) and mediate flooding and drought responses. Differential expression of many clock and SUB1 genes was found under flooding and drought conditions. Furthermore, natural variation in the amplitude and phase shifts in PRR7 and TOC1 genes was also discovered under drought and flooding conditions, respectively. PRR3 exhibited flooding- and drought-specific splicing patterns and may work in concert with PRR7 and TOC1 to achieve energy homeostasis under flooding and drought conditions. Higher expression of TOC1 also coincides with elevated levels of abscisic acid (ABA) and variation in glucose levels in the morning and afternoon, indicating that this response to abiotic stress is mediated by ABA, endogenous sugar levels, and the circadian clock to fine-tune photosynthesis and energy utilization under stress conditions. It is proposed that the presence of multiple clock gene paralogues with variation in DNA sequence, phase, and period could be used to screen exotic germplasm to find sources for drought and flooding tolerance. Furthermore, fine tuning of multiple clock gene paralogues (via a genetic engineering approach) should also facilitate the development of flooding- and drought-tolerant soybean varieties. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  8. Global transcriptome analysis reveals extensive gene remodeling, alternative splicing and differential transcription profiles in non-seed vascular plant Selaginella moellendorffii.

    Science.gov (United States)

    Zhu, Yan; Chen, Longxian; Zhang, Chengjun; Hao, Pei; Jing, Xinyun; Li, Xuan

    2017-01-25

    Selaginella moellendorffii, a lycophyte, is a model plant to study the early evolution and development of vascular plants. As the first and only sequenced lycophyte to date, the genome of S. moellendorffii revealed many conserved genes and pathways, as well as specialized genes different from flowering plants. Despite the progress made, little is known about long noncoding RNAs (lncRNA) and the alternative splicing (AS) of coding genes in S. moellendorffii. Its coding gene models have not been fully validated with transcriptome data. Furthermore, it remains important to understand whether the regulatory mechanisms similar to flowering plants are used, and how they operate in a non-seed primitive vascular plant. RNA-sequencing (RNA-seq) was performed for three S. moellendorffii tissues, root, stem, and leaf, by constructing strand-specific RNA-seq libraries from RNA purified using RiboMinus isolation protocol. A total of 176 million reads (44 Gbp) were obtained from three tissue types, and were mapped to S. moellendorffii genome. By comparing with 22,285 existing gene models of S. moellendorffii, we identified 7930 high-confidence novel coding genes (a 35.6% increase), and for the first time reported 4422 lncRNAs in a lycophyte. Further, we refined 2461 (11.0%) of existing gene models, and identified 11,030 AS events (for 5957 coding genes) revealed for the first time for lycophytes. Tissue-specific gene expression with functional implication was analyzed, and 1031, 554, and 269 coding genes, and 174, 39, and 17 lncRNAs were identified in root, stem, and leaf tissues, respectively. The expression of critical genes for vascular development stages, i.e. formation of provascular cells, xylem specification and differentiation, and phloem specification and differentiation, was compared in S. moellendorffii tissues, indicating a less complex regulatory mechanism in lycophytes than in flowering plants. The results were further strengthened by the evolutionary trend of

  9. Quantifying alternative splicing from paired-end RNA-sequencing data

    OpenAIRE

    Rossell, David; Stephan-Otto Attolini, Camille; Kroiss, Manuel; Stöcker, Almond

    2014-01-01

    RNA-sequencing has revolutionized biomedical research and, in particular, our ability to study gene alternative splicing. The problem has important implications for human health, as alternative splicing may be involved in malfunctions at the cellular level and multiple diseases. However, the high-dimensional nature of the data and the existence of experimental biases pose serious data analysis challenges. We find that the standard data summaries used to study alternative splicing are severely...

  10. Expression pattern of the AHP gene family from Arabidopsis thaliana and organ specific alternative splicing in the AHP5 gene

    Czech Academy of Sciences Publication Activity Database

    Hradilová, Jana; Brzobohatý, Břetislav

    2007-01-01

    Roč. 51, č. 2 (2007), s. 257-267 ISSN 0006-3134 Grant - others:GA MŠk(CZ) LN00A081; GA AV ČR(CZ) IAA600040612 Program:LN; IA Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : Arabidopsis two component systems * gene expression analysis * real time RT-PCR Subject RIV: BO - Biophysics Impact factor: 1.259, year: 2007

  11. Alternative splicing: the pledge, the turn, and the prestige : The key role of alternative splicing in human biological systems.

    Science.gov (United States)

    Gallego-Paez, L M; Bordone, M C; Leote, A C; Saraiva-Agostinho, N; Ascensão-Ferreira, M; Barbosa-Morais, N L

    2017-09-01

    Alternative pre-mRNA splicing is a tightly controlled process conducted by the spliceosome, with the assistance of several regulators, resulting in the expression of different transcript isoforms from the same gene and increasing both transcriptome and proteome complexity. The differences between alternative isoforms may be subtle but enough to change the function or localization of the translated proteins. A fine control of the isoform balance is, therefore, needed throughout developmental stages and adult tissues or physiological conditions and it does not come as a surprise that several diseases are caused by its deregulation. In this review, we aim to bring the splicing machinery on stage and raise the curtain on its mechanisms and regulation throughout several systems and tissues of the human body, from neurodevelopment to the interactions with the human microbiome. We discuss, on one hand, the essential role of alternative splicing in assuring tissue function, diversity, and swiftness of response in these systems or tissues, and on the other hand, what goes wrong when its regulatory mechanisms fail. We also focus on the possibilities that splicing modulation therapies open for the future of personalized medicine, along with the leading techniques in this field. The final act of the spliceosome, however, is yet to be fully revealed, as more knowledge is needed regarding the complex regulatory network that coordinates alternative splicing and how its dysfunction leads to disease.

  12. Body Temperature Cycles Control Rhythmic Alternative Splicing in Mammals.

    Science.gov (United States)

    Preußner, Marco; Goldammer, Gesine; Neumann, Alexander; Haltenhof, Tom; Rautenstrauch, Pia; Müller-McNicoll, Michaela; Heyd, Florian

    2017-08-03

    The core body temperature of all mammals oscillates with the time of the day. However, direct molecular consequences of small, physiological changes in body temperature remain largely elusive. Here we show that body temperature cycles drive rhythmic SR protein phosphorylation to control an alternative splicing (AS) program. A temperature change of 1°C is sufficient to induce a concerted splicing switch in a large group of functionally related genes, rendering this splicing-based thermometer much more sensitive than previously described temperature-sensing mechanisms. AS of two exons in the 5' UTR of the TATA-box binding protein (Tbp) highlights the general impact of this mechanism, as it results in rhythmic TBP protein levels with implications for global gene expression in vivo. Together our data establish body temperature-driven AS as a core clock-independent oscillator in mammalian peripheral clocks. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. A Comprehensive Analysis of Alternative Splicing in Paleopolyploid Maize

    Directory of Open Access Journals (Sweden)

    Wenbin Mei

    2017-05-01

    Full Text Available Identifying and characterizing alternative splicing (AS enables our understanding of the biological role of transcript isoform diversity. This study describes the use of publicly available RNA-Seq data to identify and characterize the global diversity of AS isoforms in maize using the inbred lines B73 and Mo17, and a related species, sorghum. Identification and characterization of AS within maize tissues revealed that genes expressed in seed exhibit the largest differential AS relative to other tissues examined. Additionally, differences in AS between the two genotypes B73 and Mo17 are greatest within genes expressed in seed. We demonstrate that changes in the level of alternatively spliced transcripts (intron retention and exon skipping do not solely reflect differences in total transcript abundance, and we present evidence that intron retention may act to fine-tune gene expression across seed development stages. Furthermore, we have identified temperature sensitive AS in maize and demonstrate that drought-induced changes in AS involve distinct sets of genes in reproductive and vegetative tissues. Examining our identified AS isoforms within B73 × Mo17 recombinant inbred lines (RILs identified splicing QTL (sQTL. The 43.3% of cis-sQTL regulated junctions are actually identified as alternatively spliced junctions in our analysis, while 10 Mb windows on each side of 48.2% of trans-sQTLs overlap with splicing related genes. Using sorghum as an out-group enabled direct examination of loss or conservation of AS between homeologous genes representing the two subgenomes of maize. We identify several instances where AS isoforms that are conserved between one maize homeolog and its sorghum ortholog are absent from the second maize homeolog, suggesting that these AS isoforms may have been lost after the maize whole genome duplication event. This comprehensive analysis provides new insights into the complexity of AS in maize.

  14. Muscle-specific splicing factors ASD-2 and SUP-12 cooperatively switch alternative pre-mRNA processing patterns of the ADF/cofilin gene in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Genta Ohno

    Full Text Available Pre-mRNAs are often processed in complex patterns in tissue-specific manners to produce a variety of protein isoforms from single genes. However, mechanisms orchestrating the processing of the entire transcript are not well understood. Muscle-specific alternative pre-mRNA processing of the unc-60 gene in Caenorhabditis elegans, encoding two tissue-specific isoforms of ADF/cofilin with distinct biochemical properties in regulating actin organization, provides an excellent in vivo model of complex and tissue-specific pre-mRNA processing; it consists of a single first exon and two separate series of downstream exons. Here we visualize the complex muscle-specific processing pattern of the unc-60 pre-mRNA with asymmetric fluorescence reporter minigenes. By disrupting juxtaposed CUAAC repeats and UGUGUG stretch in intron 1A, we demonstrate that these elements are required for retaining intron 1A, as well as for switching the processing patterns of the entire pre-mRNA from non-muscle-type to muscle-type. Mutations in genes encoding muscle-specific RNA-binding proteins ASD-2 and SUP-12 turned the colour of the unc-60 reporter worms. ASD-2 and SUP-12 proteins specifically and cooperatively bind to CUAAC repeats and UGUGUG stretch in intron 1A, respectively, to form a ternary complex in vitro. Immunohistochemical staining and RT-PCR analyses demonstrate that ASD-2 and SUP-12 are also required for switching the processing patterns of the endogenous unc-60 pre-mRNA from UNC-60A to UNC-60B in muscles. Furthermore, systematic analyses of partially spliced RNAs reveal the actual orders of intron removal for distinct mRNA isoforms. Taken together, our results demonstrate that muscle-specific splicing factors ASD-2 and SUP-12 cooperatively promote muscle-specific processing of the unc-60 gene, and provide insight into the mechanisms of complex pre-mRNA processing; combinatorial regulation of a single splice site by two tissue-specific splicing regulators

  15. Pre-mRNA mis-splicing of sarcomeric genes in heart failure.

    Science.gov (United States)

    Zhu, Chaoqun; Chen, Zhilong; Guo, Wei

    2017-08-01

    Pre-mRNA splicing is an important biological process that allows production of multiple proteins from a single gene in the genome, and mainly contributes to protein diversity in eukaryotic organisms. Alternative splicing is commonly governed by RNA binding proteins to meet the ever-changing demands of the cell. However, the mis-splicing may lead to human diseases. In the heart of human, mis-regulation of alternative splicing has been associated with heart failure. In this short review, we focus on alternative splicing of sarcomeric genes and review mis-splicing related heart failure with relatively well studied Sarcomeric genes and splicing mechanisms with identified regulatory factors. The perspective of alternative splicing based therapeutic strategies in heart failure has also been discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. A novel CDX2 isoform regulates alternative splicing.

    Directory of Open Access Journals (Sweden)

    Matthew E Witek

    Full Text Available Gene expression is a dynamic and coordinated process coupling transcription with pre-mRNA processing. This regulation enables tissue-specific transcription factors to induce expression of specific transcripts that are subsequently amplified by alternative splicing allowing for increased proteome complexity and functional diversity. The intestine-specific transcription factor CDX2 regulates development and maintenance of the intestinal epithelium by inducing expression of genes characteristic of the mature enterocyte phenotype. Here, sequence analysis of CDX2 mRNA from colonic mucosa-derived tissues revealed an alternatively spliced transcript (CDX2/AS that encodes a protein with a truncated homeodomain and a novel carboxy-terminal domain enriched in serine and arginine residues (RS domain. CDX2 and CDX2/AS exhibited distinct nuclear expression patterns with minimal areas of co-localization. CDX2/AS did not activate the CDX2-dependent promoter of guanylyl cyclase C nor inhibit transcriptional activity of CDX2. Unlike CDX2, CDX2/AS co-localized with the putative splicing factors ASF/SF2 and SC35. CDX2/AS altered splicing patterns of CD44v5 and Tra2-β1 minigenes in Lovo colon cancer cells independent of CDX2 expression. These data demonstrate unique dual functions of the CDX2 gene enabling it to regulate gene expression through both transcription (CDX2 and pre-mRNA processing (CDX2/AS.

  17. Histone and RNA-binding protein interaction creates crosstalk network for regulation of alternative splicing.

    Science.gov (United States)

    Kim, Yong-Eun; Park, Chungoo; Kim, Kyoon Eon; Kim, Kee K

    2018-04-30

    Alternative splicing is an essential process in eukaryotes, as it increases the complexity of gene expression by generating multiple proteins from a single pre-mRNA. However, information on the regulatory mechanisms for alternative splicing is lacking, because splicing occurs over a short period via the transient interactions of proteins within functional complexes of the spliceosome. Here, we investigated in detail the molecular mechanisms connecting alternative splicing with epigenetic mechanisms. We identified interactions between histone proteins and splicing factors such as Rbfox2, Rbfox3, and splicing factor proline and glutamine rich protein (SFPQ) by in vivo crosslinking and immunoprecipitation. Furthermore, we confirmed that splicing factors were bound to specific modified residues of histone proteins. Additionally, changes in histone methylation due to histone methyltransferase inhibitor treatment notably affected alternative splicing in selected genes. Therefore, we suggested that there may be crosstalk mechanisms connecting histone modifications and RNA-binding proteins that increase the local concentration of RNA-binding proteins in alternative exon loci of nucleosomes by binding specific modified histone proteins, leading to alternative splicing. This crosstalk mechanism may play a major role in epigenetic processes such as histone modification and the regulation of alternative splicing. Copyright © 2018 Elsevier Inc. All rights reserved.

  18. Oligophrenin-1 (OPHN1, a gene involved in X-linked intellectual disability, undergoes RNA editing and alternative splicing during human brain development.

    Directory of Open Access Journals (Sweden)

    Sabina Barresi

    Full Text Available Oligophrenin-1 (OPHN1 encodes for a Rho-GTPase-activating protein, important for dendritic morphogenesis and synaptic function. Mutations in this gene have been identified in patients with X-linked intellectual disability associated with cerebellar hypoplasia. ADAR enzymes are responsible for A-to-I RNA editing, an essential post-transcriptional RNA modification contributing to transcriptome and proteome diversification. Specifically, ADAR2 activity is essential for brain development and function. Herein, we show that the OPHN1 transcript undergoes post-transcriptional modifications such as A-to-I RNA editing and alternative splicing in human brain and other tissues. We found that OPHN1 editing is detectable already at the 18th week of gestation in human brain with a boost of editing at weeks 20 to 33, concomitantly with OPHN1 expression increase and the appearance of a novel OPHN1 splicing isoform. Our results demonstrate that multiple post-transcriptional events occur on OPHN1, a gene playing an important role in brain function and development.

  19. Epilepsy caused by an abnormal alternative splicing with dosage effect of the SV2A gene in a chicken model.

    Directory of Open Access Journals (Sweden)

    Marine Douaud

    Full Text Available Photosensitive reflex epilepsy is caused by the combination of an individual's enhanced sensitivity with relevant light stimuli, such as stroboscopic lights or video games. This is the most common reflex epilepsy in humans; it is characterized by the photoparoxysmal response, which is an abnormal electroencephalographic reaction, and seizures triggered by intermittent light stimulation. Here, by using genetic mapping, sequencing and functional analyses, we report that a mutation in the acceptor site of the second intron of SV2A (the gene encoding synaptic vesicle glycoprotein 2A is causing photosensitive reflex epilepsy in a unique vertebrate model, the Fepi chicken strain, a spontaneous model where the neurological disorder is inherited as an autosomal recessive mutation. This mutation causes an aberrant splicing event and significantly reduces the level of SV2A mRNA in homozygous carriers. Levetiracetam, a second generation antiepileptic drug, is known to bind SV2A, and SV2A knock-out mice develop seizures soon after birth and usually die within three weeks. The Fepi chicken survives to adulthood and responds to levetiracetam, suggesting that the low-level expression of SV2A in these animals is sufficient to allow survival, but does not protect against seizures. Thus, the Fepi chicken model shows that the role of the SV2A pathway in the brain is conserved between birds and mammals, in spite of a large phylogenetic distance. The Fepi model appears particularly useful for further studies of physiopathology of reflex epilepsy, in comparison with induced models of epilepsy in rodents. Consequently, SV2A is a very attractive candidate gene for analysis in the context of both mono- and polygenic generalized epilepsies in humans.

  20. Genome-wide analysis of SRSF10-regulated alternative splicing by deep sequencing of chicken transcriptome

    Directory of Open Access Journals (Sweden)

    Xuexia Zhou

    2014-12-01

    Full Text Available Splicing factor SRSF10 is known to function as a sequence-specific splicing activator that is capable of regulating alternative splicing both in vitro and in vivo. We recently used an RNA-seq approach coupled with bioinformatics analysis to identify the extensive splicing network regulated by SRSF10 in chicken cells. We found that SRSF10 promoted both exon inclusion and exclusion. Functionally, many of the SRSF10-verified alternative exons are linked to pathways of response to external stimulus. Here we describe in detail the experimental design, bioinformatics analysis and GO/pathway enrichment analysis of SRSF10-regulated genes to correspond with our data in the Gene Expression Omnibus with accession number GSE53354. Our data thus provide a resource for studying regulation of alternative splicing in vivo that underlines biological functions of splicing regulatory proteins in cells.

  1. Fine mapping of the latency-related gene of herpes simplex virus type 1: alternative splicing produces distinct latency-related RNAs containing open reading frames

    International Nuclear Information System (INIS)

    Wechsler, S.L.; Nesburn, A.B.; Watson, R.; Slanina, S.M.; Ghiasi, H.

    1988-01-01

    The latency-related (LR) gene of herpes simplex virus type 1 (HSV-1) is transcriptionally active during HSV-1 latency, producing at least two LR-RNAs. The LR gene partially overlaps the immediate-early gene ICP0 and is transcribed in the opposite direction from ICP0, producing LR-RNAs that are complementary (antisense) to ICP0 mRNA. The LR gene is thought to be involved in HSV-1 latency. The authors report here the time mapping and partial sequence analysis of this HSV-1 LR gene. 32 P-labeled genomic DNA restriction fragments and synthetic oligonucleotides were used as probes for in situ hybridizations and Northern (RNA) blot hybridizations of RNA from trigeminal ganglia of rabbits latently infected with HSV-1. The two most abundant LR-RNAs appeared to share their 5' and 3' ends and to be produced by alternative splicing. These LR-RNAs were approximately 2 and 1.3 to 1.5 kilobases in length and were designated LR-RNA 1 and LF-RNA 2, respectively. LR-RNA 1 appeared to have at least one intron removed, while LR-RNA 2 appeared to have at least two introns removed. The LR-RNAs contained two potential long open reading frames, suggesting the possibility that one or more of the LR-RNAs may be a functional mRNA

  2. Alternative Splicing and Tissue-specific Elastin Misassembly Act as Biological Modifiers of Human Elastin Gene Frameshift Mutations Associated with Dominant Cutis Laxa*

    Science.gov (United States)

    Sugitani, Hideki; Hirano, Eiichi; Knutsen, Russell H.; Shifren, Adrian; Wagenseil, Jessica E.; Ciliberto, Christopher; Kozel, Beth A.; Urban, Zsolt; Davis, Elaine C.; Broekelmann, Thomas J.; Mecham, Robert P.

    2012-01-01

    Elastin is the extracellular matrix protein in vertebrates that provides elastic recoil to blood vessels, the lung, and skin. Because the elastin gene has undergone significant changes in the primate lineage, modeling elastin diseases in non-human animals can be problematic. To investigate the pathophysiology underlying a class of elastin gene mutations leading to autosomal dominant cutis laxa, we engineered a cutis laxa mutation (single base deletion) into the human elastin gene contained in a bacterial artificial chromosome. When expressed as a transgene in mice, mutant elastin was incorporated into elastic fibers in the skin and lung with adverse effects on tissue function. In contrast, only low levels of mutant protein incorporated into aortic elastin, which explains why the vasculature is relatively unaffected in this disease. RNA stability studies found that alternative exon splicing acts as a modifier of disease severity by influencing the spectrum of mutant transcripts that survive nonsense-mediated decay. Our results confirm the critical role of the C-terminal region of tropoelastin in elastic fiber assembly and suggest tissue-specific differences in the elastin assembly pathway. PMID:22573328

  3. PathwaySplice: An R package for unbiased pathway analysis of alternative splicing in RNA-Seq data.

    Science.gov (United States)

    Yan, Aimin; Ban, Yuguang; Gao, Zhen; Chen, Xi; Wang, Lily

    2018-04-24

    Pathway analysis of alternative splicing would be biased without accounting for the different number of exons or junctions associated with each gene, because genes with higher number of exons or junctions are more likely to be included in the "significant" gene list in alternative splicing. We present PathwaySplice, an R package that (1) Performs pathway analysis that explicitly adjusts for the number of exons or junctions associated with each gene; (2) Visualizes selection bias due to different number of exons or junctions for each gene and formally tests for presence of bias using logistic regression; (3) Supports gene sets based on the Gene Ontology terms, as well as more broadly defined gene sets (e.g. MSigDB) or user defined gene sets; (4) Identifies the significant genes driving pathway significance and (5) Organizes significant pathways with an enrichment map, where pathways with large number of overlapping genes are grouped together in a network graph. https://bioconductor.org/packages/release/bioc/html/PathwaySplice.html. lily.wangg@gmail.com, xi.steven.chen@gmail.com.

  4. SpliceSeq: a resource for analysis and visualization of RNA-Seq data on alternative splicing and its functional impacts.

    Science.gov (United States)

    Ryan, Michael C; Cleland, James; Kim, RyangGuk; Wong, Wing Chung; Weinstein, John N

    2012-09-15

    SpliceSeq is a resource for RNA-Seq data that provides a clear view of alternative splicing and identifies potential functional changes that result from splice variation. It displays intuitive visualizations and prioritized lists of results that highlight splicing events and their biological consequences. SpliceSeq unambiguously aligns reads to gene splice graphs, facilitating accurate analysis of large, complex transcript variants that cannot be adequately represented in other formats. SpliceSeq is freely available at http://bioinformatics.mdanderson.org/main/SpliceSeq:Overview. The application is a Java program that can be launched via a browser or installed locally. Local installation requires MySQL and Bowtie. mryan@insilico.us.com Supplementary data are available at Bioinformatics online.

  5. Detection and quantification of alternative splice sites in Arabidopsis genes AtDCL2 and AtPTB2 with highly sensitive surface enhanced Raman spectroscopy (SERS) and gold nanoprobes.

    Science.gov (United States)

    Kadam, Ulhas S; Schulz, Burkhard; Irudayaraj, Joseph

    2014-05-02

    Alternative splicing (AS) increases the size of the transcriptome and proteome to enhance the physiological capacity of cells. We demonstrate surface enhanced Raman spectroscopy (SERS) in combination with a DNA hybridization analytical platform to identify and quantify AS genes in plants. AS in AtDCL2 and AtPTB2 were investigated using non-fluorescent Raman probes using a 'sandwich assay'. Utilizing Raman probes conjugated to gold nanoparticles we demonstrate the recognition of RNA sequences specific to AtDCL2 and AtPTB2 splice junction variants with detection sensitivity of up to 0.1 fM. Published by Elsevier B.V.

  6. Functions for fission yeast splicing factors SpSlu7 and SpPrp18 in alternative splice-site choice and stress-specific regulated splicing.

    Directory of Open Access Journals (Sweden)

    Geetha Melangath

    Full Text Available Budding yeast spliceosomal factors ScSlu7 and ScPrp18 interact and mediate intron 3'ss choice during second step pre-mRNA splicing. The fission yeast genome with abundant multi-intronic transcripts, degenerate splice signals and SR proteins is an apt unicellular fungal model to deduce roles for core spliceosomal factors in alternative splice-site choice, intron retention and to study the cellular implications of regulated splicing. From our custom microarray data we deduce a stringent reproducible subset of S. pombe alternative events. We examined the role of factors SpSlu7 or SpPrp18 for these splice events and investigated the relationship to growth phase and stress. Wild-type log and stationary phase cells showed ats1+ exon 3 skipped and intron 3 retained transcripts. Interestingly the non-consensus 5'ss in ats1+ intron 3 caused SpSlu7 and SpPrp18 dependent intron retention. We validated the use of an alternative 5'ss in dtd1+ intron 1 and of an upstream alternative 3'ss in DUF3074 intron 1. The dtd1+ intron 1 non-canonical 5'ss yielded an alternative mRNA whose levels increased in stationary phase. Utilization of dtd1+ intron 1 sub-optimal 5' ss required functional SpPrp18 and SpSlu7 while compromise in SpSlu7 function alone hampered the selection of the DUF3074 intron 1 non canonical 3'ss. We analysed the relative abundance of these splice isoforms during mild thermal, oxidative and heavy metal stress and found stress-specific splice patterns for ats1+ and DUF3074 intron 1 some of which were SpSlu7 and SpPrp18 dependent. By studying ats1+ splice isoforms during compromised transcription elongation rates in wild-type, spslu7-2 and spprp18-5 mutant cells we found dynamic and intron context-specific effects in splice-site choice. Our work thus shows the combinatorial effects of splice site strength, core splicing factor functions and transcription elongation kinetics to dictate alternative splice patterns which in turn serve as an additional

  7. Comprehensive analysis of alternative splicing and functionality in neuronal differentiation of P19 cells.

    Directory of Open Access Journals (Sweden)

    Hitoshi Suzuki

    Full Text Available BACKGROUND: Alternative splicing, which produces multiple mRNAs from a single gene, occurs in most human genes and contributes to protein diversity. Many alternative isoforms are expressed in a spatio-temporal manner, and function in diverse processes, including in the neural system. METHODOLOGY/PRINCIPAL FINDINGS: The purpose of the present study was to comprehensively investigate neural-splicing using P19 cells. GeneChip Exon Array analysis was performed using total RNAs purified from cells during neuronal cell differentiation. To efficiently and readily extract the alternative exon candidates, 9 filtering conditions were prepared, yielding 262 candidate exons (236 genes. Semiquantitative RT-PCR results in 30 randomly selected candidates suggested that 87% of the candidates were differentially alternatively spliced in neuronal cells compared to undifferentiated cells. Gene ontology and pathway analyses suggested that many of the candidate genes were associated with neural events. Together with 66 genes whose functions in neural cells or organs were reported previously, 47 candidate genes were found to be linked to 189 events in the gene-level profile of neural differentiation. By text-mining for the alternative isoform, distinct functions of the isoforms of 9 candidate genes indicated by the result of Exon Array were confirmed. CONCLUSIONS/SIGNIFICANCE: Alternative exons were successfully extracted. Results from the informatics analyses suggested that neural events were primarily governed by genes whose expression was increased and whose transcripts were differentially alternatively spliced in the neuronal cells. In addition to known functions in neural cells or organs, the uninvestigated alternative splicing events of 11 genes among 47 candidate genes suggested that cell cycle events are also potentially important. These genes may help researchers to differentiate the roles of alternative splicing in cell differentiation and cell

  8. Tools to covisualize and coanalyze proteomic data with genomes and transcriptomes: validation of genes and alternative mRNA splicing

    DEFF Research Database (Denmark)

    Pang, Chi; Tay, Aidan; Aya, Carlos

    2014-01-01

    contigs, along with RNA-seq reads. This is done in the Integrated Genome Viewer (IGV). A Results Analyzer reports the precise base position where LC-MS/MS-derived peptides cover genes or gene isoforms, on the chromosomes or contigs where this occurs. In prokaryotes, the PG Nexus pipeline facilitates...... the validation of genes, where annotation or gene prediction is available, or the discovery of genes using a "virtual protein"-based unbiased approach. We illustrate this with a comprehensive proteogenomics analysis of two strains of Campylobacter concisus . For higher eukaryotes, the PG Nexus facilitates gene...

  9. Alternative splicing of exon 17 and a missense mutation in exon 20 of the insulin receptor gene in two brothers with a novel syndrome of insulin resistance (congenital fiber-type disproportion myopathy)

    DEFF Research Database (Denmark)

    Vorwerk, P; Christoffersen, C T; Müller, J

    1999-01-01

    to be compound heterozygotes for mutations in the IR gene. The maternal allele was alternatively spliced in exon 17 due to a point mutation in the -1 donor splice site of the exon. The abnormal skipping of exon 17 shifts the amino acid reading frame and leads to a truncated IR, missing the entire tyrosine kinase......The insulin receptor (IR) in two brothers with a rare syndrome of congenital muscle fiber type disproportion myopathy (CFTDM) associated with diabetes and severe insulin resistance was studied. By direct sequencing of Epstein-Barr virus-transformed lymphocytes both patients were found...... domain. In the correct spliced variant, the point mutation is silent and results in a normally translated IR. The paternal allele carries a missense mutation in the tyrosine kinase domain. All three cDNA variants were present in the lymphocytes of the patients. Purified IR from 293 cells overexpressing...

  10. Coding potential of the products of alternative splicing in human.

    KAUST Repository

    Leoni, Guido

    2011-01-20

    BACKGROUND: Analysis of the human genome has revealed that as much as an order of magnitude more of the genomic sequence is transcribed than accounted for by the predicted and characterized genes. A number of these transcripts are alternatively spliced forms of known protein coding genes; however, it is becoming clear that many of them do not necessarily correspond to a functional protein. RESULTS: In this study we analyze alternative splicing isoforms of human gene products that are unambiguously identified by mass spectrometry and compare their properties with those of isoforms of the same genes for which no peptide was found in publicly available mass spectrometry datasets. We analyze them in detail for the presence of uninterrupted functional domains, active sites as well as the plausibility of their predicted structure. We report how well each of these strategies and their combination can correctly identify translated isoforms and derive a lower limit for their specificity, that is, their ability to correctly identify non-translated products. CONCLUSIONS: The most effective strategy for correctly identifying translated products relies on the conservation of active sites, but it can only be applied to a small fraction of isoforms, while a reasonably high coverage, sensitivity and specificity can be achieved by analyzing the presence of non-truncated functional domains. Combining the latter with an assessment of the plausibility of the modeled structure of the isoform increases both coverage and specificity with a moderate cost in terms of sensitivity.

  11. Coding potential of the products of alternative splicing in human.

    KAUST Repository

    Leoni, Guido; Le Pera, Loredana; Ferrè , Fabrizio; Raimondo, Domenico; Tramontano, Anna

    2011-01-01

    BACKGROUND: Analysis of the human genome has revealed that as much as an order of magnitude more of the genomic sequence is transcribed than accounted for by the predicted and characterized genes. A number of these transcripts are alternatively spliced forms of known protein coding genes; however, it is becoming clear that many of them do not necessarily correspond to a functional protein. RESULTS: In this study we analyze alternative splicing isoforms of human gene products that are unambiguously identified by mass spectrometry and compare their properties with those of isoforms of the same genes for which no peptide was found in publicly available mass spectrometry datasets. We analyze them in detail for the presence of uninterrupted functional domains, active sites as well as the plausibility of their predicted structure. We report how well each of these strategies and their combination can correctly identify translated isoforms and derive a lower limit for their specificity, that is, their ability to correctly identify non-translated products. CONCLUSIONS: The most effective strategy for correctly identifying translated products relies on the conservation of active sites, but it can only be applied to a small fraction of isoforms, while a reasonably high coverage, sensitivity and specificity can be achieved by analyzing the presence of non-truncated functional domains. Combining the latter with an assessment of the plausibility of the modeled structure of the isoform increases both coverage and specificity with a moderate cost in terms of sensitivity.

  12. Alternative splicing and expression of the insulin-like growth factor (IGF-1) gene in osteoblasts under mechanical stretch

    Institute of Scientific and Technical Information of China (English)

    XIAN Chengyu; WANG Yuanliang; ZHANG Bingbing; TANG Liling; PAN Jun; LUO Yanfeng; JIANG Peng; LI Dajun

    2006-01-01

    Insulin-like growth factor 1 (IGF-1) promotes osteoblasts differentiation and bone formation,and its expression is induced by mechanical stretch,thus IGF-1 has been considered an effector molecule that links mechanical stimulation and local tissue responses. In this study, a mechanical stretching device was designed to apply physiological level static or cyclic stretching stimulation to osteoblasts.Different isoforms of IGF-1 mRNA were amplified by RT-PCR from the cells using respective primers and these amplified products were sequenced. An isoform of IGF-1 splicing product was found to be selectively produced by osteoblasts under stretching stimulation. This IGF-1 isoform had identical sequence with the mechano growth factor (MGF) which was originally identified in muscle cells. Regulations of the expression of the liver-type IGF (L.IGF-1) and MGF in osteoblasts under stretch stimulation were further studied using semi-quantitative RT-PCR.Stretch stimulation was found to promot the expression of IGF-1 (L.IGF-1 and MGF), and for both isoforms expression was more effectively stimulated by cyclic stretch than static stretch. MGF was detected only in osteoblasts subjected to mechanical stretch,suggesting MGF was a stretch sensitive growth factor.Expression of MGF peaked earlier than that of L.IGF-1, which was similar to their regulation in muscie and suggested similar roles of MGF and L.IGF-1in bone as in muscle cells. The functions of MGF and L.IGF-1 in osteoblasts shall be established by further experimental studies.

  13. Identification of Alternative Splice Variants Using Unique Tryptic Peptide Sequences for Database Searches.

    Science.gov (United States)

    Tran, Trung T; Bollineni, Ravi C; Strozynski, Margarita; Koehler, Christian J; Thiede, Bernd

    2017-07-07

    Alternative splicing is a mechanism in eukaryotes by which different forms of mRNAs are generated from the same gene. Identification of alternative splice variants requires the identification of peptides specific for alternative splice forms. For this purpose, we generated a human database that contains only unique tryptic peptides specific for alternative splice forms from Swiss-Prot entries. Using this database allows an easy access to splice variant-specific peptide sequences that match to MS data. Furthermore, we combined this database without alternative splice variant-1-specific peptides with human Swiss-Prot. This combined database can be used as a general database for searching of LC-MS data. LC-MS data derived from in-solution digests of two different cell lines (LNCaP, HeLa) and phosphoproteomics studies were analyzed using these two databases. Several nonalternative splice variant-1-specific peptides were found in both cell lines, and some of them seemed to be cell-line-specific. Control and apoptotic phosphoproteomes from Jurkat T cells revealed several nonalternative splice variant-1-specific peptides, and some of them showed clear quantitative differences between the two states.

  14. The function and developmental expression of alternatively spliced isoforms of amphioxus and Xenopus laevis Pax2/5/8 genes: revealing divergence at the invertebrate to vertebrate transition

    Czech Academy of Sciences Publication Activity Database

    Short, S.; Kozmik, Zbyněk; Holland, L. Z.

    2012-01-01

    Roč. 318, č. 7 (2012), s. 555-571 ISSN 1552-5007 R&D Projects: GA ČR GAP305/10/2141; GA MŠk LH12047 Grant - others:NSF(US) MCB 06-20019 Institutional research plan: CEZ:AV0Z50520514 Keywords : Pax2/5/8 * alternative splicing * eye development * amphioxus * Xenopus laevis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.123, year: 2012

  15. Naturally occurring BRCA2 alternative mRNA splicing events in clinically relevant samples

    DEFF Research Database (Denmark)

    Fackenthal, James D; Yoshimatsu, Toshio; Zhang, Bifeng

    2016-01-01

    patterns and thereby disrupt gene function. mRNA analyses are therefore among the tests used to interpret the clinical significance of some genetic variants. However, these could be confounded by the appearance of naturally occurring alternative transcripts unrelated to germline sequence variation...... to characterise the spectrum of naturally occurring BRCA2 mRNA alternate-splicing events. METHODS: mRNA was prepared from several blood and breast tissue-derived cells and cell lines by contributing ENIGMA laboratories. cDNA representing BRCA2 alternate splice sites was amplified and visualised using capillary...... or agarose gel electrophoresis, followed by sequencing. RESULTS: We demonstrate the existence of 24 different BRCA2 mRNA alternate-splicing events in lymphoblastoid cell lines and both breast cancer and non-cancerous breast cell lines. CONCLUSIONS: These naturally occurring alternate-splicing events...

  16. Targeting Splicing in Prostate Cancer

    OpenAIRE

    Effrosyni Antonopoulou; Michael Ladomery

    2018-01-01

    Over 95% of human genes are alternatively spliced, expressing splice isoforms that often exhibit antagonistic functions. We describe genes whose alternative splicing has been linked to prostate cancer; namely VEGFA, KLF6, BCL2L2, ERG, and AR. We discuss opportunities to develop novel therapies that target specific splice isoforms, or that target the machinery of splicing. Therapeutic approaches include the development of small molecule inhibitors of splice factor kinases, splice isoform speci...

  17. Connecting the dots: chromatin and alternative splicing in EMT.

    Science.gov (United States)

    Warns, Jessica A; Davie, James R; Dhasarathy, Archana

    2016-02-01

    Nature has devised sophisticated cellular machinery to process mRNA transcripts produced by RNA Polymerase II, removing intronic regions and connecting exons together, to produce mature RNAs. This process, known as splicing, is very closely linked to transcription. Alternative splicing, or the ability to produce different combinations of exons that are spliced together from the same genomic template, is a fundamental means of regulating protein complexity. Similar to transcription, both constitutive and alternative splicing can be regulated by chromatin and its associated factors in response to various signal transduction pathways activated by external stimuli. This regulation can vary between different cell types, and interference with these pathways can lead to changes in splicing, often resulting in aberrant cellular states and disease. The epithelial to mesenchymal transition (EMT), which leads to cancer metastasis, is influenced by alternative splicing events of chromatin remodelers and epigenetic factors such as DNA methylation and non-coding RNAs. In this review, we will discuss the role of epigenetic factors including chromatin, chromatin remodelers, DNA methyltransferases, and microRNAs in the context of alternative splicing, and discuss their potential involvement in alternative splicing during the EMT process.

  18. Genetic variations and alternative splicing. The Glioma associated oncogene 1, GLI1.

    Directory of Open Access Journals (Sweden)

    Peter eZaphiropoulos

    2012-07-01

    Full Text Available Alternative splicing is a post-transcriptional regulatory process that is attaining stronger recognition as a modulator of gene expression. Alternative splicing occurs when the primary RNA transcript is differentially processed into more than one mature RNAs. This is the result of a variable definition/inclusion of the exons, the sequences that are excised from the primary RNA to form the mature RNAs. Consequently, RNA expression can generate a collection of differentially spliced RNAs, which may distinctly influence subsequent biological events, such as protein synthesis or other biomolecular interactions. Still the mechanisms that control exon definition and exon inclusion are not fully clarified. This mini-review highlights advances in this field as well as the impact of single nucleotide polymorphisms in affecting splicing decisions. The Glioma associated oncogene 1, GLI1, is taken as an example in addressing the role of nucleotide substitutions for splicing regulation.

  19. The Role of Alternative Splicing in the Control of Immune Homeostasis and Cellular Differentiation.

    Science.gov (United States)

    Yabas, Mehmet; Elliott, Hannah; Hoyne, Gerard F

    2015-12-22

    Alternative splicing of pre-mRNA helps to enhance the genetic diversity within mammalian cells by increasing the number of protein isoforms that can be generated from one gene product. This provides a great deal of flexibility to the host cell to alter protein function, but when dysregulation in splicing occurs this can have important impact on health and disease. Alternative splicing is widely used in the mammalian immune system to control the development and function of antigen specific lymphocytes. In this review we will examine the splicing of pre-mRNAs yielding key proteins in the immune system that regulate apoptosis, lymphocyte differentiation, activation and homeostasis, and discuss how defects in splicing can contribute to diseases. We will describe how disruption to trans-acting factors, such as heterogeneous nuclear ribonucleoproteins (hnRNPs), can impact on cell survival and differentiation in the immune system.

  20. Genome wide identification of aberrant alternative splicing events in myotonic dystrophy type 2.

    Science.gov (United States)

    Perfetti, Alessandra; Greco, Simona; Fasanaro, Pasquale; Bugiardini, Enrico; Cardani, Rosanna; Garcia-Manteiga, Jose M; Manteiga, Jose M Garcia; Riba, Michela; Cittaro, Davide; Stupka, Elia; Meola, Giovanni; Martelli, Fabio

    2014-01-01

    Myotonic dystrophy type 2 (DM2) is a genetic, autosomal dominant disease due to expansion of tetraplet (CCTG) repetitions in the first intron of the ZNF9/CNBP gene. DM2 is a multisystemic disorder affecting the skeletal muscle, the heart, the eye and the endocrine system. According to the proposed pathological mechanism, the expanded tetraplets have an RNA toxic effect, disrupting the splicing of many mRNAs. Thus, the identification of aberrantly spliced transcripts is instrumental for our understanding of the molecular mechanisms underpinning the disease. The aim of this study was the identification of new aberrant alternative splicing events in DM2 patients. By genome wide analysis of 10 DM2 patients and 10 controls (CTR), we identified 273 alternative spliced exons in 218 genes. While many aberrant splicing events were already identified in the past, most were new. A subset of these events was validated by qPCR assays in 19 DM2 and 15 CTR subjects. To gain insight into the molecular pathways involving the identified aberrantly spliced genes, we performed a bioinformatics analysis with Ingenuity system. This analysis indicated a deregulation of development, cell survival, metabolism, calcium signaling and contractility. In conclusion, our genome wide analysis provided a database of aberrant splicing events in the skeletal muscle of DM2 patients. The affected genes are involved in numerous pathways and networks important for muscle physio-pathology, suggesting that the identified variants may contribute to DM2 pathogenesis.

  1. Genetic disruption of the alternative splicing of drebrin gene impairs context-dependent fear learning in adulthood.

    Science.gov (United States)

    Kojima, N; Hanamura, K; Yamazaki, H; Ikeda, T; Itohara, S; Shirao, T

    2010-01-13

    Dendritic spines are postsynaptic structures at excitatory synapses that play important roles in synaptic transmission and plasticity. Dendritic spine morphology and function are regulated by an actin-based cytoskeletal network. Drebrin A, an adult form of drebrin, is an actin-binding protein in dendritic spines, and its decrease is purportedly concerned with synaptic dysfunction in Alzheimer's disease. Rapid conversion of drebrin E, an embryonic form of drebrin, to drebrin A occurs in parallel with synaptic maturation. To understand the physiological role of drebrin isoform conversion in vivo, we generated knockout mice in which a drebrin A-specific exon was deleted from the drebrin gene. Drebrin A-specific knockout (DAKO) mice expressed drebrin E, which substituted for drebrin A. Subcellular fractionation experiment indicated that cytosolic form of drebrin was increased in the brains of DAKO mice. Furthermore, drebrin accumulation in synaptosomes of DAKO mice was much higher than that of wild-type (WT) mice. DAKO mice were viable and showed no apparent abnormalities in their gross brain morphology and general behaviors. However, DAKO mice were impaired in a context-dependent freezing after fear conditioning. These data indicate that drebrin A plays an indispensable role in some processes of generating fear learning and memory.

  2. Sex determination in insects: a binary decision based on alternative splicing.

    Science.gov (United States)

    Salz, Helen K

    2011-08-01

    The gene regulatory networks that control sex determination vary between species. Despite these differences, comparative studies in insects have found that alternative splicing is reiteratively used in evolution to control expression of the key sex-determining genes. Sex determination is best understood in Drosophila where activation of the RNA binding protein-encoding gene Sex-lethal is the central female-determining event. Sex-lethal serves as a genetic switch because once activated it controls its own expression by a positive feedback splicing mechanism. Sex fate choice in is also maintained by self-sustaining positive feedback splicing mechanisms in other dipteran and hymenopteran insects, although different RNA binding protein-encoding genes function as the binary switch. Studies exploring the mechanisms of sex-specific splicing have revealed the extent to which sex determination is integrated with other developmental regulatory networks. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Antitumorigenic potential of STAT3 alternative splicing modulation.

    Science.gov (United States)

    Zammarchi, Francesca; de Stanchina, Elisa; Bournazou, Eirini; Supakorndej, Teerawit; Martires, Kathryn; Riedel, Elyn; Corben, Adriana D; Bromberg, Jacqueline F; Cartegni, Luca

    2011-10-25

    Signal transducer and activator of transcription 3 (STAT3) plays a central role in the activation of multiple oncogenic pathways. Splicing variant STAT3β uses an alternative acceptor site within exon 23 that leads to a truncated isoform lacking the C-terminal transactivation domain. Depending on the context, STAT3β can act as a dominant-negative regulator of transcription and promote apoptosis. We show that modified antisense oligonucleotides targeted to a splicing enhancer that regulates STAT3 exon 23 alternative splicing specifically promote a shift of expression from STAT3α to STAT3β. Induction of endogenous STAT3β leads to apoptosis and cell-cycle arrest in cell lines with persistent STAT3 tyrosine phosphorylation compared with total STAT3 knockdown obtained by forced splicing-dependent nonsense-mediated decay (FSD-NMD). Comparison of the molecular effects of splicing redirection to STAT3 knockdown reveals a unique STAT3β signature, with a down-regulation of specific targets (including lens epithelium-derived growth factor, p300/CBP-associated factor, CyclinC, peroxisomal biogenesis factor 1, and STAT1β) distinct from canonical STAT3 targets typically associated with total STAT3 knockdown. Furthermore, similar in vivo redirection of STAT3 alternative splicing leads to tumor regression in a xenograft cancer model, demonstrating how pharmacological manipulation of a single key splicing event can manifest powerful antitumorigenic properties and validating endogenous splicing reprogramming as an effective cancer therapeutic approach.

  4. Alternative splicing of mutually exclusive exons--a review.

    Science.gov (United States)

    Pohl, Martin; Bortfeldt, Ralf H; Grützmann, Konrad; Schuster, Stefan

    2013-10-01

    Alternative splicing (AS) of pre-mRNAs in higher eukaryotes and several viruses is one major source of protein diversity. Usually, the following major subtypes of AS are distinguished: exon skipping, intron retention, and alternative 3' and 5' splice sites. Moreover, mutually exclusive exons (MXEs) represent a rare subtype. In the splicing of MXEs, two (or more) splicing events are not independent anymore, but are executed or disabled in a coordinated manner. In this review, several bioinformatics approaches for analyzing MXEs are presented and discussed. In particular, we revisit suitable definitions and nomenclatures, and bioinformatics tools for finding MXEs, adjacent and non-adjacent MXEs, clustered and grouped MXEs. Moreover, the molecular mechanisms for splicing MXEs proposed in the literature are reviewed and discussed. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  5. The Functional Impact of Alternative Splicing in Cancer.

    Science.gov (United States)

    Climente-González, Héctor; Porta-Pardo, Eduard; Godzik, Adam; Eyras, Eduardo

    2017-08-29

    Alternative splicing changes are frequently observed in cancer and are starting to be recognized as important signatures for tumor progression and therapy. However, their functional impact and relevance to tumorigenesis remain mostly unknown. We carried out a systematic analysis to characterize the potential functional consequences of alternative splicing changes in thousands of tumor samples. This analysis revealed that a subset of alternative splicing changes affect protein domain families that are frequently mutated in tumors and potentially disrupt protein-protein interactions in cancer-related pathways. Moreover, there was a negative correlation between the number of these alternative splicing changes in a sample and the number of somatic mutations in drivers. We propose that a subset of the alternative splicing changes observed in tumors may represent independent oncogenic processes that could be relevant to explain the functional transformations in cancer, and some of them could potentially be considered alternative splicing drivers (AS drivers). Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  6. Automated Eukaryotic Gene Structure Annotation Using EVidenceModeler and the Program to Assemble Spliced Alignments

    Energy Technology Data Exchange (ETDEWEB)

    Haas, B J; Salzberg, S L; Zhu, W; Pertea, M; Allen, J E; Orvis, J; White, O; Buell, C R; Wortman, J R

    2007-12-10

    EVidenceModeler (EVM) is presented as an automated eukaryotic gene structure annotation tool that reports eukaryotic gene structures as a weighted consensus of all available evidence. EVM, when combined with the Program to Assemble Spliced Alignments (PASA), yields a comprehensive, configurable annotation system that predicts protein-coding genes and alternatively spliced isoforms. Our experiments on both rice and human genome sequences demonstrate that EVM produces automated gene structure annotation approaching the quality of manual curation.

  7. Hereditary cancer genes are highly susceptible to splicing mutations

    Science.gov (United States)

    Soemedi, Rachel; Maguire, Samantha; Murray, Michael F.; Monaghan, Sean F.

    2018-01-01

    Substitutions that disrupt pre-mRNA splicing are a common cause of genetic disease. On average, 13.4% of all hereditary disease alleles are classified as splicing mutations mapping to the canonical 5′ and 3′ splice sites. However, splicing mutations present in exons and deeper intronic positions are vastly underreported. A recent re-analysis of coding mutations in exon 10 of the Lynch Syndrome gene, MLH1, revealed an extremely high rate (77%) of mutations that lead to defective splicing. This finding is confirmed by extending the sampling to five other exons in the MLH1 gene. Further analysis suggests a more general phenomenon of defective splicing driving Lynch Syndrome. Of the 36 mutations tested, 11 disrupted splicing. Furthermore, analyzing past reports suggest that MLH1 mutations in canonical splice sites also occupy a much higher fraction (36%) of total mutations than expected. When performing a comprehensive analysis of splicing mutations in human disease genes, we found that three main causal genes of Lynch Syndrome, MLH1, MSH2, and PMS2, belonged to a class of 86 disease genes which are enriched for splicing mutations. Other cancer genes were also enriched in the 86 susceptible genes. The enrichment of splicing mutations in hereditary cancers strongly argues for additional priority in interpreting clinical sequencing data in relation to cancer and splicing. PMID:29505604

  8. Hereditary cancer genes are highly susceptible to splicing mutations.

    Directory of Open Access Journals (Sweden)

    Christy L Rhine

    2018-03-01

    Full Text Available Substitutions that disrupt pre-mRNA splicing are a common cause of genetic disease. On average, 13.4% of all hereditary disease alleles are classified as splicing mutations mapping to the canonical 5' and 3' splice sites. However, splicing mutations present in exons and deeper intronic positions are vastly underreported. A recent re-analysis of coding mutations in exon 10 of the Lynch Syndrome gene, MLH1, revealed an extremely high rate (77% of mutations that lead to defective splicing. This finding is confirmed by extending the sampling to five other exons in the MLH1 gene. Further analysis suggests a more general phenomenon of defective splicing driving Lynch Syndrome. Of the 36 mutations tested, 11 disrupted splicing. Furthermore, analyzing past reports suggest that MLH1 mutations in canonical splice sites also occupy a much higher fraction (36% of total mutations than expected. When performing a comprehensive analysis of splicing mutations in human disease genes, we found that three main causal genes of Lynch Syndrome, MLH1, MSH2, and PMS2, belonged to a class of 86 disease genes which are enriched for splicing mutations. Other cancer genes were also enriched in the 86 susceptible genes. The enrichment of splicing mutations in hereditary cancers strongly argues for additional priority in interpreting clinical sequencing data in relation to cancer and splicing.

  9. Genome-wide association between DNA methylation and alternative splicing in an invertebrate

    Directory of Open Access Journals (Sweden)

    Flores Kevin

    2012-09-01

    Full Text Available Abstract Background Gene bodies are the most evolutionarily conserved targets of DNA methylation in eukaryotes. However, the regulatory functions of gene body DNA methylation remain largely unknown. DNA methylation in insects appears to be primarily confined to exons. Two recent studies in Apis mellifera (honeybee and Nasonia vitripennis (jewel wasp analyzed transcription and DNA methylation data for one gene in each species to demonstrate that exon-specific DNA methylation may be associated with alternative splicing events. In this study we investigated the relationship between DNA methylation, alternative splicing, and cross-species gene conservation on a genome-wide scale using genome-wide transcription and DNA methylation data. Results We generated RNA deep sequencing data (RNA-seq to measure genome-wide mRNA expression at the exon- and gene-level. We produced a de novo transcriptome from this RNA-seq data and computationally predicted splice variants for the honeybee genome. We found that exons that are included in transcription are higher methylated than exons that are skipped during transcription. We detected enrichment for alternative splicing among methylated genes compared to unmethylated genes using fisher’s exact test. We performed a statistical analysis to reveal that the presence of DNA methylation or alternative splicing are both factors associated with a longer gene length and a greater number of exons in genes. In concordance with this observation, a conservation analysis using BLAST revealed that each of these factors is also associated with higher cross-species gene conservation. Conclusions This study constitutes the first genome-wide analysis exhibiting a positive relationship between exon-level DNA methylation and mRNA expression in the honeybee. Our finding that methylated genes are enriched for alternative splicing suggests that, in invertebrates, exon-level DNA methylation may play a role in the construction of splice

  10. Evolution of alternative splicing regulation: changes in predicted exonic splicing regulators are not associated with changes in alternative splicing levels in primates

    DEFF Research Database (Denmark)

    Irimia, Manuel; Rukov, Jakob Lewin; Roy, Scott William

    2009-01-01

    and changes in alternative splicing levels. This observation holds across different ESR exon positions, exon lengths, and 5' splice site strengths. We suggest that this lack of association is mainly due to the great importance of context for ESR functionality: many ESR-like motifs in primates may have little...

  11. Benzo[a]pyrene treatment leads to changes in nuclear protein expression and alternative splicing

    Energy Technology Data Exchange (ETDEWEB)

    Yan Chunlan; Wu Wei [Department of Toxicology, Zhejiang University School of Public Health, 388 Yu-Hang-Tang Road, Hangzhou, Zhejiang 310058 (China); Li Haiyan [Department of Toxicology, Zhejiang University School of Public Health, 388 Yu-Hang-Tang Road, Hangzhou, Zhejiang 310058 (China); Huzhou Maternity and Child Care Hospital, Huzhou, Zhejiang 313000 (China); Zhang Guanglin [Department of Toxicology, Zhejiang University School of Public Health, 388 Yu-Hang-Tang Road, Hangzhou, Zhejiang 310058 (China); Duerksen-Hughes, Penelope J. [Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92354 (United States); Zhu Xinqiang, E-mail: zhuxq@zju.edu.cn [Department of Toxicology, Zhejiang University School of Public Health, 388 Yu-Hang-Tang Road, Hangzhou, Zhejiang 310058 (China); Yang Jun, E-mail: gastate@zju.edu.cn [Department of Toxicology, Zhejiang University School of Public Health, 388 Yu-Hang-Tang Road, Hangzhou, Zhejiang 310058 (China); Zhejiang-California International Nanosystems Institute, Hangzhou, Zhejiang 310029 (China)

    2010-04-01

    Benzo[a]pyrene (BaP) is a potent pro-carcinogen generated from the combustion of fossil fuel and cigarette smoke. Previously, using a proteomic approach, we have shown that BaP can induce changes in the expression of many cellular proteins, including transcription regulators. In the present study, using a similar approach, we examined the nuclear protein response to BaP in HeLa cells and found that BaP treatment caused expression changes in many nuclear proteins. Twenty-four of these proteins were successfully identified, several of which are involved in the alternative splicing of mRNA, DNA replication, recombination, and repair. The changed expression levels were further confirmed by immunoblot analysis using specific antibodies for two proteins, Lamin A and mitotic checkpoint protein Bub3. The nuclear localization of these two proteins was also confirmed by confocal microscopy. To determine whether alternative splicing was activated following BaP treatment, we examined Fas and CD44, two genes previously shown to be targets of alternative splicing in respond to DNA damage. While no significant activation of alternative splicing was observed for Fas, CD44 splicing variants were found after BaP treatment. Together, these data show that DNA damage induces dramatic changes in nuclear protein expression, and that alternative splicing might be involved in the cellular response to DNA damage.

  12. Alternative splicing of the human gene SYBL1 modulates protein domain architecture of longin VAMP7/TI-VAMP, showing both non-SNARE and synaptobrevin-like isoforms

    Directory of Open Access Journals (Sweden)

    De Franceschi Nicola

    2011-05-01

    Full Text Available Abstract Background The control of intracellular vesicle trafficking is an ideal target to weigh the role of alternative splicing in shaping genomes to make cells. Alternative splicing has been reported for several Soluble N-ethylmaleimide-sensitive factor Attachment protein REceptors of the vesicle (v-SNAREs or of the target membrane (t-SNARES, which are crucial to intracellular membrane fusion and protein and lipid traffic in Eukaryotes. However, splicing has not yet been investigated in Longins, i.e. the most widespread v-SNAREs. Longins are essential in Eukaryotes and prototyped by VAMP7, Sec22b and Ykt6, sharing a conserved N-terminal Longin domain which regulates membrane fusion and subcellular targeting. Human VAMP7/TI-VAMP, encoded by gene SYBL1, is involved in multiple cell pathways, including control of neurite outgrowth. Results Alternative splicing of SYBL1 by exon skipping events results in the production of a number of VAMP7 isoforms. In-frame or frameshift coding sequence modifications modulate domain architecture of VAMP7 isoforms, which can lack whole domains or domain fragments and show variant or extra domains. Intriguingly, two main types of VAMP7 isoforms either share the inhibitory Longin domain and lack the fusion-promoting SNARE motif, or vice versa. Expression analysis in different tissues and cell lines, quantitative real time RT-PCR and confocal microscopy analysis of fluorescent protein-tagged isoforms demonstrate that VAMP7 variants have different tissue specificities and subcellular localizations. Moreover, design and use of isoform-specific antibodies provided preliminary evidence for the existence of splice variants at the protein level. Conclusions Previous evidence on VAMP7 suggests inhibitory functions for the Longin domain and fusion/growth promoting activity for the Δ-longin molecule. Thus, non-SNARE isoforms with Longin domain and non-longin SNARE isoforms might have somehow opposite regulatory functions

  13. Assessment of orthologous splicing isoforms in human and mouse orthologous genes

    Directory of Open Access Journals (Sweden)

    Horner David S

    2010-10-01

    Full Text Available Abstract Background Recent discoveries have highlighted the fact that alternative splicing and alternative transcripts are the rule, rather than the exception, in metazoan genes. Since multiple transcript and protein variants expressed by the same gene are, by definition, structurally distinct and need not to be functionally equivalent, the concept of gene orthology should be extended to the transcript level in order to describe evolutionary relationships between structurally similar transcript variants. In other words, the identification of true orthology relationships between gene products now should progress beyond primary sequence and "splicing orthology", consisting in ancestrally shared exon-intron structures, is required to define orthologous isoforms at transcript level. Results As a starting step in this direction, in this work we performed a large scale human- mouse gene comparison with a twofold goal: first, to assess if and to which extent traditional gene annotations such as RefSeq capture genuine splicing orthology; second, to provide a more detailed annotation and quantification of true human-mouse orthologous transcripts defined as transcripts of orthologous genes exhibiting the same splicing patterns. Conclusions We observed an identical exon/intron structure for 32% of human and mouse orthologous genes. This figure increases to 87% using less stringent criteria for gene structure similarity, thus implying that for about 13% of the human RefSeq annotated genes (and about 25% of the corresponding transcripts we could not identify any mouse transcript showing sufficient similarity to be confidently assigned as a splicing ortholog. Our data suggest that current gene and transcript data may still be rather incomplete - with several splicing variants still unknown. The observation that alternative splicing produces large numbers of alternative transcripts and proteins, some of them conserved across species and others truly species

  14. In Vitro and In Vivo Modulation of Alternative Splicing by the Biguanide Metformin

    Directory of Open Access Journals (Sweden)

    Delphine Laustriat

    2015-01-01

    Full Text Available Major physiological changes are governed by alternative splicing of RNA, and its misregulation may lead to specific diseases. With the use of a genome-wide approach, we show here that this splicing step can be modified by medication and demonstrate the effects of the biguanide metformin, on alternative splicing. The mechanism of action involves AMPK activation and downregulation of the RBM3 RNA-binding protein. The effects of metformin treatment were tested on myotonic dystrophy type I (DM1, a multisystemic disease considered to be a spliceopathy. We show that this drug promotes a corrective effect on several splicing defects associated with DM1 in derivatives of human embryonic stem cells carrying the causal mutation of DM1 as well as in primary myoblasts derived from patients. The biological effects of metformin were shown to be compatible with typical therapeutic dosages in a clinical investigation involving diabetic patients. The drug appears to act as a modifier of alternative splicing of a subset of genes and may therefore have novel therapeutic potential for many more diseases besides those directly linked to defective alternative splicing.

  15. Genome-wide analysis of alternative splicing of pre-mRNA under salt stress in Arabidopsis

    KAUST Repository

    Ding, Feng; Cui, Peng; Wang, Zhenyu; Zhang, ShouDong; Ali, Shahjahan; Xiong, Liming

    2014-01-01

    Background: Alternative splicing (AS) of precursor mRNA (pre-mRNA) is an important gene regulation process that potentially regulates many physiological processes in plants, including the response to abiotic stresses such as salt stress

  16. Fine-scale variation and genetic determinants of alternative splicing across individuals.

    Directory of Open Access Journals (Sweden)

    Jasmin Coulombe-Huntington

    2009-12-01

    Full Text Available Recently, thanks to the increasing throughput of new technologies, we have begun to explore the full extent of alternative pre-mRNA splicing (AS in the human transcriptome. This is unveiling a vast layer of complexity in isoform-level expression differences between individuals. We used previously published splicing sensitive microarray data from lymphoblastoid cell lines to conduct an in-depth analysis on splicing efficiency of known and predicted exons. By combining publicly available AS annotation with a novel algorithm designed to search for AS, we show that many real AS events can be detected within the usually unexploited, speculative majority of the array and at significance levels much below standard multiple-testing thresholds, demonstrating that the extent of cis-regulated differential splicing between individuals is potentially far greater than previously reported. Specifically, many genes show subtle but significant genetically controlled differences in splice-site usage. PCR validation shows that 42 out of 58 (72% candidate gene regions undergo detectable AS, amounting to the largest scale validation of isoform eQTLs to date. Targeted sequencing revealed a likely causative SNP in most validated cases. In all 17 incidences where a SNP affected a splice-site region, in silico splice-site strength modeling correctly predicted the direction of the micro-array and PCR results. In 13 other cases, we identified likely causative SNPs disrupting predicted splicing enhancers. Using Fst and REHH analysis, we uncovered significant evidence that 2 putative causative SNPs have undergone recent positive selection. We verified the effect of five SNPs using in vivo minigene assays. This study shows that splicing differences between individuals, including quantitative differences in isoform ratios, are frequent in human populations and that causative SNPs can be identified using in silico predictions. Several cases affected disease-relevant genes and

  17. Deep Sequence Analysis of Non-Small Cell Lung Cancer: Integrated Analysis of Gene Expression, Alternative Splicing, and Single Nucleotide Variations in Lung Adenocarcinomas with and without Oncogenic KRAS Mutations

    International Nuclear Information System (INIS)

    Kalari, Krishna R.; Rossell, David; Necela, Brian M.; Asmann, Yan W.; Nair, Asha

    2012-01-01

    KRAS mutations are highly prevalent in non-small cell lung cancer (NSCLC), and tumors harboring these mutations tend to be aggressive and resistant to chemotherapy. We used next-generation sequencing technology to identify pathways that are specifically altered in lung tumors harboring a KRAS mutation. Paired-end RNA-sequencing of 15 primary lung adenocarcinoma tumors (8 harboring mutant KRAS and 7 with wild-type KRAS) were performed. Sequences were mapped to the human genome, and genomic features, including differentially expressed genes, alternate splicing isoforms and single nucleotide variants, were determined for tumors with and without KRAS mutation using a variety of computational methods. Network analysis was carried out on genes showing differential expression (374 genes), alternate splicing (259 genes), and SNV-related changes (65 genes) in NSCLC tumors harboring a KRAS mutation. Genes exhibiting two or more connections from the lung adenocarcinoma network were used to carry out integrated pathway analysis. The most significant signaling pathways identified through this analysis were the NFκB, ERK1/2, and AKT pathways. A 27 gene mutant KRAS-specific sub network was extracted based on gene–gene connections from the integrated network, and interrogated for druggable targets. Our results confirm previous evidence that mutant KRAS tumors exhibit activated NFκB, ERK1/2, and AKT pathways and may be preferentially sensitive to target therapeutics toward these pathways. In addition, our analysis indicates novel, previously unappreciated links between mutant KRAS and the TNFR and PPARγ signaling pathways, suggesting that targeted PPARγ antagonists and TNFR inhibitors may be useful therapeutic strategies for treatment of mutant KRAS lung tumors. Our study is the first to integrate genomic features from RNA-Seq data from NSCLC and to define a first draft genomic landscape model that is unique to tumors with oncogenic KRAS mutations.

  18. Phosphoproteomics reveals that glycogen synthase kinase-3 phosphorylates multiple splicing factors and is associated with alternative splicing

    Science.gov (United States)

    Shinde, Mansi Y.; Sidoli, Simone; Kulej, Katarzyna; Mallory, Michael J.; Radens, Caleb M.; Reicherter, Amanda L.; Myers, Rebecca L.; Barash, Yoseph; Lynch, Kristen W.; Garcia, Benjamin A.; Klein, Peter S.

    2017-01-01

    Glycogen synthase kinase-3 (GSK-3) is a constitutively active, ubiquitously expressed protein kinase that regulates multiple signaling pathways. In vitro kinase assays and genetic and pharmacological manipulations of GSK-3 have identified more than 100 putative GSK-3 substrates in diverse cell types. Many more have been predicted on the basis of a recurrent GSK-3 consensus motif ((pS/pT)XXX(S/T)), but this prediction has not been tested by analyzing the GSK-3 phosphoproteome. Using stable isotope labeling of amino acids in culture (SILAC) and MS techniques to analyze the repertoire of GSK-3–dependent phosphorylation in mouse embryonic stem cells (ESCs), we found that ∼2.4% of (pS/pT)XXX(S/T) sites are phosphorylated in a GSK-3–dependent manner. A comparison of WT and Gsk3a;Gsk3b knock-out (Gsk3 DKO) ESCs revealed prominent GSK-3–dependent phosphorylation of multiple splicing factors and regulators of RNA biosynthesis as well as proteins that regulate transcription, translation, and cell division. Gsk3 DKO reduced phosphorylation of the splicing factors RBM8A, SRSF9, and PSF as well as the nucleolar proteins NPM1 and PHF6, and recombinant GSK-3β phosphorylated these proteins in vitro. RNA-Seq of WT and Gsk3 DKO ESCs identified ∼190 genes that are alternatively spliced in a GSK-3–dependent manner, supporting a broad role for GSK-3 in regulating alternative splicing. The MS data also identified posttranscriptional regulation of protein abundance by GSK-3, with ∼47 proteins (1.4%) whose levels increased and ∼78 (2.4%) whose levels decreased in the absence of GSK-3. This study provides the first unbiased analysis of the GSK-3 phosphoproteome and strong evidence that GSK-3 broadly regulates alternative splicing. PMID:28916722

  19. Semi-supervised Learning Predicts Approximately One Third of the Alternative Splicing Isoforms as Functional Proteins

    Directory of Open Access Journals (Sweden)

    Yanqi Hao

    2015-07-01

    Full Text Available Alternative splicing acts on transcripts from almost all human multi-exon genes. Notwithstanding its ubiquity, fundamental ramifications of splicing on protein expression remain unresolved. The number and identity of spliced transcripts that form stably folded proteins remain the sources of considerable debate, due largely to low coverage of experimental methods and the resulting absence of negative data. We circumvent this issue by developing a semi-supervised learning algorithm, positive unlabeled learning for splicing elucidation (PULSE; http://www.kimlab.org/software/pulse, which uses 48 features spanning various categories. We validated its accuracy on sets of bona fide protein isoforms and directly on mass spectrometry (MS spectra for an overall AU-ROC of 0.85. We predict that around 32% of “exon skipping” alternative splicing events produce stable proteins, suggesting that the process engenders a significant number of previously uncharacterized proteins. We also provide insights into the distribution of positive isoforms in various functional classes and into the structural effects of alternative splicing.

  20. Detection of alternative splice variants at the proteome level in Aspergillus flavus.

    Science.gov (United States)

    Chang, Kung-Yen; Georgianna, D Ryan; Heber, Steffen; Payne, Gary A; Muddiman, David C

    2010-03-05

    Identification of proteins from proteolytic peptides or intact proteins plays an essential role in proteomics. Researchers use search engines to match the acquired peptide sequences to the target proteins. However, search engines depend on protein databases to provide candidates for consideration. Alternative splicing (AS), the mechanism where the exon of pre-mRNAs can be spliced and rearranged to generate distinct mRNA and therefore protein variants, enable higher eukaryotic organisms, with only a limited number of genes, to have the requisite complexity and diversity at the proteome level. Multiple alternative isoforms from one gene often share common segments of sequences. However, many protein databases only include a limited number of isoforms to keep minimal redundancy. As a result, the database search might not identify a target protein even with high quality tandem MS data and accurate intact precursor ion mass. We computationally predicted an exhaustive list of putative isoforms of Aspergillus flavus proteins from 20 371 expressed sequence tags to investigate whether an alternative splicing protein database can assign a greater proportion of mass spectrometry data. The newly constructed AS database provided 9807 new alternatively spliced variants in addition to 12 832 previously annotated proteins. The searches of the existing tandem MS spectra data set using the AS database identified 29 new proteins encoded by 26 genes. Nine fungal genes appeared to have multiple protein isoforms. In addition to the discovery of splice variants, AS database also showed potential to improve genome annotation. In summary, the introduction of an alternative splicing database helps identify more proteins and unveils more information about a proteome.

  1. Expression analysis of a heat-inducible, Myo-inositol-1-phosphate synthase (MIPS) gene from wheat and the alternatively spliced variants of rice and Arabidopsis.

    Science.gov (United States)

    Khurana, Neetika; Chauhan, Harsh; Khurana, Paramjit

    2012-01-01

    Molecular dissection and a deeper analysis of the heat stress response mechanism in wheat have been poorly understood so far. This study delves into the molecular basis of action of TaMIPS, a heat stress-inducible enzyme that was identified through PCR-select subtraction technology, which is named here as TaMIPS2. MIPS (L-Myo-inositol-phosphate synthase) is important for the normal growth and development in plants. Expression profiling showed that TaMIPS2 is expressed during different developing seed stages upon heat stress. Also, the transcript levels increase in unfertilized ovaries and significant amounts are present during the recovery period providing evidence that MIPS is crucial for its role in heat stress recovery and flower development. Alternatively spliced forms from rice and Arabidopsis were also identified and their expression analysis revealed that apart from heat stress, some of the spliced variants were also inducible by drought, NaCl, Cold, ABA, BR, SA and mannitol. In silico promoter analysis revealed various cis-elements that could contribute for the differential regulation of MIPS in different plant systems. Phylogenetic analysis indicated that MIPS are highly conserved among monocots and dicots and TaMIPS2 grouped specifically with monocots. Comparative analyses was undertaken by different experimental approaches, i.e., semi-quantitative RT-PCR, quantitative RT-PCR, Genevestigator as a reference expression tool and motif analysis to predict the possible function of TaMIPS2 in regulating the different aspects of plant development under abiotic stress in wheat.

  2. Retrotransposons of the Tnt1B family are mobile in Nicotiana plumbaginifolia and can induce alternative splicing of the host gene upon insertion.

    Science.gov (United States)

    Leprinc, A S; Grandbastien, M A; Christian, M

    2001-11-01

    Active retrotransposons have been identified in Nicotiana plumbaginifolia by their ability to disrupt the nitrate reductase gene in chlorate-resistant mutants selected from protoplast-derived cultures. In mutants E23 and F97, two independent insertions of Tnp2, a new retrotransposon closely related to the tobacco Tnt1 elements, were detected in the nitrate reductase gene. These two Tnp2 elements are members of the Tnt1B subfamily which shows that Tnt1B elements can be active and mutagenic in the N. plumbaginifolia genome. Furthermore, these results suggest that Tnt1B is the most active family of Tntl elements in N. plumbaginifolia, whereas in tobacco only members of the Tnt1A subfamily were found inserted in the nitrate reductase gene. The transcriptional regulations of Tnp2 and Tnt1A elements are most probably different due to non-conserved U3 regions. Our results thus support the hypothesis that different Nicotiana species contain different active Tntl subfamilies and that only one active Tntl subfamily might be maintained in each of these species. The Tnp2 insertion found in the F97 mutant was found to be spliced out of the nitrate reductase mRNA by activation of cryptic donor and acceptor sites in the nitrate reductase and the Tnp2 sequences respectively.

  3. The conserved splicing factor SUA controls alternative splicing of the developmental regulator ABI3 in Arabidopsis.

    NARCIS (Netherlands)

    Sugliani, M.; Brambilla, V.; Clerkx, E.J.M.; Koornneef, M.; Soppe, W.J.J.

    2010-01-01

    ABSCISIC ACID INSENSITIVE3 (ABI3) is a major regulator of seed maturation in Arabidopsis thaliana. We detected two ABI3 transcripts, ABI3- and ABI3-ß, which encode full-length and truncated proteins, respectively. Alternative splicing of ABI3 is developmentally regulated, and the ABI3-ß transcript

  4. Triiodothyronine affects the alternative splicing of thyroid hormone receptor alpha mRNA

    NARCIS (Netherlands)

    Timmer, D. C.; Bakker, O.; Wiersinga, W. M.

    2003-01-01

    The c-erbAalpha gene encodes two thyroid hormone receptors, TRalpha1 and TRalpha2, that arise from alternative splicing of the TRalpha pre-mRNA. TRalpha2 is not able to bind triiodothyronine (T-3) and acts as a weak antagonist of TRs. It has been suggested that the balance of TRalpha1 to TRalpha2 is

  5. High qualitative and quantitative conservation of alternative splicing in Caenorhabditis elegans and Caenorhabditis briggsae

    DEFF Research Database (Denmark)

    Rukov, Jakob Lewin; Irimia, Manuel; Mørk, Søren

    2007-01-01

    Alternative splicing (AS) is an important contributor to proteome diversity and is regarded as an explanatory factor for the relatively low number of human genes compared with less complex animals. To assess the evolutionary conservation of AS and its developmental regulation, we have investigated...... the qualitative and quantitative expression of 21 orthologous alternative splice events through the development of 2 nematode species separated by 85-110 Myr of evolutionary time. We demonstrate that most of these alternative splice events present in Caenorhabditis elegans are conserved in Caenorhabditis briggsae....... Moreover, we find that relative isoform expression levels vary significantly during development for 78% of the AS events and that this quantitative variation is highly conserved between the 2 species. Our results suggest that AS is generally tightly regulated through development and that the regulatory...

  6. Lariat sequencing in a unicellular yeast identifies regulated alternative splicing of exons that are evolutionarily conserved with humans.

    Science.gov (United States)

    Awan, Ali R; Manfredo, Amanda; Pleiss, Jeffrey A

    2013-07-30

    Alternative splicing is a potent regulator of gene expression that vastly increases proteomic diversity in multicellular eukaryotes and is associated with organismal complexity. Although alternative splicing is widespread in vertebrates, little is known about the evolutionary origins of this process, in part because of the absence of phylogenetically conserved events that cross major eukaryotic clades. Here we describe a lariat-sequencing approach, which offers high sensitivity for detecting splicing events, and its application to the unicellular fungus, Schizosaccharomyces pombe, an organism that shares many of the hallmarks of alternative splicing in mammalian systems but for which no previous examples of exon-skipping had been demonstrated. Over 200 previously unannotated splicing events were identified, including examples of regulated alternative splicing. Remarkably, an evolutionary analysis of four of the exons identified here as subject to skipping in S. pombe reveals high sequence conservation and perfect length conservation with their homologs in scores of plants, animals, and fungi. Moreover, alternative splicing of two of these exons have been documented in multiple vertebrate organisms, making these the first demonstrations of identical alternative-splicing patterns in species that are separated by over 1 billion y of evolution.

  7. Sex Determination in Insects: a binary decision based on alternative splicing

    OpenAIRE

    Salz, Helen K.

    2011-01-01

    The gene regulatory networks that control sex determination vary between species. Despite these differences, comparative studies in insects have found that alternative splicing is reiteratively used in evolution to control expression of the key sex determining genes. Sex determination is best understood in Drosophila where activation of the RNA binding protein encoding gene Sex-lethal is the central female-determining event. Sex-lethal serves as a genetic switch because once activated it cont...

  8. Widespread evolutionary conservation of alternatively spliced exons in caenorhabditis

    DEFF Research Database (Denmark)

    Irimia, Manuel; Rukov, Jakob L; Penny, David

    2007-01-01

    Alternative splicing (AS) contributes to increased transcriptome and proteome diversity in various eukaryotic lineages. Previous studies showed low levels of conservation of alternatively spliced (cassette) exons within mammals and within dipterans. We report a strikingly different pattern...... in Caenorhabditis nematodes-more than 92% of cassette exons from Caenorhabditis elegans are conserved in Caenorhabditis briggsae and/or Caenorhabditis remanei. High levels of conservation extend to minor-form exons (present in a minority of transcripts) and are particularly pronounced for exons showing complex...... patterns of splicing. The functionality of the vast majority of cassette exons is underscored by various other features. We suggest that differences in conservation between lineages reflect differences in levels of functionality and further suggest that these differences are due to differences in intron...

  9. Computational Analysis of an Evolutionarily Conserved VertebrateMuscle Alternative Splicing Program

    Energy Technology Data Exchange (ETDEWEB)

    Das, Debopriya; Clark, Tyson A.; Schweitzer, Anthony; Marr,Henry; Yamamoto, Miki L.; Parra, Marilyn K.; Arribere, Josh; Minovitsky,Simon; Dubchak, Inna; Blume, John E.; Conboy, John G.

    2006-06-15

    A novel exon microarray format that probes gene expression with single exon resolution was employed to elucidate critical features of a vertebrate muscle alternative splicing program. A dataset of 56 microarray-defined, muscle-enriched exons and their flanking introns were examined computationally in order to investigate coordination of the muscle splicing program. Candidate intron regulatory motifs were required to meet several stringent criteria: significant over-representation near muscle-enriched exons, correlation with muscle expression, and phylogenetic conservation among genomes of several vertebrate orders. Three classes of regulatory motifs were identified in the proximal downstream intron, within 200nt of the target exons: UGCAUG, a specific binding site for Fox-1 related splicing factors; ACUAAC, a novel branchpoint-like element; and UG-/UGC-rich elements characteristic of binding sites for CELF splicing factors. UGCAUG was remarkably enriched, being present in nearly one-half of all cases. These studies suggest that Fox and CELF splicing factors play a major role in enforcing the muscle-specific alternative splicing program, facilitating expression of a set of unique isoforms of cytoskeletal proteins that are critical to muscle cell differentiation. Supplementary materials: There are four supplementary tables and one supplementary figure. The tables provide additional detailed information concerning the muscle-enriched datasets, and about over-represented oligonucleotide sequences in the flanking introns. The supplementary figure shows RT-PCR data confirming the muscle-enriched expression of exons predicted from the microarray analysis.

  10. Analysis and prediction of gene splice sites in four Aspergillus genomes

    DEFF Research Database (Denmark)

    Wang, Kai; Ussery, David; Brunak, Søren

    2009-01-01

    Several Aspergillus fungal genomic sequences have been published, with many more in progress. Obviously, it is essential to have high-quality, consistently annotated sets of proteins from each of the genomes, in order to make meaningful comparisons. We have developed a dedicated, publicly available......, splice site prediction program called NetAspGene, for the genus Aspergillus. Gene sequences from Aspergillus fumigatus, the most common mould pathogen, were used to build and test our model. Compared to many animals and plants, Aspergillus contains smaller introns; thus we have applied a larger window...... better splice site prediction than other available tools. NetAspGene will be very helpful for the study in Aspergillus splice sites and especially in alternative splicing. A webpage for NetAspGene is publicly available at http://www.cbs.dtu.dk/services/NetAspGene....

  11. RRM domain of Arabidopsis splicing factor SF1 is important for pre-mRNA splicing of a specific set of genes

    KAUST Repository

    Lee, Keh Chien

    2017-04-11

    The RNA recognition motif of Arabidopsis splicing factor SF1 affects the alternative splicing of FLOWERING LOCUS M pre-mRNA and a heat shock transcription factor HsfA2 pre-mRNA. Splicing factor 1 (SF1) plays a crucial role in 3\\' splice site recognition by binding directly to the intron branch point. Although plant SF1 proteins possess an RNA recognition motif (RRM) domain that is absent in its fungal and metazoan counterparts, the role of the RRM domain in SF1 function has not been characterized. Here, we show that the RRM domain differentially affects the full function of the Arabidopsis thaliana AtSF1 protein under different experimental conditions. For example, the deletion of RRM domain influences AtSF1-mediated control of flowering time, but not the abscisic acid sensitivity response during seed germination. The alternative splicing of FLOWERING LOCUS M (FLM) pre-mRNA is involved in flowering time control. We found that the RRM domain of AtSF1 protein alters the production of alternatively spliced FLM-β transcripts. We also found that the RRM domain affects the alternative splicing of a heat shock transcription factor HsfA2 pre-mRNA, thereby mediating the heat stress response. Taken together, our results suggest the importance of RRM domain for AtSF1-mediated alternative splicing of a subset of genes involved in the regulation of flowering and adaptation to heat stress.

  12. A high quality Arabidopsis transcriptome for accurate transcript-level analysis of alternative splicing

    KAUST Repository

    Zhang, Runxuan

    2017-04-05

    Alternative splicing generates multiple transcript and protein isoforms from the same gene and thus is important in gene expression regulation. To date, RNA-sequencing (RNA-seq) is the standard method for quantifying changes in alternative splicing on a genome-wide scale. Understanding the current limitations of RNA-seq is crucial for reliable analysis and the lack of high quality, comprehensive transcriptomes for most species, including model organisms such as Arabidopsis, is a major constraint in accurate quantification of transcript isoforms. To address this, we designed a novel pipeline with stringent filters and assembled a comprehensive Reference Transcript Dataset for Arabidopsis (AtRTD2) containing 82,190 non-redundant transcripts from 34 212 genes. Extensive experimental validation showed that AtRTD2 and its modified version, AtRTD2-QUASI, for use in Quantification of Alternatively Spliced Isoforms, outperform other available transcriptomes in RNA-seq analysis. This strategy can be implemented in other species to build a pipeline for transcript-level expression and alternative splicing analyses.

  13. A high quality Arabidopsis transcriptome for accurate transcript-level analysis of alternative splicing

    KAUST Repository

    Zhang, Runxuan; Calixto, Cristiane  P.  G.; Marquez, Yamile; Venhuizen, Peter; Tzioutziou, Nikoleta A.; Guo, Wenbin; Spensley, Mark; Entizne, Juan Carlos; Lewandowska, Dominika; ten  Have, Sara; Frei  dit  Frey, Nicolas; Hirt, Heribert; James, Allan B.; Nimmo, Hugh G.; Barta, Andrea; Kalyna, Maria; Brown, John  W.  S.

    2017-01-01

    Alternative splicing generates multiple transcript and protein isoforms from the same gene and thus is important in gene expression regulation. To date, RNA-sequencing (RNA-seq) is the standard method for quantifying changes in alternative splicing on a genome-wide scale. Understanding the current limitations of RNA-seq is crucial for reliable analysis and the lack of high quality, comprehensive transcriptomes for most species, including model organisms such as Arabidopsis, is a major constraint in accurate quantification of transcript isoforms. To address this, we designed a novel pipeline with stringent filters and assembled a comprehensive Reference Transcript Dataset for Arabidopsis (AtRTD2) containing 82,190 non-redundant transcripts from 34 212 genes. Extensive experimental validation showed that AtRTD2 and its modified version, AtRTD2-QUASI, for use in Quantification of Alternatively Spliced Isoforms, outperform other available transcriptomes in RNA-seq analysis. This strategy can be implemented in other species to build a pipeline for transcript-level expression and alternative splicing analyses.

  14. Role of an SNP in Alternative Splicing of Bovine NCF4 and Mastitis Susceptibility.

    Directory of Open Access Journals (Sweden)

    Zhihua Ju

    Full Text Available Neutrophil cytosolic factor 4 (NCF4 is component of the nicotinamide dinucleotide phosphate oxidase complex, a key factor in biochemical pathways and innate immune responses. In this study, splice variants and functional single-nucleotide polymorphism (SNP of NCF4 were identified to determine the variability and association of the gene with susceptibility to bovine mastitis characterized by inflammation. A novel splice variant, designated as NCF4-TV and characterized by the retention of a 48 bp sequence in intron 9, was detected in the mammary gland tissues of infected cows. The expression of the NCF4-reference main transcript in the mastitic mammary tissues was higher than that in normal tissues. A novel SNP, g.18174 A>G, was also found in the retained 48 bp region of intron 9. To determine whether NCF4-TV could be due to the g.18174 A>G mutation, we constructed two mini-gene expression vectors with the wild-type or mutant NCF4 g.18174 A>G fragment. The vectors were then transiently transfected into 293T cells, and alternative splicing of NCF4 was analyzed by reverse transcription-PCR and sequencing. Mini-gene splicing assay demonstrated that the aberrantly spliced NCF4-TV with 48 bp retained fragment in intron 9 could be due to g.18174 A>G, which was associated with milk somatic count score and increased risk of mastitis infection in cows. NCF4 expression was also regulated by alternative splicing. This study proposes that NCF4 splice variants generated by functional SNP are important risk factors for mastitis susceptibility in dairy cows.

  15. Chemotherapy induces alternative transcription and splicing: Facts and hopes for cancer treatment.

    Science.gov (United States)

    Lambert, Charles A; Garbacki, Nancy; Colige, Alain C

    2017-10-01

    Alternative promoter usage, alternative splicing and alternative cleavage/polyadenylation (referred here as to alternative transcription and splicing) are main instruments to diversify the transcriptome from a limited set of genes. There is a good deal of evidence that chemotherapeutic drugs affect these processes, but the therapeutic incidence of these effects is poorly documented. The scope of this study is to review the impact of chemotherapy on alternative transcription and splicing and to discuss potential implications in cancer therapy. A literature survey identified >2200 events induced by chemotherapeutic drugs. The molecular pathways involved in these regulations are briefly discussed. The GO terms associated with the alternative transcripts are mainly related to cell cycle/division, mRNA processing, DNA repair, macromolecules catabolism and chromatin. A large fraction (43%) of transcripts are also related to the new hallmarks of cancer, mostly genetic instability and replicative immortality. Finally, we ask the question of the impact of alternative transcription and splicing on drug efficacy and of the possible curative benefit of combining chemotherapy and pharmaceutical regulation of this process. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Alternative splicing at the intersection of biological timing, development, and stress responses.

    Science.gov (United States)

    Staiger, Dorothee; Brown, John W S

    2013-10-01

    High-throughput sequencing for transcript profiling in plants has revealed that alternative splicing (AS) affects a much higher proportion of the transcriptome than was previously assumed. AS is involved in most plant processes and is particularly prevalent in plants exposed to environmental stress. The identification of mutations in predicted splicing factors and spliceosomal proteins that affect cell fate, the circadian clock, plant defense, and tolerance/sensitivity to abiotic stress all point to a fundamental role of splicing/AS in plant growth, development, and responses to external cues. Splicing factors affect the AS of multiple downstream target genes, thereby transferring signals to alter gene expression via splicing factor/AS networks. The last two to three years have seen an ever-increasing number of examples of functional AS. At a time when the identification of AS in individual genes and at a global level is exploding, this review aims to bring together such examples to illustrate the extent and importance of AS, which are not always obvious from individual publications. It also aims to ensure that plant scientists are aware that AS is likely to occur in the genes that they study and that dynamic changes in AS and its consequences need to be considered routinely.

  17. The mouse Gtl2 gene is differentially expressed during embryonic development, encodes multiple alternatively spliced transcripts, and may act as an RNA.

    Science.gov (United States)

    Schuster-Gossler, K; Bilinski, P; Sado, T; Ferguson-Smith, A; Gossler, A

    1998-06-01

    We have isolated a novel mouse gene (Gtl2) from the site of a gene trap integration (Gtl2lacZ) that gave rise to developmentally regulated lacZ expression, and a dominant parental-origin-dependent phenotype. Heterozygous Gtl2lacZ mice that inherited the transgene from the father showed a proportionate dwarfism phenotype, whereas the penetrance and expressivity of the phenotype was strongly reduced in Gtl2lacZ mice that inherited the transgene from the mother. Gtl2 expression is highly similar to the beta-galactosidase staining pattern, and is down-regulated but not abolished in mice carrying the Gtl2lacZ insertion. In early postimplantation embryos, Gtl2 is expressed in the visceral yolk sac and embryonic ectoderm. During subsequent development and organogenesis, Gtl2 transcripts are abundant in the paraxial mesoderm closely correlated with myogenic differentiation, in parts of the central nervous system, and in the epithelial ducts of developing excretory organs. The Gtl2 gene gives rise to various differentially spliced transcripts, which contain multiple small open reading frames (ORF). However, none of the ATG codons of these ORFs is in the context of a strong Kozak consensus sequence for initiation of translation, suggesting that Gtl2 might function as an RNA. Nuclear Gtl2 RNA was detected in a temporally and spatially regulated manner, and partially processed Gtl2 transcripts were readily detected in Northern blot hybridizations of polyadenylated RNA, suggesting that primary Gtl2 transcripts are differently processed in various cell types during development. Gtl2 transcript levels are present in parthenogenic embryos but may be reduced, consistent with the pattern of inheritance of the Gtl2lacZ phenotype.

  18. Duplicated Gephyrin Genes Showing Distinct Tissue Distribution and Alternative Splicing Patterns Mediate Molybdenum Cofactor Biosynthesis, Glycine Receptor Clustering, and Escape Behavior in Zebrafish*

    Science.gov (United States)

    Ogino, Kazutoyo; Ramsden, Sarah L.; Keib, Natalie; Schwarz, Günter; Harvey, Robert J.; Hirata, Hiromi

    2011-01-01

    Gephyrin mediates the postsynaptic clustering of glycine receptors (GlyRs) and GABAA receptors at inhibitory synapses and molybdenum-dependent enzyme (molybdoenzyme) activity in non-neuronal tissues. Gephyrin knock-out mice show a phenotype resembling both defective glycinergic transmission and molybdenum cofactor (Moco) deficiency and die within 1 day of birth due to starvation and dyspnea resulting from deficits in motor and respiratory networks, respectively. To address whether gephyrin function is conserved among vertebrates and whether gephyrin deficiency affects molybdoenzyme activity and motor development, we cloned and characterized zebrafish gephyrin genes. We report here that zebrafish have two gephyrin genes, gphna and gphnb. The former is expressed in all tissues and has both C3 and C4 cassette exons, and the latter is expressed predominantly in the brain and spinal cord and harbors only C4 cassette exons. We confirmed that all of the gphna and gphnb splicing isoforms have Moco synthetic activity. Antisense morpholino knockdown of either gphna or gphnb alone did not disturb synaptic clusters of GlyRs in the spinal cord and did not affect touch-evoked escape behaviors. However, on knockdown of both gphna and gphnb, embryos showed impairments in GlyR clustering in the spinal cord and, as a consequence, demonstrated touch-evoked startle response behavior by contracting antagonistic muscles simultaneously, instead of displaying early coiling and late swimming behaviors, which are executed by side-to-side muscle contractions. These data indicate that duplicated gephyrin genes mediate Moco biosynthesis and control postsynaptic clustering of GlyRs, thereby mediating key escape behaviors in zebrafish. PMID:20843816

  19. Alternative splicing of the porcine glycogen synthase kinase 3β (GSK-3β gene with differential expression patterns and regulatory functions.

    Directory of Open Access Journals (Sweden)

    Linjie Wang

    Full Text Available Glycogen synthase kinase 3 (GSK3α and GSK3β are serine/threonine kinases involved in numerous cellular processes and diverse diseases including mood disorders, Alzheimer's disease, diabetes, and cancer. However, in pigs, the information on GSK3 is very limited. Identification and characterization of pig GSK3 are not only important for pig genetic improvement, but also contribute to the understanding and development of porcine models for human disease prevention and treatment.Five different isoforms of GSK3β were identified in porcine different tissues, in which three isoforms are novel. These isoforms had differential expression patterns in the fetal and adult of the porcine different tissues. The mRNA expression level of GSK3β isoforms was differentially regulated during the course of the insulin treatment, suggesting that different GSK3β isoforms may have different roles in insulin signaling pathway. Moreover, GSK3β5 had a different role on regulating the glycogen synthase activity, phosphorylation and the expression of porcine GYS1 and GYS2 gene compared to other GSK3β isoforms.We are the first to report five different isoforms of GSK3β identified from the porcine different tissues. Splice variants of GSK3β exhibit differential activity towards glycogen synthase. These results provide new insight into roles of the GSK3β on regulating glycogen metabolism.

  20. Strengths and weaknesses of EST-based prediction of tissue-specific alternative splicing

    Directory of Open Access Journals (Sweden)

    Vingron Martin

    2004-09-01

    Full Text Available Abstract Background Alternative splicing contributes significantly to the complexity of the human transcriptome and proteome. Computational prediction of alternative splice isoforms are usually based on EST sequences that also allow to approximate the expression pattern of the related transcripts. However, the limited number of tissues represented in the EST data as well as the different cDNA construction protocols may influence the predictive capacity of ESTs to unravel tissue-specifically expressed transcripts. Methods We predict tissue and tumor specific splice isoforms based on the genomic mapping (SpliceNest of the EST consensus sequences and library annotation provided in the GeneNest database. We further ascertain the potentially rare tissue specific transcripts as the ones represented only by ESTs derived from normalized libraries. A subset of the predicted tissue and tumor specific isoforms are then validated via RT-PCR experiments over a spectrum of 40 tissue types. Results Our strategy revealed 427 genes with at least one tissue specific transcript as well as 1120 genes showing tumor specific isoforms. While our experimental evaluation of computationally predicted tissue-specific isoforms revealed a high success rate in confirming the expression of these isoforms in the respective tissue, the strategy frequently failed to detect the expected restricted expression pattern. The analysis of putative lowly expressed transcripts using normalized cDNA libraries suggests that our ability to detect tissue-specific isoforms strongly depends on the expression level of the respective transcript as well as on the sensitivity of the experimental methods. Especially splice isoforms predicted to be disease-specific tend to represent transcripts that are expressed in a set of healthy tissues rather than novel isoforms. Conclusions We propose to combine the computational prediction of alternative splice isoforms with experimental validation for

  1. Identification of interleukin-26 in the dromedary camel (Camelus dromedarius): Evidence of alternative splicing and isolation of novel splice variants.

    Science.gov (United States)

    Premraj, Avinash; Nautiyal, Binita; Aleyas, Abi G; Rasool, Thaha Jamal

    2015-10-01

    Interleukin-26 (IL-26) is a member of the IL-10 family of cytokines. Though conserved across vertebrates, the IL-26 gene is functionally inactivated in a few mammals like rat, mouse and horse. We report here the identification, isolation and cloning of the cDNA of IL-26 from the dromedary camel. The camel cDNA contains a 516 bp open reading frame encoding a 171 amino acid precursor protein, including a 21 amino acid signal peptide. Sequence analysis revealed high similarity with other mammalian IL-26 homologs and the conservation of IL-10 cytokine family domain structure including key amino acid residues. We also report the identification and cloning of four novel transcript variants produced by alternative splicing at the Exon 3-Exon 4 regions of the gene. Three of the alternative splice variants had premature termination codons and are predicted to code for truncated proteins. The transcript variant 4 (Tv4) having an insertion of an extra 120 bp nucleotides in the ORF was predicted to encode a full length protein product with 40 extra amino acid residues. The mRNA transcripts of all the variants were identified in lymph node, where as fewer variants were observed in other tissues like blood, liver and kidney. The expression of Tv2 and Tv3 were found to be up regulated in mitogen induced camel peripheral blood mononuclear cells. IL-26-Tv2 expression was also induced in camel fibroblast cells infected with Camel pox virus in-vitro. The identification of the transcript variants of IL-26 from the dromedary camel is the first report of alternative splicing for IL-26 in a species in which the gene has not been inactivated. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Rbfox-regulated alternative splicing is critical for zebrafish cardiac and skeletal muscle function

    Science.gov (United States)

    Gallagher, Thomas L.; Arribere, Joshua A.; Geurts, Paul A.; Exner, Cameron R. T.; McDonald, Kent L.; Dill, Kariena K.; Marr, Henry L.; Adkar, Shaunak S.; Garnett, Aaron T.; Amacher, Sharon L.; Conboy, John G.

    2012-01-01

    Rbfox RNA binding proteins are implicated as regulators of phylogenetically-conserved alternative splicing events important for muscle function. To investigate the function of rbfox genes, we used morpholino-mediated knockdown of muscle-expressed rbfox1l and rbfox2 in zebrafish embryos. Single and double morphant embryos exhibited changes in splicing of overlapping sets of bioinformatically-predicted rbfox target exons, many of which exhibit a muscle-enriched splicing pattern that is conserved in vertebrates. Thus, conservation of intronic Rbfox binding motifs is a good predictor of Rbfox-regulated alternative splicing. Morphology and development of single morphant embryos was strikingly normal; however, muscle development in double morphants was severely disrupted. Defects in cardiac muscle were marked by reduced heart rate and in skeletal muscle by complete paralysis. The predominance of wavy myofibers and abnormal thick and thin filaments in skeletal muscle revealed that myofibril assembly is defective and disorganized in double morphants. Ultra-structural analysis revealed that although sarcomeres with electron dense M- and Z-bands are present in muscle fibers of rbfox1l/rbox2 morphants, they are substantially reduced in number and alignment. Importantly, splicing changes and morphological defects were rescued by expression of morpholino-resistant rbfox cDNA. Additionally, a target-blocking MO complementary to a single UGCAUG motif adjacent to an rbfox target exon of fxr1 inhibited inclusion in a similar manner to rbfox knockdown, providing evidence that Rbfox regulates the splicing of target exons via direct binding to intronic regulatory motifs. We conclude that Rbfox proteins regulate an alternative splicing program essential for vertebrate heart and skeletal muscle function. PMID:21925157

  3. Rbfox-regulated alternative splicing is critical for zebrafish cardiac and skeletal muscle functions.

    Science.gov (United States)

    Gallagher, Thomas L; Arribere, Joshua A; Geurts, Paul A; Exner, Cameron R T; McDonald, Kent L; Dill, Kariena K; Marr, Henry L; Adkar, Shaunak S; Garnett, Aaron T; Amacher, Sharon L; Conboy, John G

    2011-11-15

    Rbfox RNA binding proteins are implicated as regulators of phylogenetically-conserved alternative splicing events important for muscle function. To investigate the function of rbfox genes, we used morpholino-mediated knockdown of muscle-expressed rbfox1l and rbfox2 in zebrafish embryos. Single and double morphant embryos exhibited changes in splicing of overlapping sets of bioinformatically-predicted rbfox target exons, many of which exhibit a muscle-enriched splicing pattern that is conserved in vertebrates. Thus, conservation of intronic Rbfox binding motifs is a good predictor of Rbfox-regulated alternative splicing. Morphology and development of single morphant embryos were strikingly normal; however, muscle development in double morphants was severely disrupted. Defects in cardiac muscle were marked by reduced heart rate and in skeletal muscle by complete paralysis. The predominance of wavy myofibers and abnormal thick and thin filaments in skeletal muscle revealed that myofibril assembly is defective and disorganized in double morphants. Ultra-structural analysis revealed that although sarcomeres with electron dense M- and Z-bands are present in muscle fibers of rbfox1l/rbox2 morphants, they are substantially reduced in number and alignment. Importantly, splicing changes and morphological defects were rescued by expression of morpholino-resistant rbfox cDNA. Additionally, a target-blocking MO complementary to a single UGCAUG motif adjacent to an rbfox target exon of fxr1 inhibited inclusion in a similar manner to rbfox knockdown, providing evidence that Rbfox regulates the splicing of target exons via direct binding to intronic regulatory motifs. We conclude that Rbfox proteins regulate an alternative splicing program essential for vertebrate heart and skeletal muscle functions. Published by Elsevier Inc.

  4. Chinmo prevents transformer alternative splicing to maintain male sex identity.

    Directory of Open Access Journals (Sweden)

    Lydia Grmai

    2018-02-01

    Full Text Available Reproduction in sexually dimorphic animals relies on successful gamete production, executed by the germline and aided by somatic support cells. Somatic sex identity in Drosophila is instructed by sex-specific isoforms of the DMRT1 ortholog Doublesex (Dsx. Female-specific expression of Sex-lethal (Sxl causes alternative splicing of transformer (tra to the female isoform traF. In turn, TraF alternatively splices dsx to the female isoform dsxF. Loss of the transcriptional repressor Chinmo in male somatic stem cells (CySCs of the testis causes them to "feminize", resembling female somatic stem cells in the ovary. This somatic sex transformation causes a collapse of germline differentiation and male infertility. We demonstrate this feminization occurs by transcriptional and post-transcriptional regulation of traF. We find that chinmo-deficient CySCs upregulate tra mRNA as well as transcripts encoding tra-splice factors Virilizer (Vir and Female lethal (2d (Fl(2d. traF splicing in chinmo-deficient CySCs leads to the production of DsxF at the expense of the male isoform DsxM, and both TraF and DsxF are required for CySC sex transformation. Surprisingly, CySC feminization upon loss of chinmo does not require Sxl but does require Vir and Fl(2d. Consistent with this, we show that both Vir and Fl(2d are required for tra alternative splicing in the female somatic gonad. Our work reveals the need for transcriptional regulation of tra in adult male stem cells and highlights a previously unobserved Sxl-independent mechanism of traF production in vivo. In sum, transcriptional control of the sex determination hierarchy by Chinmo is critical for sex maintenance in sexually dimorphic tissues and is vital in the preservation of fertility.

  5. Chinmo prevents transformer alternative splicing to maintain male sex identity.

    Science.gov (United States)

    Grmai, Lydia; Hudry, Bruno; Miguel-Aliaga, Irene; Bach, Erika A

    2018-02-01

    Reproduction in sexually dimorphic animals relies on successful gamete production, executed by the germline and aided by somatic support cells. Somatic sex identity in Drosophila is instructed by sex-specific isoforms of the DMRT1 ortholog Doublesex (Dsx). Female-specific expression of Sex-lethal (Sxl) causes alternative splicing of transformer (tra) to the female isoform traF. In turn, TraF alternatively splices dsx to the female isoform dsxF. Loss of the transcriptional repressor Chinmo in male somatic stem cells (CySCs) of the testis causes them to "feminize", resembling female somatic stem cells in the ovary. This somatic sex transformation causes a collapse of germline differentiation and male infertility. We demonstrate this feminization occurs by transcriptional and post-transcriptional regulation of traF. We find that chinmo-deficient CySCs upregulate tra mRNA as well as transcripts encoding tra-splice factors Virilizer (Vir) and Female lethal (2)d (Fl(2)d). traF splicing in chinmo-deficient CySCs leads to the production of DsxF at the expense of the male isoform DsxM, and both TraF and DsxF are required for CySC sex transformation. Surprisingly, CySC feminization upon loss of chinmo does not require Sxl but does require Vir and Fl(2)d. Consistent with this, we show that both Vir and Fl(2)d are required for tra alternative splicing in the female somatic gonad. Our work reveals the need for transcriptional regulation of tra in adult male stem cells and highlights a previously unobserved Sxl-independent mechanism of traF production in vivo. In sum, transcriptional control of the sex determination hierarchy by Chinmo is critical for sex maintenance in sexually dimorphic tissues and is vital in the preservation of fertility.

  6. Conservation and sex-specific splicing of the doublesex gene

    Indian Academy of Sciences (India)

    Genetic control of sex determination in insects has been best characterized in Drosophila melanogaster, where the master gene Sxl codes for RNA that is sex specifically spliced to produce a functional protein only in females. SXL regulates the sex-specific splicing of transformer (tra) RNA which, in turn, regulates the ...

  7. Identification of alternative splice variants in Aspergillus flavus through comparison of multiple tandem MS search algorithms

    Directory of Open Access Journals (Sweden)

    Chang Kung-Yen

    2011-07-01

    Full Text Available Abstract Background Database searching is the most frequently used approach for automated peptide assignment and protein inference of tandem mass spectra. The results, however, depend on the sequences in target databases and on search algorithms. Recently by using an alternative splicing database, we identified more proteins than with the annotated proteins in Aspergillus flavus. In this study, we aimed at finding a greater number of eligible splice variants based on newly available transcript sequences and the latest genome annotation. The improved database was then used to compare four search algorithms: Mascot, OMSSA, X! Tandem, and InsPecT. Results The updated alternative splicing database predicted 15833 putative protein variants, 61% more than the previous results. There was transcript evidence for 50% of the updated genes compared to the previous 35% coverage. Database searches were conducted using the same set of spectral data, search parameters, and protein database but with different algorithms. The false discovery rates of the peptide-spectrum matches were estimated Conclusions We were able to detect dozens of new peptides using the improved alternative splicing database with the recently updated annotation of the A. flavus genome. Unlike the identifications of the peptides and the RefSeq proteins, large variations existed between the putative splice variants identified by different algorithms. 12 candidates of putative isoforms were reported based on the consensus peptide-spectrum matches. This suggests that applications of multiple search engines effectively reduced the possible false positive results and validated the protein identifications from tandem mass spectra using an alternative splicing database.

  8. RNA-Seq analysis and annotation of a draft blueberry genome assembly identifies candidate genes involved in fruit ripening, biosynthesis of bioactive compounds, and stage-specific alternative splicing.

    Science.gov (United States)

    Gupta, Vikas; Estrada, April D; Blakley, Ivory; Reid, Rob; Patel, Ketan; Meyer, Mason D; Andersen, Stig Uggerhøj; Brown, Allan F; Lila, Mary Ann; Loraine, Ann E

    2015-01-01

    Blueberries are a rich source of antioxidants and other beneficial compounds that can protect against disease. Identifying genes involved in synthesis of bioactive compounds could enable the breeding of berry varieties with enhanced health benefits. Toward this end, we annotated a previously sequenced draft blueberry genome assembly using RNA-Seq data from five stages of berry fruit development and ripening. Genome-guided assembly of RNA-Seq read alignments combined with output from ab initio gene finders produced around 60,000 gene models, of which more than half were similar to proteins from other species, typically the grape Vitis vinifera. Comparison of gene models to the PlantCyc database of metabolic pathway enzymes identified candidate genes involved in synthesis of bioactive compounds, including bixin, an apocarotenoid with potential disease-fighting properties, and defense-related cyanogenic glycosides, which are toxic. Cyanogenic glycoside (CG) biosynthetic enzymes were highly expressed in green fruit, and a candidate CG detoxification enzyme was up-regulated during fruit ripening. Candidate genes for ethylene, anthocyanin, and 400 other biosynthetic pathways were also identified. Homology-based annotation using Blast2GO and InterPro assigned Gene Ontology terms to around 15,000 genes. RNA-Seq expression profiling showed that blueberry growth, maturation, and ripening involve dynamic gene expression changes, including coordinated up- and down-regulation of metabolic pathway enzymes and transcriptional regulators. Analysis of RNA-seq alignments identified developmentally regulated alternative splicing, promoter use, and 3' end formation. We report genome sequence, gene models, functional annotations, and RNA-Seq expression data that provide an important new resource enabling high throughput studies in blueberry.

  9. DNA damage regulates alternative splicing through changes in POL II elongation

    International Nuclear Information System (INIS)

    Munoz, M.J.; Perez Santangelo, M.S.; De la Mata, M.; Kornblihtt, A.R.

    2008-01-01

    Many apoptotic genes are regulated via alternative splicing (AS) but little is known about the mechanisms controlling AS in stress situations derived from DNA damage. Here we show that ultraviolet (UV) radiation affects co-transcriptional, but not post transcriptional, AS through a systemic mechanism involving a CDK-9-dependent hyper phosphorylation of RNA polymerase II carboxy terminal domain (CTD) and a subsequent and unprecedented inhibition of transcriptional elongation, estimated in vivo and in real time by FRAP. To mimic this hyper phosphorylation we used CTD mutants with serines 2 or 5 substituted by glutamic acids and found that they not only display lower elongation rates but duplicate the effects of UV light on AS in the absence of irradiation. Consistently, substitution of the serines with alanines prevents the UV effect on splicing. These results represent the first in vivo proof of modulation of elongation in response to an environmental signal, affecting in turn the kinetic coupling between transcription and splicing. (authors)

  10. Alternative Splicing of G9a Regulates Neuronal Differentiation

    Directory of Open Access Journals (Sweden)

    Ana Fiszbein

    2016-03-01

    Full Text Available Chromatin modifications are critical for the establishment and maintenance of differentiation programs. G9a, the enzyme responsible for histone H3 lysine 9 dimethylation in mammalian euchromatin, exists as two isoforms with differential inclusion of exon 10 (E10 through alternative splicing. We find that the G9a methyltransferase is required for differentiation of the mouse neuronal cell line N2a and that E10 inclusion increases during neuronal differentiation of cultured cells, as well as in the developing mouse brain. Although E10 inclusion greatly stimulates overall H3K9me2 levels, it does not affect G9a catalytic activity. Instead, E10 increases G9a nuclear localization. We show that the G9a E10+ isoform is necessary for neuron differentiation and regulates the alternative splicing pattern of its own pre-mRNA, enhancing E10 inclusion. Overall, our findings indicate that by regulating its own alternative splicing, G9a promotes neuron differentiation and creates a positive feedback loop that reinforces cellular commitment to differentiation.

  11. Alternative splicing originates different domain structure organization of Lutzomyia longipalpis chitinases.

    Science.gov (United States)

    Ortigão-Farias, João Ramalho; Di-Blasi, Tatiana; Telleria, Erich Loza; Andorinho, Ana Carolina; Lemos-Silva, Thais; Ramalho-Ortigão, Marcelo; Tempone, Antônio Jorge; Traub-Csekö, Yara Maria

    2018-02-01

    BACKGROUND The insect chitinase gene family is composed by more than 10 paralogs, which can codify proteins with different domain structures. In Lutzomyia longipalpis, the main vector of visceral leishmaniasis in Brazil, a chitinase cDNA from adult female insects was previously characterized. The predicted protein contains one catalytic domain and one chitin-binding domain (CBD). The expression of this gene coincided with the end of blood digestion indicating a putative role in peritrophic matrix degradation. OBJECTIVES To determine the occurrence of alternative splicing in chitinases of L. longipalpis. METHODS We sequenced the LlChit1 gene from a genomic clone and the three spliced forms obtained by reverse transcription polymerase chain reaction (RT-PCR) using larvae cDNA. FINDINGS We showed that LlChit1 from L. longipalpis immature forms undergoes alternative splicing. The spliced form corresponding to the adult cDNA was named LlChit1A and the two larvae specific transcripts were named LlChit1B and LlChit1C. The B and C forms possess stop codons interrupting the translation of the CBD. The A form is present in adult females post blood meal, L4 larvae and pre-pupae, while the other two forms are present only in L4 larvae and disappear just before pupation. Two bands of the expected size were identified by Western blot only in L4 larvae. MAIN CONCLUSIONS We show for the first time alternative splicing generating chitinases with different domain structures increasing our understanding on the finely regulated digestion physiology and shedding light on a potential target for controlling L. longipalpis larval development.

  12. Loss of Endocan tumorigenic properties after alternative splicing of exon 2

    International Nuclear Information System (INIS)

    Depontieu, Florence; Grigoriu, Bogdan-Dragos; Scherpereel, Arnaud; Adam, Estelle; Delehedde, Maryse; Gosset, Philippe; Lassalle, Philippe

    2008-01-01

    Endocan was originally described as a dermatan sulfate proteoglycan found freely circulating in the blood. Endocan expression confers tumorigenic properties to epithelial cell lines or accelerate the growth of already tumorigenic cells. This molecule is the product of a single gene composed of 3 exons. Previous data showed that endocan mRNA is subject to alternative splicing with possible generation of two protein products. In the present study we identified, and functionally characterized, the alternative spliced product of the endocan gene: the exon 2-deleted endocan, called endocanΔ2. Stable, endocanΔ2-overexpressing cell lines were generated to investigate the biological activities of this new alternatively spliced product of endocan gene. Tumorigenesis was studied by inoculating endocan and endocanΔ2 expressing cell lines subcutaneously in SCID mice. Biochemical properties of endocan and endocanΔ2 were studied after production of recombinant proteins in various cell lines of human and murine origin. Our results showed that the exon 2 deletion impairs synthesis of the glycan chain, known to be involved in the pro-tumoral effect of endocan. EndocanΔ2 did not promote tumor formation by 293 cells implanted in the skin of severe combined immunodeficient (SCID) mice. Our results emphasize the key role of the polypeptide sequence encoded by the exon 2 of endocan gene in tumorigenesis, and suggest that this sequence could be a target for future therapies against cancer

  13. Analysis of alternative splicing events for cancer diagnosis using a multiplexing nanophotonic biosensor.

    Science.gov (United States)

    Huertas, César S; Domínguez-Zotes, Santos; Lechuga, Laura M

    2017-01-25

    Personalized medicine is a promising tool not only for prevention, screening and development of more efficient treatment strategies, but also for diminishing the side effects caused by current therapies. Deciphering gene regulation pathways provides a reliable prognostic analysis to elucidate the origin of grave diseases and facilitate the selection of the most adequate treatment for each individual. Alternative splicing of mRNA precursors is one of these gene regulation pathways and enables cells to generate different protein outputs from the same gene depending on their developmental or homeostatic status. Its deregulation is strongly linked to disease onset and progression constituting a relevant and innovative class of biomarker. Herein we report a highly selective and sensitive nanophotonic biosensor based on the direct monitoring of the aberrant alternative splicing of Fas gene. Unlike conventional methods, the nanobiosensor performs a real-time detection of the specific isoforms in the fM-pM range without any cDNA synthesis or PCR amplification requirements. The nanobiosensor has been proven isoform-specific with no crosshybridization, greatly minimizing detection biases. The demonstrated high sensitivity and specificity make our nanobiosensor ideal for examining significant tumor-associated expression shifts of alternatively spliced isoforms for the early and accurate theranostics of cancer.

  14. High resolution analysis of the human transcriptome: detection of extensive alternative splicing independent of transcriptional activity

    Directory of Open Access Journals (Sweden)

    Rouet Fabien

    2009-10-01

    Full Text Available Abstract Background Commercially available microarrays have been used in many settings to generate expression profiles for a variety of applications, including target selection for disease detection, classification, profiling for pharmacogenomic response to therapeutics, and potential disease staging. However, many commercially available microarray platforms fail to capture transcript diversity produced by alternative splicing, a major mechanism for driving proteomic diversity through transcript heterogeneity. Results The human Genome-Wide SpliceArray™ (GWSA, a novel microarray platform, utilizes an existing probe design concept to monitor such transcript diversity on a genome scale. The human GWSA allows the detection of alternatively spliced events within the human genome through the use of exon body and exon junction probes to provide a direct measure of each transcript, through simple calculations derived from expression data. This report focuses on the performance and validation of the array when measured against standards recently published by the Microarray Quality Control (MAQC Project. The array was shown to be highly quantitative, and displayed greater than 85% correlation with the HG-U133 Plus 2.0 array at the gene level while providing more extensive coverage of each gene. Almost 60% of splice events among genes demonstrating differential expression of greater than 3 fold also contained extensive splicing alterations. Importantly, almost 10% of splice events within the gene set displaying constant overall expression values had evidence of transcript diversity. Two examples illustrate the types of events identified: LIM domain 7 showed no differential expression at the gene level, but demonstrated deregulation of an exon skip event, while erythrocyte membrane protein band 4.1 -like 3 was differentially expressed and also displayed deregulation of a skipped exon isoform. Conclusion Significant changes were detected independent of

  15. Meta-Analysis of Multiple Sclerosis Microarray Data Reveals Dysregulation in RNA Splicing Regulatory Genes

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    Elvezia Maria Paraboschi

    2015-09-01

    Full Text Available Abnormalities in RNA metabolism and alternative splicing (AS are emerging as important players in complex disease phenotypes. In particular, accumulating evidence suggests the existence of pathogenic links between multiple sclerosis (MS and altered AS, including functional studies showing that an imbalance in alternatively-spliced isoforms may contribute to disease etiology. Here, we tested whether the altered expression of AS-related genes represents a MS-specific signature. A comprehensive comparative analysis of gene expression profiles of publicly-available microarray datasets (190 MS cases, 182 controls, followed by gene-ontology enrichment analysis, highlighted a significant enrichment for differentially-expressed genes involved in RNA metabolism/AS. In detail, a total of 17 genes were found to be differentially expressed in MS in multiple datasets, with CELF1 being dysregulated in five out of seven studies. We confirmed CELF1 downregulation in MS (p = 0.0015 by real-time RT-PCRs on RNA extracted from blood cells of 30 cases and 30 controls. As a proof of concept, we experimentally verified the unbalance in alternatively-spliced isoforms in MS of the NFAT5 gene, a putative CELF1 target. In conclusion, for the first time we provide evidence of a consistent dysregulation of splicing-related genes in MS and we discuss its possible implications in modulating specific AS events in MS susceptibility genes.

  16. Molecular characterization of the α-subunit of Na⁺/K⁺ ATPase from the euryhaline barnacle Balanus improvisus reveals multiple genes and differential expression of alternative splice variants.

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    Ulrika Lind

    Full Text Available The euryhaline bay barnacle Balanus improvisus has one of the broadest salinity tolerances of any barnacle species. It is able to complete its life cycle in salinities close to freshwater (3 PSU up to fully marine conditions (35 PSU and is regarded as one of few truly brackish-water species. Na⁺/K⁺ ATPase (NAK has been shown to be important for osmoregulation when marine organisms are challenged by changing salinities, and we therefore cloned and examined the expression of different NAKs from B. improvisus. We found two main gene variants, NAK1 and NAK2, which were approximately 70% identical at the protein level. The NAK1 mRNA existed in a long and short variant with the encoded proteins differing only by 27 N-terminal amino acids. This N-terminal stretch was coded for by a separate exon, and the two variants of NAK1 mRNAs appeared to be created by alternative splicing. We furthermore showed that the two NAK1 isoforms were differentially expressed in different life stages and in various tissues of adult barnacle, i.e the long isoform was predominant in cyprids and in adult cirri. In barnacle cyprid larvae that were exposed to a combination of different salinities and pCO2 levels, the expression of the long NAK1 mRNA increased relative to the short in low salinities. We suggest that the alternatively spliced long variant of the Nak1 protein might be of importance for osmoregulation in B. improvisus in low salinity conditions.

  17. Opioid inhibition of N-type Ca2+ channels and spinal analgesia couple to alternative splicing.

    Science.gov (United States)

    Andrade, Arturo; Denome, Sylvia; Jiang, Yu-Qiu; Marangoudakis, Spiro; Lipscombe, Diane

    2010-10-01

    Alternative pre-mRNA splicing occurs extensively in the nervous systems of complex organisms, including humans, considerably expanding the potential size of the proteome. Cell-specific alternative pre-mRNA splicing is thought to optimize protein function for specialized cellular tasks, but direct evidence for this is limited. Transmission of noxious thermal stimuli relies on the activity of N-type Ca(V)2.2 calcium channels in nociceptors. Using an exon-replacement strategy in mice, we show that mutually exclusive splicing patterns in the Ca(V)2.2 gene modulate N-type channel function in nociceptors, leading to a change in morphine analgesia. Exon 37a (e37a) enhances μ-opioid receptor-mediated inhibition of N-type calcium channels by promoting activity-independent inhibition. In the absence of e37a, spinal morphine analgesia is weakened in vivo but the basal response to noxious thermal stimuli is not altered. Our data suggest that highly specialized, discrete cellular responsiveness in vivo can be attributed to alternative splicing events regulated at the level of individual neurons.

  18. CIR, a corepressor of CBF1, binds to PAP-1 and effects alternative splicing

    International Nuclear Information System (INIS)

    Maita, Hiroshi; Kitaura, Hirotake; Ariga, Hiroyoshi; Iguchi-Ariga, Sanae M.M.

    2005-01-01

    We have reported that PAP-1, a product of a causative gene for autosomal retinitis pigmentosa, plays a role in splicing. In this study, CIR, a protein originally identified as a CBF1-interacting protein and reported to act as a transcriptional corepressor, was identified as a PAP-1 binding protein and its function as a splicing factor was investigated. In addition to a basic lysine and acidic serine-rich (BA) domain and a zinc knuckle-like motif, CIR has an arginine/serine dipeptide repeat (RS) domain in its C terminal region. The RS domain has been reported to be present in the superfamily of SR proteins, which are involved in splicing reactions. We generated CIR mutants with deletions of each BA and RS domain and studied their subcellular localizations and interactions with PAP-1 and other SR proteins, including SC35, SF2/ASF, and U2AF 35 . CIR was found to interact with U2AF 35 through the BA domain, with SC35 and SF2/ASF through the RS domain, and with PAP-1 outside the BA domain in vivo and in vitro. CIR was found to be colocalized with SC35 and PAP-1 in nuclear speckles. Then the effect of CIR on splicing was investigated using the E1a minigene as a reporter in HeLa cells. Ectopic expression of CIR with the E1a minigene changed the ratio of spliced isoforms of E1a that were produced by alternative selection of 5'-splice sites. These results indicate that CIR is a member of the family of SR-related proteins and that CIR plays a role in splicing regulation

  19. Splice Site Mutations in the ATP7A Gene

    DEFF Research Database (Denmark)

    Skjørringe, Tina; Tümer, Zeynep; Møller, Lisbeth Birk

    2011-01-01

    Menkes disease (MD) is caused by mutations in the ATP7A gene. We describe 33 novel splice site mutations detected in patients with MD or the milder phenotypic form, Occipital Horn Syndrome. We review these 33 mutations together with 28 previously published splice site mutations. We investigate 12...... mutations for their effect on the mRNA transcript in vivo. Transcriptional data from another 16 mutations were collected from the literature. The theoretical consequences of splice site mutations, predicted with the bioinformatics tool Human Splice Finder, were investigated and evaluated in relation...... to in vivo results. Ninety-six percent of the mutations identified in 45 patients with classical MD were predicted to have a significant effect on splicing, which concurs with the absence of any detectable wild-type transcript in all 19 patients investigated in vivo. Sixty-seven percent of the mutations...

  20. Alternative splicing and extensive RNA editing of human TPH2 transcripts.

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    Maik Grohmann

    Full Text Available Brain serotonin (5-HT neurotransmission plays a key role in the regulation of mood and has been implicated in a variety of neuropsychiatric conditions. Tryptophan hydroxylase (TPH is the rate-limiting enzyme in the biosynthesis of 5-HT. Recently, we discovered a second TPH isoform (TPH2 in vertebrates, including man, which is predominantly expressed in brain, while the previously known TPH isoform (TPH1 is primarly a non-neuronal enzyme. Overwhelming evidence now points to TPH2 as a candidate gene for 5-HT-related psychiatric disorders. To assess the role of TPH2 gene variability in the etiology of psychiatric diseases we performed cDNA sequence analysis of TPH2 transcripts from human post mortem amygdala samples obtained from individuals with psychiatric disorders (drug abuse, schizophrenia, suicide and controls. Here we show that TPH2 exists in two alternatively spliced variants in the coding region, denoted TPH2a and TPH2b. Moreover, we found evidence that the pre-mRNAs of both splice variants are dynamically RNA-edited in a mutually exclusive manner. Kinetic studies with cell lines expressing recombinant TPH2 variants revealed a higher activity of the novel TPH2B protein compared with the previously known TPH2A, whereas RNA editing was shown to inhibit the enzymatic activity of both TPH2 splice variants. Therefore, our results strongly suggest a complex fine-tuning of central nervous system 5-HT biosynthesis by TPH2 alternative splicing and RNA editing. Finally, we present molecular and large-scale linkage data evidencing that deregulated alternative splicing and RNA editing is involved in the etiology of psychiatric diseases, such as suicidal behaviour.

  1. Quantitative evaluation of alternatively spliced mRNA isoforms by label-free real-time plasmonic sensing.

    Science.gov (United States)

    Huertas, César S; Carrascosa, L G; Bonnal, S; Valcárcel, J; Lechuga, L M

    2016-04-15

    Alternative splicing of mRNA precursors enables cells to generate different protein outputs from the same gene depending on their developmental or homeostatic status. Its deregulation is strongly linked to disease onset and progression. Current methodologies for monitoring alternative splicing demand elaborate procedures and often present difficulties in discerning between closely related isoforms, e.g. due to cross-hybridization during their detection. Herein, we report a general methodology using a Surface Plasmon Resonance (SPR) biosensor for label-free monitoring of alternative splicing events in real-time, without any cDNA synthesis or PCR amplification requirements. We applied this methodology to RNA isolated from HeLa cells for the quantification of alternatively spliced isoforms of the Fas gene, involved in cancer progression through regulation of programmed cell death. We demonstrate that our methodology is isoform-specific, with virtually no cross-hybridization, achieving limits of detection (LODs) in the picoMolar (pM) range. Similar results were obtained for the detection of the BCL-X gene mRNA isoforms. The results were independently validated by RT-qPCR, with excellent concordance in the determination of isoform ratios. The simplicity and robustness of this biosensor technology can greatly facilitate the exploration of alternative splicing biomarkers in disease diagnosis and therapy. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. The Cancer Exome Generated by Alternative mRNA Splicing Dilutes Predicted HLA Class I Epitope Density

    DEFF Research Database (Denmark)

    Stranzl, Thomas; Larsen, Mette Voldby; Lund, Ole

    2012-01-01

    Several studies have shown that cancers actively regulate alternative splicing. Altered splicing mechanisms in cancer lead to cancer-specific transcripts different from the pool of transcripts occurring only in healthy tissue. At the same time, altered presentation of HLA class I epitopes...... is frequently observed in various types of cancer. Down-regulation of genes related to HLA class I antigen processing has been observed in several cancer types, leading to fewer HLA class I antigens on the cell surface. Here, we use a peptidome wide analysis of predicted alternative splice forms, based...... on a publicly available database, to show that peptides over-represented in cancer splice variants comprise significantly fewer predicted HLA class I epitopes compared to peptides from normal transcripts. Peptides over-represented in cancer transcripts are in the case of the three most common HLA class I...

  3. Changes in Alternative Splicing in Apis Mellifera Bees Fed Apis Cerana Royal Jelly

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    Shi Yuan Yuan

    2014-12-01

    Full Text Available The Western honey bee (Apis mellifera is a social insect characterized by caste differentiation in which the queen bee and worker bees display marked differences in morphology, behavior, reproduction, and longevity despite their identical genomes. The main causative factor in caste differentiation is the food fed to queen larvae, termed royal jelly (RJ. Alternative splicing (AS is an important RNA-mediated post-transcriptional process in eukaryotes. Here we report AS changes in A. mellifera after being fed either A. mellifera RJ or A. cerana RJ. The results demonstrated that the RJ type affected 4 types of AS in adult A. mellifera: exon skipping, intron retention, alternative 5’ splice sites, and alternative 3’splice sites. After feeding with A. cerana RJ, AS occurred in many genes in adult A. mellifera that encode proteins involved in development, growth, the tricarboxylic acid cycle, and substance metabolism. This study provides the first evidence that heterospecific RJ can influence the AS of many genes related to honey bee development and growth.

  4. Regulation of alternative VEGF-A mRNA splicing is a therapeutic target for analgesia.

    Science.gov (United States)

    Hulse, R P; Beazley-Long, N; Hua, J; Kennedy, H; Prager, J; Bevan, H; Qiu, Y; Fernandes, E S; Gammons, M V; Ballmer-Hofer, K; Gittenberger de Groot, A C; Churchill, A J; Harper, S J; Brain, S D; Bates, D O; Donaldson, L F

    2014-11-01

    Vascular endothelial growth factor-A (VEGF-A) is best known as a key regulator of the formation of new blood vessels. Neutralization of VEGF-A with anti-VEGF therapy e.g. bevacizumab, can be painful, and this is hypothesized to result from a loss of VEGF-A-mediated neuroprotection. The multiple vegf-a gene products consist of two alternatively spliced families, typified by VEGF-A165a and VEGF-A165b (both contain 165 amino acids), both of which are neuroprotective. Under pathological conditions, such as in inflammation and cancer, the pro-angiogenic VEGF-A165a is upregulated and predominates over the VEGF-A165b isoform. We show here that in rats and mice VEGF-A165a and VEGF-A165b have opposing effects on pain, and that blocking the proximal splicing event - leading to the preferential expression of VEGF-A165b over VEGF165a - prevents pain in vivo. VEGF-A165a sensitizes peripheral nociceptive neurons through actions on VEGFR2 and a TRPV1-dependent mechanism, thus enhancing nociceptive signaling. VEGF-A165b blocks the effect of VEGF-A165a. After nerve injury, the endogenous balance of VEGF-A isoforms switches to greater expression of VEGF-Axxxa compared to VEGF-Axxxb, through an SRPK1-dependent pre-mRNA splicing mechanism. Pharmacological inhibition of SRPK1 after traumatic nerve injury selectively reduced VEGF-Axxxa expression and reversed associated neuropathic pain. Exogenous VEGF-A165b also ameliorated neuropathic pain. We conclude that the relative levels of alternatively spliced VEGF-A isoforms are critical for pain modulation under both normal conditions and in sensory neuropathy. Altering VEGF-Axxxa/VEGF-Axxxb balance by targeting alternative RNA splicing may be a new analgesic strategy. Copyright © 2014. Published by Elsevier Inc.

  5. Poliovirus 2A protease triggers a selective nucleo-cytoplasmic redistribution of splicing factors to regulate alternative pre-mRNA splicing.

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    Enrique Álvarez

    Full Text Available Poliovirus protease 2A (2A(pro obstructs host gene expression by reprogramming transcriptional and post-transcriptional regulatory events during infection. Here we demonstrate that expression of 2A(pro induces a selective nucleo-cytoplasm translocation of several important RNA binding proteins and splicing factors. Subcellular fractionation studies, together with immunofluorescence microscopy revealed an asymmetric distribution of HuR and TIA1/TIAR in 2A(pro expressing cells, which modulates splicing of the human Fas exon 6. Consistent with this result, knockdown of HuR or overexpression of TIA1/TIAR, leads to Fas exon 6 inclusion in 2A(pro-expressing cells. Therefore, poliovirus 2A(pro can target alternative pre-mRNA splicing by regulating protein shuttling between the nucleus and the cytoplasm.

  6. Genome-wide analysis of alternative splicing of pre-mRNA under salt stress in Arabidopsis

    KAUST Repository

    Ding, Feng

    2014-06-04

    Background: Alternative splicing (AS) of precursor mRNA (pre-mRNA) is an important gene regulation process that potentially regulates many physiological processes in plants, including the response to abiotic stresses such as salt stress.Results: To analyze global changes in AS under salt stress, we obtained high-coverage (~200 times) RNA sequencing data from Arabidopsis thaliana seedlings that were treated with different concentrations of NaCl. We detected that ~49% of all intron-containing genes were alternatively spliced under salt stress, 10% of which experienced significant differential alternative splicing (DAS). Furthermore, AS increased significantly under salt stress compared with under unstressed conditions. We demonstrated that most DAS genes were not differentially regulated by salt stress, suggesting that AS may represent an independent layer of gene regulation in response to stress. Our analysis of functional categories suggested that DAS genes were associated with specific functional pathways, such as the pathways for the responses to stresses and RNA splicing. We revealed that serine/arginine-rich (SR) splicing factors were frequently and specifically regulated in AS under salt stresses, suggesting a complex loop in AS regulation for stress adaptation. We also showed that alternative splicing site selection (SS) occurred most frequently at 4 nucleotides upstream or downstream of the dominant sites and that exon skipping tended to link with alternative SS.Conclusions: Our study provided a comprehensive view of AS under salt stress and revealed novel insights into the potential roles of AS in plant response to salt stress. 2014 Ding et al.; licensee BioMed Central Ltd.

  7. Identification of a novel splicing form of amelogenin gene in a reptile, Ctenosaura similis.

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    Xinping Wang

    Full Text Available Amelogenin, the major enamel matrix protein in tooth development, has been demonstrated to play a significant role in tooth enamel formation. Previous studies have identified the alternative splicing of amelogenin in many mammalian vertebrates as one mechanism for amelogenin heterogeneous expression in teeth. While amelogenin and its splicing forms in mammalian vertebrates have been cloned and sequenced, the amelogenin gene, especially its splicing forms in non-mammalian species, remains largely unknown. To better understand the mechanism underlying amelogenin evolution, we previously cloned and characterized an amelogenin gene sequence from a squamate, the green iguana. In this study, we employed RT-PCR to amplify the amelogenin gene from the black spiny-tailed iguana Ctenosaura similis teeth, and discovered a novel splicing form of the amelogenin gene. The transcript of the newly identified iguana amelogenin gene (named C. Similis-T2L is 873 nucleotides long encoding an expected polypeptide of 206 amino acids. The C. Similis-T2L contains a unique exon denominated exon X, which is located between exon 5 and exon 6. The C. Similis-T2L contains 7 exons including exon 1, 2, 3, 5, X, 6, and 7. Analysis of the secondary and tertiary structures of T2L amelogenin protein demonstrated that exon X has a dramatic effect on the amelogenin structures. This is the first report to provide definitive evidence for the amelogenin alternative splicing in non-mammalian vertebrates, revealing a unique exon X and the splicing form of the amelogenin gene transcript in Ctenosaura similis.

  8. Alternative splicing of a single transcription factor drives selfish reproductive behavior in honeybee workers (Apis mellifera).

    Science.gov (United States)

    Jarosch, Antje; Stolle, Eckart; Crewe, Robin M; Moritz, Robin F A

    2011-09-13

    In eusocial insects the production of daughters is generally restricted to mated queens, and unmated workers are functionally sterile. The evolution of this worker sterility has been plausibly explained by kin selection theory [Hamilton W (1964) J Theor Biol 7:1-52], and many traits have evolved to prevent conflict over reproduction among the females in an insect colony. In honeybees (Apis mellifera), worker reproduction is regulated by the queen, brood pheromones, and worker policing. However, workers of the Cape honeybee, Apis mellifera capensis, can evade this control and establish themselves as social parasites by activating their ovaries, parthenogenetically producing diploid female offspring (thelytoky) and producing queen-like amounts of queen pheromones. All these traits have been shown to be strongly influenced by a single locus on chromosome 13 [Lattorff HMG, et al. (2007) Biol Lett 3:292-295]. We screened this region for candidate genes and found that alternative splicing of a gene homologous to the gemini transcription factor of Drosophila controls worker sterility. Knocking out the critical exon in a series of RNAi experiments resulted in rapid worker ovary activation-one of the traits characteristic of the social parasites. This genetic switch may be controlled by a short intronic splice enhancer motif of nine nucleotides attached to the alternative splice site. The lack of this motif in parasitic Cape honeybee clones suggests that the removal of nine nucleotides from the altruistic worker genome may be sufficient to turn a honeybee from an altruistic worker into a parasite.

  9. Periostin shows increased evolutionary plasticity in its alternatively spliced region

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    Hoersch Sebastian

    2010-01-01

    Full Text Available Abstract Background Periostin (POSTN is a secreted extracellular matrix protein of poorly defined function that has been related to bone and heart development as well as to cancer. In human and mouse, it is known to undergo alternative splicing in its C-terminal region, which is devoid of known protein domains. Differential expression of periostin, sometimes of specific splicing isoforms, is observed in a broad range of human cancers, including breast, pancreatic, and colon cancer. Here, we combine genomic and transcriptomic sequence data from vertebrate organisms to study the evolution of periostin and particularly of its C-terminal region. Results We found that the C-terminal part of periostin is markedly more variable among vertebrates than the rest of periostin in terms of exon count, length, and splicing pattern, which we interpret as a consequence of neofunctionalization after the split between periostin and its paralog transforming growth factor, beta-induced (TGFBI. We also defined periostin's sequential 13-amino acid repeat units - well conserved in teleost fish, but more obscure in higher vertebrates - whose secondary structure is predicted to be consecutive beta strands. We suggest that these beta strands may mediate binding interactions with other proteins through an extended beta-zipper in a manner similar to the way repeat units in bacterial cell wall proteins have been reported to bind human fibronectin. Conclusions Our results, obtained with the help of the increasingly large collection of complete vertebrate genomes, document the evolutionary plasticity of periostin's C-terminal region, and for the first time suggest a basis for its functional role.

  10. Novel Alternative Splice Variants of Mouse Cdk5rap2.

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    Nadine Kraemer

    Full Text Available Autosomal recessive primary microcephaly (MCPH is a rare neurodevelopmental disorder characterized by a pronounced reduction of brain volume and intellectual disability. A current model for the microcephaly phenotype invokes a stem cell proliferation and differentiation defect, which has moved the disease into the spotlight of stem cell biology and neurodevelopmental science. Homozygous mutations of the Cyclin-dependent kinase-5 regulatory subunit-associated protein 2 gene CDK5RAP2 are one genetic cause of MCPH. To further characterize the pathomechanism underlying MCPH, we generated a conditional Cdk5rap2 LoxP/hCMV Cre mutant mouse. Further analysis, initiated on account of a lack of a microcephaly phenotype in these mutant mice, revealed the presence of previously unknown splice variants of the Cdk5rap2 gene that are at least in part accountable for the lack of microcephaly in the mice.

  11. Structural organization of the human and mouse laminin beta2 chain genes, and alternative splicing at the 5' end of the human transcript

    DEFF Research Database (Denmark)

    Durkin, M E; Gautam, M; Loechel, F

    1996-01-01

    We have determined the structural organization of the human and mouse genes that encode the laminin beta2 chain (s-laminin), an essential component of the basement membranes of the neuromuscular synapse and the kidney glomerulus. The human and mouse genes have a nearly identical exon-intron organ......We have determined the structural organization of the human and mouse genes that encode the laminin beta2 chain (s-laminin), an essential component of the basement membranes of the neuromuscular synapse and the kidney glomerulus. The human and mouse genes have a nearly identical exon...

  12. A DNMT3B alternatively spliced exon and encoded peptide are novel biomarkers of human pluripotent stem cells.

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    Sailesh Gopalakrishna-Pillai

    Full Text Available A major obstacle in human stem cell research is the limited number of reagents capable of distinguishing pluripotent stem cells from partially differentiated or incompletely reprogrammed derivatives. Although human embryonic stem cells (hESCs and induced pluripotent stem cells (iPSCs express numerous alternatively spliced transcripts, little attention has been directed at developing splice variant-encoded protein isoforms as reagents for stem cell research. In this study, several genes encoding proteins involved in important signaling pathways were screened to detect alternatively spliced transcripts that exhibited differential expression in pluripotent stem cells (PSCs relative to spontaneously differentiated cells (SDCs. Transcripts containing the alternatively spliced exon 10 of the de novo DNA methyltransferase gene, DNMT3B, were identified that are expressed in PSCs. To demonstrate the utility and superiority of splice variant specific reagents for stem cell research, a peptide encoded by DNMT3B exon 10 was used to generate an antibody, SG1. The SG1 antibody detects a single DNMT3B protein isoform that is expressed only in PSCs but not in SDCs. The SG1 antibody is also demonstrably superior to other antibodies at distinguishing PSCs from SDCs in mixed cultures containing both pluripotent stem cells and partially differentiated derivatives. The tightly controlled down regulation of DNMT3B exon 10 containing transcripts (and exon 10 encoded peptide upon spontaneous differentiation of PSCs suggests that this DNMT3B splice isoform is characteristic of the pluripotent state. Alternatively spliced exons, and the proteins they encode, represent a vast untapped reservoir of novel biomarkers that can be used to develop superior reagents for stem cell research and to gain further insight into mechanisms controlling stem cell pluripotency.

  13. Single molecule analysis of c-myb alternative splicing reveals novel classifiers for precursor B-ALL.

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    Ye E Zhou

    Full Text Available The c-Myb transcription factor, a key regulator of proliferation and differentiation in hematopoietic and other cell types, has an N-terminal DNA binding domain and a large C-terminal domain responsible for transcriptional activation, negative regulation and determining target gene specificity. Overexpression and rearrangement of the c-myb gene (MYB has been reported in some patients with leukemias and other types of cancers, implicating activated alleles of c-myb in the development of human tumors. Alternative RNA splicing can produce variants of c-myb with qualitatively distinct transcriptional activities that may be involved in transformation and leukemogenesis. Here, by performing a detailed, single molecule assay we found that c-myb alternative RNA splicing was elevated and much more complex in leukemia samples than in cell lines or CD34+ hematopoietic progenitor cells from normal donors. The results revealed that leukemia samples express more than 60 different c-myb splice variants, most of which have multiple alternative splicing events and were not detectable by conventional microarray or PCR approaches. For example, the single molecule assay detected 21 and 22 splice variants containing the 9B and 9S exons, respectively, most of which encoded unexpected variant forms of c-Myb protein. Furthermore, the detailed analysis identified some splice variants whose expression correlated with poor survival in a small cohort of precursor B-ALL samples. Our findings indicate that single molecule assays can reveal complexities in c-myb alternative splicing that have potential as novel biomarkers and could help explain the role of c-Myb variants in the development of human leukemia.

  14. Alternative splicing affects the targeting sequence of peroxisome proteins in Arabidopsis.

    Science.gov (United States)

    An, Chuanjing; Gao, Yuefang; Li, Jinyu; Liu, Xiaomin; Gao, Fuli; Gao, Hongbo

    2017-07-01

    A systematic analysis of the Arabidopsis genome in combination with localization experiments indicates that alternative splicing affects the peroxisomal targeting sequence of at least 71 genes in Arabidopsis. Peroxisomes are ubiquitous eukaryotic cellular organelles that play a key role in diverse metabolic functions. All peroxisome proteins are encoded by nuclear genes and target to peroxisomes mainly through two types of targeting signals: peroxisomal targeting signal type 1 (PTS1) and PTS2. Alternative splicing (AS) is a process occurring in all eukaryotes by which a single pre-mRNA can generate multiple mRNA variants, often encoding proteins with functional differences. However, the effects of AS on the PTS1 or PTS2 and the targeting of the protein were rarely studied, especially in plants. Here, we systematically analyzed the genome of Arabidopsis, and found that the C-terminal targeting sequence PTS1 of 66 genes and the N-terminal targeting sequence PTS2 of 5 genes are affected by AS. Experimental determination of the targeting of selected protein isoforms further demonstrated that AS at both the 5' and 3' region of a gene can affect the inclusion of PTS2 and PTS1, respectively. This work underscores the importance of AS on the global regulation of peroxisome protein targeting.

  15. A statistical method for predicting splice variants between two groups of samples using GeneChip® expression array data

    Directory of Open Access Journals (Sweden)

    Olson James M

    2006-04-01

    Full Text Available Abstract Background Alternative splicing of pre-messenger RNA results in RNA variants with combinations of selected exons. It is one of the essential biological functions and regulatory components in higher eukaryotic cells. Some of these variants are detectable with the Affymetrix GeneChip® that uses multiple oligonucleotide probes (i.e. probe set, since the target sequences for the multiple probes are adjacent within each gene. Hybridization intensity from a probe correlates with abundance of the corresponding transcript. Although the multiple-probe feature in the current GeneChip® was designed to assess expression values of individual genes, it also measures transcriptional abundance for a sub-region of a gene sequence. This additional capacity motivated us to develop a method to predict alternative splicing, taking advance of extensive repositories of GeneChip® gene expression array data. Results We developed a two-step approach to predict alternative splicing from GeneChip® data. First, we clustered the probes from a probe set into pseudo-exons based on similarity of probe intensities and physical adjacency. A pseudo-exon is defined as a sequence in the gene within which multiple probes have comparable probe intensity values. Second, for each pseudo-exon, we assessed the statistical significance of the difference in probe intensity between two groups of samples. Differentially expressed pseudo-exons are predicted to be alternatively spliced. We applied our method to empirical data generated from GeneChip® Hu6800 arrays, which include 7129 probe sets and twenty probes per probe set. The dataset consists of sixty-nine medulloblastoma (27 metastatic and 42 non-metastatic samples and four cerebellum samples as normal controls. We predicted that 577 genes would be alternatively spliced when we compared normal cerebellum samples to medulloblastomas, and predicted that thirteen genes would be alternatively spliced when we compared metastatic

  16. An in vivo genetic screen for genes involved in spliced leader trans-splicing indicates a crucial role for continuous de novo spliced leader RNP assembly.

    Science.gov (United States)

    Philippe, Lucas; Pandarakalam, George C; Fasimoye, Rotimi; Harrison, Neale; Connolly, Bernadette; Pettitt, Jonathan; Müller, Berndt

    2017-08-21

    Spliced leader (SL) trans-splicing is a critical element of gene expression in a number of eukaryotic groups. This process is arguably best understood in nematodes, where biochemical and molecular studies in Caenorhabditis elegans and Ascaris suum have identified key steps and factors involved. Despite this, the precise details of SL trans-splicing have yet to be elucidated. In part, this is because the systematic identification of the molecules involved has not previously been possible due to the lack of a specific phenotype associated with defects in this process. We present here a novel GFP-based reporter assay that can monitor SL1 trans-splicing in living C. elegans. Using this assay, we have identified mutants in sna-1 that are defective in SL trans-splicing, and demonstrate that reducing function of SNA-1, SNA-2 and SUT-1, proteins that associate with SL1 RNA and related SmY RNAs, impairs SL trans-splicing. We further demonstrate that the Sm proteins and pICln, SMN and Gemin5, which are involved in small nuclear ribonucleoprotein assembly, have an important role in SL trans-splicing. Taken together these results provide the first in vivo evidence for proteins involved in SL trans-splicing, and indicate that continuous replacement of SL ribonucleoproteins consumed during trans-splicing reactions is essential for effective trans-splicing. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  17. High expression of PTBP1 promote invasion of colorectal cancer by alternative splicing of cortactin.

    Science.gov (United States)

    Wang, Zhi-Na; Liu, Dan; Yin, Bin; Ju, Wen-Yi; Qiu, Hui-Zhong; Xiao, Yi; Chen, Yuan-Jia; Peng, Xiao-Zhong; Lu, Chong-Mei

    2017-05-30

    Polypyrimidine tract-binding protein 1 (PTBP1) involving in almost all steps of mRNA regulation including alternative splicing metabolism during tumorigenesis due to its RNA-binding activity. Initially, we found that high expressed PTBP1 and poor prognosis was interrelated in colorectal cancer (CRC) patients with stages II and III CRC, which widely different in prognosis and treatment, by immunohistochemistry. PTBP1 was also upregulated in colon cancer cell lines. In our study, knockdown of PTBP1 by siRNA transfection decreased cell proliferation and invasion in vitro. Denovirus shRNA knockdown of PTBP1 inhibited colorectal cancer growth in vivo. Furthermore, PTBP1 regulates alternative splicing of many target genes involving in tumorgenesis in colon cancer cells. We confirmed that the splicing of cortactin exon 11 which was only contained in cortactin isoform-a, as a PTBP1 target. Knockdown of PTBP1 decreased the expression of cortactin isoform-a by exclusion of exon 11. Also the mRNA levels of PTBP1 and cortactin isoform-a were cooperatively expressed in colorectal cancer tissues. Knocking down cortactin isoform-a significantly decreased cell migration and invasion in colorectal cancer cells. Overexpression of cortactin isoform-a could rescue PTBP1-knockdown effect of cell motility. In summary the study revealed that PTBP1 facilitates colorectal cancer migration and invasion activities by inclusion of cortactin exon 11.

  18. Multi-species sequence comparison reveals conservation of ghrelin gene-derived splice variants encoding a truncated ghrelin peptide.

    Science.gov (United States)

    Seim, Inge; Jeffery, Penny L; Thomas, Patrick B; Walpole, Carina M; Maugham, Michelle; Fung, Jenny N T; Yap, Pei-Yi; O'Keeffe, Angela J; Lai, John; Whiteside, Eliza J; Herington, Adrian C; Chopin, Lisa K

    2016-06-01

    The peptide hormone ghrelin is a potent orexigen produced predominantly in the stomach. It has a number of other biological actions, including roles in appetite stimulation, energy balance, the stimulation of growth hormone release and the regulation of cell proliferation. Recently, several ghrelin gene splice variants have been described. Here, we attempted to identify conserved alternative splicing of the ghrelin gene by cross-species sequence comparisons. We identified a novel human exon 2-deleted variant and provide preliminary evidence that this splice variant and in1-ghrelin encode a C-terminally truncated form of the ghrelin peptide, termed minighrelin. These variants are expressed in humans and mice, demonstrating conservation of alternative splicing spanning 90 million years. Minighrelin appears to have similar actions to full-length ghrelin, as treatment with exogenous minighrelin peptide stimulates appetite and feeding in mice. Forced expression of the exon 2-deleted preproghrelin variant mirrors the effect of the canonical preproghrelin, stimulating cell proliferation and migration in the PC3 prostate cancer cell line. This is the first study to characterise an exon 2-deleted preproghrelin variant and to demonstrate sequence conservation of ghrelin gene-derived splice variants that encode a truncated ghrelin peptide. This adds further impetus for studies into the alternative splicing of the ghrelin gene and the function of novel ghrelin peptides in vertebrates.

  19. Genetic analysis of complement C1s deficiency associated with systemic lupus erythematosus highlights alternative splicing of normal C1s gene

    DEFF Research Database (Denmark)

    Amano, Mariane T; Ferriani, Virgínia P L; Florido, Marlene P C

    2008-01-01

    Deficiencies of complement proteins of the classical pathway are strongly associated with the development of autoimmune diseases. Deficiency of C1r has been observed to occur concomitantly with deficiency in C1s and 9 out of 15 reported cases presented systemic lupus erythematosus (SLE). Here, we...... describe a family in which all four children are deficient in C1s but only two of them developed SLE. Hemolytic activity mediated by the alternative and the lectin pathways were normal, but classical pathway activation was absent in all children's sera. C1s was undetectable, while in the parents' sera...

  20. Proteogenomic analysis reveals alternative splicing and translation as part of the abscisic acid response in Arabidopsis seedlings.

    Science.gov (United States)

    Zhu, Fu-Yuan; Chen, Mo-Xian; Ye, Neng-Hui; Shi, Lu; Ma, Kai-Long; Yang, Jing-Fang; Cao, Yun-Ying; Zhang, Youjun; Yoshida, Takuya; Fernie, Alisdair R; Fan, Guang-Yi; Wen, Bo; Zhou, Ruo; Liu, Tie-Yuan; Fan, Tao; Gao, Bei; Zhang, Di; Hao, Ge-Fei; Xiao, Shi; Liu, Ying-Gao; Zhang, Jianhua

    2017-08-01

    In eukaryotes, mechanisms such as alternative splicing (AS) and alternative translation initiation (ATI) contribute to organismal protein diversity. Specifically, splicing factors play crucial roles in responses to environment and development cues; however, the underlying mechanisms are not well investigated in plants. Here, we report the parallel employment of short-read RNA sequencing, single molecule long-read sequencing and proteomic identification to unravel AS isoforms and previously unannotated proteins in response to abscisic acid (ABA) treatment. Combining the data from the two sequencing methods, approximately 83.4% of intron-containing genes were alternatively spliced. Two AS types, which are referred to as alternative first exon (AFE) and alternative last exon (ALE), were more abundant than intron retention (IR); however, by contrast to AS events detected under normal conditions, differentially expressed AS isoforms were more likely to be translated. ABA extensively affects the AS pattern, indicated by the increasing number of non-conventional splicing sites. This work also identified thousands of unannotated peptides and proteins by ATI based on mass spectrometry and a virtual peptide library deduced from both strands of coding regions within the Arabidopsis genome. The results enhance our understanding of AS and alternative translation mechanisms under normal conditions, and in response to ABA treatment. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  1. The emerging role of alternative splicing in senescence and aging.

    Science.gov (United States)

    Deschênes, Mathieu; Chabot, Benoit

    2017-10-01

    Deregulation of precursor mRNA splicing is associated with many illnesses and has been linked to age-related chronic diseases. Here we review recent progress documenting how defects in the machinery that performs intron removal and controls splice site selection contribute to cellular senescence and organismal aging. We discuss the functional association linking p53, IGF-1, SIRT1, and ING-1 splice variants with senescence and aging, and review a selection of splicing defects occurring in accelerated aging (progeria), vascular aging, and Alzheimer's disease. Overall, it is becoming increasingly clear that changes in the activity of splicing factors and in the production of key splice variants can impact cellular senescence and the aging phenotype. © 2017 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  2. Alternative splicing enriched cDNA libraries identify breast cancer-associated transcripts

    Science.gov (United States)

    2010-01-01

    Background Alternative splicing (AS) is a central mechanism in the generation of genomic complexity and is a major contributor to transcriptome and proteome diversity. Alterations of the splicing process can lead to deregulation of crucial cellular processes and have been associated with a large spectrum of human diseases. Cancer-associated transcripts are potential molecular markers and may contribute to the development of more accurate diagnostic and prognostic methods and also serve as therapeutic targets. Alternative splicing-enriched cDNA libraries have been used to explore the variability generated by alternative splicing. In this study, by combining the use of trapping heteroduplexes and RNA amplification, we developed a powerful approach that enables transcriptome-wide exploration of the AS repertoire for identifying AS variants associated with breast tumor cells modulated by ERBB2 (HER-2/neu) oncogene expression. Results The human breast cell line (C5.2) and a pool of 5 ERBB2 over-expressing breast tumor samples were used independently for the construction of two AS-enriched libraries. In total, 2,048 partial cDNA sequences were obtained, revealing 214 alternative splicing sequence-enriched tags (ASSETs). A subset with 79 multiple exon ASSETs was compared to public databases and reported 138 different AS events. A high success rate of RT-PCR validation (94.5%) was obtained, and 2 novel AS events were identified. The influence of ERBB2-mediated expression on AS regulation was evaluated by capillary electrophoresis and probe-ligation approaches in two mammary cell lines (Hb4a and C5.2) expressing different levels of ERBB2. The relative expression balance between AS variants from 3 genes was differentially modulated by ERBB2 in this model system. Conclusions In this study, we presented a method for exploring AS from any RNA source in a transcriptome-wide format, which can be directly easily adapted to next generation sequencers. We identified AS transcripts

  3. Identification of a chemical inhibitor for nuclear speckle formation: Implications for the function of nuclear speckles in regulation of alternative pre-mRNA splicing

    Energy Technology Data Exchange (ETDEWEB)

    Kurogi, Yutaro; Matsuo, Yota; Mihara, Yuki; Yagi, Hiroaki; Shigaki-Miyamoto, Kaya; Toyota, Syukichi; Azuma, Yuko [Department of Biological Sciences, Graduate School of Science and Technology, Kumamoto University, Chuo-ku, Kumamoto 860-8555 (Japan); Igarashi, Masayuki [Laboratory of Disease Biology, Institute of Microbial Chemistry, Shinagawa-ku, Tokyo 141-0021 (Japan); Tani, Tokio, E-mail: ttani@sci.kumamoto-u.ac.jp [Department of Biological Sciences, Graduate School of Science and Technology, Kumamoto University, Chuo-ku, Kumamoto 860-8555 (Japan)

    2014-03-28

    Highlights: • We identified tubercidin as a compound inducing aberrant formation of the speckles. • Tubercidin causes delocalization of poly (A){sup +}RNAs from nuclear speckles. • Tubercidin induces dispersion of splicing factors from nuclear speckles. • Tubercidin affects alternative pre-mRNA splicing. • Nuclear speckles play a role in regulation of alternative pre-mRNA splicing. - Abstract: Nuclear speckles are subnuclear structures enriched with RNA processing factors and poly (A){sup +} RNAs comprising mRNAs and poly (A){sup +} non-coding RNAs (ncRNAs). Nuclear speckles are thought to be involved in post-transcriptional regulation of gene expression, such as pre-mRNA splicing. By screening 3585 culture extracts of actinomycetes with in situ hybridization using an oligo dT probe, we identified tubercidin, an analogue of adenosine, as an inhibitor of speckle formation, which induces the delocalization of poly (A){sup +} RNA and dispersion of splicing factor SRSF1/SF2 from nuclear speckles in HeLa cells. Treatment with tubercidin also decreased steady-state MALAT1 long ncRNA, thought to be involved in the retention of SRSF1/SF2 in nuclear speckles. In addition, we found that tubercidin treatment promoted exon skipping in the alternative splicing of Clk1 pre-mRNA. These results suggest that nuclear speckles play a role in modulating the concentration of splicing factors in the nucleoplasm to regulate alternative pre-mRNA splicing.

  4. Tracking the evolution of alternatively spliced exons within the Dscam family

    Directory of Open Access Journals (Sweden)

    Vision Todd J

    2006-02-01

    Full Text Available Abstract Background The Dscam gene in the fruit fly, Drosophila melanogaster, contains twenty-four exons, four of which are composed of tandem arrays that each undergo mutually exclusive alternative splicing (4, 6, 9 and 17, potentially generating 38,016 protein isoforms. This degree of transcript diversity has not been found in mammalian homologs of Dscam. We examined the molecular evolution of exons within this gene family to locate the point of divergence for this alternative splicing pattern. Results Using the fruit fly Dscam exons 4, 6, 9 and 17 as seed sequences, we iteratively searched sixteen genomes for homologs, and then performed phylogenetic analyses of the resulting sequences to examine their evolutionary history. We found homologs in the nematode, arthropod and vertebrate genomes, including homologs in several vertebrates where Dscam had not been previously annotated. Among these, only the arthropods contain homologs arranged in tandem arrays indicative of mutually exclusive splicing. We found no homologs to these exons within the Arabidopsis, yeast, tunicate or sea urchin genomes but homologs to several constitutive exons from fly Dscam were present within tunicate and sea urchin. Comparing the rate of turnover within the tandem arrays of the insect taxa (fruit fly, mosquito and honeybee, we found the variants within exons 4 and 17 are well conserved in number and spatial arrangement despite 248–283 million years of divergence. In contrast, the variants within exons 6 and 9 have undergone considerable turnover since these taxa diverged, as indicated by deeply branching taxon-specific lineages. Conclusion Our results suggest that at least one Dscam exon array may be an ancient duplication that predates the divergence of deuterostomes from protostomes but that there is no evidence for the presence of arrays in the common ancestor of vertebrates. The different patterns of conservation and turnover among the Dscam exon arrays

  5. MAISTAS: a tool for automatic structural evaluation of alternative splicing products.

    KAUST Repository

    Floris, Matteo; Raimondo, Domenico; Leoni, Guido; Orsini, Massimiliano; Marcatili, Paolo; Tramontano, Anna

    2011-01-01

    MOTIVATION: Analysis of the human genome revealed that the amount of transcribed sequence is an order of magnitude greater than the number of predicted and well-characterized genes. A sizeable fraction of these transcripts is related to alternatively spliced forms of known protein coding genes. Inspection of the alternatively spliced transcripts identified in the pilot phase of the ENCODE project has clearly shown that often their structure might substantially differ from that of other isoforms of the same gene, and therefore that they might perform unrelated functions, or that they might even not correspond to a functional protein. Identifying these cases is obviously relevant for the functional assignment of gene products and for the interpretation of the effect of variations in the corresponding proteins. RESULTS: Here we describe a publicly available tool that, given a gene or a protein, retrieves and analyses all its annotated isoforms, provides users with three-dimensional models of the isoform(s) of his/her interest whenever possible and automatically assesses whether homology derived structural models correspond to plausible structures. This information is clearly relevant. When the homology model of some isoforms of a gene does not seem structurally plausible, the implications are that either they assume a structure unrelated to that of the other isoforms of the same gene with presumably significant functional differences, or do not correspond to functional products. We provide indications that the second hypothesis is likely to be true for a substantial fraction of the cases. AVAILABILITY: http://maistas.bioinformatica.crs4.it/.

  6. MAISTAS: a tool for automatic structural evaluation of alternative splicing products.

    KAUST Repository

    Floris, Matteo

    2011-04-15

    MOTIVATION: Analysis of the human genome revealed that the amount of transcribed sequence is an order of magnitude greater than the number of predicted and well-characterized genes. A sizeable fraction of these transcripts is related to alternatively spliced forms of known protein coding genes. Inspection of the alternatively spliced transcripts identified in the pilot phase of the ENCODE project has clearly shown that often their structure might substantially differ from that of other isoforms of the same gene, and therefore that they might perform unrelated functions, or that they might even not correspond to a functional protein. Identifying these cases is obviously relevant for the functional assignment of gene products and for the interpretation of the effect of variations in the corresponding proteins. RESULTS: Here we describe a publicly available tool that, given a gene or a protein, retrieves and analyses all its annotated isoforms, provides users with three-dimensional models of the isoform(s) of his/her interest whenever possible and automatically assesses whether homology derived structural models correspond to plausible structures. This information is clearly relevant. When the homology model of some isoforms of a gene does not seem structurally plausible, the implications are that either they assume a structure unrelated to that of the other isoforms of the same gene with presumably significant functional differences, or do not correspond to functional products. We provide indications that the second hypothesis is likely to be true for a substantial fraction of the cases. AVAILABILITY: http://maistas.bioinformatica.crs4.it/.

  7. Aberrant Splicing of Estrogen Receptor, HER2, and CD44 Genes in Breast Cancer

    Directory of Open Access Journals (Sweden)

    Kazushi Inoue

    2015-01-01

    Full Text Available Breast cancer (BC is the most common cause of cancer-related death among women under the age of 50 years. Established biomarkers, such as hormone receptors (estrogen receptor [ER]/progesterone receptor and human epidermal growth factor receptor 2 (HER2, play significant roles in the selection of patients for endocrine and trastuzumab therapies. However, the initial treatment response is often followed by tumor relapse with intrinsic resistance to the first-line therapy, so it has been expected to identify novel molecular markers to improve the survival and quality of life of patients. Alternative splicing of pre-messenger RNAs is a ubiquitous and flexible mechanism for the control of gene expression in mammalian cells. It provides cells with the opportunity to create protein isoforms with different, even opposing, functions from a single genomic locus. Aberrant alternative splicing is very common in cancer where emerging tumor cells take advantage of this flexibility to produce proteins that promote cell growth and survival. While a number of splicing alterations have been reported in human cancers, we focus on aberrant splicing of ER , HER2 , and CD44 genes from the viewpoint of BC development. ERα36 , a splice variant from the ER1 locus, governs nongenomic membrane signaling pathways triggered by estrogen and confers 4-hydroxytamoxifen resistance in BC therapy. The alternative spliced isoform of HER2 lacking exon 20 (Δ16HER2 has been reported in human BC; this isoform is associated with transforming ability than the wild-type HER2 and recapitulates the phenotypes of endocrine therapy-resistant BC. Although both CD44 splice isoforms ( CD44s , CD44v play essential roles in BC development, CD44v is more associated with those with favorable prognosis, such as luminal A subtype, while CD44s is linked to those with poor prognosis, such as HER2 or basal cell subtypes that are often metastatic. Hence, the detection of splice variants from these loci

  8. TGFβ1-mediated expression and alternative splicing of Fibronectin Extra Domain A in human podocyte culture.

    Science.gov (United States)

    Madne, Tarunkumar Hemraj; Dockrell, Mark Edward Carl

    2018-02-28

    Alternative splicing is a fundamental phenomenon to build protein diversity in health and diseases. Extra Domain A+ Fibronectin (EDA+Fn) is an alternatively spliced form of fibronectin protein present in the extra cellular matrix (ECM) in renal fibrosis. Podocytes are spectacular cell type and play a key role in filtration and synthesise ECM proteins in renal physiology and pathology. TGFβ1 is a strong stimulator of ECM proteins in renal injury. In this study, we have investigated alternative splicing of EDA+ Fn in human podocytes in response to TGFβ1. We have performed western blotting and immunofluorescence to characterise the expression of the EDA+Fn protein, real-time PCR for RNA expression and RT-PCR to look for alternative splicing of EDA+Fn in conditionally immortalised human podocytes culture.We used TGFβ1 as a stimulator and SB431542 and SRPIN340 for inhibitory studies. In this work, for the first time we have demonstrated in human podocytes culture EDA+Fn is expressed in the basal condition and TGFβ1 2.5ng/ml induced the Fn mRNA and EDA+Fn protein expression demonstrated by real-time PCR, western blotting and immunofluorescence. TGFβ1 2.5ng/ml induced the alternative splicing of EDA+Fn shown by conventional RT-PCR. Studies with ALK5 inhibitor SB431542 and SRPIN340 show that TGFβ1 induced alternative splicing of EDA+Fn was by the ALK5 receptor and the SR proteins.  In human podocytes culture, alternative splicing of EDA+Fn occurs at basal conditions and TGFβ1 further induced the alternative splicing of EDA+Fn via ALK5 receptor activation and SR proteins. This is the first evidence of basal and TGFβ1 mediated alternative splicing of EDA+Fn in human podocytes culture.

  9. Decreased alternative splicing of estrogen receptor-α mRNA in the Alzheimer's disease brain

    NARCIS (Netherlands)

    Ishunina, Tatjana A.; Swaab, Dick F.

    2012-01-01

    In this study we identified 62 estrogen receptor alpha (ERα) mRNA splice variants in different human brain areas of Alzheimer's disease (AD) and control cases and classified them into 12 groups. Forty-eight of these splice forms were identified for the first time. The distribution of alternatively

  10. Functional characterisation of an intron retaining K+ transporter of barley reveals intron-mediated alternate splicing

    KAUST Repository

    Shahzad, K.; Rauf, M.; Ahmed, M.; Malik, Z. A.; Habib, I.; Ahmed, Z.; Mahmood, K.; Ali, R.; Masmoudi, K.; Lemtiri-Chlieh, Fouad; Gehring, Christoph A; Berkowitz, G. A.; Saeed, N. A.

    2015-01-01

    Intron retention in transcripts and the presence of 5 and 3 splice sites within these introns mediate alternate splicing, which is widely observed in animals and plants. Here, functional characterisation of the K+ transporter, HvHKT2;1, with stably

  11. From General Aberrant Alternative Splicing in Cancers and Its Therapeutic Application to the Discovery of an Oncogenic DMTF1 Isoform

    Directory of Open Access Journals (Sweden)

    Na Tian

    2017-03-01

    Full Text Available Alternative pre-mRNA splicing is a crucial process that allows the generation of diversified RNA and protein products from a multi-exon gene. In tumor cells, this mechanism can facilitate cancer development and progression through both creating oncogenic isoforms and reducing the expression of normal or controllable protein species. We recently demonstrated that an alternative cyclin D-binding myb-like transcription factor 1 (DMTF1 pre-mRNA splicing isoform, DMTF1β, is increasingly expressed in breast cancer and promotes mammary tumorigenesis in a transgenic mouse model. Aberrant pre-mRNA splicing is a typical event occurring for many cancer-related functional proteins. In this review, we introduce general aberrant pre-mRNA splicing in cancers and discuss its therapeutic application using our recent discovery of the oncogenic DMTF1 isoform as an example. We also summarize new insights in designing novel targeting strategies of cancer therapies based on the understanding of deregulated pre-mRNA splicing mechanisms.

  12. Deciphering Transcriptome and Complex Alternative Splicing Transcripts in Mammary Gland Tissues from Cows Naturally Infected with Staphylococcus aureus Mastitis

    Science.gov (United States)

    Jiang, Qiang; Yang, Chun Hong; Zhang, Yan; Sun, Yan; Li, Rong Ling; Wang, Chang Fa; Zhong, Ji Feng; Huang, Jin Ming

    2016-01-01

    Alternative splicing (AS) contributes to the complexity of the mammalian proteome and plays an important role in diseases, including infectious diseases. The differential AS patterns of these transcript sequences between the healthy (HS3A) and mastitic (HS8A) cows naturally infected by Staphylococcus aureus were compared to understand the molecular mechanisms underlying mastitis resistance and susceptibility. In this study, using the Illumina paired-end RNA sequencing method, 1352 differentially expressed genes (DEGs) with higher than twofold changes were found in the HS3A and HS8A mammary gland tissues. Gene ontology and KEGG pathway analyses revealed that the cytokine–cytokine receptor interaction pathway is the most significantly enriched pathway. Approximately 16k annotated unigenes were respectively identified in two libraries, based on the bovine Bos taurus UMD3.1 sequence assembly and search. A total of 52.62% and 51.24% annotated unigenes were alternatively spliced in term of exon skipping, intron retention, alternative 5′ splicing and alternativesplicing. Additionally, 1,317 AS unigenes were HS3A-specific, whereas 1,093 AS unigenes were HS8A-specific. Some immune-related genes, such as ITGB6, MYD88, ADA, ACKR1, and TNFRSF1B, and their potential relationships with mastitis were highlighted. From Chromosome 2, 4, 6, 7, 10, 13, 14, 17, and 20, 3.66% (HS3A) and 5.4% (HS8A) novel transcripts, which harbor known quantitative trait locus associated with clinical mastitis, were identified. Many DEGs in the healthy and mastitic mammary glands are involved in immune, defense, and inflammation responses. These DEGs, which exhibit diverse and specific splicing patterns and events, can endow dairy cattle with the potential complex genetic resistance against mastitis. PMID:27459697

  13. Two splice variants of the bovine lactoferrin gene identified in Staphylococcus aureus isolated from mastitis in dairy cattle.

    Science.gov (United States)

    Huang, J M; Wang, Z Y; Ju, Z H; Wang, C F; Li, Q L; Sun, T; Hou, Q L; Hang, S Q; Hou, M H; Zhong, J F

    2011-12-21

    Bovine lactoferrin (bLF) is a member of the transferrin family; it plays an important role in the innate immune response. We identified novel splice variants of the bLF gene in mastitis-infected and healthy cows. Reverse transcription-polymerase chain reaction (RT-PCR) and clone sequencing analysis were used to screen the splice variants of the bLF gene in the mammary gland, spleen and liver tissues. One main transcript corresponding to the bLF reference sequence was found in three tissues in both healthy and mastitis-infected cows. Quantitative real-time PCR analysis showed that the expression levels of the LF gene's main transcript were not significantly different in tissues from healthy versus mastitis-infected cows. However, the new splice variant, LF-AS2, which has the exon-skipping alternative splicing pattern, was only identified in mammary glands infected with Staphylococcus aureus. Sequencing analysis showed that the new splice variant was 251 bp in length, including exon 1, part of exon 2, part of exon 16, and exon 17. We conclude that bLF may play a role in resistance to mastitis through alternative splicing mechanisms.

  14. Alternative Splicing of MBD2 Supports Self-Renewal in Human Pluripotent Stem Cells

    Science.gov (United States)

    Lu, Yu; Loh, Yuin-Han; Li, Hu; Cesana, Marcella; Ficarro, Scott B.; Parikh, Jignesh R.; Salomonis, Nathan; Toh, Cheng-Xu Delon; Andreadis, Stelios T.; Luckey, C. John; Collins, James J.; Daley, George Q.; Marto, Jarrod A.

    2014-01-01

    Summary Alternative RNA splicing (AS) regulates proteome diversity, including isoform-specific expression of several pluripotency genes. Here, we integrated global gene expression and proteomic analyses and identified a molecular signature suggesting a central role for AS in maintaining human pluripotent stem cell (hPSC) self-renewal. We demonstrate the splicing factor SFRS2 is an OCT4 target gene required for pluripotency. SFRS2 regulates AS of the methyl-CpG-binding protein MBD2, whose isoforms play opposing roles in maintenance of, and reprogramming to, pluripotency. While both MDB2a and MBD2c are enriched at the OCT4 and NANOG promoters, MBD2a preferentially interacts with repressive NuRD chromatin remodeling factors and promotes hPSC differentiation, whereas overexpression of MBD2c enhances reprogramming of fibroblasts to pluripotency. The miR-301 and miR-302 families provide additional regulation by targeting SFRS2 and MDB2a. These data suggest that OCT4, SFRS2, and MBD2 participate in a positive feedback loop, regulating proteome diversity complexity in support of hPSC self-renewal and reprogramming. PMID:24813856

  15. Loss of Pnn expression attenuates expression levels of SR family splicing factors and modulates alternative pre-mRNA splicing in vivo

    International Nuclear Information System (INIS)

    Chiu Yali; Ouyang Pin

    2006-01-01

    SR and SR-related proteins have been implicated as trans-acting factors that play an important role in splice selection and are involved at specific stages of spliceosome formation. A well-established property of SR protein splicing factors is their ability to influence selection of alternative splice sites in a concentration-dependent manner. Identification of molecules that regulate SR family protein expression is therefore of vital importance in RNA biology. Here we report that depletion of Pnn expression, a SR-related protein with functions involved in pre-mRNA splicing and mRNA export, induces reduced expression of a subset of cellular proteins, especially that of SR family proteins, including SC35, SRm300, SRp55, and SRp40, but not that of other nuclear proteins, such as p53, Mdm2, and ki67. Knocking down Pnn expression was achieved in vitro by siRNA transfection. Expression levels of SR and SR-related proteins in Pnn-depleted cells as compared to those in control cells were evaluated by immunofluorescent staining and Western blot with specific antibodies. In addition, we also demonstrate that loss of Pnn expression could modulate splice site selection of model reporter gene in vivo. Our finding is significant in terms of regulation of SR protein cellular concentration because it reveals that Pnn may play a general role in the control of the cellular amount of family SR proteins through down-regulation of its own expression, thereby providing us with a better understanding of the cellular mechanism by which Pnn fulfills its biological function

  16. Alternative Pre-mRNA Splicing in Mammals and Teleost Fish: A Effective Strategy for the Regulation of Immune Responses Against Pathogen Infection.

    Science.gov (United States)

    Chang, Ming Xian; Zhang, Jie

    2017-07-15

    Pre-mRNA splicing is the process by which introns are removed and the protein coding elements assembled into mature mRNAs. Alternative pre-mRNA splicing provides an important source of transcriptome and proteome complexity through selectively joining different coding elements to form mRNAs, which encode proteins with similar or distinct functions. In mammals, previous studies have shown the role of alternative splicing in regulating the function of the immune system, especially in the regulation of T-cell activation and function. As lower vertebrates, teleost fish mainly rely on a large family of pattern recognition receptors (PRRs) to recognize pathogen-associated molecular patterns (PAMPs) from various invading pathogens. In this review, we summarize recent advances in our understanding of alternative splicing of piscine PRRs including peptidoglycan recognition proteins (PGRPs), nucleotide binding and oligomerization domain (NOD)-like receptors (NLRs), retinoic acid-inducible gene-I (RIG-I)-like receptors (RLRs) and their downstream signaling molecules, compared to splicing in mammals. We also discuss what is known and unknown about the function of splicing isoforms in the innate immune responses against pathogens infection in mammals and teleost fish. Finally, we highlight the consequences of alternative splicing in the innate immune system and give our view of important directions for future studies.

  17. Characterization of a novel splicing variant in the RAPTOR gene

    International Nuclear Information System (INIS)

    Sun Chang; Southard, Catherine; Di Rienzo, Anna

    2009-01-01

    The mammalian target of rapamycin (mTOR) plays an essential role in the regulation of cell growth, proliferation and apoptosis. Raptor, the regulatory associated protein of mTOR, is an important member in this signaling pathway. In the present report, we identified and characterized a novel splicing variant of this gene, RAPTOR v 2, in which exons 14-17, 474 bp in total, are omitted from the mRNA. This deletion does not change the open reading frame, but causes a nearly complete absence of HEAT repeats, which were shown to be involved in the binding of mTOR substrates. Real time PCR performed on 48 different human tissues demonstrated the ubiquitous presence of this splice variant. Quantification of mRNA levels in lymphoblastoid cell lines (LCL) from 56 unrelated HapMap individuals revealed that the expression of this splicing form is quite variable. One synonymous SNP, rs2289759 in exon 14, was predicted by ESEfinder to cause a significant gain/loss of SRp55 and/or SF2/ASF binding sites, and thus potentially influence splicing. This prediction was confirmed by linear regression analysis between the ratio of RAPTOR v 2 to total RAPTOR mRNA levels and the SNP genotype in the above 56 individuals (r = 0.281 and P = 0.036). Moreover, the functional evaluation indicated that this splicing isoform is expected to retain the ability to bind mTOR, but is unlikely to bind mTOR substrates, hence affecting signal transduction and further cell proliferation

  18. Co-option of the piRNA pathway for germline-specific alternative splicing of C. elegans TOR.

    Science.gov (United States)

    Barberán-Soler, Sergio; Fontrodona, Laura; Ribó, Anna; Lamm, Ayelet T; Iannone, Camilla; Cerón, Julián; Lehner, Ben; Valcárcel, Juan

    2014-09-25

    Many eukaryotic genes contain embedded antisense transcripts and repetitive sequences of unknown function. We report that male germline-specific expression of an antisense transcript contained in an intron of C. elegans Target of Rapamycin (TOR, let-363) is associated with (1) accumulation of endo-small interfering RNAs (siRNAs) against an embedded Helitron transposon and (2) activation of an alternative 3' splice site of TOR. The germline-specific Argonaute proteins PRG-1 and CSR-1, which participate in self/nonself RNA recognition, antagonistically regulate the generation of these endo-siRNAs, TOR mRNA levels, and 3' splice-site selection. Supply of exogenous double-stranded RNA against the region of sense/antisense overlap reverses changes in TOR expression and splicing and suppresses the progressive multigenerational sterility phenotype of prg-1 mutants. We propose that recognition of a "nonself" intronic transposon by endo-siRNAs/the piRNA system provides physiological regulation of expression and alternative splicing of a host gene that, in turn, contributes to the maintenance of germline function across generations. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  19. CELF1 preferentially binds to exon-intron boundary and regulates alternative splicing in HeLa cells.

    Science.gov (United States)

    Xia, Heng; Chen, Dong; Wu, Qijia; Wu, Gang; Zhou, Yanhong; Zhang, Yi; Zhang, Libin

    2017-09-01

    The current RIP-seq approach has been developed for the identification of genome-wide interaction between RNA binding protein (RBP) and the bound RNA transcripts, but still rarely for identifying its binding sites. In this study, we performed RIP-seq experiments in HeLa cells using a monoclonal antibody against CELF1. Mapping of the RIP-seq reads showed a biased distribution at the 3'UTR and intronic regions. A total of 15,285 and 1384 CELF1-specific sense and antisense peaks were identified using the ABLIRC software tool. Our bioinformatics analyses revealed that 5' and 3' splice site motifs and GU-rich motifs were highly enriched in the CELF1-bound peaks. Furthermore, transcriptome analyses revealed that alternative splicing was globally regulated by CELF1 in HeLa cells. For example, the inclusion of exon 16 of LMO7 gene, a marker gene of breast cancer, is positively regulated by CELF1. Taken together, we have shown that RIP-seq data can be used to decipher RBP binding sites and reveal an unexpected landscape of the genome-wide CELF1-RNA interactions in HeLa cells. In addition, we found that CELF1 globally regulates the alternative splicing by binding the exon-intron boundary in HeLa cells, which will deepen our understanding of the regulatory roles of CELF1 in the pre-mRNA splicing process. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Alternative Splicing in Breast Cancer and the Potential Development of Therapeutic Tools.

    Science.gov (United States)

    Martínez-Montiel, Nancy; Anaya-Ruiz, Maricruz; Pérez-Santos, Martín; Martínez-Contreras, Rebeca D

    2017-10-05

    Alternative splicing is a key molecular mechanism now considered as a hallmark of cancer that has been associated with the expression of distinct isoforms during the onset and progression of the disease. The leading cause of cancer-related deaths in women worldwide is breast cancer, and even when the role of alternative splicing in this type of cancer has been established, the function of this mechanism in breast cancer biology is not completely decoded. In order to gain a comprehensive view of the role of alternative splicing in breast cancer biology and development, we summarize here recent findings regarding alternative splicing events that have been well documented for breast cancer evolution, considering its prognostic and therapeutic value. Moreover, we analyze how the response to endocrine and chemical therapies could be affected due to alternative splicing and differential expression of variant isoforms. With all this knowledge, it becomes clear that targeting alternative splicing represents an innovative approach for breast cancer therapeutics and the information derived from current studies could guide clinical decisions with a direct impact in the clinical advances for breast cancer patients nowadays.

  1. Alternative Splicing of CHEK2 and Codeletion with NF2 Promote Chromosomal Instability in Meningioma

    Directory of Open Access Journals (Sweden)

    Hong Wei Yang

    2012-01-01

    Full Text Available Mutations of the NF2 gene on chromosome 22q are thought to initiate tumorigenesis in nearly 50% of meningiomas, and 22q deletion is the earliest and most frequent large-scale chromosomal abnormality observed in these tumors. In aggressive meningiomas, 22q deletions are generally accompanied by the presence of large-scale segmental abnormalities involving other chromosomes, but the reasons for this association are unknown. We find that large-scale chromosomal alterations accumulate during meningioma progression primarily in tumors harboring 22q deletions, suggesting 22q-associated chromosomal instability. Here we show frequent codeletion of the DNA repair and tumor suppressor gene, CHEK2, in combination with NF2 on chromosome 22q in a majority of aggressive meningiomas. In addition, tumor-specific splicing of CHEK2 in meningioma leads to decreased functional Chk2 protein expression. We show that enforced Chk2 knockdown in meningioma cells decreases DNA repair. Furthermore, Chk2 depletion increases centrosome amplification, thereby promoting chromosomal instability. Taken together, these data indicate that alternative splicing and frequent codeletion of CHEK2 and NF2 contribute to the genomic instability and associated development of aggressive biologic behavior in meningiomas.

  2. New splice site acceptor mutation in AIRE gene in autoimmune polyendocrine syndrome type 1.

    Directory of Open Access Journals (Sweden)

    Mireia Mora

    Full Text Available Autoimmune polyglandular syndrome type 1 (APS-1, OMIM 240300 is a rare autosomal recessive disorder, characterized by the presence of at least two of three major diseases: hypoparathyroidism, Addison's disease, and chronic mucocutaneous candidiasis. We aim to identify the molecular defects and investigate the clinical and mutational characteristics in an index case and other members of a consanguineous family. We identified a novel homozygous mutation in the splice site acceptor (SSA of intron 5 (c.653-1G>A in two siblings with different clinical outcomes of APS-1. Coding DNA sequencing revealed that this AIRE mutation potentially compromised the recognition of the constitutive SSA of intron 5, splicing upstream onto a nearby cryptic SSA in intron 5. Surprisingly, the use of an alternative SSA entails the uncovering of a cryptic donor splice site in exon 5. This new transcript generates a truncated protein (p.A214fs67X containing the first 213 amino acids and followed by 68 aberrant amino acids. The mutation affects the proper splicing, not only at the acceptor but also at the donor splice site, highlighting the complexity of recognizing suitable splicing sites and the importance of sequencing the intron-exon junctions for a more precise molecular diagnosis and correct genetic counseling. As both siblings were carrying the same mutation but exhibited a different APS-1 onset, and one of the brothers was not clinically diagnosed, our finding highlights the possibility to suspect mutations in the AIRE gene in cases of childhood chronic candidiasis and/or hypoparathyroidism otherwise unexplained, especially when the phenotype is associated with other autoimmune diseases.

  3. TGFβ1-mediated PI3K/Akt and p38 MAP kinase dependent alternative splicing of fibronectin extra domain A in human podocyte culture.

    Science.gov (United States)

    Madne, Tarunkumar Hemraj; Dockrell, Mark Edward Carl

    2018-04-30

    Alternative splicing is an important gene regulation process to distribute proteins in health and diseases. Extra Domain A+ Fibronectin (EDA+Fn) is an alternatively spliced form of fibronectin (Fn) protein, present in the extra cellular matrix (ECM) and a recognised marker of various pathologies. TGFβ1 has been shown to induce alternative splicing of EDA+Fn in many cell types. Podocytes are spectacular cell type and play a key role in filtration and synthesise ECM proteins in renal physiology and pathology. In our previous study we have demonstrated expression and alternative splicing of EDA+Fn in basal condition in human podocytes culture. TGFβ1 further induced the basal expression and alternative splicing of EDA+Fn through Alk5 receptor and SR proteins. In this study, we have investigated TGFβ1 mediated signalling involved in alternative splicing of EDA+Fn in human podocytes. We have performed western blotting to characterise the expression of the EDA+Fn protein and other signalling proteins and RT-PCR to look for signalling pathways involved in regulation of alternative splicing of EDA+Fn in conditionally immortalised human podocytes culture.We have used TGFβ1 as a stimulator and SB431542, SB202190 and LY294002 for inhibitory studies. In this work, we have demonstrated in human podocytes culture TGFβ1 2.5ng/ml induced phosphorylation of Smad1/5/8, Smad2 and Smad3 via the ALK5 receptor. TGFβ1 significantly induced the PI3K/Akt pathway and the PI3K/Akt pathway inhibitor LY294002 significantly downregulated basal as well as TGFβ1 induced alternative splicing of EDA+Fn in human podocytes. In addition to this, TGFβ1 significantly induced the p38 MAP kinase signalling pathway and p38 MAP kinase signalling pathway inhibitor SB202190 downregulated the TGFβ1-mediated alternative splicing of EDA+Fn in human podocytes. The results with PI3K and p38 MAP kinase signalling pathway suggest that inhibiting PI3K signalling pathway downregulated the basal alternative

  4. Expression analysis of an evolutionarily conserved alternative splicing factor, Sfrs10, in age-related macular degeneration.

    Directory of Open Access Journals (Sweden)

    Devi Krishna Priya Karunakaran

    Full Text Available Age-related macular degeneration (AMD is the most common cause of blindness in the elderly population. Hypoxic stress created in the micro-environment of the photoreceptors is thought to be the underlying cause that results in the pathophysiology of AMD. However, association of AMD with alternative splicing mediated gene regulation is not well explored. Alternative Splicing is one of the primary mechanisms in humans by which fewer protein coding genes are able to generate a vast proteome. Here, we investigated the expression of a known stress response gene and an alternative splicing factor called Serine-Arginine rich splicing factor 10 (Sfrs10. Sfrs10 is a member of the serine-arginine (SR rich protein family and is 100% identical at the amino acid level in most mammals. Immunoblot analysis on retinal extracts from mouse, rat, and chicken showed a single immunoreactive band. Further, immunohistochemistry on adult mouse, rat and chicken retinae showed pan-retinal expression. However, SFRS10 was not detected in normal human retina but was observed as distinct nuclear speckles in AMD retinae. This is in agreement with previous reports that show Sfrs10 to be a stress response gene, which is upregulated under hypoxia. The difference in the expression of Sfrs10 between humans and lower mammals and the upregulation of SFRS10 in AMD is further reflected in the divergence of the promoter sequence between these species. Finally, SFRS10+ speckles were independent of the SC35+ SR protein speckles or the HSF1+ stress granules. In all, our data suggests that SFRS10 is upregulated and forms distinct stress-induced speckles and might be involved in AS of stress response genes in AMD.

  5. Misregulation of Alternative Splicing in a Mouse Model of Rett Syndrome.

    Directory of Open Access Journals (Sweden)

    Ronghui Li

    2016-06-01

    Full Text Available Mutations in the human MECP2 gene cause Rett syndrome (RTT, a severe neurodevelopmental disorder that predominantly affects girls. Despite decades of work, the molecular function of MeCP2 is not fully understood. Here we report a systematic identification of MeCP2-interacting proteins in the mouse brain. In addition to transcription regulators, we found that MeCP2 physically interacts with several modulators of RNA splicing, including LEDGF and DHX9. These interactions are disrupted by RTT causing mutations, suggesting that they may play a role in RTT pathogenesis. Consistent with the idea, deep RNA sequencing revealed misregulation of hundreds of splicing events in the cortex of Mecp2 knockout mice. To reveal the functional consequence of altered RNA splicing due to the loss of MeCP2, we focused on the regulation of the splicing of the flip/flop exon of Gria2 and other AMPAR genes. We found a significant splicing shift in the flip/flop exon toward the flop inclusion, leading to a faster decay in the AMPAR gated current and altered synaptic transmission. In summary, our study identified direct physical interaction between MeCP2 and splicing factors, a novel MeCP2 target gene, and established functional connection between a specific RNA splicing change and synaptic phenotypes in RTT mice. These results not only help our understanding of the molecular function of MeCP2, but also reveal potential drug targets for future therapies.

  6. cis-Acting and trans-acting modulation of equine infectious anemia virus alternative RNA splicing

    International Nuclear Information System (INIS)

    Liao, Huey-Jane; Baker, Carl C.; Princler, Gerald L.; Derse, David

    2004-01-01

    Equine infectious anemia virus (EIAV), a lentivirus distantly related to HIV-1, encodes regulatory proteins, EIAV Tat (ETat) and Rev (ERev), from a four-exon mRNA. Exon 3 of the tat/rev mRNA contains a 30-nucleotide purine-rich element (PRE) which binds both ERev and SF2/ASF, a member of the SR family of RNA splicing factors. To better understand the role of this element in the regulation of EIAV pre-mRNA splicing, we quantified the effects of mutation or deletion of the PRE on exon 3 splicing in vitro and on alternative splicing in vivo. We also determined the branch point elements upstream of exons 3 and 4. In vitro splicing of exon 3 to exon 4 was not affected by mutation of the PRE, and addition of purified SR proteins enhanced splicing independently of the PRE. In vitro splicing of exon 2 to exon 3 was dependent on the PRE; under conditions of excess SR proteins, either the PRE or the 5' splice site of exon 3 was sufficient to activate splicing. We applied isoform-specific primers in real-time RT-PCR reactions to quantitatively analyze alternative splicing in cells transfected with rev-minus EIAV provirus constructs. In the context of provirus with wild-type exon 3, greater than 80% of the viral mRNAs were multiply spliced, and of these, less than 1% excluded exon 3. Deletion of the PRE resulted in a decrease in the relative amount of multiply spliced mRNA to about 40% of the total and approximately 39% of the viral mRNA excluded exon 3. Ectopic expression of ERev caused a decrease in the relative amount of multiply spliced mRNA to approximately 50% of the total and increased mRNAs that excluded exon 3 to about 4%. Over-expression of SF2/ASF in cells transfected with wild-type provirus constructs inhibited splicing but did not significantly alter exon 3 skipping

  7. Intron-Mediated Alternative Splicing of WOOD-ASSOCIATED NAC TRANSCRIPTION FACTOR1B Regulates Cell Wall Thickening during Fiber Development in Populus Species1[W

    Science.gov (United States)

    Zhao, Yunjun; Sun, Jiayan; Xu, Peng; Zhang, Rui; Li, Laigeng

    2014-01-01

    Alternative splicing is an important mechanism involved in regulating the development of multicellular organisms. Although many genes in plants undergo alternative splicing, little is understood of its significance in regulating plant growth and development. In this study, alternative splicing of black cottonwood (Populus trichocarpa) wood-associated NAC domain transcription factor (PtrWNDs), PtrWND1B, is shown to occur exclusively in secondary xylem fiber cells. PtrWND1B is expressed with a normal short-transcript PtrWND1B-s as well as its alternative long-transcript PtrWND1B-l. The intron 2 structure of the PtrWND1B gene was identified as a critical sequence that causes PtrWND1B alternative splicing. Suppression of PtrWND1B expression specifically inhibited fiber cell wall thickening. The two PtrWND1B isoforms play antagonistic roles in regulating cell wall thickening during fiber cell differentiation in Populus spp. PtrWND1B-s overexpression enhanced fiber cell wall thickening, while overexpression of PtrWND1B-l repressed fiber cell wall thickening. Alternative splicing may enable more specific regulation of processes such as fiber cell wall thickening during wood formation. PMID:24394777

  8. Intron-mediated alternative splicing of WOOD-ASSOCIATED NAC TRANSCRIPTION FACTOR1B regulates cell wall thickening during fiber development in Populus species.

    Science.gov (United States)

    Zhao, Yunjun; Sun, Jiayan; Xu, Peng; Zhang, Rui; Li, Laigeng

    2014-02-01

    Alternative splicing is an important mechanism involved in regulating the development of multicellular organisms. Although many genes in plants undergo alternative splicing, little is understood of its significance in regulating plant growth and development. In this study, alternative splicing of black cottonwood (Populus trichocarpa) wood-associated NAC domain transcription factor (PtrWNDs), PtrWND1B, is shown to occur exclusively in secondary xylem fiber cells. PtrWND1B is expressed with a normal short-transcript PtrWND1B-s as well as its alternative long-transcript PtrWND1B-l. The intron 2 structure of the PtrWND1B gene was identified as a critical sequence that causes PtrWND1B alternative splicing. Suppression of PtrWND1B expression specifically inhibited fiber cell wall thickening. The two PtrWND1B isoforms play antagonistic roles in regulating cell wall thickening during fiber cell differentiation in Populus spp. PtrWND1B-s overexpression enhanced fiber cell wall thickening, while overexpression of PtrWND1B-l repressed fiber cell wall thickening. Alternative splicing may enable more specific regulation of processes such as fiber cell wall thickening during wood formation.

  9. SRSF3 represses the expression of PDCD4 protein by coordinated regulation of alternative splicing, export and translation

    Energy Technology Data Exchange (ETDEWEB)

    Park, Seung Kuk; Jeong, Sunjoo, E-mail: sjsj@dankook.ac.kr

    2016-02-05

    Gene expression is regulated at multiple steps, such as transcription, splicing, export, degradation and translation. Considering diverse roles of SR proteins, we determined whether the tumor-related splicing factor SRSF3 regulates the expression of the tumor-suppressor protein, PDCD4, at multiple steps. As we have reported previously, knockdown of SRSF3 increased the PDCD4 protein level in SW480 colon cancer cells. More interestingly, here we showed that the alternative splicing and the nuclear export of minor isoforms of pdcd4 mRNA were repressed by SRSF3, but the translation step was unaffected. In contrast, only the translation step of the major isoform of pdcd4 mRNA was repressed by SRSF3. Therefore, overexpression of SRSF3 might be relevant to the repression of all isoforms of PDCD4 protein levels in most types of cancer cell. We propose that SRSF3 could act as a coordinator of the expression of PDCD4 protein via two mechanisms on two alternatively spliced mRNA isoforms.

  10. Temperature induced alternative splicing is affected in sdg8 and sdg26

    OpenAIRE

    Pajoro, A.; Severing, E.I.; Immink, G.H.

    2017-01-01

    Plants developed a plasticity to environmental conditions, such as temperature, that allows their adaptation. A change in ambient temperature leads to changes in the transcriptome in plants, such as the production of different splicing isoforms. Here we study temperature induced alternative splicing events in Arabidopsis thaliana wild-type and two epigenetic mutants, sdg8-2 and sdg26-1 using an RNA-seq approach.

  11. Molecular analysis of human argininosuccinate lyase: Mutant characterization and alternative splicing of the coding region

    International Nuclear Information System (INIS)

    Walker, D.C.; McCloskey, D.A.; Simard, L.R.; McInnes, R.R.

    1990-01-01

    Argininosuccinic acid lyase (ASAL) deficiency is a clinically heterogeneous autosomal recessive urea cycle disorder. The authors previously established by complementation analysis that 29 ASAL-deficient patients have heterogeneous mutations in a single gene. To prove that the ASAL structural gene is the affected locus, they sequenced polymerase chain reaction-amplified ASAL cDNA of a representative mutant from the single complementation group. Fibroblast strain 944 from a late-onset patient who was the product of a consanguineous mating, had only a single base-pair change in the coding region, a C-283→ T transition at a CpG dinucleotide in exon 3. This substitution converts Arg-95 to Cys (R95C), occurs in a stretch of 13 residues that is identical in yeast and human ASAL, and was present in both of the patient's alleles but not in 14 other mutant or 10 normal alleles. They observed that amplified cDNA from mutant 944 and normal cells (liver, keratinocytes, lymphoblasts, and fibroblasts) contained, in addition to the expected 5' 513-base-pair band, a prominent 318-base-pair ASAL band formed by the splicing of exon 2 from the transcript. The short transcript maintains the ASAL reading frame but removes Lys-51, a residue that may be essential for catalysis, since it binds the argininosuccinate substrate. They conclude (i) that the identification of the R95C mutation in strain 944 demonstrates that virtually all ASAL deficiency results from defects in the ASAL structural gene and (ii) that minor alternative splicing of the coding region occurs at the ASAL locus

  12. Dietary Fat Quantity and Type Induce Transcriptome-Wide Effects on Alternative Splicing of Pre-mRNA in Rat Skeletal Muscle.

    Science.gov (United States)

    Black, Adam J; Ravi, Suhana; Jefferson, Leonard S; Kimball, Scot R; Schilder, Rudolf J

    2017-09-01

    Background: Fat-enriched diets produce metabolic changes in skeletal muscle, which in turn can mediate changes in gene regulation. Objective: We examined the high-fat-diet-induced changes in skeletal muscle gene expression by characterizing variations in pre-mRNA alternative splicing. Methods: Affymetrix Exon Array analysis was performed on the transcriptome of the gastrocnemius/plantaris complex of male obesity-prone Sprague-Dawley rats fed a 10% or 60% fat (lard) diet for 2 or 8 wk. The validation of exon array results was focused on troponin T ( Tnnt3 ). Tnnt3 splice form analyses were extended in studies of rats fed 10% or 30% fat diets across 1- to 8-wk treatment periods and rats fed 10% or 45% fat diets with fat sources from lard or mono- or polyunsaturated fats for 2 wk. Nuclear magnetic resonance (NMR) was used to measure body composition. Results: Consumption of a 60% fat diet for 2 or 8 wk resulted in alternative splicing of 668 and 726 pre-mRNAs, respectively, compared with rats fed a 10% fat diet. Tnnt3 transcripts were alternatively spliced in rats fed a 60% fat diet for either 2 or 8 wk. The high-fat-diet-induced changes in Tnnt3 alternative splicing were observed in rats fed a 30% fat diet across 1- to 8-wk treatment periods. Moreover, this effect depended on fat type, because Tnnt3 alternative splicing occurred in response to 45% fat diets enriched with lard but not in response to diets enriched with mono- or polyunsaturated fatty acids. Fat mass (a proxy for obesity as measured by NMR) did not differ between groups in any study. Conclusions: Rat skeletal muscle responds to overconsumption of dietary fat by modifying gene expression through pre-mRNA alternative splicing. Variations in Tnnt3 alternative splicing occur independently of obesity and are dependent on dietary fat quantity and suggest a role for saturated fatty acids in the high-fat-diet-induced modifications in Tnnt3 alternative splicing. © 2017 American Society for Nutrition.

  13. Effects of airborne particulate matter on alternative pre-mRNA splicing in colon cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Buggiano, Valeria; Petrillo, Ezequiel; Alló, Mariano; Lafaille, Celina [Laboratorio de Fisiología y Biología Molecular, Departamento de Fisiología, Biología Molecular y Celular, IFIBYNE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, C1428EHA Buenos Aires (Argentina); Redal, María Ana [Instituto de Ciencias Básicas y Medicina Experimental, Hospital Italiano de Buenos Aires (Argentina); Alghamdi, Mansour A. [Department of Environmental Sciences, Faculty of Meteorology, Environment and Arid Land Agriculture, King Abdulaziz University, Jeddah (Saudi Arabia); Khoder, Mamdouh I. [Department of Environmental Sciences, Faculty of Meteorology, Environment and Arid Land Agriculture, King Abdulaziz University, Jeddah (Saudi Arabia); Center of Excellence in Environmental Studies, King Abdulaziz University, Jeddah (Saudi Arabia); Shamy, Magdy [Department of Environmental Sciences, Faculty of Meteorology, Environment and Arid Land Agriculture, King Abdulaziz University, Jeddah (Saudi Arabia); Muñoz, Manuel J., E-mail: mmunoz@fbmc.fcen.uba.ar [Laboratorio de Fisiología y Biología Molecular, Departamento de Fisiología, Biología Molecular y Celular, IFIBYNE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, C1428EHA Buenos Aires (Argentina); and others

    2015-07-15

    Alternative pre-mRNA splicing plays key roles in determining tissue- and species-specific cell differentiation as well as in the onset of hereditary disease and cancer, being controlled by multiple post- and co-transcriptional regulatory mechanisms. We report here that airborne particulate matter, resulting from industrial pollution, inhibits expression and specifically affects alternative splicing at the 5′ untranslated region of the mRNA encoding the bone morphogenetic protein BMP4 in human colon cells in culture. These effects are consistent with a previously reported role for BMP4 in preventing colon cancer development, suggesting that ingestion of particulate matter could contribute to the onset of colon cell proliferation. We also show that the underlying mechanism might involve changes in transcriptional elongation. This is the first study to demonstrate that particulate matter causes non-pleiotropic changes in alternative splicing. - Highlights: • Airborne particulate matter (PM10) affects alternative splicing in colon cells. • PM10 upregulates one of the two mRNA variants of the growth factor BMP-4. • This variant has a longer 5′ unstranslated region and introduces an upstream AUG. • By regulating BMP-4 mRNA splicing PM10 inhibits total expression of BMP-4 protein. • BMP-4 downregulation was previously reported to be associated to colon cancer.

  14. Expanding the action of duplex RNAs into the nucleus: redirecting alternative splicing

    Science.gov (United States)

    Liu, Jing; Hu, Jiaxin; Corey, David R.

    2012-01-01

    Double-stranded RNAs are powerful agents for silencing gene expression in the cytoplasm of mammalian cells. The potential for duplex RNAs to control expression in the nucleus has received less attention. Here, we investigate the ability of small RNAs to redirect splicing. We identify RNAs targeting an aberrant splice site that restore splicing and production of functional protein. RNAs can target sequences within exons or introns and affect the inclusion of exons within SMN2 and dystrophin, genes responsible for spinal muscular atrophy and Duchenne muscular dystrophy, respectively. Duplex RNAs recruit argonaute 2 (AGO2) to pre-mRNA transcripts and altered splicing requires AGO2 expression. AGO2 promotes transcript cleavage in the cytoplasm, but recruitment of AGO2 to pre-mRNAs does not reduce transcript levels, exposing a difference between cytoplasmic and nuclear pathways. Involvement of AGO2 in splicing, a classical nuclear process, reinforces the conclusion from studies of RNA-mediated transcriptional silencing that RNAi pathways can be adapted to function in the mammalian nucleus. These data provide a new strategy for controlling splicing and expand the reach of small RNAs within the nucleus of mammalian cells. PMID:21948593

  15. Species-Specific Expression of Full-Length and Alternatively Spliced Variant Forms of CDK5RAP2.

    Directory of Open Access Journals (Sweden)

    John S Y Park

    Full Text Available CDK5RAP2 is one of the primary microcephaly genes that are associated with reduced brain size and mental retardation. We have previously shown that human CDK5RAP2 exists as a full-length form (hCDK5RAP2 or an alternatively spliced variant form (hCDK5RAP2-V1 that is lacking exon 32. The equivalent of hCDK5RAP2-V1 has been reported in rat and mouse but the presence of full-length equivalent hCDK5RAP2 in rat and mouse has not been examined. Here, we demonstrate that rat expresses both a full length and an alternatively spliced variant form of CDK5RAP2 that are equivalent to our previously reported hCDK5RAP2 and hCDK5RAP2-V1, repectively. However, mouse expresses only one form of CDK5RAP2 that is equivalent to the human and rat alternatively spliced variant forms. Knowledge of this expression of different forms of CDK5RAP2 in human, rat and mouse is essential in selecting the appropriate model for studies of CDK5RAP2 and primary microcephaly but our findings further indicate the evolutionary divergence of mouse from the human and rat species.

  16. Somatic Mutational Landscape of Splicing Factor Genes and Their Functional Consequences across 33 Cancer Types

    Directory of Open Access Journals (Sweden)

    Michael Seiler

    2018-04-01

    Full Text Available Summary: Hotspot mutations in splicing factor genes have been recently reported at high frequency in hematological malignancies, suggesting the importance of RNA splicing in cancer. We analyzed whole-exome sequencing data across 33 tumor types in The Cancer Genome Atlas (TCGA, and we identified 119 splicing factor genes with significant non-silent mutation patterns, including mutation over-representation, recurrent loss of function (tumor suppressor-like, or hotspot mutation profile (oncogene-like. Furthermore, RNA sequencing analysis revealed altered splicing events associated with selected splicing factor mutations. In addition, we were able to identify common gene pathway profiles associated with the presence of these mutations. Our analysis suggests that somatic alteration of genes involved in the RNA-splicing process is common in cancer and may represent an underappreciated hallmark of tumorigenesis. : Seiler et al. report that 119 splicing factor genes carry putative driver mutations over 33 tumor types in TCGA. The most common mutations appear to be mutually exclusive and are associated with lineage-independent altered splicing. Samples with these mutations show deregulation of cell-autonomous pathways and immune infiltration. Keywords: splicing, SF3B1, U2AF1, SRSF2, RBM10, FUBP1, cancer, mutation

  17. Spliced

    DEFF Research Database (Denmark)

    Addison, Courtney Page

    2017-01-01

    Human gene therapy (HGT) aims to cure disease by inserting or editing the DNA of patients with genetic conditions. Since foundational genetic techniques came into use in the 1970s, the field has developed to the point that now three therapies have market approval, and over 1800 clinical trials have...

  18. Optimization of oligonucleotide arrays and RNA amplification protocols for analysis of transcript structure and alternative splicing.

    Science.gov (United States)

    Castle, John; Garrett-Engele, Phil; Armour, Christopher D; Duenwald, Sven J; Loerch, Patrick M; Meyer, Michael R; Schadt, Eric E; Stoughton, Roland; Parrish, Mark L; Shoemaker, Daniel D; Johnson, Jason M

    2003-01-01

    Microarrays offer a high-resolution means for monitoring pre-mRNA splicing on a genomic scale. We have developed a novel, unbiased amplification protocol that permits labeling of entire transcripts. Also, hybridization conditions, probe characteristics, and analysis algorithms were optimized for detection of exons, exon-intron edges, and exon junctions. These optimized protocols can be used to detect small variations and isoform mixtures, map the tissue specificity of known human alternative isoforms, and provide a robust, scalable platform for high-throughput discovery of alternative splicing.

  19. The transcriptome of Utricularia vulgaris, a rootless plant with minimalist genome, reveals extreme alternative splicing and only moderate sequence similarity with Utricularia gibba

    Czech Academy of Sciences Publication Activity Database

    Bárta, J.; Stone, James D.; Pech, J.; Sirová, D.; Adamec, Lubomír; Campbell, M. A.; Štorchová, H.

    2015-01-01

    Roč. 15, MAR 7 (2015), s. 1-14, no. 78 ISSN 1471-2229 R&D Projects: GA ČR(CZ) GAP504/11/0783 Institutional support: RVO:67985939 Keywords : transcriptome * root-associated genes * alternative splicing Subject RIV: EF - Botanics Impact factor: 3.631, year: 2015

  20. The transcriptome of Utricularia vulgaris, a rootless plant with minimalist genome, reveals extreme alternative splicing and only moderate sequence similarity with Utricularia gibba

    Czech Academy of Sciences Publication Activity Database

    Bárta, J.; Stone, James D.; Pech, J.; Sirová, D.; Adamec, L.; Campbell, M. A.; Štorchová, Helena

    2015-01-01

    Roč. 15, MAR 7 2015 (2015) ISSN 1471-2229 R&D Projects: GA ČR(CZ) GAP504/11/0783 Institutional support: RVO:61389030 Keywords : Transcriptome * Root-associated genes * Alternative splicing Subject RIV: EF - Botanics Impact factor: 3.631, year: 2015

  1. RRM domain of Arabidopsis splicing factor SF1 is important for pre-mRNA splicing of a specific set of genes

    KAUST Repository

    Lee, Keh Chien; Jang, Yun Hee; Kim, SoonKap; Park, Hyo-Young; Thu, May Phyo; Lee, Jeong Hwan; Kim, Jeong-Kook

    2017-01-01

    , but not the abscisic acid sensitivity response during seed germination. The alternative splicing of FLOWERING LOCUS M (FLM) pre-mRNA is involved in flowering time control. We found that the RRM domain of AtSF1 protein alters the production of alternatively spliced FLM

  2. HIV-1 infection induces changes in expression of cellular splicing factors that regulate alternative viral splicing and virus production in macrophages

    Directory of Open Access Journals (Sweden)

    Purcell Damian FJ

    2008-02-01

    Full Text Available Abstract Background Macrophages are important targets and long-lived reservoirs of HIV-1, which are not cleared of infection by currently available treatments. In the primary monocyte-derived macrophage model of infection, replication is initially productive followed by a decline in virion output over ensuing weeks, coincident with a decrease in the levels of the essential viral transactivator protein Tat. We investigated two possible mechanisms in macrophages for regulation of viral replication, which appears to be primarily regulated at the level of tat mRNA: 1 differential mRNA stability, used by cells and some viruses for the rapid regulation of gene expression and 2 control of HIV-1 alternative splicing, which is essential for optimal viral replication. Results Following termination of transcription at increasing times after infection in macrophages, we found that tat mRNA did indeed decay more rapidly than rev or nef mRNA, but with similar kinetics throughout infection. In addition, tat mRNA decayed at least as rapidly in peripheral blood lymphocytes. Expression of cellular splicing factors in uninfected and infected macrophage cultures from the same donor showed an inverse pattern over time between enhancing factors (members of the SR family of RNA binding proteins and inhibitory factors (members of the hnRNP family. While levels of the SR protein SC35 were greatly up-regulated in the first week or two after infection, hnRNPs of the A/B and H groups were down-regulated. Around the peak of virus production in each culture, SC35 expression declined to levels in uninfected cells or lower, while the hnRNPs increased to control levels or above. We also found evidence for increased cytoplasmic expression of SC35 following long-term infection. Conclusion While no evidence of differential regulation of tat mRNA decay was found in macrophages following HIV-1 infection, changes in the balance of cellular splicing factors which regulate alternative

  3. Multiple promoters and alternative splicing: Hoxa5 transcriptional complexity in the mouse embryo.

    Directory of Open Access Journals (Sweden)

    Yan Coulombe

    2010-05-01

    Full Text Available The genomic organization of Hox clusters is fundamental for the precise spatio-temporal regulation and the function of each Hox gene, and hence for correct embryo patterning. Multiple overlapping transcriptional units exist at the Hoxa5 locus reflecting the complexity of Hox clustering: a major form of 1.8 kb corresponding to the two characterized exons of the gene and polyadenylated RNA species of 5.0, 9.5 and 11.0 kb. This transcriptional intricacy raises the question of the involvement of the larger transcripts in Hox function and regulation.We have undertaken the molecular characterization of the Hoxa5 larger transcripts. They initiate from two highly conserved distal promoters, one corresponding to the putative Hoxa6 promoter, and a second located nearby Hoxa7. Alternative splicing is also involved in the generation of the different transcripts. No functional polyadenylation sequence was found at the Hoxa6 locus and all larger transcripts use the polyadenylation site of the Hoxa5 gene. Some larger transcripts are potential Hoxa6/Hoxa5 bicistronic units. However, even though all transcripts could produce the genuine 270 a.a. HOXA5 protein, only the 1.8 kb form is translated into the protein, indicative of its essential role in Hoxa5 gene function. The Hoxa6 mutation disrupts the larger transcripts without major phenotypic impact on axial specification in their expression domain. However, Hoxa5-like skeletal anomalies are observed in Hoxa6 mutants and these defects can be explained by the loss of expression of the 1.8 kb transcript. Our data raise the possibility that the larger transcripts may be involved in Hoxa5 gene regulation.Our observation that the Hoxa5 larger transcripts possess a developmentally-regulated expression combined to the increasing sum of data on the role of long noncoding RNAs in transcriptional regulation suggest that the Hoxa5 larger transcripts may participate in the control of Hox gene expression.

  4. Role of Bmznf-2, a Bombyx mori CCCH zinc finger gene, in masculinisation and differential splicing of Bmtra-2.

    Science.gov (United States)

    Gopinath, Gajula; Arunkumar, Kallare P; Mita, Kazuei; Nagaraju, Javaregowda

    2016-08-01

    Deciphering the regulatory factors involved in Bombyx mori sex determination has been a puzzle, challenging researchers for nearly a century now. The pre-mRNA of B. mori doublesex (Bmdsx), a master regulator gene of sexual differentiation, is differentially spliced, producing Bmdsxm and Bmdsxf transcripts in males and females respectively. The putative proteins encoded by these differential transcripts orchestrate antagonistic functions, which lead to sexual differentiation. A recent study in B. mori illustrated the role of a W-derived fem piRNA in conferring femaleness. In females, the fem piRNA was shown to suppress the activity of a Z-linked CCCH type zinc finger (znf) gene, Masculiniser (masc), which indirectly promotes the Bmdsxm type of splicing. In this study, we report a novel autosomal (Chr 25) CCCH type znf motif encoding gene Bmznf-2 as one of the potential factors in the Bmdsx sex specific differential splicing, and we also provide insights into its role in the alternative splicing of Bmtra2 by using ovary derived BmN cells. Over-expression of Bmznf-2 induced Bmdsxm type of splicing (masculinisation) with a correspondingly reduced expression of Bmdsxf type isoform in BmN cells. Further, the site-directed mutational studies targeting the tandem CCCH znf motifs revealed their indispensability in the observed phenotype of masculinisation. Additionally, the dual luciferase assays in BmN cells using 5' UTR region of the Bmznf-2 strongly implied the existence of a translational repression over this gene. From these findings, we propose Bmznf-2 to be one of the potential factors of masculinisation similar to Masc. From the growing number of Bmdsx splicing regulators, we assume that the sex determination cascade of B. mori is quite intricate in nature; hence, it has to be further investigated for its comprehensive understanding. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. CRE promoter sites modulate alternative splicing via p300-mediated histone acetylation

    Czech Academy of Sciences Publication Activity Database

    Dušková, E.; Hnilicová, Jarmila; Staněk, D.

    2014-01-01

    Roč. 11, č. 7 (2014), s. 1-10 ISSN 1547-6286 R&D Projects: GA ČR(CZ) GBP305/12/G034 Grant - others:Charles University Prague(CZ) 274111 Institutional support: RVO:61388971 Keywords : alternative splicing * fibronectin * p300 Subject RIV: EE - Microbiology, Virology Impact factor: 4.974, year: 2014

  6. CRE promoter sites modulate alternative splicing via p300-mediated histone acetylation

    Czech Academy of Sciences Publication Activity Database

    Dušková, Eva; Hnilicová, Jarmila; Staněk, David

    2014-01-01

    Roč. 11, č. 7 (2014), s. 865-874 ISSN 1547-6286 R&D Projects: GA ČR(CZ) GBP305/12/G034 Institutional support: RVO:68378050 Keywords : alternative splicing * fibronectin * p300 * histone acetylation * promoter Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.974, year: 2014

  7. Alternative splicing of cyclooxygenase-1 mRNA in the human iris

    NARCIS (Netherlands)

    Dröge, M.J; van Sorge, A.A; van Haeringen, N.J; Quax, Wim; Zaagsma, Hans; Droge, MJ

    2003-01-01

    dIn homogenates of the human iris, the nonsteroidal antiinflammatory drug (NSAID) S(+)flurbiprofen has been reported to inhibit cyclooxygenase-1 (COX-1) 70-fold more potently than in human whole blood. We hypothesized that this difference may be due to alternative splicing of COX-1 mRNA in the human

  8. Kinetic and structural characterization of an alternatively spliced variant of human mitochondrial 5'(3')-deoxyribonucleotidase

    Czech Academy of Sciences Publication Activity Database

    Pachl, Petr; Fábry, Milan; Veverka, Václav; Brynda, Jiří; Řezáčová, Pavlína

    2015-01-01

    Roč. 30, č. 1 (2015), 63-68 ISSN 1475-6366 R&D Projects: GA ČR GA203/09/0820; GA MŠk(CZ) LK11205 Institutional support: RVO:61388963 ; RVO:68378050 Keywords : 5'(3')-deoxyribonucleotidase * alternative splicing * crystal structure * hydrolase * mitochondria Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.428, year: 2015

  9. Phosphorylation inhibits DNA-binding of alternatively spliced aryl hydrocarbon receptor nuclear translocator

    International Nuclear Information System (INIS)

    Kewley, Robyn J.; Whitelaw, Murray L.

    2005-01-01

    The basic helix-loop-helix/PER-ARNT-SIM homology (bHLH/PAS) transcription factor ARNT (aryl hydrocarbon receptor nuclear translocator) is a key component of various pathways which induce the transcription of cytochrome P450 and hypoxia response genes. ARNT can be alternatively spliced to express Alt ARNT, containing an additional 15 amino acids immediately N-terminal to the DNA-binding basic region. Here, we show that ARNT and Alt ARNT proteins are differentially phosphorylated by protein kinase CKII in vitro. Phosphorylation had an inhibitory effect on DNA-binding to an E-box probe by Alt ARNT, but not ARNT, homodimers. This inhibitory phosphorylation occurs through Ser77. Moreover, a point mutant, Alt ARNT S77A, shows increased activity on an E-box reporter gene, consistent with Ser77 being a regulatory site in vivo. In contrast, DNA binding by an Alt ARNT/dioxin receptor heterodimer to the xenobiotic response element is not inhibited by phosphorylation with CKII, nor does Alt ARNT S77A behave differently from wild type Alt ARNT in the context of a dioxin receptor heterodimer

  10. PDZ-containing proteins: alternative splicing as a source of functional diversity.

    Science.gov (United States)

    Sierralta, Jimena; Mendoza, Carolina

    2004-12-01

    Scaffold proteins allow specific protein complexes to be assembled in particular regions of the cell at which they organize subcellular structures and signal transduction complexes. This characteristic is especially important for neurons, which are highly polarized cells. Among the domains contained by scaffold proteins, the PSD-95, Discs-large, ZO-1 (PDZ) domains are of particular relevance in signal transduction processes and maintenance of neuronal and epithelial polarity. These domains are specialized in the binding of the carboxyl termini of proteins allowing membrane proteins to be localized by the anchoring to the cytoskeleton mediated by PDZ-containing scaffold proteins. In vivo studies carried out in Drosophila have taught that the role of many scaffold proteins is not limited to a single process; thus, in many cases the same genes are expressed in different tissues and participate in apparently very diverse processes. In addition to the differential expression of interactors of scaffold proteins, the expression of variants of these molecular scaffolds as the result of the alternative processing of the genes that encode them is proving to be a very important source of variability and complexity on a main theme. Alternative splicing in the nervous system is well documented, where specific isoforms play roles in neurotransmission, ion channel function, neuronal cell recognition, and are developmentally regulated making it a major mechanism of functional diversity. Here we review the current state of knowledge about the diversity and the known function of PDZ-containing proteins in Drosophila with emphasis in the role played by alternatively processed forms in the diversity of functions attributed to this family of proteins.

  11. Control of fibroblast fibronectin expression and alternative splicing via the PI3K/Akt/mTOR pathway

    International Nuclear Information System (INIS)

    White, Eric S.; Sagana, Rommel L.; Booth, Adam J.; Yan, Mei; Cornett, Ashley M.; Bloomheart, Christopher A.; Tsui, Jessica L.; Wilke, Carol A.; Moore, Bethany B.; Ritzenthaler, Jeffrey D.; Roman, Jesse; Muro, Andres F.

    2010-01-01

    Fibronectin (FN), a ubiquitous glycoprotein that plays critical roles in physiologic and pathologic conditions, undergoes alternative splicing which distinguishes plasma FN (pFN) from cellular FN (cFN). Although both pFN and cFN can be incorporated into the extracellular matrix, a distinguishing feature of cFN is the inclusion of an alternatively spliced exon termed EDA (for extra type III domain A). The molecular steps involved in EDA splicing are well-characterized, but pathways influencing EDA splicing are less clear. We have previously found an obligate role for inhibition of the tumor suppressor phosphatase and tensin homologue on chromosome 10 (PTEN), the primary regulator of the PI3K/Akt pathway, in fibroblast activation. Here we show TGF-β, a potent inducer of both EDA splicing and fibroblast activation, inhibits PTEN expression and activity in mesenchymal cells, corresponding with enhanced PI3K/Akt signaling. In pten -/- fibroblasts, which resemble activated fibroblasts, inhibition of Akt attenuated FN production and decreased EDA alternative splicing. Moreover, inhibition of mammalian target of rapamycin (mTOR) in pten -/- cells also blocked FN production and EDA splicing. This effect was due to inhibition of Akt-mediated phosphorylation of the primary EDA splicing regulatory protein SF2/ASF. Importantly, FN silencing in pten -/- cells resulted in attenuated proliferation and migration. Thus, our results demonstrate that the PI3K/Akt/mTOR axis is instrumental in FN transcription and alternative splicing, which regulates cell behavior.

  12. An Alternate Splicing Variant of the Human Telomerase Catalytic Subunit Inhibits Telomerase Activity

    Directory of Open Access Journals (Sweden)

    Xiaoming Yi

    2000-09-01

    Full Text Available Telomerase, a cellular reverse transcriptase, adds telomeric repeats to chromosome ends. In normal human somatic cells, telomerase is repressed and telomeres progressively shorten, leading to proliferative senescence. Introduction of the telomerase (hTERT cDNA is sufficient to produce telomerase activity and immortalize normal human cells, suggesting that the repression of telomerase activity is transcriptional. The telomerase transcript has been shown to have at least six alternate splicing sites (four insertion sites and two deletion sites, and variants containing both or either of the deletion sites are present during development and in a panel of cancer cell lines we surveyed. One deletion (β site and all four insertions cause premature translation terminations, whereas the other deletion (α site is 36 by and lies within reverse transcriptase (RT motif A, suggesting that this deletion variant may be a candidate as a dominant-negative inhibitor of telomerase. We have cloned three alternately spliced hTERT variants that contain the α,β or both α and,β deletion sites. These alternate splicing variants along with empty vector and wild-type hTERT were introduced into normal human fibroblasts and several telomerase-positive immortal and tumor cell lines. Expression of the α site deletion variant (hTERT α− construct was confirmed by Western blotting. We found that none of the three alternate splicing variants reconstitutes telomerase activity in fibroblasts. However, hTERT α− inhibits telomerase activities in telomerase-positive cells, causes telomere shortening and eventually cell death. This alternately spliced dominant-negative variant may be important in understanding telomerase regulation during development, differentiation and in cancer progression.

  13. Specific CLK inhibitors from a novel chemotype for regulation of alternative splicing

    DEFF Research Database (Denmark)

    Fedorov, Oleg; Huber, Kilian; Eisenreich, Andreas

    2011-01-01

    There is a growing recognition of the importance of protein kinases in the control of alternative splicing. To define the underlying regulatory mechanisms, highly selective inhibitors are needed. Here, we report the discovery and characterization of the dichloroindolyl enaminonitrile KH-CB19......, a potent and highly specific inhibitor of the CDC2-like kinase isoforms 1 and 4 (CLK1/CLK4). Cocrystal structures of KH-CB19 with CLK1 and CLK3 revealed a non-ATP mimetic binding mode, conformational changes in helix aC and the phosphate binding loop and halogen bonding to the kinase hinge region. KH-CB19...... effectively suppressed phosphorylation of SR (serine/arginine) proteins in cells, consistent with its expected mechanism of action. Chemical inhibition of CLK1/CLK4 generated a unique pattern of splicing factor dephosphorylation and had at low nM concentration a profound effect on splicing of the two tissue...

  14. LRRTM3 Regulates Excitatory Synapse Development through Alternative Splicing and Neurexin Binding

    Directory of Open Access Journals (Sweden)

    Ji Won Um

    2016-02-01

    Full Text Available The four members of the LRRTM family (LRRTM1-4 are postsynaptic adhesion molecules essential for excitatory synapse development. They have also been implicated in neuropsychiatric diseases. Here, we focus on LRRTM3, showing that two distinct LRRTM3 variants generated by alternative splicing regulate LRRTM3 interaction with PSD-95, but not its excitatory synapse-promoting activity. Overexpression of either LRRTM3 variant increased excitatory synapse density in dentate gyrus (DG granule neurons, whereas LRRTM3 knockdown decreased it. LRRTM3 also controlled activity-regulated AMPA receptor surface expression in an alternative splicing-dependent manner. Furthermore, Lrrtm3-knockout mice displayed specific alterations in excitatory synapse density, excitatory synaptic transmission and excitability in DG granule neurons but not in CA1 pyramidal neurons. Lastly, LRRTM3 required only specific splice variants of presynaptic neurexins for their synaptogenic activity. Collectively, our data highlight alternative splicing and differential presynaptic ligand utilization in the regulation of LRRTMs, revealing key regulatory mechanisms for excitatory synapse development.

  15. GC content around splice sites affects splicing through pre-mRNA secondary structures

    Directory of Open Access Journals (Sweden)

    Chen Liang

    2011-01-01

    Full Text Available Abstract Background Alternative splicing increases protein diversity by generating multiple transcript isoforms from a single gene through different combinations of exons or through different selections of splice sites. It has been reported that RNA secondary structures are involved in alternative splicing. Here we perform a genomic study of RNA secondary structures around splice sites in humans (Homo sapiens, mice (Mus musculus, fruit flies (Drosophila melanogaster, and nematodes (Caenorhabditis elegans to further investigate this phenomenon. Results We observe that GC content around splice sites is closely associated with the splice site usage in multiple species. RNA secondary structure is the possible explanation, because the structural stability difference among alternative splice sites, constitutive splice sites, and skipped splice sites can be explained by the GC content difference. Alternative splice sites tend to be GC-enriched and exhibit more stable RNA secondary structures in all of the considered species. In humans and mice, splice sites of first exons and long exons tend to be GC-enriched and hence form more stable structures, indicating the special role of RNA secondary structures in promoter proximal splicing events and the splicing of long exons. In addition, GC-enriched exon-intron junctions tend to be overrepresented in tissue-specific alternative splice sites, indicating the functional consequence of the GC effect. Compared with regions far from splice sites and decoy splice sites, real splice sites are GC-enriched. We also found that the GC-content effect is much stronger than the nucleotide-order effect to form stable secondary structures. Conclusion All of these results indicate that GC content is related to splice site usage and it may mediate the splicing process through RNA secondary structures.

  16. Alternative Splicing of the Pituitary Adenylate Cyclase-Activating Polypeptide Receptor PAC1: Mechanisms of Fine Tuning of Brain Activity

    Directory of Open Access Journals (Sweden)

    Janna eBlechman

    2013-05-01

    Full Text Available Alternative splicing of the precursor mRNA encoding for the neuropeptide receptor PAC1/ADCYAP1R1 generates multiple protein products that exhibit pleiotropic activities. Recent studies in mammals and zebrafish have implicated some of these splice isoforms in control of both cellular and body homeostasis. Here, we review the regulation of PAC1 splice variants and their underlying signal transduction and physiological processes in the nervous system.

  17. Identification and characterization of NAGNAG alternative splicing in the moss Physcomitrella patens

    Directory of Open Access Journals (Sweden)

    Bolte Kathrin

    2010-04-01

    Full Text Available Abstract Background Alternative splicing (AS involving tandem acceptors that are separated by three nucleotides (NAGNAG is an evolutionarily widespread class of AS, which is well studied in Homo sapiens (human and Mus musculus (mouse. It has also been shown to be common in the model seed plants Arabidopsis thaliana and Oryza sativa (rice. In one of the first studies involving sequence-based prediction of AS in plants, we performed a genome-wide identification and characterization of NAGNAG AS in the model plant Physcomitrella patens, a moss. Results Using Sanger data, we found 295 alternatively used NAGNAG acceptors in P. patens. Using 31 features and training and test datasets of constitutive and alternative NAGNAGs, we trained a classifier to predict the splicing outcome at NAGNAG tandem splice sites (alternative splicing, constitutive at the first acceptor, or constitutive at the second acceptor. Our classifier achieved a balanced specificity and sensitivity of ≥ 89%. Subsequently, a classifier trained exclusively on data well supported by transcript evidence was used to make genome-wide predictions of NAGNAG splicing outcomes. By generation of more transcript evidence from a next-generation sequencing platform (Roche 454, we found additional evidence for NAGNAG AS, with altogether 664 alternative NAGNAGs being detected in P. patens using all currently available transcript evidence. The 454 data also enabled us to validate the predictions of the classifier, with 64% (80/125 of the well-supported cases of AS being predicted correctly. Conclusion NAGNAG AS is just as common in the moss P. patens as it is in the seed plants A. thaliana and O. sativa (but not conserved on the level of orthologous introns, and can be predicted with high accuracy. The most informative features are the nucleotides in the NAGNAG and in its immediate vicinity, along with the splice sites scores, as found earlier for NAGNAG AS in animals. Our results suggest that the

  18. Distinct Transcriptional and Alternative Splicing Signatures of Decidual CD4+ T Cells in Early Human Pregnancy

    Directory of Open Access Journals (Sweden)

    Weihong Zeng

    2017-06-01

    Full Text Available Decidual CD4+ T (dCD4 T cells are crucial for the maternal-fetal immune tolerance required for a healthy pregnancy outcome. However, their molecular and functional characteristics are not well elucidated. In this study, we performed the first analysis of transcriptional and alternative splicing (AS landscapes for paired decidual and peripheral blood CD4+ T (pCD4 T cells in human early pregnancy using high throughput mRNA sequencing. Our data showed that dCD4 T cells are endowed with a unique transcriptional signature when compared to pCD4 T cells: dCD4 T cells upregulate 1,695 genes enriched in immune system process whereas downregulate 1,011 genes mainly related to mRNA catabolic process and the ribosome. Moreover, dCD4 T cells were observed to be at M phase, and show increased activation, proliferation, and cytokine production, as well as display an effector-memory phenotype and a heterogenous nature containing Th1, Th17, and Treg cell subsets. However, dCD4 T cells undergo a comparable number of upregulated and downregulated AS events, both of which are enriched in the genes related to cellular metabolic process. And the changes at the AS event level do not reflect measurable differences at the gene expression level in dCD4 T cells. Collectively, our findings provide a comprehensive portrait of the unique transcriptional signature and AS profile of CD4+ T cells in human decidua and help us gain more understanding of the functional characteristic of these cells during early pregnancy.

  19. Alternative splicing events identified in human embryonic stem cells and neural progenitors.

    Directory of Open Access Journals (Sweden)

    Gene W Yeo

    2007-10-01

    Full Text Available Human embryonic stem cells (hESCs and neural progenitor (NP cells are excellent models for recapitulating early neuronal development in vitro, and are key to establishing strategies for the treatment of degenerative disorders. While much effort had been undertaken to analyze transcriptional and epigenetic differences during the transition of hESC to NP, very little work has been performed to understand post-transcriptional changes during neuronal differentiation. Alternative RNA splicing (AS, a major form of post-transcriptional gene regulation, is important in mammalian development and neuronal function. Human ESC, hESC-derived NP, and human central nervous system stem cells were compared using Affymetrix exon arrays. We introduced an outlier detection approach, REAP (Regression-based Exon Array Protocol, to identify 1,737 internal exons that are predicted to undergo AS in NP compared to hESC. Experimental validation of REAP-predicted AS events indicated a threshold-dependent sensitivity ranging from 56% to 69%, at a specificity of 77% to 96%. REAP predictions significantly overlapped sets of alternative events identified using expressed sequence tags and evolutionarily conserved AS events. Our results also reveal that focusing on differentially expressed genes between hESC and NP will overlook 14% of potential AS genes. In addition, we found that REAP predictions are enriched in genes encoding serine/threonine kinase and helicase activities. An example is a REAP-predicted alternative exon in the SLK (serine/threonine kinase 2 gene that is differentially included in hESC, but skipped in NP as well as in other differentiated tissues. Lastly, comparative sequence analysis revealed conserved intronic cis-regulatory elements such as the FOX1/2 binding site GCAUG as being proximal to candidate AS exons, suggesting that FOX1/2 may participate in the regulation of AS in NP and hESC. In summary, a new methodology for exon array analysis was introduced

  20. IBTK Differently Modulates Gene Expression and RNA Splicing in HeLa and K562 Cells

    Directory of Open Access Journals (Sweden)

    Giuseppe Fiume

    2016-11-01

    Full Text Available The IBTK gene encodes the major protein isoform IBTKα that was recently characterized as substrate receptor of Cul3-dependent E3 ligase, regulating ubiquitination coupled to proteasomal degradation of Pdcd4, an inhibitor of translation. Due to the presence of Ankyrin-BTB-RCC1 domains that mediate several protein-protein interactions, IBTKα could exert expanded regulatory roles, including interaction with transcription regulators. To verify the effects of IBTKα on gene expression, we analyzed HeLa and K562 cell transcriptomes by RNA-Sequencing before and after IBTK knock-down by shRNA transduction. In HeLa cells, 1285 (2.03% of 63,128 mapped transcripts were differentially expressed in IBTK-shRNA-transduced cells, as compared to cells treated with control-shRNA, with 587 upregulated (45.7% and 698 downregulated (54.3% RNAs. In K562 cells, 1959 (3.1% of 63128 mapped RNAs were differentially expressed in IBTK-shRNA-transduced cells, including 1053 upregulated (53.7% and 906 downregulated (46.3%. Only 137 transcripts (0.22% were commonly deregulated by IBTK silencing in both HeLa and K562 cells, indicating that most IBTKα effects on gene expression are cell type-specific. Based on gene ontology classification, the genes responsive to IBTK are involved in different biological processes, including in particular chromatin and nucleosomal organization, gene expression regulation, and cellular traffic and migration. In addition, IBTK RNA interference affected RNA maturation in both cell lines, as shown by the evidence of alternative 3′- and 5′-splicing, mutually exclusive exons, retained introns, and skipped exons. Altogether, these results indicate that IBTK differently modulates gene expression and RNA splicing in HeLa and K562 cells, demonstrating a novel biological role of this protein.

  1. IBTK Differently Modulates Gene Expression and RNA Splicing in HeLa and K562 Cells.

    Science.gov (United States)

    Fiume, Giuseppe; Scialdone, Annarita; Rizzo, Francesca; De Filippo, Maria Rosaria; Laudanna, Carmelo; Albano, Francesco; Golino, Gaetanina; Vecchio, Eleonora; Pontoriero, Marilena; Mimmi, Selena; Ceglia, Simona; Pisano, Antonio; Iaccino, Enrico; Palmieri, Camillo; Paduano, Sergio; Viglietto, Giuseppe; Weisz, Alessandro; Scala, Giuseppe; Quinto, Ileana

    2016-11-07

    The IBTK gene encodes the major protein isoform IBTKα that was recently characterized as substrate receptor of Cul3-dependent E3 ligase, regulating ubiquitination coupled to proteasomal degradation of Pdcd4, an inhibitor of translation. Due to the presence of Ankyrin-BTB-RCC1 domains that mediate several protein-protein interactions, IBTKα could exert expanded regulatory roles, including interaction with transcription regulators. To verify the effects of IBTKα on gene expression, we analyzed HeLa and K562 cell transcriptomes by RNA-Sequencing before and after IBTK knock-down by shRNA transduction. In HeLa cells, 1285 (2.03%) of 63,128 mapped transcripts were differentially expressed in IBTK -shRNA-transduced cells, as compared to cells treated with control-shRNA, with 587 upregulated (45.7%) and 698 downregulated (54.3%) RNAs. In K562 cells, 1959 (3.1%) of 63128 mapped RNAs were differentially expressed in IBTK -shRNA-transduced cells, including 1053 upregulated (53.7%) and 906 downregulated (46.3%). Only 137 transcripts (0.22%) were commonly deregulated by IBTK silencing in both HeLa and K562 cells, indicating that most IBTKα effects on gene expression are cell type-specific. Based on gene ontology classification, the genes responsive to IBTK are involved in different biological processes, including in particular chromatin and nucleosomal organization, gene expression regulation, and cellular traffic and migration. In addition, IBTK RNA interference affected RNA maturation in both cell lines, as shown by the evidence of alternative 3'- and 5'-splicing, mutually exclusive exons, retained introns, and skipped exons. Altogether, these results indicate that IBTK differently modulates gene expression and RNA splicing in HeLa and K562 cells, demonstrating a novel biological role of this protein.

  2. Splicing aberrations caused by constitutional RB1 gene mutations in ...

    Indian Academy of Sciences (India)

    in this family revealed skipping of exon 22 in three members of this family. In one proband, a ... This study reveals novel effects of RB1 mutations on splicing and suggests the utility of RNA analysis as an ... of life) and presence of multiple tumors (multifocal). The ..... spliced RNA have been linked to parent of origin as well as.

  3. TAPAS: tools to assist the targeted protein quantification of human alternative splice variants.

    Science.gov (United States)

    Yang, Jae-Seong; Sabidó, Eduard; Serrano, Luis; Kiel, Christina

    2014-10-15

    In proteomes of higher eukaryotes, many alternative splice variants can only be detected by their shared peptides. This makes it highly challenging to use peptide-centric mass spectrometry to distinguish and to quantify protein isoforms resulting from alternative splicing events. We have developed two complementary algorithms based on linear mathematical models to efficiently compute a minimal set of shared and unique peptides needed to quantify a set of isoforms and splice variants. Further, we developed a statistical method to estimate the splice variant abundances based on stable isotope labeled peptide quantities. The algorithms and databases are integrated in a web-based tool, and we have experimentally tested the limits of our quantification method using spiked proteins and cell extracts. The TAPAS server is available at URL http://davinci.crg.es/tapas/. luis.serrano@crg.eu or christina.kiel@crg.eu Supplementary data are available at Bioinformatics online. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  4. Subcellular RNA profiling links splicing and nuclear DICER1 to alternative cleavage and polyadenylation.

    Science.gov (United States)

    Neve, Jonathan; Burger, Kaspar; Li, Wencheng; Hoque, Mainul; Patel, Radhika; Tian, Bin; Gullerova, Monika; Furger, Andre

    2016-01-01

    Alternative cleavage and polyadenylation (APA) plays a crucial role in the regulation of gene expression across eukaryotes. Although APA is extensively studied, its regulation within cellular compartments and its physiological impact remains largely enigmatic. Here, we used a rigorous subcellular fractionation approach to compare APA profiles of cytoplasmic and nuclear RNA fractions from human cell lines. This approach allowed us to extract APA isoforms that are subjected to differential regulation and provided us with a platform to interrogate the molecular regulatory pathways that shape APA profiles in different subcellular locations. Here, we show that APA isoforms with shorter 3' UTRs tend to be overrepresented in the cytoplasm and appear to be cell-type-specific events. Nuclear retention of longer APA isoforms occurs and is partly a result of incomplete splicing contributing to the observed cytoplasmic bias of transcripts with shorter 3' UTRs. We demonstrate that the endoribonuclease III, DICER1, contributes to the establishment of subcellular APA profiles not only by expected cytoplasmic miRNA-mediated destabilization of APA mRNA isoforms, but also by affecting polyadenylation site choice. © 2016 Neve et al.; Published by Cold Spring Harbor Laboratory Press.

  5. Modulation of KCNQ1 alternative splicing regulates cardiac IKs and action potential repolarization.

    Science.gov (United States)

    Lee, Hsiang-Chun; Rudy, Yoram; Po-Yuan, Phd; Sheu, Sheng-Hsiung; Chang, Jan-Gowth; Cui, Jianmin

    2013-08-01

    Slow delayed-rectifier potassium current (IKs) channels, made of the pore-forming KCNQ1 and auxiliary KCNE1 subunits, play a key role in determining action potential duration (APD) in cardiac myocytes. The consequences of drug-induced KCNQ1 splice alteration remain unknown. To study the modulation of KCNQ1 alternative splicing by amiloride and the consequent changes in IKs and action potentials (APs) in ventricular myocytes. Canine endocardial, midmyocardial, and epicardial ventricular myocytes were isolated. Levels of KCNQ1a and KCNQ1b as well as a series of splicing factors were quantified by using the reverse transcriptase-polymerase chain reaction and Western blot. The effect of amiloride-induced changes in the KCNQ1b/total KCNQ1 ratio on AP was measured by using whole-cell patch clamp with and without isoproterenol. With 50 μmol/L of amiloride for 6 hours, KCNQ1a at transcriptional and translational levels increased in midmyocardial myocytes but decreased in endo- and epicardial myocytes. Likewise, changes in splicing factors in midmyocardial were opposite to that in endo- and epicardial myocytes. In midmyocardial myocytes amiloride shortened APD and decreased isoproterenol-induced early afterdepolarizations significantly. The same amiloride-induced effects were demonstrated by using human ventricular myocyte model for AP simulations under beta-adrenergic stimulation. Moreover, amiloride reduced the transmural dispersion of repolarization in pseudo-electrocardiogram. Amiloride regulates IKs and APs with transmural differences and reduces arrhythmogenicity through the modulation of KCNQ1 splicing. We suggested that the modulation of KCNQ1 splicing may help prevent arrhythmia. Copyright © 2013 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  6. Spliceosomal protein U1A is involved in alternative splicing and salt stress tolerance in Arabidopsis thaliana

    KAUST Repository

    Gu, Jinbao

    2017-12-01

    Soil salinity is a significant threat to sustainable agricultural production worldwide. Plants must adjust their developmental and physiological processes to cope with salt stress. Although the capacity for adaptation ultimately depends on the genome, the exceptional versatility in gene regulation provided by the spliceosome-mediated alternative splicing (AS) is essential in these adaptive processes. However, the functions of the spliceosome in plant stress responses are poorly understood. Here, we report the in-depth characterization of a U1 spliceosomal protein, AtU1A, in controlling AS of pre-mRNAs under salt stress and salt stress tolerance in Arabidopsis thaliana. The atu1a mutant was hypersensitive to salt stress and accumulated more reactive oxygen species (ROS) than the wild-type under salt stress. RNA-seq analysis revealed that AtU1A regulates AS of many genes, presumably through modulating recognition of 5′ splice sites. We showed that AtU1A is associated with the pre-mRNA of the ROS detoxification-related gene ACO1 and is necessary for the regulation of ACO1 AS. ACO1 is important for salt tolerance because ectopic expression of ACO1 in the atu1a mutant can partially rescue its salt hypersensitive phenotype. Our findings highlight the critical role of AtU1A as a regulator of pre-mRNA processing and salt tolerance in plants.

  7. AtRTD2: A Reference Transcript Dataset for accurate quantification of alternative splicing and expression changes in Arabidopsis thaliana RNA-seq data

    KAUST Repository

    Zhang, Runxuan

    2016-05-06

    Background Alternative splicing is the major post-transcriptional mechanism by which gene expression is regulated and affects a wide range of processes and responses in most eukaryotic organisms. RNA-sequencing (RNA-seq) can generate genome-wide quantification of individual transcript isoforms to identify changes in expression and alternative splicing. RNA-seq is an essential modern tool but its ability to accurately quantify transcript isoforms depends on the diversity, completeness and quality of the transcript information. Results We have developed a new Reference Transcript Dataset for Arabidopsis (AtRTD2) for RNA-seq analysis containing over 82k non-redundant transcripts, whereby 74,194 transcripts originate from 27,667 protein-coding genes. A total of 13,524 protein-coding genes have at least one alternatively spliced transcript in AtRTD2 such that about 60% of the 22,453 protein-coding, intron-containing genes in Arabidopsis undergo alternative splicing. More than 600 putative U12 introns were identified in more than 2,000 transcripts. AtRTD2 was generated from transcript assemblies of ca. 8.5 billion pairs of reads from 285 RNA-seq data sets obtained from 129 RNA-seq libraries and merged along with the previous version, AtRTD, and Araport11 transcript assemblies. AtRTD2 increases the diversity of transcripts and through application of stringent filters represents the most extensive and accurate transcript collection for Arabidopsis to date. We have demonstrated a generally good correlation of alternative splicing ratios from RNA-seq data analysed by Salmon and experimental data from high resolution RT-PCR. However, we have observed inaccurate quantification of transcript isoforms for genes with multiple transcripts which have variation in the lengths of their UTRs. This variation is not effectively corrected in RNA-seq analysis programmes and will therefore impact RNA-seq analyses generally. To address this, we have tested different genome

  8. Dynamic changes in neurexins' alternative splicing: role of Rho-associated protein kinases and relevance to memory formation.

    Directory of Open Access Journals (Sweden)

    Gabriela Rozic

    Full Text Available The three neurexins genes (NRXN1/2/3 encode polymorphic synaptic membrane proteins that are involved in cognitive functioning. Neurexins' selectivity of function is presumably conferred through differential use of 2 promoters and 5 alternative splicing sites (SS#1/2/3/4/5. In day-old rat brain neurons grown in culture, activation (depolarization induces reversible, calcium dependent, repression of NRXN2α SS#3 insert. The effects of depolarization on NRXN1/2/3α splicing and biochemical pathways mediating them were further studied in these neurons. NRXN1/2/3α splicing in the course of memory formation in vivo was also explored, using fear conditioning paradigm in rats in which the animals were trained to associate an aversive stimulus (electrical shock with a neutral context (a tone, resulting in the expression of fear responses to the neutral context.In the cultured neurons depolarization induced, beside NRXN2α SS#3, repression of SS#3 and SS#4 exons in NRXN3α but not NRXN1α. The repressions were mediated by the calcium/protein kinase C/Rho-associated protein kinase (ROCK pathway. Fear conditioning induced significant and transient repressions of the NRXN1/2/3α SS#4 exons in the rat hippocampus. ROCK inhibition prior to training attenuated the behavioral fear response, the NRXN1/2/3α splicing repressions and subsequent recovery and the levels of excitatory (PSD95 and inhibitory (gephyrin synaptic proteins in the hippocampus. No such effects were observed in the prefrontal cortex. Significant correlations existed between the fear response and hippocampal NRXN3α and NRXN2α SS#4 inserts as well as PSD95 protein levels. Hippocampal NRXN1α SS#4 insert and gephyrin levels did not correlate with the behavioral response but were negatively correlated with each other.These results show for the first time dynamic, experience related changes in NRXN1/2/3α alternative splicing in the rat brain and a role for ROCK in them. Specific neurexins

  9. Regulation of Neurexin 1[beta] Tertiary Structure and Ligand Binding through Alternative Splicing

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Kaiser C.; Kuczynska, Dorota A.; Wu, Irene J.; Murray, Beverly H.; Sheckler, Lauren R.; Rudenko, Gabby (Michigan)

    2008-08-04

    Neurexins and neuroligins play an essential role in synapse function, and their alterations are linked to autistic spectrum disorder. Interactions between neurexins and neuroligins regulate inhibitory and excitatory synaptogenesis in vitro through a splice-insert signaling code. In particular, neurexin 1{beta} carrying an alternative splice insert at site SS{number_sign}4 interacts with neuroligin 2 (found predominantly at inhibitory synapses) but much less so with other neuroligins (those carrying an insert at site B and prevalent at excitatory synapses). The structure of neurexin 1{beta}+SS{number_sign}4 reveals dramatic rearrangements to the 'hypervariable surface', the binding site for neuroligins. The splice insert protrudes as a long helix into space, triggers conversion of loop {beta}10-{beta}11 into a helix rearranging the binding site for neuroligins, and rearranges the Ca{sup 2+}-binding site required for ligand binding, increasing its affinity. Our structures reveal the mechanism by which neurexin 1{beta} isoforms acquire neuroligin splice isoform selectivity.

  10. Production of the 2400 kb Duchenne muscular dystrophy (DMD) gene transcript; transcription time and cotranscriptional splicing

    Energy Technology Data Exchange (ETDEWEB)

    Tennyson, C.N.; Worton, R.G. [Univ. of Toronto and the Hospital for Sick Children, Ontario (Canada)

    1994-09-01

    The largest known gene in any organism is the human DMD gene which has 79 exons that span 2400 kb. The extreme nature of the DMD gene raises questions concerning the time required for transcription and whether splicing begins before transcription is complete. DMD gene transcription is induced as cultured human myoblasts differentiate to form multinucleated myotubes, providing a system for studying the kinetics of transcription and splicing. Using quantitative RT-PCR, transcript accumulation was monitored from four different regions within the gene following induction of expression. By comparing the accumulation of transcripts from the 5{prime} and 3{prime} ends of the gene we have shown that approximately 12 hours are required to transcribe 1770 kb of the gene, extrapolating to a time of 16 hours for the transcription unit expressed in muscle. Comparison of accumulation profiles for spliced and total transcript demonstrated that transcripts are spliced at the 5{prime} end before transcription is complete, providing strong evidence for cotranscriptional splicing of DMD gene transcripts. Finally, the rate of transcript accumulation was reduced at the 3{prime} end of the gene relative to the 5{prime} end, perhaps due to premature termination of transcription complexes as they traverse this enormous transcription unit. The lag between transcription initiation and the appearance of complete transcripts could be important in limiting transcript production in dividing cells and to the timing of mRNA appearance in differentiating muscle.

  11. Identification of alternatively spliced isoforms of interleukin-2/15 receptor β chain in ducks.

    Science.gov (United States)

    Jeong, Jipseol; Kim, Woo H; Yeo, Jaeseung; Fernandez, Cherry P; Kim, Suk; Lee, Youn-Jeong; Lillehoj, Hyun S; Min, Wongi

    2014-12-15

    Interleukin (IL)-2 and IL-15 receptor β (IL-2/15Rβ, CD122) play important roles in signal transduction for biological functions of IL-2 and IL-15. We found that ducks possess three different IL-2/15Rβ transcripts, a conventional form (duIL-2/15Rβ) and two variants. Comparisons between the cDNA and genomic sequences revealed that the two variants, duIL-2/15Rβ-d7 and duIL-2/15Rβ-d9, were novel spliced transcripts resulting from skipping exons 7 and 9, respectively. Expression profiles of duIL-2/15Rβ and its isoforms were examined in healthy tissues, concanavalin A (ConA)-stimulated splenic lymphocytes and in livers and spleens of Riemerella anatipestifer-infected ducks using quantitative real-time PCR (qRT-PCR). Generally, duIL-2/15Rβ-d9 expression was undetectable in healthy tissues, ConA-activated samples, and R. anatipestifer-infected ducks. Expression levels of duIL-2/15Rβ transcript were relatively high to moderate in all healthy tissues tested, while duIL-2/15Rβ-d7 expression was low. Compared to untreated controls, expression levels of duIL-2/15Rβ were elevated in ConA-activated splenic lymphocytes and in livers on day 7 in R. anatipestifer-infected ducks, while duIL-2/15Rβ-d7 expression was unchanged. Additionally, COS-7 cells transfected with duIL-2/15Rβ, duIL-2/15Rβ-d7, or duIL-2/15Rβ-d9 constructs generated 73 kilodalton (kDa), 31kDa, and 40kDa proteins, respectively. This study identified three different IL-2/15Rβ transcripts, including two isoforms generated by alternative splicing and their gene expression patterns in stimulated conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Identify alternative splicing events based on position-specific evolutionary conservation.

    Directory of Open Access Journals (Sweden)

    Liang Chen

    Full Text Available The evolution of eukaryotes is accompanied by the increased complexity of alternative splicing which greatly expands genome information. One of the greatest challenges in the post-genome era is a complete revelation of human transcriptome with consideration of alternative splicing. Here, we introduce a comparative genomics approach to systemically identify alternative splicing events based on the differential evolutionary conservation between exons and introns and the high-quality annotation of the ENCODE regions. Specifically, we focus on exons that are included in some transcripts but are completely spliced out for others and we call them conditional exons. First, we characterize distinguishing features among conditional exons, constitutive exons and introns. One of the most important features is the position-specific conservation score. There are dramatic differences in conservation scores between conditional exons and constitutive exons. More importantly, the differences are position-specific. For flanking intronic regions, the differences between conditional exons and constitutive exons are also position-specific. Using the Random Forests algorithm, we can classify conditional exons with high specificities (97% for the identification of conditional exons from intron regions and 95% for the classification of known exons and fair sensitivities (64% and 32% respectively. We applied the method to the human genome and identified 39,640 introns that actually contain conditional exons and classified 8,813 conditional exons from the current RefSeq exon list. Among those, 31,673 introns containing conditional exons and 5,294 conditional exons classified from known exons cannot be inferred from RefSeq, UCSC or Ensembl annotations. Some of these de novo predictions were experimentally verified.

  13. Alternative splicing at exon 2 results in the loss of the catalytic activity of mouse DNA polymerase iota in vitro.

    Science.gov (United States)

    Kazachenko, Konstantin Y; Miropolskaya, Nataliya A; Gening, Leonid V; Tarantul, Vyacheslav Z; Makarova, Alena V

    2017-02-01

    Y-family DNA polymerase iota (Pol ι) possesses both DNA polymerase and dRP lyase activities and was suggested to be involved in DNA translesion synthesis and base excision repair in mammals. The 129 strain of mice and its derivatives have a natural nonsense codon mutation in the second exon of the Pol ι gene resulting in truncation of the Pol ι protein. These mice were widely used as a Pol ι-null model for in vivo studies of the Pol ι function. However whether 129-derived strains of mice are fully deficient in the Pol ι functions was a subject of discussion since Pol ι mRNA undergoes alternative splicing at exon 2. Here we report purification of mouse Pol ι lacking the region encoded by exon 2, which includes several conserved residues involved in catalysis. We show that the deletion abrogates both the DNA polymerase and dRP lyase activities of Pol ι in the presence of either Mg 2+ or Mn 2+ ions. Thus, 129-derived strains of mice express catalytically inactive alternatively spliced Pol ι variant, whose cellular functions, if any exist, remain to be established. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Alternative Splicing Substantially Diversifies the Transcriptome during Early Photomorphogenesis and Correlates with the Energy Availability in Arabidopsis.

    Science.gov (United States)

    Hartmann, Lisa; Drewe-Boß, Philipp; Wießner, Theresa; Wagner, Gabriele; Geue, Sascha; Lee, Hsin-Chieh; Obermüller, Dominik M; Kahles, André; Behr, Jonas; Sinz, Fabian H; Rätsch, Gunnar; Wachter, Andreas

    2016-11-01

    Plants use light as source of energy and information to detect diurnal rhythms and seasonal changes. Sensing changing light conditions is critical to adjust plant metabolism and to initiate developmental transitions. Here, we analyzed transcriptome-wide alterations in gene expression and alternative splicing (AS) of etiolated seedlings undergoing photomorphogenesis upon exposure to blue, red, or white light. Our analysis revealed massive transcriptome reprogramming as reflected by differential expression of ∼20% of all genes and changes in several hundred AS events. For more than 60% of all regulated AS events, light promoted the production of a presumably protein-coding variant at the expense of an mRNA with nonsense-mediated decay-triggering features. Accordingly, AS of the putative splicing factor REDUCED RED-LIGHT RESPONSES IN CRY1CRY2 BACKGROUND1, previously identified as a red light signaling component, was shifted to the functional variant under light. Downstream analyses of candidate AS events pointed at a role of photoreceptor signaling only in monochromatic but not in white light. Furthermore, we demonstrated similar AS changes upon light exposure and exogenous sugar supply, with a critical involvement of kinase signaling. We propose that AS is an integration point of signaling pathways that sense and transmit information regarding the energy availability in plants. © 2016 American Society of Plant Biologists. All rights reserved.

  15. Identification of a novel alternative splicing variant of hemocyanin from shrimp Litopenaeus vannamei.

    Science.gov (United States)

    Zhao, Shan; Lu, Xin; Zhang, Yueling; Zhao, Xianliang; Zhong, Mingqi; Li, Shengkang; Lun, Jingsheng

    2013-01-01

    Recent evidences suggest that invertebrates express families of immune molecules with high levels of sequence diversity. Hemocyanin is an important non-specific immune molecule present in the hemolymph of both mollusks and arthropods. In the present study, we characterized a novel alternative splicing variant of hemocyanin (cHE1) from Litopenaeus vannamei that produced mRNA transcript of 2579 bp in length. The isoform contained two additional sequences of 296 and 267 bp in the 5'- and 3'-terminus respectively, in comparison to that of wild type hemocyanin (cHE). Sequence of cHE1 shows 100% identity to that of hemocyanin genomic DNA (HE, which does not form an open reading frame), suggesting that cHE1 might be an alternative splicing variant due to intron retention. Moreover, cHE1 could be detected by RT-PCR from five tissues (heart, gill, stomach, intestine and brain), and from shrimps at stages from nauplius to mysis larva. Further, cHE1 mRNA transcripts were significantly increased in hearts after 12h of infection with Vibrio parahemolyticus or poly I: C, while no significant difference in the transcript levels of hepatopancreas cHE was detected in the pathogen-treated shrimps during the period. In summary, these studies suggested a novel splicing variant of hemocyanin in shrimp, which might be involved in shrimp resistance to pathogenic infection. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Functional characterisation of an intron retaining K+ transporter of barley reveals intron-mediated alternate splicing

    KAUST Repository

    Shahzad, K.

    2015-01-01

    Intron retention in transcripts and the presence of 5 and 3 splice sites within these introns mediate alternate splicing, which is widely observed in animals and plants. Here, functional characterisation of the K+ transporter, HvHKT2;1, with stably retained introns from barley (Hordeum vulgare) in yeast (Saccharomyces cerevisiae), and transcript profiling in yeast and transgenic tobacco (Nicotiana tabacum) is presented. Expression of intron-retaining HvHKT2;1 cDNA (HvHKT2;1-i) in trk1, trk2 yeast strain defective in K+ uptake restored growth in medium containing hygromycin in the presence of different concentrations of K+ and mediated hypersensitivity to Na+. HvHKT2;1-i produces multiple transcripts via alternate splicing of two regular introns and three exons in different compositions. HKT isoforms with retained introns and exon skipping variants were detected in relative expression analysis of (i) HvHKT2;1-i in barley under native conditions, (ii) in transgenic tobacco plants constitutively expressing HvHKT2;1-i, and (iii) in trk1, trk2 yeast expressing HvHKT2;1-i under control of an inducible promoter. Mixed proportions of three HKT transcripts: HvHKT2;1-e (first exon region), HvHKT2;1-i1 (first intron) and HvHKT2;1-i2 (second intron) were observed. The variation in transcript accumulation in response to changing K+ and Na+ concentrations was observed in both heterologous and plant systems. These findings suggest a link between intron-retaining transcripts and different splice variants to ion homeostasis, and their possible role in salt stress.

  17. Sequence variants of KHDRBS1 as high penetrance susceptibility risks for primary ovarian insufficiency by mis-regulating mRNA alternative splicing.

    Science.gov (United States)

    Wang, Binbin; Li, Lin; Zhu, Ying; Zhang, Wei; Wang, Xi; Chen, Beili; Li, Tengyan; Pan, Hong; Wang, Jing; Kee, Kehkooi; Cao, Yunxia

    2017-10-01

    Does a novel heterozygous KHDRBS1 variant, identified using whole-exome sequencing (WES) in two patients with primary ovarian insufficiency (POI) in a pedigree, cause defects in mRNA alternative splicing? The heterozygous variant of KHDRBS1 was confirmed to cause defects in alternative splicing of many genes involved in DNA replication and repair. Studies in mice revealed that Khdrbs1 deficient females are subfertile, which manifests as delayed sexual maturity and significantly reduced numbers of secondary and pre-antral follicles. No mutation of KHDRBS1, however, has been reported in patients with POI. This genetic and functional study used WES to find putative mutations in a POI pedigree. Altogether, 215 idiopathic POI patients and 400 healthy controls were screened for KHDRBS1 mutations. Two POI patients were subjected to WES to identify sequence variants. Mutational analysis of the KHDRBS1 gene in 215 idiopathic POI patients and 400 healthy controls were performed. RNA-sequencing was carried out to find the mis-regulation of gene expression due to KHDRBS1 mutation. Bioinformatics was used to analyze the change in alternative splicing events. We identified a heterozygous mutation (c.460A > G, p.M154V) in KHDRBS1 in two patients. Further mutational analysis of 215 idiopathic POI patients with the KHDRBS1 gene found one heterozygous mutation (c.263C > T, p.P88L). We failed to find these two mutations in 400 healthy control women. Using RNA-sequencing, we found that the KGN cells expressing the M154V KHDRBS1 mutant had different expression of 66 genes compared with wild-type (WT) cells. Furthermore, 145 genes were alternatively spliced in M154V cells, and these genes were enriched for DNA replication and repair function, revealing a potential underlying mechanism of the pathology that leads to POI. Although the in vitro assays demonstrated the effect of the KHDRBS1 variant on alternative splicing, further studies are needed to validate the in vivo effects on germ

  18. Polypyrimidine Tract Binding Protein Homologs from Arabidopsis Are Key Regulators of Alternative Splicing with Implications in Fundamental Developmental Processes[W

    Science.gov (United States)

    Rühl, Christina; Stauffer, Eva; Kahles, André; Wagner, Gabriele; Drechsel, Gabriele; Rätsch, Gunnar; Wachter, Andreas

    2012-01-01

    Alternative splicing (AS) generates transcript variants by variable exon/intron definition and massively expands transcriptome diversity. Changes in AS patterns have been found to be linked to manifold biological processes, yet fundamental aspects, such as the regulation of AS and its functional implications, largely remain to be addressed. In this work, widespread AS regulation by Arabidopsis thaliana Polypyrimidine tract binding protein homologs (PTBs) was revealed. In total, 452 AS events derived from 307 distinct genes were found to be responsive to the levels of the splicing factors PTB1 and PTB2, which predominantly triggered splicing of regulated introns, inclusion of cassette exons, and usage of upstream 5′ splice sites. By contrast, no major AS regulatory function of the distantly related PTB3 was found. Dependent on their position within the mRNA, PTB-regulated events can both modify the untranslated regions and give rise to alternative protein products. We find that PTB-mediated AS events are connected to diverse biological processes, and the functional implications of selected instances were further elucidated. Specifically, PTB misexpression changes AS of PHYTOCHROME INTERACTING FACTOR6, coinciding with altered rates of abscisic acid–dependent seed germination. Furthermore, AS patterns as well as the expression of key flowering regulators were massively changed in a PTB1/2 level-dependent manner. PMID:23192226

  19. Diversification of the Histone Acetyltransferase GCN5 through Alternative Splicing in Brachypodium distachyon

    Directory of Open Access Journals (Sweden)

    Alexandre Martel

    2017-12-01

    Full Text Available The epigenetic modulatory SAGA complex is involved in various developmental and stress responsive pathways in plants. Alternative transcripts of the SAGA complex's enzymatic subunit GCN5 have been identified in Brachypodium distachyon. These splice variants differ based on the presence and integrity of their conserved domain sequences: the histone acetyltransferase domain, responsible for catalytic activity, and the bromodomain, involved in acetyl-lysine binding and genomic loci targeting. GCN5 is the wild-type transcript, while alternative splice sites result in the following transcriptional variants: L-GCN5, which is missing the bromodomain and S-GCN5, which lacks the bromodomain as well as certain motifs of the histone acetyltransferase domain. Absolute mRNA quantification revealed that, across eight B. distachyon accessions, GCN5 was the dominant transcript isoform, accounting for up to 90% of the entire transcript pool, followed by L-GCN5 and S-GCN5. A cycloheximide treatment further revealed that the S-GCN5 splice variant was degraded through the nonsense-mediated decay pathway. All alternative BdGCN5 transcripts displayed similar transcript profiles, being induced during early exposure to heat and displaying higher levels of accumulation in the crown, compared to aerial tissues. All predicted protein isoforms localize to the nucleus, which lends weight to their purported epigenetic functions. S-GCN5 was incapable of forming an in vivo protein interaction with ADA2, the transcriptional adaptor that links the histone acetyltransferase subunit to the SAGA complex, while both GCN5 and L-GCN5 interacted with ADA2, which suggests that a complete histone acetyltransferase domain is required for BdGCN5-BdADA2 interaction in vivo. Thus, there has been a diversification in BdGCN5 through alternative splicing that has resulted in differences in conserved domain composition, transcript fate and in vivo protein interaction partners. Furthermore, our

  20. Alternative splicing of human elastin mRNA indicated by sequence analysis of cloned genomic and complementary DNA

    International Nuclear Information System (INIS)

    Indik, Z.; Yeh, H.; Ornstein-goldstein, N.; Sheppard, P.; Anderson, N.; Rosenbloom, J.C.; Peltonen, L.; Rosenbloom, J.

    1987-01-01

    Poly(A) + RNA, isolated from a single 7-mo fetal human aorta, was used to synthesize cDNA by the RNase H method, and the cDNA was inserted into λgt10. Recombinant phage containing elastin sequences were identified by hybridization with cloned, exon-containing fragments of the human elastin gene. Three clones containing inserts of 3.3, 2.7, and 2.3 kilobases were selected for further analysis. Three overlapping clones containing 17.8 kilobases of the human elastin gene were also isolated from genomic libraries. Complete sequence analysis of the six clones demonstrated that: (i) the cDNA encompassed the entire translated portion of the mRNA encoding 786 amino acids, including several unusual hydrophilic amino acid sequences not previously identified in porcine tropoelastin, (ii) exons encoding either hydrophobic or crosslinking domains in the protein alternated in the gene, and (iii) a great abundance of Alu repetitive sequences occurred throughout the introns. The data also indicated substantial alternative splicing of the mRNA. These results suggest the potential for significant variation in the precise molecular structure of the elastic fiber in the human population

  1. Fox-2 protein regulates the alternative splicing of scleroderma-associated lysyl hydroxylase 2 messenger RNA.

    Science.gov (United States)

    Seth, Puneet; Yeowell, Heather N

    2010-04-01

    Scleroderma (systemic sclerosis [SSc]) is a complex connective tissue disorder characterized by hardening and thickening of the skin. One hallmark of scleroderma is excessive accumulation of collagen accompanied by increased levels of pyridinoline collagen crosslinks derived from hydroxylysine residues in the collagen telopeptide domains. Lysyl hydroxylase 2 (LH2), an important alternatively spliced enzyme in collagen biosynthesis, acts as a collagen telopeptide hydroxylase. Changes in the pattern of LH2 alternative splicing, favoring increased inclusion of the alternatively spliced LH2 exon 13A, thereby increasing the levels of the long transcript of LH2 (LH2[long]), are linked to scleroderma disease. This study was undertaken to examine the role played by RNA binding protein Fox-2 in regulating exon 13A inclusion, which leads to the generation of scleroderma-associated LH2(long) messenger RNA (mRNA). Phylogenetic sequence analysis of introns flanking exon 13A was performed. A tetracycline-inducible system in T-Rex 293 cells was used to induce Fox-2 protein, and endogenous LH2(long) mRNA was determined by reverse transcriptase-polymerase chain reaction. An LH2 minigene was designed, validated, and used in Fox-2 overexpression and mutagenesis experiments. Knockdown of Fox-2 was performed in mouse embryonic fibroblasts and in fibroblasts from SSc patients. Overexpression of Fox-2 enhanced the inclusion of exon 13A and increased the generation of LH2(long) mRNA, whereas knockdown of Fox-2 decreased LH2(long) transcripts. Mutational analysis of an LH2 minigene demonstrated that 2 of the 4 Fox binding motifs flanking LH2 exon 13A are required for inclusion of exon 13A. In early passage fibroblasts derived from patients with scleroderma, the knockdown of Fox-2 protein significantly decreased the endogenous levels of LH2(long) mRNA. Our findings indicate that Fox-2 plays an integral role in the regulation of LH2 splicing. Knockdown of Fox-2 and other methods to decrease

  2. Functional analysis of the isoforms of an ABI3-like factor of Pisum sativum generated by alternative splicing.

    Science.gov (United States)

    Gagete, Andrés P; Riera, Marta; Franco, Luis; Rodrigo, M Isabel

    2009-01-01

    At least seven isoforms (PsABI3-1 to PsABI3-7) of a putative, pea ABI3-like factor, originated by alternative splicing, have been identified after cDNA cloning. A similar variability had previously only been described for monocot genes. The full-length isoform, PsABI3-1, contains the typical N-terminal acidic domains and C-terminal basic subdomains, B1 to B3. Reverse transcriptase-PCR analysis revealed that the gene is expressed just in seeds, starting at middle embryogenesis; no gene products are observed in embryo axes after 18 h post-imbibition although they are more persistent in cotyledons. The activity of the isoforms was studied by yeast one-hybrid assays. When yeast was transformed with the isoforms fused to the DNA binding domain of Gal4p, only the polypeptides PsABI3-2 and PsABI3-7 failed to complement the activity of Gal4p. Acidic domains A1 and A2 exhibit transactivating activity, but the former requires a small C-terminal extension to be active. Yeast two-hybrid analysis showed that PsABI3 is able to heterodimerize with Arabidopsis thaliana ABI5, thus proving that PsABI3 is functionally active. The minimum requirement for the interaction PsABI3-AtABI5 is the presence of the subdomain B1 with an extension, 81 amino acids long, at their C-terminal side. Finally, a transient onion transformation assay showed that both the active PsABI3-1 and the inactive PsABI3-2 isoforms are localized to nuclei. Considering that the major isoforms remain approximately constant in developing seeds although their relative proportion varied, the possible role of splicing in the regulatory network of ABA signalling is discussed.

  3. rMATS: robust and flexible detection of differential alternative splicing from replicate RNA-Seq data.

    Science.gov (United States)

    Shen, Shihao; Park, Juw Won; Lu, Zhi-xiang; Lin, Lan; Henry, Michael D; Wu, Ying Nian; Zhou, Qing; Xing, Yi

    2014-12-23

    Ultra-deep RNA sequencing (RNA-Seq) has become a powerful approach for genome-wide analysis of pre-mRNA alternative splicing. We previously developed multivariate analysis of transcript splicing (MATS), a statistical method for detecting differential alternative splicing between two RNA-Seq samples. Here we describe a new statistical model and computer program, replicate MATS (rMATS), designed for detection of differential alternative splicing from replicate RNA-Seq data. rMATS uses a hierarchical model to simultaneously account for sampling uncertainty in individual replicates and variability among replicates. In addition to the analysis of unpaired replicates, rMATS also includes a model specifically designed for paired replicates between sample groups. The hypothesis-testing framework of rMATS is flexible and can assess the statistical significance over any user-defined magnitude of splicing change. The performance of rMATS is evaluated by the analysis of simulated and real RNA-Seq data. rMATS outperformed two existing methods for replicate RNA-Seq data in all simulation settings, and RT-PCR yielded a high validation rate (94%) in an RNA-Seq dataset of prostate cancer cell lines. Our data also provide guiding principles for designing RNA-Seq studies of alternative splicing. We demonstrate that it is essential to incorporate biological replicates in the study design. Of note, pooling RNAs or merging RNA-Seq data from multiple replicates is not an effective approach to account for variability, and the result is particularly sensitive to outliers. The rMATS source code is freely available at rnaseq-mats.sourceforge.net/. As the popularity of RNA-Seq continues to grow, we expect rMATS will be useful for studies of alternative splicing in diverse RNA-Seq projects.

  4. Functional diversification of sea urchin ABCC1 (MRP1) by alternative splicing.

    Science.gov (United States)

    Gökirmak, Tufan; Campanale, Joseph P; Reitzel, Adam M; Shipp, Lauren E; Moy, Gary W; Hamdoun, Amro

    2016-06-01

    The multidrug resistance protein (MRP) family encodes a diverse repertoire of ATP-binding cassette (ABC) transporters with multiple roles in development, disease, and homeostasis. Understanding MRP evolution is central to unraveling their roles in these diverse processes. Sea urchins occupy an important phylogenetic position for understanding the evolution of vertebrate proteins and have been an important invertebrate model system for study of ABC transporters. We used phylogenetic analyses to examine the evolution of MRP transporters and functional approaches to identify functional forms of sea urchin MRP1 (also known as SpABCC1). SpABCC1, the only MRP homolog in sea urchins, is co-orthologous to human MRP1, MRP3, and MRP6 (ABCC1, ABCC3, and ABCC6) transporters. However, efflux assays revealed that alternative splicing of exon 22, a region critical for substrate interactions, could diversify functions of sea urchin MRP1. Phylogenetic comparisons also indicate that while MRP1, MRP3, and MRP6 transporters potentially arose from a single transporter in basal deuterostomes, alternative splicing appears to have been the major mode of functional diversification in invertebrates, while duplication may have served a more important role in vertebrates. These results provide a deeper understanding of the evolutionary origins of MRP transporters and the potential mechanisms used to diversify their functions in different groups of animals. Copyright © 2016 the American Physiological Society.

  5. A novel mechanism of myostatin regulation by its alternative splicing variant during myogenesis in avian species.

    Science.gov (United States)

    Shin, Sangsu; Song, Yan; Ahn, Jinsoo; Kim, Eunsoo; Chen, Paula; Yang, Shujin; Suh, Yeunsu; Lee, Kichoon

    2015-11-15

    Myostatin (MSTN) is a key negative regulator of muscle growth and development, and an increase of muscle mass is achieved by inhibiting MSTN signaling. In the current study, five alternative splicing isoforms of MSTN mRNAs in avian species were identified in various tissues. Among these five, three truncated forms of myostatin, MSTN-B, -C, and -E created premature stop codons and produced partial MSTN prodomains encoded from exon 1. MSTN-B is the second dominant isoform following full-length MSTN-A, and their expression was dynamically regulated during muscle development of chicken, turkey, and quail in vivo and in vitro. To clarify the function of MSTN-B, two stable cell lines of quail myoblasts (QM7) were generated to overexpress MSTN-A or MSTN-B. Interestingly, MSTN-B promoted both cell proliferation and differentiation similar to the function of the MSTN prodomain to counteract the negative role of MSTN on myogenesis. The coimmunoprecipitation assay revealed that MSTN-B binds to MSTN-A and reduces the generation of mature MSTN. Furthermore, the current study demonstrated that the partial prodomain encoded from exon 1 is critical for binding of MSTN-B to MSTN-A. Altogether, these data imply that alternative splicing isoforms of MSTN could negatively regulate pro-myostatin processing in muscle cells and prevent MSTN-mediated inhibition of myogenesis in avian species. Copyright © 2015 the American Physiological Society.

  6. A method of predicting changes in human gene splicing induced by genetic variants in context of cis-acting elements

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    Hicks Chindo

    2010-01-01

    Full Text Available Abstract Background Polymorphic variants and mutations disrupting canonical splicing isoforms are among the leading causes of human hereditary disorders. While there is a substantial evidence of aberrant splicing causing Mendelian diseases, the implication of such events in multi-genic disorders is yet to be well understood. We have developed a new tool (SpliceScan II for predicting the effects of genetic variants on splicing and cis-regulatory elements. The novel Bayesian non-canonical 5'GC splice site (SS sensor used in our tool allows inference on non-canonical exons. Results Our tool performed favorably when compared with the existing methods in the context of genes linked to the Autism Spectrum Disorder (ASD. SpliceScan II was able to predict more aberrant splicing isoforms triggered by the mutations, as documented in DBASS5 and DBASS3 aberrant splicing databases, than other existing methods. Detrimental effects behind some of the polymorphic variations previously associated with Alzheimer's and breast cancer could be explained by changes in predicted splicing patterns. Conclusions We have developed SpliceScan II, an effective and sensitive tool for predicting the detrimental effects of genomic variants on splicing leading to Mendelian and complex hereditary disorders. The method could potentially be used to screen resequenced patient DNA to identify de novo mutations and polymorphic variants that could contribute to a genetic disorder.

  7. Mutation analysis of pre-mRNA splicing genes in Chinese families with retinitis pigmentosa

    Science.gov (United States)

    Pan, Xinyuan; Chen, Xue; Liu, Xiaoxing; Gao, Xiang; Kang, Xiaoli; Xu, Qihua; Chen, Xuejuan; Zhao, Kanxing; Zhang, Xiumei; Chu, Qiaomei; Wang, Xiuying

    2014-01-01

    Purpose Seven genes involved in precursor mRNA (pre-mRNA) splicing have been implicated in autosomal dominant retinitis pigmentosa (adRP). We sought to detect mutations in all seven genes in Chinese families with RP, to characterize the relevant phenotypes, and to evaluate the prevalence of mutations in splicing genes in patients with adRP. Methods Six unrelated families from our adRP cohort (42 families) and two additional families with RP with uncertain inheritance mode were clinically characterized in the present study. Targeted sequence capture with next-generation massively parallel sequencing (NGS) was performed to screen mutations in 189 genes including all seven pre-mRNA splicing genes associated with adRP. Variants detected with NGS were filtered with bioinformatics analyses, validated with Sanger sequencing, and prioritized with pathogenicity analysis. Results Mutations in pre-mRNA splicing genes were identified in three individual families including one novel frameshift mutation in PRPF31 (p.Leu366fs*1) and two known mutations in SNRNP200 (p.Arg681His and p.Ser1087Leu). The patients carrying SNRNP200 p.R681H showed rapid disease progression, and the family carrying p.S1087L presented earlier onset ages and more severe phenotypes compared to another previously reported family with p.S1087L. In five other families, we identified mutations in other RP-related genes, including RP1 p. Ser781* (novel), RP2 p.Gln65* (novel) and p.Ile137del (novel), IMPDH1 p.Asp311Asn (recurrent), and RHO p.Pro347Leu (recurrent). Conclusions Mutations in splicing genes identified in the present and our previous study account for 9.5% in our adRP cohort, indicating the important role of pre-mRNA splicing deficiency in the etiology of adRP. Mutations in the same splicing gene, or even the same mutation, could correlate with different phenotypic severities, complicating the genotype–phenotype correlation and clinical prognosis. PMID:24940031

  8. Isolation of a candidate human telomerase catalytic subunit gene, which reveals complex splicing patterns in different cell types.

    Science.gov (United States)

    Kilian, A; Bowtell, D D; Abud, H E; Hime, G R; Venter, D J; Keese, P K; Duncan, E L; Reddel, R R; Jefferson, R A

    1997-11-01

    Telomerase is a multicomponent reverse transcriptase enzyme that adds DNA repeats to the ends of chromosomes using its RNA component as a template for synthesis. Telomerase activity is detected in the germline as well as the majority of tumors and immortal cell lines, and at low levels in several types of normal cells. We have cloned a human gene homologous to a protein from Saccharomyces cerevisiae and Euplotes aediculatus that has reverse transcriptase motifs and is thought to be the catalytic subunit of telomerase in those species. This gene is present in the human genome as a single copy sequence with a dominant transcript of approximately 4 kb in a human colon cancer cell line, LIM1215. The cDNA sequence was determined using clones from a LIM1215 cDNA library and by RT-PCR, cRACE and 3'RACE on mRNA from the same source. We show that the gene is expressed in several normal tissues, telomerase-positive post-crisis (immortal) cell lines and various tumors but is not expressed in the majority of normal tissues analyzed, pre-crisis (non-immortal) cells and telomerase-negative immortal (ALT) cell lines. Multiple products were identified by RT-PCR using primers within the reverse transcriptase domain. Sequencing of these products suggests that they arise by alternative splicing. Strikingly, various tumors, cell lines and even normal tissues (colonic crypt and testis) showed considerable differences in the splicing patterns. Alternative splicing of the telomerase catalytic subunit transcript may be important for the regulation of telomerase activity and may give rise to proteins with different biochemical functions.

  9. A novel splice variant of the Fas gene in patients with cutaneous T-cell lymphoma.

    Science.gov (United States)

    van Doorn, Remco; Dijkman, Remco; Vermeer, Maarten H; Starink, Theo M; Willemze, Rein; Tensen, Cornelis P

    2002-10-01

    Defective apoptosis signaling has been implicated in the pathogenesis of primary cutaneous T-cell lymphomas (CTCLs), a group of malignancies derived from skin-homing T cells. An important mediator of apoptosis in T cells is the Fas receptor. We identified a novel splice variant of the Fas gene that displays retention of intron 5 and encodes a dysfunctional Fas protein in 13 of 22 patients (59%) in both early and advanced CTCL. Impairment of Fas-induced apoptosis resulting from aberrant splicing potentially contributes to the development and progression of CTCL by allowing continued clonal expansion of activated T cells and by reducing susceptibility to antitumor immune responses.

  10. Alternative splicing variants of human Fbx4 disturb cyclin D1 proteolysis in human cancer

    Energy Technology Data Exchange (ETDEWEB)

    Chu, Xiufeng; Zhang, Ting; Wang, Jie; Li, Meng; Zhang, Xiaolei; Tu, Jing [Department of Microbiology and Infectious Disease Center, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191 (China); Sun, Shiqin [College of Pharmacy, Harbin Medical University-Daqing, Daqing, Heilongjiang 163319 (China); Chen, Xiangmei, E-mail: xm_chen6176@bjmu.edu.cn [Department of Microbiology and Infectious Disease Center, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191 (China); Lu, Fengmin [Department of Microbiology and Infectious Disease Center, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191 (China)

    2014-04-25

    Highlights: • The expression of Fbx4 was significantly lower in HCC tissues. • Novel splicing variants of Fbx4 were identified. • These novel variants are much more abundant in human cancer tissues and cells. • The novel Fbx4 isoforms could promote cell proliferation and migration in vitro. • These isoforms showed less capability for cyclin D1 binding and degradation. - Abstract: Fbx4 is a specific substrate recognition component of SCF ubiquitin ligases that catalyzes the ubiquitination and subsequent degradation of cyclin D1 and Trx1. Two isoforms of human Fbx4 protein, the full length Fbx4α and the C-terminal truncated Fbx4β have been identified, but their functions remain elusive. In this study, we demonstrated that the mRNA level of Fbx4 was significantly lower in hepatocellular carcinoma tissues than that in the corresponding non-tumor tissues. More importantly, we identified three novel splicing variants of Fbx4: Fbx4γ (missing 168–245nt of exon1), Fbx4δ (missing exon6) and a N-terminal reading frame shift variant (missing exon2). Using cloning sequencing and RT-PCR, we demonstrated these novel splice variants are much more abundant in human cancer tissues and cell lines than that in normal tissues. When expressed in Sk-Hep1 and NIH3T3 cell lines, Fbx4β, Fbx4γ and Fbx4δ could promote cell proliferation and migration in vitro. Concordantly, these isoforms could disrupt cyclin D1 degradation and therefore increase cyclin D1 expression. Moreover, unlike the full-length isoform Fbx4α that mainly exists in cytoplasm, Fbx4β, Fbx4γ, and Fbx4δ locate in both cytoplasm and nucleus. Since cyclin D1 degradation takes place in cytoplasm, the nuclear distribution of these Fbx4 isoforms may not be involved in the down-regulation of cytoplasmic cyclin D1. These results define the impact of alternative splicing on Fbx4 function, and suggest that the attenuated cyclin D1 degradation by these novel Fbx4 isoforms provides a new insight for aberrant

  11. Alternative splicing variants of human Fbx4 disturb cyclin D1 proteolysis in human cancer

    International Nuclear Information System (INIS)

    Chu, Xiufeng; Zhang, Ting; Wang, Jie; Li, Meng; Zhang, Xiaolei; Tu, Jing; Sun, Shiqin; Chen, Xiangmei; Lu, Fengmin

    2014-01-01

    Highlights: • The expression of Fbx4 was significantly lower in HCC tissues. • Novel splicing variants of Fbx4 were identified. • These novel variants are much more abundant in human cancer tissues and cells. • The novel Fbx4 isoforms could promote cell proliferation and migration in vitro. • These isoforms showed less capability for cyclin D1 binding and degradation. - Abstract: Fbx4 is a specific substrate recognition component of SCF ubiquitin ligases that catalyzes the ubiquitination and subsequent degradation of cyclin D1 and Trx1. Two isoforms of human Fbx4 protein, the full length Fbx4α and the C-terminal truncated Fbx4β have been identified, but their functions remain elusive. In this study, we demonstrated that the mRNA level of Fbx4 was significantly lower in hepatocellular carcinoma tissues than that in the corresponding non-tumor tissues. More importantly, we identified three novel splicing variants of Fbx4: Fbx4γ (missing 168–245nt of exon1), Fbx4δ (missing exon6) and a N-terminal reading frame shift variant (missing exon2). Using cloning sequencing and RT-PCR, we demonstrated these novel splice variants are much more abundant in human cancer tissues and cell lines than that in normal tissues. When expressed in Sk-Hep1 and NIH3T3 cell lines, Fbx4β, Fbx4γ and Fbx4δ could promote cell proliferation and migration in vitro. Concordantly, these isoforms could disrupt cyclin D1 degradation and therefore increase cyclin D1 expression. Moreover, unlike the full-length isoform Fbx4α that mainly exists in cytoplasm, Fbx4β, Fbx4γ, and Fbx4δ locate in both cytoplasm and nucleus. Since cyclin D1 degradation takes place in cytoplasm, the nuclear distribution of these Fbx4 isoforms may not be involved in the down-regulation of cytoplasmic cyclin D1. These results define the impact of alternative splicing on Fbx4 function, and suggest that the attenuated cyclin D1 degradation by these novel Fbx4 isoforms provides a new insight for aberrant

  12. α6-Integrin alternative splicing: distinct cytoplasmic variants in stem cell fate specification and niche interaction.

    Science.gov (United States)

    Zhou, Zijing; Qu, Jing; He, Li; Peng, Hong; Chen, Ping; Zhou, Yong

    2018-05-02

    α6-Integrin subunit (also known as CD49f) is a stemness signature that has been found on the plasma membrane of more than 30 stem cell populations. A growing body of studies have focused on the critical role of α6-containing integrins (α6β1 and α6β4) in the regulation of stem cell properties, lineage-specific differentiation, and niche interaction. α6-Integrin subunit can be alternatively spliced at the post-transcriptional level, giving rise to divergent isoforms which differ in the cytoplasmic and/or extracellular domains. The cytoplasmic domain of integrins is an important functional part of integrin-mediated signals. Structural changes in the cytoplasmic domain of α6 provide an efficient means for the regulation of stem cell responses to biochemical stimuli and/or biophysical cues in the stem cell niche, thus impacting stem cell fate determination. In this review, we summarize the current knowledge on the structural variants of the α6-integrin subunit and spatiotemporal expression of α6 cytoplasmic variants in embryonic and adult stem/progenitor cells. We highlight the roles of α6 cytoplasmic variants in stem cell fate decision and niche interaction, and discuss the potential mechanisms involved. Understanding of the distinct functions of α6 splicing variants in stem cell biology may inform the rational design of novel stem cell-based therapies for a range of human diseases.

  13. Regulation of alternative splicing of Slo K+ channels in adrenal and pituitary during the stress-hyporesponsive period of rat development.

    Science.gov (United States)

    Lai, Guey-Jen; McCobb, David P

    2006-08-01

    Stress triggers release of ACTH from the pituitary, glucocorticoids from the adrenal cortex, and epinephrine from the adrenal medulla. Although functions differ, these hormone systems interact in many ways. Previous evidence indicates that pituitary and steroid hormones regulate alternative splicing of the Slo gene at the stress axis-regulated exon (STREX), with functional implications for the calcium-activated K+ channels prominent in adrenal medullary and pituitary cells. Here we examine the role of corticosterone in Slo splicing regulation in pituitary and adrenal tissues during the stress-hyporesponsive period of early rat postnatal life. The sharp drop in plasma corticosterone (CORT) that defines this period offers a unique opportunity to test CORT's role in Slo splicing. We report that in both adrenal and pituitary tissues, the percentage of Slo transcripts having STREX declines and recovers in parallel with CORT. Moreover, addition of 500 nm CORT to cultures of anterior pituitary cells from 13-, 21-, and 30-d postnatal animals increased the percentage of Slo transcripts with STREX, whereas 20 microm CORT reduced STREX representation. Applied to adrenal chromaffin cells, 20 microm CORT decreased STREX inclusion, whereas neither 500 nm nor 2 microm had any effect. The mineralocorticoid receptor antagonist RU28318 abolished the effect of 500 nm CORT on splicing in pituitary cells, whereas the glucocorticoid receptor antagonist RU38486 blocked the effect of 20 microm CORT on adrenal chromaffin cells. These results support the hypothesis that the abrupt, transient drop in CORT during the stress-hyporesponsive period drives the transient decline in STREX splice variant representation in pituitary, but not adrenal.

  14. Alternative splicing targeting the hTAF4-TAFH domain of TAF4 represses proliferation and accelerates chondrogenic differentiation of human mesenchymal stem cells.

    Directory of Open Access Journals (Sweden)

    Jekaterina Kazantseva

    Full Text Available Transcription factor IID (TFIID activity can be regulated by cellular signals to specifically alter transcription of particular subsets of genes. Alternative splicing of TFIID subunits is often the result of external stimulation of upstream signaling pathways. We studied tissue distribution and cellular expression of different splice variants of TFIID subunit TAF4 mRNA and biochemical properties of its isoforms in human mesenchymal stem cells (hMSCs to reveal the role of different isoforms of TAF4 in the regulation of proliferation and differentiation. Expression of TAF4 transcripts with exons VI or VII deleted, which results in a structurally modified hTAF4-TAFH domain, increases during early differentiation of hMSCs into osteoblasts, adipocytes and chondrocytes. Functional analysis data reveals that TAF4 isoforms with the deleted hTAF4-TAFH domain repress proliferation of hMSCs and preferentially promote chondrogenic differentiation at the expense of other developmental pathways. This study also provides initial data showing possible cross-talks between TAF4 and TP53 activity and switching between canonical and non-canonical WNT signaling in the processes of proliferation and differentiation of hMSCs. We propose that TAF4 isoforms generated by the alternative splicing participate in the conversion of the cellular transcriptional programs from the maintenance of stem cell state to differentiation, particularly differentiation along the chondrogenic pathway.

  15. Drosophila muscleblind is involved in troponin T alternative splicing and apoptosis.

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    Marta Vicente-Crespo

    2008-02-01

    Full Text Available Muscleblind-like proteins (MBNL have been involved in a developmental switch in the use of defined cassette exons. Such transition fails in the CTG repeat expansion disease myotonic dystrophy due, in part, to sequestration of MBNL proteins by CUG repeat RNA. Four protein isoforms (MblA-D are coded by the unique Drosophila muscleblind gene.We used evolutionary, genetic and cell culture approaches to study muscleblind (mbl function in flies. The evolutionary study showed that the MblC protein isoform was readily conserved from nematods to Drosophila, which suggests that it performs the most ancestral muscleblind functions. Overexpression of MblC in the fly eye precursors led to an externally rough eye morphology. This phenotype was used in a genetic screen to identify five dominant suppressors and 13 dominant enhancers including Drosophila CUG-BP1 homolog aret, exon junction complex components tsunagi and Aly, and pro-apoptotic genes Traf1 and reaper. We further investigated Muscleblind implication in apoptosis and splicing regulation. We found missplicing of troponin T in muscleblind mutant pupae and confirmed Muscleblind ability to regulate mouse fast skeletal muscle Troponin T (TnnT3 minigene splicing in human HEK cells. MblC overexpression in the wing imaginal disc activated apoptosis in a spatially restricted manner. Bioinformatics analysis identified a conserved FKRP motif, weakly resembling a sumoylation target site, in the MblC-specific sequence. Site-directed mutagenesis of the motif revealed no change in activity of mutant MblC on TnnT3 minigene splicing or aberrant binding to CUG repeat RNA, but altered the ability of the protein to form perinuclear aggregates and enhanced cell death-inducing activity of MblC overexpression.Taken together our genetic approach identify cellular processes influenced by Muscleblind function, whereas in vivo and cell culture experiments define Drosophila troponin T as a new Muscleblind target, reveal a

  16. Resveratrol, by modulating RNA processing factor levels, can influence the alternative splicing of pre-mRNAs.

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    M Andrea Markus

    Full Text Available Alternative pre-mRNA splicing defects can contribute to, or result from, various diseases, including cancer. Aberrant mRNAs, splicing factors and other RNA processing factors have therefore become targets for new therapeutic interventions. Here we report that the natural polyphenol resveratrol can modulate alternative splicing in a target-specific manner. We transfected minigenes of several alternatively spliceable primary mRNAs into HEK293 cells in the presence or absence of 1, 5, 20 and 50 µM resveratrol and measured exon levels by semi-quantitative PCR after separation by agarose gel electrophoresis. We found that 20 µg/ml and 50 µg/ml of resveratrol affected exon inclusion of SRp20 and SMN2 pre-mRNAs, but not CD44v5 or tau pre-mRNAs. By Western blotting and immunofluorescence we showed that this effect may be due to the ability of resveratrol to change the protein level but not the localization of several RNA processing factors. The processing factors that increased significantly were ASF/SF2, hnRNPA1 and HuR, but resveratrol did not change the levels of RBM4, PTBP1 and U2AF35. By means of siRNA-mediated knockdown we depleted cells of SIRT1, regarded as a major target of resveratrol, and showed that the effect on splicing was not dependent on SIRT1. Our results suggest that resveratrol might be an attractive small molecule to treat diseases in which aberrant splicing has been implicated, and justify more extensive research on the effects of resveratrol on the splicing machinery.

  17. Resveratrol, by modulating RNA processing factor levels, can influence the alternative splicing of pre-mRNAs.

    Science.gov (United States)

    Markus, M Andrea; Marques, Francine Z; Morris, Brian J

    2011-01-01

    Alternative pre-mRNA splicing defects can contribute to, or result from, various diseases, including cancer. Aberrant mRNAs, splicing factors and other RNA processing factors have therefore become targets for new therapeutic interventions. Here we report that the natural polyphenol resveratrol can modulate alternative splicing in a target-specific manner. We transfected minigenes of several alternatively spliceable primary mRNAs into HEK293 cells in the presence or absence of 1, 5, 20 and 50 µM resveratrol and measured exon levels by semi-quantitative PCR after separation by agarose gel electrophoresis. We found that 20 µg/ml and 50 µg/ml of resveratrol affected exon inclusion of SRp20 and SMN2 pre-mRNAs, but not CD44v5 or tau pre-mRNAs. By Western blotting and immunofluorescence we showed that this effect may be due to the ability of resveratrol to change the protein level but not the localization of several RNA processing factors. The processing factors that increased significantly were ASF/SF2, hnRNPA1 and HuR, but resveratrol did not change the levels of RBM4, PTBP1 and U2AF35. By means of siRNA-mediated knockdown we depleted cells of SIRT1, regarded as a major target of resveratrol, and showed that the effect on splicing was not dependent on SIRT1. Our results suggest that resveratrol might be an attractive small molecule to treat diseases in which aberrant splicing has been implicated, and justify more extensive research on the effects of resveratrol on the splicing machinery.

  18. Intronic PAH gene mutations cause a splicing defect by a novel mechanism involving U1snRNP binding downstream of the 5' splice site

    DEFF Research Database (Denmark)

    Martínez-Pizarro, Ainhoa; Dembic, Maja; Pérez, Belén

    2018-01-01

    Phenylketonuria (PKU), one of the most common inherited diseases of amino acid metabolism, is caused by mutations in the phenylalanine hydroxylase (PAH) gene. Recently, PAH exon 11 was identified as a vulnerable exon due to a weak 3' splice site, with different exonic mutations affecting exon 11 ...

  19. Generation of Chimeric RNAs by cis-splicing of adjacent genes (cis-SAGe) in mammals.

    Science.gov (United States)

    Zhuo, Jian-Shu; Jing, Xiao-Yan; Du, Xin; Yang, Xiu-Qin

    2018-02-20

    Chimeric RNA molecules, possessing exons from two or more independent genes, are traditionally believed to be produced by chromosome rearrangement. However, recent studies revealed that cis-splicing of adjacent genes (cis- SAGe) is one of the major mechanisms underlying the formation of chimeric RNAs. cis-SAGe refers to intergenic splicing of directly adjacent genes with the same transcriptional orientation, resulting in read-through transcripts, termed chimeric RNAs, which contain sequences from two or more parental genes. cis-SAGe was first identified in tumor cells, since then its potential in carcinogenesis has attracted extensive attention. More and more scientists are focusing on it. With the development of research, cis-SAGe was found to be ubiquitous in various normal tissues, and might make a crucial contribution to the formation of novel genes in the evolution of genomes. In this review, we summarize the splicing pattern, expression characteristics, possible mechanisms, and significance of cis-SAGe in mammals. This review will be helpful for general understanding of the current status and development tendency of cis-SAGe.

  20. Genome-Wide Transcriptome Analysis Reveals Extensive Alternative Splicing Events in the Protoscoleces of Echinococcus granulosus and Echinococcus multilocularis

    Science.gov (United States)

    Liu, Shuai; Zhou, Xiaosu; Hao, Lili; Piao, Xianyu; Hou, Nan; Chen, Qijun

    2017-01-01

    Alternative splicing (AS), as one of the most important topics in the post-genomic era, has been extensively studied in numerous organisms. However, little is known about the prevalence and characteristics of AS in Echinococcus species, which can cause significant health problems to humans and domestic animals. Based on high-throughput RNA-sequencing data, we performed a genome-wide survey of AS in two major pathogens of echinococcosis-Echinococcus granulosus and Echinococcus multilocularis. Our study revealed that the prevalence and characteristics of AS in protoscoleces of the two parasites were generally consistent with each other. A total of 6,826 AS events from 3,774 E. granulosus genes and 6,644 AS events from 3,611 E. multilocularis genes were identified in protoscolex transcriptomes, indicating that 33–36% of genes were subject to AS in the two parasites. Strikingly, intron retention instead of exon skipping was the predominant type of AS in Echinococcus species. Moreover, analysis of the Kyoto Encyclopedia of Genes and Genomes pathway indicated that genes that underwent AS events were significantly enriched in multiple pathways mainly related to metabolism (e.g., purine, fatty acid, galactose, and glycerolipid metabolism), signal transduction (e.g., Jak-STAT, VEGF, Notch, and GnRH signaling pathways), and genetic information processing (e.g., RNA transport and mRNA surveillance pathways). The landscape of AS obtained in this study will not only facilitate future investigations on transcriptome complexity and AS regulation during the life cycle of Echinococcus species, but also provide an invaluable resource for future functional and evolutionary studies of AS in platyhelminth parasites. PMID:28588571

  1. Identification of alternatively spliced TIMP-1 mRNA in cancer cell lines and colon cancer tissue

    DEFF Research Database (Denmark)

    Usher, Pernille Autzen; Sieuwerts, A.M.; Bartels, Annette

    2007-01-01

    TIMP-1 is a promising new candidate as a prognostic marker in colorectal and breast cancer. We now describe the discovery of two alternatively spliced variants of TIMP-1 mRNA. The two variants lacking exon 2 (del-2) and 5 (del-5), respectively, were identified in human cancer cell lines by RT......-PCR. The del-2 variant was, furthermore, detected in extracts from 12 colorectal cancer tissue samples. By western blotting additional bands of lower molecular mass than full-length TIMP-1 were identified in tumor tissue, but not in plasma samples obtained from cancer patients. The two splice variants of TIMP...

  2. Alternative splicing of T cell receptor (TCR) alpha chain transcripts containing V alpha 1 or V alpha 14 elements.

    Science.gov (United States)

    Mahotka, C; Hansen-Hagge, T E; Bartram, C R

    1995-10-01

    Human acute lymphoblastic leukemia cell lines represent valuable tools to investigate distinct steps of the complex regulatory pathways underlying T cell receptor recombination and expression. A case in point are V delta 2D delta 3 and subsequent V delta 2D delta 3J alpha rearrangements observed in human leukemic pre-B cells as well as in normal lymphopoiesis. The functional expression of these unusual (VD) delta (JC) alpha hybrids is almost exclusively prevented by alternative splicing events. In this report we show that alternative splicing at cryptic splice donor sites within V elements is not a unique feature of hybrid TCR delta/alpha transcripts. Among seven V alpha families analyzed by RT-PCR, alternatively spliced products were observed in TCR alpha recombinations containing V alpha 1 or V alpha 14 elements. In contrast to normal peripheral blood cells and thymocytes, the leukemia cell line JM expressing functional V alpha 1J alpha 3C alpha transcripts lacked evidence of aberrant TCR alpha RNA species.

  3. Seed Dormancy in Arabidopsis Requires Self-Binding Ability of DOG1 Protein and the Presence of Multiple Isoforms Generated by Alternative Splicing.

    Directory of Open Access Journals (Sweden)

    Kazumi Nakabayashi

    2015-12-01

    Full Text Available The Arabidopsis protein DELAY OF GERMINATION 1 (DOG1 is a key regulator of seed dormancy, which is a life history trait that determines the timing of seedling emergence. The amount of DOG1 protein in freshly harvested seeds determines their dormancy level. DOG1 has been identified as a major dormancy QTL and variation in DOG1 transcript levels between accessions contributes to natural variation for seed dormancy. The DOG1 gene is alternatively spliced. Alternative splicing increases the transcriptome and proteome diversity in higher eukaryotes by producing transcripts that encode for proteins with altered or lost function. It can also generate tissue specific transcripts or affect mRNA stability. Here we suggest a different role for alternative splicing of the DOG1 gene. DOG1 produces five transcript variants encoding three protein isoforms. Transgenic dog1 mutant seeds expressing single DOG1 transcript variants from the endogenous DOG1 promoter did not complement because they were non-dormant and lacked DOG1 protein. However, transgenic plants overexpressing single DOG1 variants from the 35S promoter could accumulate protein and showed complementation. Simultaneous expression of two or more DOG1 transcript variants from the endogenous DOG1 promoter also led to increased dormancy levels and accumulation of DOG1 protein. This suggests that single isoforms are functional, but require the presence of additional isoforms to prevent protein degradation. Subsequently, we found that the DOG1 protein can bind to itself and that this binding is required for DOG1 function but not for protein accumulation. Natural variation for DOG1 binding efficiency was observed among Arabidopsis accessions and contributes to variation in seed dormancy.

  4. FLNC Gene Splice Mutations Cause Dilated Cardiomyopathy

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    Rene L. Begay, BS

    2016-08-01

    Full Text Available A genetic etiology has been identified in 30% to 40% of dilated cardiomyopathy (DCM patients, yet only 50% of these cases are associated with a known causative gene variant. Thus, in order to understand the pathophysiology of DCM, it is necessary to identify and characterize additional genes. In this study, whole exome sequencing in combination with segregation analysis was used to identify mutations in a novel gene, filamin C (FLNC, resulting in a cardiac-restricted DCM pathology. Here we provide functional data via zebrafish studies and protein analysis to support a model implicating FLNC haploinsufficiency as a mechanism of DCM.

  5. PAP-1, the mutated gene underlying the RP9 form of dominant retinitis pigmentosa, is a splicing factor

    International Nuclear Information System (INIS)

    Maita, Hiroshi; Kitaura, Hirotake; Keen, T. Jeffrey; Inglehearn, Chris F.; Ariga, Hiroyoshi; Iguchi-Ariga, Sanae M.M.

    2004-01-01

    PAP-1 is an in vitro phosphorylation target of the Pim-1 oncogene. Although PAP-1 binds to Pim-1, it is not a substrate for phosphorylation by Pim-1 in vivo. PAP-1 has recently been implicated as the defective gene in RP9, one type of autosomal dominant retinitis pigmentosa (adRP). However, RP9 is a rare disease and only two missense mutations have been described, so the report of a link between PAP-1 and RP9 was tentative. The precise cellular role of PAP-1 was also unknown at that time. We now report that PAP-1 localizes in nuclear speckles containing the splicing factor SC35 and interacts directly with another splicing factor, U2AF35. Furthermore, we used in vitro and in vivo splicing assays to show that PAP-1 has an activity, which alters the pattern of pre-mRNA splicing and that this activity is dependent on the phosphorylation state of PAP-1. We used the same splicing assay to examine the activities of two mutant forms of PAP-1 found in RP9 patients. The results showed that while one of the mutations, H137L, had no effect on splicing activity compared with that of wild-type PAP-1, the other, D170G, resulted in both a defect in splicing activity and a decreased proportion of phosphorylated PAP-1. The D170G mutation may therefore cause RP by altering splicing of retinal genes through a decrease in PAP-1 phosphorylation. These results demonstrate that PAP-1 has a role in pre-mRNA splicing and, given that three other splicing factors have been implicated in adRP, this finding provides compelling further evidence that PAP-1 is indeed the RP9 gene

  6. Deep Surveying of the Transcriptional and Alternative Splicing Signatures for Decidual CD8+ T Cells at the First Trimester of Human Healthy Pregnancy

    Directory of Open Access Journals (Sweden)

    Weihong Zeng

    2018-05-01

    Full Text Available Decidual CD8+ (dCD8 T cells have been proposed to play important roles in immune protection against the invading pathogens and in tolerance toward the growing semi-allogeneic fetus during early pregnancy. However, their phenotypic and functional characteristics remain poorly defined. Here, we performed the first analysis of the transcriptional and alternative splicing (AS signatures for human first-trimester dCD8 T cells using high-throughput mRNA sequencing. Our data revealed that dCD8 T cells have distinct transcriptional and AS landscapes when compared with their autologous peripheral blood CD8+ (pCD8 T counterparts. Furthermore, human dCD8 T cells were observed to contain CD8-Treg and effector-memory T-cell subsets, and display enhanced functionality in terms of degranulation and cytokine production on a per-cell basis. Additionally, we have identified the novel splice junctions that use a high ratio of the non-canonical splicing motif GC-AG and found that AS is not a major contributor to the gene expression-level changes between paired pCD8 and dCD8 T cells. Together, our findings not only provide a comprehensive framework of the transcriptional and AS landscapes but also reveal the functional feature of human dCD8 T cells, which are of great importance in understanding the biology of these cells and the physiology of human healthy pregnancy.

  7. Evaluation of Energy Balance on Human Telomerase Reverse Transcriptase (hTERT) Alternative Splicing by Semi-quantitative RT-PCR in Human Umbilical Vein Endothelial Cells.

    Science.gov (United States)

    Behjati, Mohaddeseh; Hashemi, Mohammad; Kazemi, Mohammad; Salehi, Mansoor; Javanmard, Shaghayegh Haghjooy

    2017-01-01

    Decreased high-energy phosphate level is involved in endothelial cell injury and dysfunction. Reduced telomerase activity in endothelial cells in parallel with reduced energy levels might be due to altered direction of alternative splicing machine as a complication of depleted energy during the process of atherosclerosis. Isolated human umbilical vein endothelial cells (HUVECs) were treated for 24 hours by oligomycine (OM) and 2-deoxy glucose (2-DG). After 24 hours, the effect of energy depletion on telomerase splicing pattern was evaluated using RT-PCR. Indeed, in both treated and untargeted cells, nitric oxide (NO) and von Willebrand factor (vWF) were measured. ATP was depleted in treated cells by 43.9% compared with control group. We observed a slight decrease in NO levels ( P = 0.09) and vWF ( P = 0.395) in the setting of 49.36% ATP depletion. In both groups, no telomerase gene expression was seen. Telomerase and housekeeping gene expression were found in positive control group (colon cancer tissue) and sample tissue. The absence of telomerase gene expression in HUVECs might be due to the mortality of these cells or the low level of telomerase gene expression in these cells under normal circumstances.

  8. Alternative Splice Variants Modulates Dominant-Negative Function of Helios in T-Cell Leukemia.

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    Shaorong Zhao

    Full Text Available The molecular defects which lead to multistep incidences of human T-cell leukemia have yet to be identified. The DNA-binding protein Helios (known as IKZF2, a member of the Ikaros family of Krüppel-like zinc-finger proteins, functions pivotally in T-cell differentiation and activation. In this study, we identify three novel short Helios splice variants which are T-cell leukemic specific, and demonstrate their dominant-negative function. We then test the cellular localization of distinct Helios isoforms, as well as their capability to form heterodimer with Ikaros, and the association with complexes comprising histone deacetylase (HDAC. In addition, the ectopic expression of T-cell leukemic Helios isoforms interferes with T-cell proliferation and apoptosis. The gene expression profiling and pathway analysis indicated the enrichment of signaling pathways essential for gene expression, translation, cell cycle checkpoint, and response to DNA damage stimulus. These data indicate the molecular function of Helios to be involved in the leukemogenesis and phenotype of T-cell leukemia, and also reveal Helios deregulation as a novel marker for T-cell leukemia.

  9. Alternative splicing in colon, bladder, and prostate cancer identified by exon-array analysis

    DEFF Research Database (Denmark)

    Thorsen, Kasper; Sørensen, Karina D.; Brems-Eskildsen, Anne Sofie

    2008-01-01

    , PIK4CB, TPM1, and VCL). The validated tumor-specific splicing alterations were highly consistent, enabling clear separation of normal and cancer samples and in some cases even of different tumor stages. A subset of the tumor-specific splicing alterations (ACTN1, CALD1, and VCL) was found in all three...

  10. Modelling reveals kinetic advantages of co-transcriptional splicing.

    Directory of Open Access Journals (Sweden)

    Stuart Aitken

    2011-10-01

    Full Text Available Messenger RNA splicing is an essential and complex process for the removal of intron sequences. Whereas the composition of the splicing machinery is mostly known, the kinetics of splicing, the catalytic activity of splicing factors and the interdependency of transcription, splicing and mRNA 3' end formation are less well understood. We propose a stochastic model of splicing kinetics that explains data obtained from high-resolution kinetic analyses of transcription, splicing and 3' end formation during induction of an intron-containing reporter gene in budding yeast. Modelling reveals co-transcriptional splicing to be the most probable and most efficient splicing pathway for the reporter transcripts, due in part to a positive feedback mechanism for co-transcriptional second step splicing. Model comparison is used to assess the alternative representations of reactions. Modelling also indicates the functional coupling of transcription and splicing, because both the rate of initiation of transcription and the probability that step one of splicing occurs co-transcriptionally are reduced, when the second step of splicing is abolished in a mutant reporter.

  11. Modelling reveals kinetic advantages of co-transcriptional splicing.

    Science.gov (United States)

    Aitken, Stuart; Alexander, Ross D; Beggs, Jean D

    2011-10-01

    Messenger RNA splicing is an essential and complex process for the removal of intron sequences. Whereas the composition of the splicing machinery is mostly known, the kinetics of splicing, the catalytic activity of splicing factors and the interdependency of transcription, splicing and mRNA 3' end formation are less well understood. We propose a stochastic model of splicing kinetics that explains data obtained from high-resolution kinetic analyses of transcription, splicing and 3' end formation during induction of an intron-containing reporter gene in budding yeast. Modelling reveals co-transcriptional splicing to be the most probable and most efficient splicing pathway for the reporter transcripts, due in part to a positive feedback mechanism for co-transcriptional second step splicing. Model comparison is used to assess the alternative representations of reactions. Modelling also indicates the functional coupling of transcription and splicing, because both the rate of initiation of transcription and the probability that step one of splicing occurs co-transcriptionally are reduced, when the second step of splicing is abolished in a mutant reporter.

  12. A Gene Gun-mediated Nonviral RNA trans-splicing Strategy for Col7a1 Repair

    Directory of Open Access Journals (Sweden)

    Patricia Peking

    2016-01-01

    Full Text Available RNA trans-splicing represents an auspicious option for the correction of genetic mutations at RNA level. Mutations within COL7A1 causing strong reduction or absence of type VII collagen are associated with the severe skin blistering disease dystrophic epidermolysis bullosa. The human COL7A1 mRNA constitutes a suitable target for this RNA therapy approach, as only a portion of the almost 9 kb transcript has to be delivered into the target cells. Here, we have proven the feasibility of 5′ trans-splicing into the Col7a1 mRNA in vitro and in vivo. We designed a 5′ RNA trans-splicing molecule, capable of replacing Col7a1 exons 1–15 and verified it in a fluorescence-based trans-splicing model system. Specific and efficient Col7a1 trans-splicing was confirmed in murine keratinocytes. To analyze trans-splicing in vivo, we used gene gun delivery of a minicircle expressing a FLAG-tagged 5′ RNA trans-splicing molecule into the skin of wild-type mice. Histological and immunofluorescence analysis of bombarded skin sections revealed vector delivery and expression within dermis and epidermis. Furthermore, we have detected trans-spliced type VII collagen protein using FLAG-tag antibodies. In conclusion, we describe a novel in vivo nonviral RNA therapy approach to restore type VII collagen expression for causative treatment of dystrophic epidermolysis bullosa.

  13. A liver X receptor (LXR)-β alternative splicing variant (LXRBSV) acts as an RNA co-activator of LXR-β

    International Nuclear Information System (INIS)

    Hashimoto, Koshi; Ishida, Emi; Matsumoto, Shunichi; Shibusawa, Nobuyuki; Okada, Shuichi; Monden, Tsuyoshi; Satoh, Tetsurou; Yamada, Masanobu; Mori, Masatomo

    2009-01-01

    We report the isolation and functional characterization of a novel transcriptional co-activator, termed LXRBSV. LXRBSV is an alternative splicing variant of liver X receptor (LXR)-β LXRBSV has an intronic sequence between exons 2 and 3 in the mouse LXR-β gene. The LXRBSV gene is expressed in various tissues including the liver and brain. We sub-cloned LXRBSV into pSG5, a mammalian expression vector, and LXRBSV in pSG5 augmented human Sterol Response Element Binding Protein (SREBP)-1c promoter activity in HepG2 cells in a ligand (TO901317) dependent manner. The transactivation mediated by LXRBSV is selective for LXR-β. The LXRBSV protein was deduced to be 64 amino acids in length; however, a GAL4-LXRBSV fusion protein was not able to induce transactivation. Serial deletion constructs of LXRBSV demonstrated that the intronic sequence inserted in LXRBSV is required for its transactivation activity. An ATG mutant of LXRBSV was able to induce transactivation as wild type. Furthermore, LXRBSV functions in the presence of cycloheximide. Taken together, we have concluded that LXRBSV acts as an RNA transcript not as a protein. In the current study, we have demonstrated for the first time that an alternative splicing variant of a nuclear receptor acts as an RNA co-activator.

  14. Functional SNPs of INCENP Affect Semen Quality by Alternative Splicing Mode and Binding Affinity with the Target Bta-miR-378 in Chinese Holstein Bulls.

    Directory of Open Access Journals (Sweden)

    Juan Liu

    Full Text Available Inner centromere protein (INCENP plays an important role in mitosis and meiosis as the main member of chromosomal passenger protein complex (CPC. To investigate the functional markers of the INCENP gene associated with semen quality, the single nucleotide polymorphisms (SNPs g.19970 A>G and g.34078 T>G were identified and analyzed. The new splice variant INCENP-TV is characterized by the deletion of exon 12. The g.19970 A>G in the exonic splicing enhancer (ESE motif region results in an aberrant splice variant by constructing two minigene expression vectors using the pSPL3 exon capturing vector and transfecting vectors into MLTC-1 cells. INCENP-TV was more highly expressed than INCENP-reference in adult bull testes. The g.34078 T>G located in the binding region of bta-miR-378 could affect the expression of INCENP, which was verified by luciferase assay. To analyze comprehensively the correlation of SNPs with sperm quality, haplotype combinations constructed by g.19970 A>G and g.34078 T>G, as well as g.-692 C>T and g.-556 G>T reported in our previous studies, were analyzed. The bulls with H1H12 and H2H2 exhibited a higher ejaculate volume than those with H2H10 and H9H12, respectively (P G and g.34078 T>G in INCENP both of which appear to change the molecular and biological characteristics of the mRNA transcribed from the locus may serve as a biomarkers of male bovine fertility by affecting alternative splicing mode and binding affinity with the target bta-miR-378.

  15. Dynamic regulation of genome-wide pre-mRNA splicing and stress tolerance by the Sm-like protein LSm5 in Arabidopsis

    KAUST Repository

    Cui, Peng; Zhang, ShouDong; Ding, Feng; Ali, Shahjahan; Xiong, Liming

    2014-01-01

    alternative splicing. Further, SAD1 modulates the splicing of stress-responsive genes, particularly under salt-stress conditions. Finally, we find that overexpression of SAD1 in Arabidopsis improves salt tolerance in transgenic plants, which correlates

  16. A family with hereditary hemochromatosis carrying HFE gene splice site mutation: a case report

    Directory of Open Access Journals (Sweden)

    NING Huibin

    2017-01-01

    Full Text Available ObjectiveTo investigate a new type of HFE gene mutation in a family with hereditary hemochromatosis (HH. MethodsThe analysis of HFE gene was performed for one patient with a confirmed diagnosis of HH and five relatives. Blood genomic DNA was extracted and PCR multiplication was performed for the exon and intron splice sequences of related HFE, HJV, HAMP, transferrin receptor 2 (TfR2, and SLC40A1 genes. After agarose gel electrophoresis and purification, bi-directional direct sequencing was performed to detect mutation sites. ResultsThe proband had abnormal liver function and increases in serum iron, total iron binding capacity, serum ferritin, and transferrin saturation, as well as T→C homozygous mutation in the fourth base of intron 2 in the intervening sequence of the exon EXON2 of HFE gene (IVs 2+4T→C, C/C homozygous, splicing, abnormal. There were no abnormalities in HJV, HAMP, TfR2, and SLC40A1 genes. The proband′s son had the same homozygous mutation, three relatives had heterozygous mutations, and one relative had no abnormal mutations. ConclusionGene detection plays an important role in the diagnosis of hemochromatosis, and IVs 2+4T→C mutation may be a new pathogenic mutation for HH in China.

  17. MITA/STING and Its Alternative Splicing Isoform MRP Restrict Hepatitis B Virus Replication.

    Science.gov (United States)

    Liu, Shuhui; Zhao, Kaitao; Su, Xi; Lu, Lu; Zhao, He; Zhang, Xianwen; Wang, Yun; Wu, Chunchen; Chen, Jizheng; Zhou, Yuan; Hu, Xue; Wang, Yanyi; Lu, Mengji; Chen, Xinwen; Pei, Rongjuan

    2017-01-01

    An efficient clearance of hepatitis B virus (HBV) requires the coordinated work of both the innate and adaptive immune responses. MITA/STING, an adapter protein of the innate immune signaling pathways, plays a key role in regulating innate and adaptive immune responses to DNA virus infection. Previously, we identified an alternatively spliced isoform of MITA/STING, called MITA-related protein (MRP), and found that MRP could specifically block MITA-mediated interferon (IFN) induction while retaining the ability to activate NF-κB. Here, we asked whether MITA/STING and MRP were able to control the HBV replication. Both MITA/STING and MRP significantly inhibited HBV replication in vitro. MITA overexpression stimulated IRF3-IFN pathway; while MRP overexpression activated NF-κB pathway, suggesting these two isoforms may inhibit HBV replication through different ways. Using a hydrodynamic injection (HI) mouse model, we found that HBV replication was reduced following MITA/STING and MRP expression vectors in mice and was enhanced by the knockout of MITA/STING (MITA/STING-/-). The HBV specific humoral and CD8+ T cell responses were impaired in MITA/STING deficient mice, suggesting the participation of MITA/STING in the initiation of host adaptive immune responses. In summary, our data suggest that MITA/STING and MRP contribute to HBV control via modulation of the innate and adaptive responses.

  18. Structural Insights into RNA Recognition by the Alternate-Splicing Regulator CUG-Binding Protein 1

    Energy Technology Data Exchange (ETDEWEB)

    M Teplova; J Song; H Gaw; A Teplov; D Patel

    2011-12-31

    CUG-binding protein 1 (CUGBP1) regulates multiple aspects of nuclear and cytoplasmic mRNA processing, with implications for onset of myotonic dystrophy. CUGBP1 harbors three RRM domains and preferentially targets UGU-rich mRNA elements. We describe crystal structures of CUGBP1 RRM1 and tandem RRM1/2 domains bound to RNAs containing tandem UGU(U/G) elements. Both RRM1 in RRM1-RNA and RRM2 in RRM1/2-RNA complexes use similar principles to target UGU(U/G) elements, with recognition mediated by face-to-edge stacking and water-mediated hydrogen-bonding networks. The UG step adopts a left-handed Z-RNA conformation, with the syn guanine recognized through Hoogsteen edge-protein backbone hydrogen-bonding interactions. NMR studies on the RRM1/2-RNA complex establish that both RRM domains target tandem UGUU motifs in solution, whereas filter-binding assays identify a preference for recognition of GU over AU or GC steps. We discuss the implications of CUGBP1-mediated targeting and sequestration of UGU(U/G) elements on pre-mRNA alternative-splicing regulation, translational regulation, and mRNA decay.

  19. Alarin but not its alternative-splicing form, GALP (Galanin-like peptide) has antimicrobial activity

    Energy Technology Data Exchange (ETDEWEB)

    Wada, Akihiro, E-mail: a-wada@nagasaki-u.ac.jp [Department of Bacteriology, Institute of Tropical Medicine, Nagasaki University, Nagasaki 8528523 (Japan); Wong, Pooi-Fong [Department of Pharmacology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur (Malaysia); Hojo, Hironobu [Department of Applied Biochemistry, Institute of Glycoscience, Tokai University, Kanagawa 2591292 (Japan); Hasegawa, Makoto [Department of Bioscience, Faculty of Bioscience, Nagahama Institute of Bio-Science and Technology, Shiga 5260829 (Japan); Ichinose, Akitoyo [Electron Microscopy Shop Central Laboratory, Institute of Tropical Medicine, Nagasaki University, Nagasaki 8528523 (Japan); Llanes, Rafael [Institute Pedro Kouri, Havana (Cuba); Kubo, Yoshinao [Division of Cytokine Signaling, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 8528523 (Japan); Senba, Masachika [Department of Pathology, Institute of Tropical Medicine, Nagasaki University, Nagasaki 8528523 (Japan); Ichinose, Yoshio [Kenya Research Station, Institute of Tropical Medicine, Nagasaki University, Nagasaki 8528523 (Japan)

    2013-05-03

    Highlights: • Alarin inhibits the growth of E. coli but not S. aureus. • Alarin’s potency is comparable to LL-37 in inhibiting the growth of E. coli. • Alarin can cause bacterial membrane blebbing. • Alalin does not induce hemolysis on erythrocytes. -- Abstract: Alarin is an alternative-splicing form of GALP (galanin-like peptide). It shares only 5 conserved amino acids at the N-terminal region with GALP which is involved in a diverse range of normal brain functions. This study seeks to investigate whether alarin has additional functions due to its differences from GALP. Here, we have shown using a radial diffusion assay that alarin but not GALP inhibited the growth of Escherichia coli (strain ML-35). The conserved N-terminal region, however, remained essential for the antimicrobial activity of alarin as truncated peptides showed reduced killing effect. Moreover, alarin inhibited the growth of E. coli in a similar potency as human cathelicidin LL-37, a well-studied antimicrobial peptide. Electron microscopy further showed that alarin induced bacterial membrane blebbing but unlike LL-37, it did not cause hemolysis of erythrocytes. In addition, alarin is only active against the gram-negative bacteria, E. coli but not the gram-positive bacteria, Staphylococcus aureus. Thus, these data suggest that alarin has potentials as an antimicrobial and should be considered for the development in human therapeutics.

  20. Ultraviolet B (UVB) induced DNA damage affects alternative splicing in skin cells

    International Nuclear Information System (INIS)

    Munoz, M.J.; Nieto Moreno, N.; Kornblihtt, A.R.

    2010-01-01

    The ultraviolet (UV) radiation from the Sun that reaches the Earth's surface is a combination of low (UVA, 320-400 nm) and high (UVB, 290-320 nm) energy light. UVB light causes two types of mutagenic DNA lesions: thymine dimers and (6-4) photo-products. UVB mutagenesis is a critical step in the generation of different forms of skin cancer, which develops almost exclusively in sun exposed areas. We have previously shown that RNA polymerase II (pol II) hyperphosphorylation induced by UVC (254 nm) irradiation of non-skin cells inhibits pol II elongation rates which in turn affects alternative splicing (AS) patterns, altering the synthesis of pro- and anti-apoptotic isoforms of key proteins like Bcl-x or Caspase 9 (C9). Since the UVC radiation is fully filtered by the ozone layer and AS regulation in skin pathologies has been poorly studied, we decided to extend our studies to human keratinocytes in culture treated with UVB (302 nm) light. We observed that pol II hyperphosphorylation is increased upon UVB irradiation, being this modification necessary for the observed change in AS of a model cassette exon. Moreover, UVB irradiation induces the proapoptotic mRNA isoforms of Bcl-x and C9 consistently with a key role of AS in skin response to DNA damage. (authors)

  1. Histone demethylase JMJD1A promotes alternative splicing of AR variant 7 (AR-V7) in prostate cancer cells.

    Science.gov (United States)

    Fan, Lingling; Zhang, Fengbo; Xu, Songhui; Cui, Xiaolu; Hussain, Arif; Fazli, Ladan; Gleave, Martin; Dong, Xuesen; Qi, Jianfei

    2018-05-15

    Formation of the androgen receptor splicing variant 7 (AR-V7) is one of the major mechanisms by which resistance of prostate cancer to androgen deprivation therapy occurs. The histone demethylase JMJD1A (Jumonji domain containing 1A) functions as a key coactivator for AR by epigenetic regulation of H3K9 methylation marks. Here, we describe a role for JMJD1A in AR-V7 expression. While JMJD1A knockdown had no effect on full-length AR (AR-FL), it reduced AR-V7 levels in prostate cancer cells. Reexpression of AR-V7 in the JMJD1A-knockdown cells elevated expression of select AR targets and partially rescued prostate cancer cell growth in vitro and in vivo. The AR-V7 protein level correlated positively with JMJD1A in a subset of human prostate cancer specimens. Mechanistically, we found that JMJD1A promoted alternative splicing of AR-V7 through heterogeneous nuclear ribonucleoprotein F (HNRNPF), a splicing factor known to regulate exon inclusion. Knockdown of JMJD1A or HNRNPF inhibited splicing of AR-V7, but not AR-FL, in a minigene reporter assay. JMJD1A was found to interact with and promote the recruitment of HNRNPF to a cryptic exon 3b on AR pre-mRNA for the generation of AR-V7. Taken together, the role of JMJD1A in AR-FL coactivation and AR-V7 alternative splicing highlights JMJD1A as a potentially promising target for prostate cancer therapy.

  2. DEDB: a database of Drosophila melanogaster exons in splicing graph form

    Directory of Open Access Journals (Sweden)

    Tan Tin

    2004-12-01

    Full Text Available Abstract Background A wealth of quality genomic and mRNA/EST sequences in recent years has provided the data required for large-scale genome-wide analysis of alternative splicing. We have capitalized on this by constructing a database that contains alternative splicing information organized as splicing graphs, where all transcripts arising from a single gene are collected, organized and classified. The splicing graph then serves as the basis for the classification of the various types of alternative splicing events. Description DEDB http://proline.bic.nus.edu.sg/dedb/index.html is a database of Drosophila melanogaster exons obtained from FlyBase arranged in a splicing graph form that permits the creation of simple rules allowing for the classification of alternative splicing events. Pfam domains were also mapped onto the protein sequences allowing users to access the impact of alternative splicing events on domain organization. Conclusions DEDB's catalogue of splicing graphs facilitates genome-wide classification of alternative splicing events for genome analysis. The splicing graph viewer brings together genome, transcript, protein and domain information to facilitate biologists in understanding the implications of alternative splicing.

  3. The effects of multiple features of alternatively spliced exons on the KA/KS ratio test

    Directory of Open Access Journals (Sweden)

    Chen Feng-Chi

    2006-05-01

    Full Text Available Abstract Background The evolution of alternatively spliced exons (ASEs is of primary interest because these exons are suggested to be a major source of functional diversity of proteins. Many exon features have been suggested to affect the evolution of ASEs. However, previous studies have relied on the KA/KS ratio test without taking into consideration information sufficiency (i.e., exon length > 75 bp, cross-species divergence > 5% of the studied exons, leading to potentially biased interpretations. Furthermore, which exon feature dominates the results of the KA/KS ratio test and whether multiple exon features have additive effects have remained unexplored. Results In this study, we collect two different datasets for analysis – the ASE dataset (which includes lineage-specific ASEs and conserved ASEs and the ACE dataset (which includes only conserved ASEs. We first show that information sufficiency can significantly affect the interpretation of relationship between exons features and the KA/KS ratio test results. After discarding exons with insufficient information, we use a Boolean method to analyze the relationship between test results and four exon features (namely length, protein domain overlapping, inclusion level, and exonic splicing enhancer (ESE frequency for the ASE dataset. We demonstrate that length and protein domain overlapping are dominant factors, and they have similar impacts on test results of ASEs. In addition, despite the weak impacts of inclusion level and ESE motif frequency when considered individually, combination of these two factors still have minor additive effects on test results. However, the ACE dataset shows a slightly different result in that inclusion level has a marginally significant effect on test results. Lineage-specific ASEs may have contributed to the difference. Overall, in both ASEs and ACEs, protein domain overlapping is the most dominant exon feature while ESE frequency is the weakest one in affecting

  4. Accumulation of GC donor splice signals in mammals

    Directory of Open Access Journals (Sweden)

    Koonin Eugene V

    2008-07-01

    Full Text Available Abstract The GT dinucleotide in the first two intron positions is the most conserved element of the U2 donor splice signals. However, in a small fraction of donor sites, GT is replaced by GC. A substantial enrichment of GC in donor sites of alternatively spliced genes has been observed previously in human, nematode and Arabidopsis, suggesting that GC signals are important for regulation of alternative splicing. We used parsimony analysis to reconstruct evolution of donor splice sites and inferred 298 GT > GC conversion events compared to 40 GC > GT conversion events in primate and rodent genomes. Thus, there was substantive accumulation of GC donor splice sites during the evolution of mammals. Accumulation of GC sites might have been driven by selection for alternative splicing. Reviewers This article was reviewed by Jerzy Jurka and Anton Nekrutenko. For the full reviews, please go to the Reviewers' Reports section.

  5. Ott1 (Rbm15) regulates thrombopoietin response in hematopoietic stem cells through alternative splicing of c-Mpl.

    Science.gov (United States)

    Xiao, Nan; Laha, Suparna; Das, Shankar P; Morlock, Kayla; Jesneck, Jonathan L; Raffel, Glen D

    2015-02-05

    Thrombopoietin (Thpo) signaling through the c-Mpl receptor promotes either quiescence or proliferation of hematopoietic stem cells (HSCs) in a concentration-dependent manner; however, in vivo Thpo serum levels are responsive to platelet mass rather than HSC demands, suggesting additional regulation exists. Ott1 (Rbm15), a spliceosomal component originally identified as a fusion partner in t(1;22)-associated acute megakaryocytic leukemia, is also essential for maintaining HSC quiescence under stress. Ott1 controls the alternative splicing of a dominant negative isoform, Mpl-TR, capable of inhibiting HSC engraftment and attenuating Thpo signaling. Ott1, which associates with Hdac3 and the histone methyltransferase, Setd1b, binds to both c-Mpl RNA and chromatin and regulates H4 acetylation and H3K4me3 marks. Histone deacetylase or histone methyltransferase inhibition also increases Mpl-TR levels, suggesting that Ott1 uses an underlying epigenetic mechanism to control alternative splicing of c-Mpl. Manipulation of Ott1-dependent alternative splicing may therefore provide a novel pharmacologic avenue for regulating HSC quiescence and proliferation in response to Thpo. © 2015 by The American Society of Hematology.

  6. Transcript levels, alternative splicing and proteolytic cleavage of TFIIIA control 5S rRNA accumulation during Arabidopsis thaliana development.

    Science.gov (United States)

    Layat, Elodie; Cotterell, Sylviane; Vaillant, Isabelle; Yukawa, Yasushi; Tutois, Sylvie; Tourmente, Sylvette

    2012-07-01

    Ribosome biogenesis is critical for eukaryotic cells and requires coordinated synthesis of the protein and rRNA moieties of the ribosome, which are therefore highly regulated. 5S ribosomal RNA, an essential component of the large ribosomal subunit, is transcribed by RNA polymerase III and specifically requires transcription factor IIIA (TFIIIA). To obtain insight into the regulation of 5S rRNA transcription, we have investigated the expression of 5S rRNA and the exon-skipped (ES) and exon-including (EI) TFIIIA transcripts, two transcript isoforms that result from alternative splicing of the TFIIIA gene, and TFIIIA protein amounts with respect to requirements for 5S rRNA during development. We show that 5S rRNA quantities are regulated through distinct but complementary mechanisms operating through transcriptional and post-transcriptional control of TFIIIA transcripts as well as at the post-translational level through proteolytic cleavage of the TFIIIA protein. During the reproductive phase, high expression of the TFIIIA gene together with low proteolytic cleavage contributes to accumulation of functional, full-length TFIIIA protein, and results in 5S rRNA accumulation in the seed. In contrast, just after germination, the levels of TFIIIA-encoding transcripts are low and stable. Full-length TFIIIA protein is undetectable, and the level of 5S rRNA stored in the embryo progressively decreases. After day 4, in correlation with the reorganization of 5S rDNA chromatin to a mature state, full-length TFIIIA protein with transcriptional activity accumulates and permits de novo transcription of 5S rRNA. © 2012 The Authors. The Plant Journal © 2012 Blackwell Publishing Ltd.

  7. Fibrillin binds calcium and is coded by cDNAs that reveal a multidomain structure and alternatively spliced exons at the 5[prime] end

    Energy Technology Data Exchange (ETDEWEB)

    Corson, G.M.; Chalberg, S.C.; Charbonneau, N.L.; Sakai, L.Y. (Oregon Health Sciences Univ., Portland (United States)); Dietz, H.C. (Johns Hopkins Univ. School of Medicine, Baltimore, MD (United States))

    1993-08-01

    Fibrillin is an important structural protein of the extracellular matrix. It is a large cysteine-rich glycoprotein with extensive intrachain disulfide bonds, likely contributed by multiple EGF-like repeats. The authors have previously published 6.9 kb of FBN1 cDNA sequence. FBN1 cDNA clones that extend the sequence 3089 bp in the 5[prime] direction are described in this report. The deduced primary structure suggests that fibrillin in composed of multiple domains. The most predominant features the presence of 43 calcium binding EGF-like repeats. They demonstrate here that fibrillin molecules bind calcium. In addition, three alternatively spliced exons at the 5[prime] end are described. Analysis of 5.8 kb of surrounding genomic sequence revealed a 1.8-kb CpG island spanning the alternatively spliced exons and the next downstream exon. Since FBN1 is the gene responsible for Marfan syndrome, the information presented here will be useful in identifying new mutations and in understanding the function of fibrillin in the pathogenesis of the disease. 42 refs., 7 figs.

  8. Multiple independent insertions of 5S rRNA genes in the spliced-leader gene family of trypanosome species.

    Science.gov (United States)

    Beauparlant, Marc A; Drouin, Guy

    2014-02-01

    Analyses of the 5S rRNA genes found in the spliced-leader (SL) gene repeat units of numerous trypanosome species suggest that such linkages were not inherited from a common ancestor, but were the result of independent 5S rRNA gene insertions. In trypanosomes, 5S rRNA genes are found either in the tandemly repeated units coding for SL genes or in independent tandemly repeated units. Given that trypanosome species where 5S rRNA genes are within the tandemly repeated units coding for SL genes are phylogenetically related, one might hypothesize that this arrangement is the result of an ancestral insertion of 5S rRNA genes into the tandemly repeated SL gene family of trypanosomes. Here, we use the types of 5S rRNA genes found associated with SL genes, the flanking regions of the inserted 5S rRNA genes and the position of these insertions to show that most of the 5S rRNA genes found within SL gene repeat units of trypanosome species were not acquired from a common ancestor but are the results of independent insertions. These multiple 5S rRNA genes insertion events in trypanosomes are likely the result of frequent founder events in different hosts and/or geographical locations in species having short generation times.

  9. Landscape of the spliced leader trans-splicing mechanism in Schistosoma mansoni.

    Science.gov (United States)

    Boroni, Mariana; Sammeth, Michael; Gava, Sandra Grossi; Jorge, Natasha Andressa Nogueira; Macedo, Andréa Mara; Machado, Carlos Renato; Mourão, Marina Moraes; Franco, Glória Regina

    2018-03-01

    Spliced leader dependent trans-splicing (SLTS) has been described as an important RNA regulatory process that occurs in different organisms, including the trematode Schistosoma mansoni. We identified more than seven thousand putative SLTS sites in the parasite, comprising genes with a wide spectrum of functional classes, which underlines the SLTS as a ubiquitous mechanism in the parasite. Also, SLTS gene expression levels span several orders of magnitude, showing that SLTS frequency is not determined by the expression level of the target gene, but by the presence of particular gene features facilitating or hindering the trans-splicing mechanism. Our in-depth investigation of SLTS events demonstrates widespread alternative trans-splicing (ATS) acceptor sites occurring in different regions along the entire gene body, highlighting another important role of SLTS generating alternative RNA isoforms in the parasite, besides the polycistron resolution. Particularly for introns where SLTS directly competes for the same acceptor substrate with cis-splicing, we identified for the first time additional and important features that might determine the type of splicing. Our study substantially extends the current knowledge of RNA processing by SLTS in S. mansoni, and provide basis for future studies on the trans-splicing mechanism in other eukaryotes.

  10. Herboxidiene triggers splicing repression and abiotic stress responses in plants

    KAUST Repository

    Alshareef, Sahar; Ling, Yu; Butt, Haroon; Mariappan, Kiruthiga G.; Benhamed, Moussa; Mahfouz, Magdy M.

    2017-01-01

    Constitutive and alternative splicing of pre-mRNAs from multiexonic genes controls the diversity of the proteome; these precisely regulated processes also fine-tune responses to cues related to growth, development, and stresses. Small

  11. Upstream ORF affects MYCN translation depending on exon 1b alternative splicing

    International Nuclear Information System (INIS)

    Besançon, Roger; Puisieux, Alain; Valsesia-Wittmann, Sandrine; Locher, Clara; Delloye-Bourgeois, Céline; Furhman, Lydie; Tutrone, Giovani; Bertrand, Christophe; Jallas, Anne-Catherine; Garin, Elisabeth

    2009-01-01

    The MYCN gene is transcribed into two major mRNAs: one full-length (MYCN) and one exon 1b-spliced (MYCN Δ1b ) mRNA. But nothing is known about their respective ability to translate the MYCN protein. Plasmids were prepared to enable translation from the upstream (uORF) and major ORF of the two MYCN transcripts. Translation was studied after transfection in neuroblastoma SH-EP cell line. Impact of the upstream AUG on translation was evaluated after directed mutagenesis. Functional study with the two MYCN mRNAs was conducted by a cell viability assay. Existence of a new protein encoded by the MYCN Δ1b uORF was explored by designing a rabbit polyclonal antibody against a specific epitope of this protein. Both are translated, but higher levels of protein were seen with MYCN Δ1b mRNA. An upstream ORF was shown to have positive cis-regulatory activity on translation from MYCN but not from MYCN Δ1b mRNA. In transfected SH-EP neuroblastoma cells, high MYCN dosage obtained with MYCN Δ1b mRNA translation induces an antiapoptotic effect after serum deprivation that was not observed with low MYCN expression obtained with MYCN mRNA. Here, we showed that MYCNOT: MYCN Overlap Transcript, a new protein of unknown function is translated from the upstream AUG of MYCN Δ1b mRNA. Existence of upstream ORF in MYCN transcripts leads to a new level of MYCN regulation. The resulting MYCN dosage has a weak but significant anti-apoptotic activity after intrinsic apoptosis induction

  12. Splicing defect in FKBP10 gene causes autosomal recessive osteogenesis imperfecta disease: a case report.

    Science.gov (United States)

    Maghami, Fatemeh; Tabei, Seyed Mohammad Bagher; Moravej, Hossein; Dastsooz, Hassan; Modarresi, Farzaneh; Silawi, Mohammad; Faghihi, Mohammad Ali

    2018-05-25

    Osteogenesis imperfecta (OI) is a group of connective tissue disorder caused by mutations of genes involved in the production of collagen and its supporting proteins. Although the majority of reported OI variants are in COL1A1 and COL1A2 genes, recent reports have shown problems in other non-collagenous genes involved in the post translational modifications, folding and transport, transcription and proliferation of osteoblasts, bone mineralization, and cell signaling. Up to now, 17 types of OI have been reported in which types I to IV are the most frequent cases with autosomal dominant pattern of inheritance. Here we report an 8- year- old boy with OI who has had multiple fractures since birth and now he is wheelchair-dependent. To identify genetic cause of OI in our patient, whole exome sequencing (WES) was carried out and it revealed a novel deleterious homozygote splice acceptor site mutation (c.1257-2A > G, IVS7-2A > G) in FKBP10 gene in the patient. Then, the identified mutation was confirmed using Sanger sequencing in the proband as homozygous and in his parents as heterozygous, indicating its autosomal recessive pattern of inheritance. In addition, we performed RT-PCR on RNA transcripts originated from skin fibroblast of the proband to analyze the functional effect of the mutation on splicing pattern of FKBP10 gene and it showed skipping of the exon 8 of this gene. Moreover, Real-Time PCR was carried out to quantify the expression level of FKBP10 in the proband and his family members in which it revealed nearly the full decrease in the level of FKBP10 expression in the proband and around 75% decrease in its level in the carriers of the mutation, strongly suggesting the pathogenicity of the mutation. Our study identified, for the first time, a private pathogenic splice site mutation in FKBP10 gene and further prove the involvement of this gene in the rare cases of autosomal recessive OI type XI with distinguished clinical manifestations.

  13. TRIMe7-CypA, an alternative splicing isoform of TRIMCyp in rhesus macaque, negatively modulates TRIM5α activity

    Energy Technology Data Exchange (ETDEWEB)

    Na, Lei [Harbin Veterinary Research Institute of the Chinese Academy of Agricultural Sciences, Harbin 150001 (China); Tang, Yan-Dong [Harbin Veterinary Research Institute of the Chinese Academy of Agricultural Sciences, Harbin 150001 (China); Biotechnology Institute of Southern Medical University, Guangzhou 510515 (China); Liu, Jian-Dong; Yu, Chang-Qing; Sun, Liu-Ke; Lin, Yue-Zhi; Wang, Xue-Feng [Harbin Veterinary Research Institute of the Chinese Academy of Agricultural Sciences, Harbin 150001 (China); Wang, Xiaojun, E-mail: xjw@hvri.ac.cn [Harbin Veterinary Research Institute of the Chinese Academy of Agricultural Sciences, Harbin 150001 (China); Zhou, Jian-Hua, E-mail: jianhua_uc@126.com [Harbin Veterinary Research Institute of the Chinese Academy of Agricultural Sciences, Harbin 150001 (China); Harbin Pharmaceutical Group Biovaccine Company, Harbin 150069 (China)

    2014-04-04

    Highlights: • TRIMe7-CypA expresses in rhesus and pig-tailed, but not long-tailed macaques. • TRIMe7-CypA does not show the restriction to a HIV-GFP report virus in vitro. • It acts as a negative modulator to TRIM5α likely by competitive inhibition. - Abstract: The existence of innate, host-specific restriction factors is a major obstacle to the development of nonhuman primate models for AIDS studies, and TRIM5α is one of the most important of these restriction factors. In recent years, a TRIM5 chimeric gene that was retrotransposed by a cyclophilin A (CypA) cDNA was identified in certain macaque species. The TRIM5α-CypA fusion protein, TRIMCyp, which was expressed in these monkeys, had lost its restriction ability toward HIV-1. We previously found that TRIMe7-CypA, an alternative splicing isoform of the TRIMCyp transcripts, was expressed in pig-tailed and rhesus macaques but absent in long-tailed macaques. In this study, the anti-HIV-1 activity of TRIMe7-CypA in the rhesus macaque (RhTRIMe7-CypA) was investigated. The over-expression of RhTRIMe7-CypA in CrFK, HeLa and HEK293T cells did not restrict the infection or replication of an HIV-1-GFP reporter virus in these cells. As a positive control, rhesus (rh)TRIM5α strongly inhibited the reporter virus. Intriguingly, the anti-HIV-1 activity of RhTRIM5α was significantly reduced in a dose-dependent manner by the co-repression of RhTRIMe7-CypA. Our data indicate that although the RhTRIMe7-CypA isoform does not appear to restrict HIV-1, it may act as a negative modulator of TRIM family proteins, presumably by competitive inhibition.

  14. TRIMe7-CypA, an alternative splicing isoform of TRIMCyp in rhesus macaque, negatively modulates TRIM5α activity

    International Nuclear Information System (INIS)

    Na, Lei; Tang, Yan-Dong; Liu, Jian-Dong; Yu, Chang-Qing; Sun, Liu-Ke; Lin, Yue-Zhi; Wang, Xue-Feng; Wang, Xiaojun; Zhou, Jian-Hua

    2014-01-01

    Highlights: • TRIMe7-CypA expresses in rhesus and pig-tailed, but not long-tailed macaques. • TRIMe7-CypA does not show the restriction to a HIV-GFP report virus in vitro. • It acts as a negative modulator to TRIM5α likely by competitive inhibition. - Abstract: The existence of innate, host-specific restriction factors is a major obstacle to the development of nonhuman primate models for AIDS studies, and TRIM5α is one of the most important of these restriction factors. In recent years, a TRIM5 chimeric gene that was retrotransposed by a cyclophilin A (CypA) cDNA was identified in certain macaque species. The TRIM5α-CypA fusion protein, TRIMCyp, which was expressed in these monkeys, had lost its restriction ability toward HIV-1. We previously found that TRIMe7-CypA, an alternative splicing isoform of the TRIMCyp transcripts, was expressed in pig-tailed and rhesus macaques but absent in long-tailed macaques. In this study, the anti-HIV-1 activity of TRIMe7-CypA in the rhesus macaque (RhTRIMe7-CypA) was investigated. The over-expression of RhTRIMe7-CypA in CrFK, HeLa and HEK293T cells did not restrict the infection or replication of an HIV-1-GFP reporter virus in these cells. As a positive control, rhesus (rh)TRIM5α strongly inhibited the reporter virus. Intriguingly, the anti-HIV-1 activity of RhTRIM5α was significantly reduced in a dose-dependent manner by the co-repression of RhTRIMe7-CypA. Our data indicate that although the RhTRIMe7-CypA isoform does not appear to restrict HIV-1, it may act as a negative modulator of TRIM family proteins, presumably by competitive inhibition

  15. Pig StAR: mRNA expression and alternative splicing in testis and Leydig cells, and association analyses with testicular morphology traits.

    Science.gov (United States)

    Zhang, Yanghai; Cui, Yang; Zhang, Xuelian; Wang, Yimin; Gao, Jiayang; Yu, Ting; Lv, Xiaoyan; Pan, Chuanying

    2018-05-31

    Steroidogenic acute regulatory protein (StAR), primarily expressed in Leydig cells (LCs) in the mammalian testes, is essential for testosterone biosynthesis and male fertility. However, no previous reports have explored the expression profiles, alternative splicing and genetic variations of StAR gene in pig. The aim of current study was to explore the expression profiles in different tissues and different types of testicular cells (LCs; spermatogonial stem cells, SSCs; Sertoli cells, SCs), to identify different splice variants and their expression levels, as well as to detect the indel polymorphism in pig StAR gene. Expression analysis results revealed that StAR was widely expressed in all tested tissues and the expression level in testis was significantly higher than that in other tissues (P StAR mRNA expression level was significantly higher in LCs than others (P StAR-a, StAR-b and StAR-c, were first found in pig. Further study showed StAR-a was highly expressed in both testis and LCs when compared with other variants (P StAR-a was the primary variant at StAR gene post-transcription and may facilitate the combination and transportation of cholesterol with StAR. In addition, a 5-bp duplicated deletion (NC_010457.5:g.5524-5528 delACTTG) was verified in the porcine StAR gene, which was closely related to male testicular morphology traits (P StAR gene might be a positive allele. Briefly, the current findings suggest that StAR and StAR-a play imperative roles in male fertility and the 5-bp indel can be a potential DNA marker for the marker-assisted selection in boar. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. Early diagnostic value of survivin and its alternative splice variants in breast cancer

    International Nuclear Information System (INIS)

    Khan, Salma; Bennit, Heather Ferguson; Turay, David; Perez, Mia; Mirshahidi, Saied; Yuan, Yuan; Wall, Nathan R

    2014-01-01

    The inhibitor of apoptosis (IAP) protein Survivin and its splice variants are differentially expressed in breast cancer tissues. Our previous work showed Survivin is released from tumor cells via small membrane-bound vesicles called exosomes. We, therefore, hypothesize that analysis of serum exosomal Survivin and its splice variants may provide a novel biomarker for early diagnosis of breast cancer. We collected sera from forty breast cancer patients and ten control patients who were disease free for 5 years after treatment. In addition, twenty-three paired breast cancer tumor tissues from those same 40 patients were analyzed for splice variants. Serum levels of Survivin were analyzed using ELISA and exosomes were isolated from this serum using the commercially available ExoQuick kit, with subsequent Western blots and immunohistochemistry performed. Survivin levels were significantly higher in all the breast cancer samples compared to controls (p < 0.05) with exosome amounts significantly higher in cancer patient sera compared to controls (p < 0.01). While Survivin and Survivin-∆Ex3 splice variant expression and localization was identical in serum exosomes, differential expression of Survivin-2B protein existed in the exosomes. Similarly, Survivin and Survivin-∆Ex3 proteins were the predominant forms detected in all of the breast cancer tissues evaluated in this study, whereas a more variable expression of Survivin-2B level was found at different cancer stages. In this study we show for the first time that like Survivin, the Survivin splice variants are also exosomally packaged in the breast cancer patients’ sera, mimicking the survivin splice variant pattern that we also report in breast cancer tissues. Differential expression of exosomal-Survivin, particularly Survivin-2B, may serve as a diagnostic and/or prognostic marker, a “liquid biopsy” if you will, in early breast cancer patients. Furthermore, a more thorough understanding of the role of this

  17. Transportin-SR is required for proper splicing of resistance genes and plant immunity.

    Directory of Open Access Journals (Sweden)

    Shaohua Xu

    2011-06-01

    Full Text Available Transportin-SR (TRN-SR is a member of the importin-β super-family that functions as the nuclear import receptor for serine-arginine rich (SR proteins, which play diverse roles in RNA metabolism. Here we report the identification and cloning of mos14 (modifier of snc1-1, 14, a mutation that suppresses the immune responses conditioned by the auto-activated Resistance (R protein snc1 (suppressor of npr1-1, constitutive 1. MOS14 encodes a nuclear protein with high similarity to previously characterized TRN-SR proteins in animals. Yeast two-hybrid assays showed that MOS14 interacts with AtRAN1 via its N-terminus and SR proteins via its C-terminus. In mos14-1, localization of several SR proteins to the nucleus was impaired, confirming that MOS14 functions as a TRN-SR. The mos14-1 mutation results in altered splicing patterns of SNC1 and another R gene RPS4 and compromised resistance mediated by snc1 and RPS4, suggesting that nuclear import of SR proteins by MOS14 is required for proper splicing of these two R genes and is important for their functions in plant immunity.

  18. Systematic Profiling of Poly(A)+ Transcripts Modulated by Core 3’ End Processing and Splicing Factors Reveals Regulatory Rules of Alternative Cleavage and Polyadenylation

    Science.gov (United States)

    Li, Wencheng; You, Bei; Hoque, Mainul; Zheng, Dinghai; Luo, Wenting; Ji, Zhe; Park, Ji Yeon; Gunderson, Samuel I.; Kalsotra, Auinash; Manley, James L.; Tian, Bin

    2015-01-01

    Alternative cleavage and polyadenylation (APA) results in mRNA isoforms containing different 3’ untranslated regions (3’UTRs) and/or coding sequences. How core cleavage/polyadenylation (C/P) factors regulate APA is not well understood. Using siRNA knockdown coupled with deep sequencing, we found that several C/P factors can play significant roles in 3’UTR-APA. Whereas Pcf11 and Fip1 enhance usage of proximal poly(A) sites (pAs), CFI-25/68, PABPN1 and PABPC1 promote usage of distal pAs. Strong cis element biases were found for pAs regulated by CFI-25/68 or Fip1, and the distance between pAs plays an important role in APA regulation. In addition, intronic pAs are substantially regulated by splicing factors, with U1 mostly inhibiting C/P events in introns near the 5’ end of gene and U2 suppressing those in introns with features for efficient splicing. Furthermore, PABPN1 inhibits expression of transcripts with pAs near the transcription start site (TSS), a property possibly related to its role in RNA degradation. Finally, we found that groups of APA events regulated by C/P factors are also modulated in cell differentiation and development with distinct trends. Together, our results support an APA code where an APA event in a given cellular context is regulated by a number of parameters, including relative location to the TSS, splicing context, distance between competing pAs, surrounding cis elements and concentrations of core C/P factors. PMID:25906188

  19. Systematic profiling of poly(A+ transcripts modulated by core 3' end processing and splicing factors reveals regulatory rules of alternative cleavage and polyadenylation.

    Directory of Open Access Journals (Sweden)

    Wencheng Li

    2015-04-01

    Full Text Available Alternative cleavage and polyadenylation (APA results in mRNA isoforms containing different 3' untranslated regions (3'UTRs and/or coding sequences. How core cleavage/polyadenylation (C/P factors regulate APA is not well understood. Using siRNA knockdown coupled with deep sequencing, we found that several C/P factors can play significant roles in 3'UTR-APA. Whereas Pcf11 and Fip1 enhance usage of proximal poly(A sites (pAs, CFI-25/68, PABPN1 and PABPC1 promote usage of distal pAs. Strong cis element biases were found for pAs regulated by CFI-25/68 or Fip1, and the distance between pAs plays an important role in APA regulation. In addition, intronic pAs are substantially regulated by splicing factors, with U1 mostly inhibiting C/P events in introns near the 5' end of gene and U2 suppressing those in introns with features for efficient splicing. Furthermore, PABPN1 inhibits expression of transcripts with pAs near the transcription start site (TSS, a property possibly related to its role in RNA degradation. Finally, we found that groups of APA events regulated by C/P factors are also modulated in cell differentiation and development with distinct trends. Together, our results support an APA code where an APA event in a given cellular context is regulated by a number of parameters, including relative location to the TSS, splicing context, distance between competing pAs, surrounding cis elements and concentrations of core C/P factors.

  20. Dynamic ASXL1 Exon Skipping and Alternative Circular Splicing in Single Human Cells.

    Directory of Open Access Journals (Sweden)

    Winston Koh

    Full Text Available Circular RNAs comprise a poorly understood new class of noncoding RNA. In this study, we used a combination of targeted deletion, high-resolution splicing detection, and single-cell sequencing to deeply probe ASXL1 circular splicing. We found that efficient circular splicing required the canonical transcriptional start site and inverted AluSx elements. Sequencing-based interrogation of isoforms after ASXL1 overexpression identified promiscuous linear splicing between all exons, with the two most abundant non-canonical linear products skipping the exons that produced the circular isoforms. Single-cell sequencing revealed a strong preference for either the linear or circular ASXL1 isoforms in each cell, and found the predominant exon skipping product is frequently co-expressed with its reciprocal circular isoform. Finally, absolute quantification of ASXL1 isoforms confirmed our findings and suggests that standard methods overestimate circRNA abundance. Taken together, these data reveal a dynamic new view of circRNA genesis, providing additional framework for studying their roles in cellular biology.

  1. Novel splice site mutation in the growth hormone receptor gene in Turkish patients with Laron-type dwarfism.

    Science.gov (United States)

    Arman, Ahmet; Ozon, Alev; Isguven, Pinar S; Coker, Ajda; Peker, Ismail; Yordam, Nursen

    2008-01-01

    Growth hormone (GH) is involved in growth, and fat and carbohydrate metabolism. Interaction of GH with the GH receptor (GHR) is necessary for systemic and local production of insulin-like growth factor-I (IGF-I) which mediates GH actions. Mutations in the GHR cause severe postnatal growth failure; the disorder is an autosomal recessive genetic disease resulting in GH insensitivity, called Laron syndrome. It is characterized by dwarfism with elevated serum GH and low levels of IGF-I. We analyzed the GHR gene for mutations and polymorphisms in eight patients with Laron-type dwarfism from six families. We found three missense mutations (S40L, V125A, I526L), one nonsense mutation (W157X), and one splice site mutation in the extracellular domain of GHR. Furthermore, G168G and exon 3 deletion polymorphisms were detected in patients with Laron syndrome. The splice site mutation, which is a novel mutation, was located at the donor splice site of exon 2/ intron 2 within GHR. Although this mutation changed the highly conserved donor splice site consensus sequence GT to GGT by insertion of a G residue, the intron splicing between exon 2 and exon 3 was detected in the patient. These results imply that the splicing occurs arthe GT site in intron 2, leaving the extra inserted G residue at the end of exon 2, thus changing the open reading frame of GHR resulting in a premature termination codon in exon 3.

  2. Permanent Neonatal Diabetes Caused by Creation of an Ectopic Splice Site within the INS Gene

    Science.gov (United States)

    Gastaldo, Elena; Harries, Lorna W.; Rubio-Cabezas, Oscar; Castaño, Luis

    2012-01-01

    Background The aim of this study was to characterize the genetic etiology in a patient who presented with permanent neonatal diabetes at 2 months of age. Methodology/Principal Findings Regulatory elements and coding exons 2 and 3 of the INS gene were amplified and sequenced from genomic and complementary DNA samples. A novel heterozygous INS mutation within the terminal intron of the gene was identified in the proband and her affected father. This mutation introduces an ectopic splice site leading to the insertion of 29 nucleotides from the intronic sequence into the mature mRNA, which results in a longer and abnormal transcript. Conclusions/Significance This study highlights the importance of routinely sequencing the exon-intron boundaries and the need to carry out additional studies to confirm the pathogenicity of any identified intronic genetic variants. PMID:22235272

  3. Genome-wide survey of allele-specific splicing in humans

    Directory of Open Access Journals (Sweden)

    Scheffler Konrad

    2008-06-01

    Full Text Available Abstract Background Accurate mRNA splicing depends on multiple regulatory signals encoded in the transcribed RNA sequence. Many examples of mutations within human splice regulatory regions that alter splicing qualitatively or quantitatively have been reported and allelic differences in mRNA splicing are likely to be a common and important source of phenotypic diversity at the molecular level, in addition to their contribution to genetic disease susceptibility. However, because the effect of a mutation on the efficiency of mRNA splicing is often difficult to predict, many mutations that cause disease through an effect on splicing are likely to remain undiscovered. Results We have combined a genome-wide scan for sequence polymorphisms likely to affect mRNA splicing with analysis of publicly available Expressed Sequence Tag (EST and exon array data. The genome-wide scan uses published tools and identified 30,977 SNPs located within donor and acceptor splice sites, branch points and exonic splicing enhancer elements. For 1,185 candidate splicing polymorphisms the difference in splicing between alternative alleles was corroborated by publicly available exon array data from 166 lymphoblastoid cell lines. We developed a novel probabilistic method to infer allele-specific splicing from EST data. The method uses SNPs and alternative mRNA isoforms mapped to EST sequences and models both regulated alternative splicing as well as allele-specific splicing. We have also estimated heritability of splicing and report that a greater proportion of genes show evidence of splicing heritability than show heritability of overall gene expression level. Our results provide an extensive resource that can be used to assess the possible effect on splicing of human polymorphisms in putative splice-regulatory sites. Conclusion We report a set of genes showing evidence of allele-specific splicing from an integrated analysis of genomic polymorphisms, EST data and exon array

  4. The C-terminal domain of Brd2 is important for chromatin interaction and regulation of transcription and alternative splicing

    Czech Academy of Sciences Publication Activity Database

    Hnilicová, Jarmila; Hozeifi, Samira; Stejskalová, Eva; Dušková, Eva; Poser, I.; Humpolíčková, Jana; Hof, Martin; Staněk, David

    2013-01-01

    Roč. 24, č. 22 (2013), s. 3557-3568 ISSN 1059-1524 R&D Projects: GA AV ČR KAN200520801; GA ČR GAP305/10/0424; GA ČR GBP208/12/G016; GA ČR(CZ) GBP305/12/G034 Institutional support: RVO:68378050 ; RVO:61388955 Keywords : Brd2 * alternative splicing * chromatin Subject RIV: EB - Genetics ; Molecular Biology; CF - Physical ; Theoretical Chemistry (UFCH-W) Impact factor: 4.548, year: 2013

  5. Fox-2 Splicing Factor Binds to a Conserved Intron Motif to PromoteInclusion of Protein 4.1R Alternative Exon 16

    Energy Technology Data Exchange (ETDEWEB)

    Ponthier, Julie L.; Schluepen, Christina; Chen, Weiguo; Lersch,Robert A.; Gee, Sherry L.; Hou, Victor C.; Lo, Annie J.; Short, Sarah A.; Chasis, Joel A.; Winkelmann, John C.; Conboy, John G.

    2006-03-01

    Activation of protein 4.1R exon 16 (E16) inclusion during erythropoiesis represents a physiologically important splicing switch that increases 4.1R affinity for spectrin and actin. Previous studies showed that negative regulation of E16 splicing is mediated by the binding of hnRNP A/B proteins to silencer elements in the exon and that downregulation of hnRNP A/B proteins in erythroblasts leads to activation of E16 inclusion. This paper demonstrates that positive regulation of E16 splicing can be mediated by Fox-2 or Fox-1, two closely related splicing factors that possess identical RNA recognition motifs. SELEX experiments with human Fox-1 revealed highly selective binding to the hexamer UGCAUG. Both Fox-1 and Fox-2 were able to bind the conserved UGCAUG elements in the proximal intron downstream of E16, and both could activate E16 splicing in HeLa cell co-transfection assays in a UGCAUG-dependent manner. Conversely, knockdown of Fox-2 expression, achieved with two different siRNA sequences resulted in decreased E16 splicing. Moreover, immunoblot experiments demonstrate mouse erythroblasts express Fox-2, but not Fox-1. These findings suggest that Fox-2 is a physiological activator of E16 splicing in differentiating erythroid cells in vivo. Recent experiments show that UGCAUG is present in the proximal intron sequence of many tissue-specific alternative exons, and we propose that the Fox family of splicing enhancers plays an important role in alternative splicing switches during differentiation in metazoan organisms.

  6. Splice Variants of the Castor WRI1 Gene Upregulate Fatty Acid and Oil Biosynthesis When Expressed in Tobacco Leaves.

    Science.gov (United States)

    Ji, Xia-Jie; Mao, Xue; Hao, Qing-Ting; Liu, Bao-Ling; Xue, Jin-Ai; Li, Run-Zhi

    2018-01-05

    The plant-specific WRINKLED1 (WRI1) is a member of the AP2/EREBP class of transcription factors that positively regulate oil biosynthesis in plant tissues. Limited information is available for the role of WRI1 in oil biosynthesis in castor bean ( Ricinus connunis L.), an important industrial oil crop. Here, we report the identification of two alternatively spliced transcripts of RcWRI1 , designated as RcWRI1-A and RcWRI1-B . The open reading frames of RcWRI1-A (1341 bp) and RcWRI1-B (1332 bp) differ by a stretch of 9 bp, such that the predicted RcWRI1-B lacks the three amino acid residues "VYL" that are present in RcWRI1-A. The RcWRI1-A transcript is present in flowers, leaves, pericarps and developing seeds, while the RcWRI1-B mRNA is only detectable in developing seeds. When the two isoforms were individually introduced into an Arabidopsis wri1-1 loss-of-function mutant, total fatty acid content was almost restored to the wild-type level, and the percentage of the wrinkled seeds was largely reduced in the transgenic lines relative to the wri1-1 mutant line. Transient expression of each RcWRI1 splice isoform in N. benthamiana leaves upregulated the expression of the WRI1 target genes, and consequently increased the oil content by 4.3-4.9 fold when compared with the controls, and RcWRI1-B appeared to be more active than RcWRI1-A . Both RcWRI1-A and RcWRI1-B can be used as a key transcriptional regulator to enhance fatty acid and oil biosynthesis in leafy biomass.

  7. Splice Variants of the Castor WRI1 Gene Upregulate Fatty Acid and Oil Biosynthesis When Expressed in Tobacco Leaves

    Directory of Open Access Journals (Sweden)

    Xia-Jie Ji

    2018-01-01

    Full Text Available The plant-specific WRINKLED1 (WRI1 is a member of the AP2/EREBP class of transcription factors that positively regulate oil biosynthesis in plant tissues. Limited information is available for the role of WRI1 in oil biosynthesis in castor bean (Ricinus connunis L., an important industrial oil crop. Here, we report the identification of two alternatively spliced transcripts of RcWRI1, designated as RcWRI1-A and RcWRI1-B. The open reading frames of RcWRI1-A (1341 bp and RcWRI1-B (1332 bp differ by a stretch of 9 bp, such that the predicted RcWRI1-B lacks the three amino acid residues “VYL” that are present in RcWRI1-A. The RcWRI1-A transcript is present in flowers, leaves, pericarps and developing seeds, while the RcWRI1-B mRNA is only detectable in developing seeds. When the two isoforms were individually introduced into an Arabidopsis wri1-1 loss-of-function mutant, total fatty acid content was almost restored to the wild-type level, and the percentage of the wrinkled seeds was largely reduced in the transgenic lines relative to the wri1-1 mutant line. Transient expression of each RcWRI1 splice isoform in N. benthamiana leaves upregulated the expression of the WRI1 target genes, and consequently increased the oil content by 4.3–4.9 fold when compared with the controls, and RcWRI1-B appeared to be more active than RcWRI1-A. Both RcWRI1-A and RcWRI1-B can be used as a key transcriptional regulator to enhance fatty acid and oil biosynthesis in leafy biomass.

  8. Functional characterization of two novel splicing mutations in the OCA2 gene associated with oculocutaneous albinism type II.

    Science.gov (United States)

    Rimoldi, Valeria; Straniero, Letizia; Asselta, Rosanna; Mauri, Lucia; Manfredini, Emanuela; Penco, Silvana; Gesu, Giovanni P; Del Longo, Alessandra; Piozzi, Elena; Soldà, Giulia; Primignani, Paola

    2014-03-01

    Oculocutaneous albinism (OCA) is characterized by hypopigmentation of the skin, hair and eye, and by ophthalmologic abnormalities caused by a deficiency in melanin biosynthesis. OCA type II (OCA2) is one of the four commonly-recognized forms of albinism, and is determined by mutation in the OCA2 gene. In the present study, we investigated the molecular basis of OCA2 in two siblings and one unrelated patient. The mutational screening of the OCA2 gene identified two hitherto-unknown putative splicing mutations. The first one (c.1503+5G>A), identified in an Italian proband and her affected sibling, lies in the consensus sequence of the donor splice site of OCA2 intron 14 (IVS14+5G>A), in compound heterozygosity with a frameshift mutation, c.1450_1451insCTGCCCTGACA, which is predicted to determine the premature termination of the polypeptide chain (p.I484Tfs*19). In-silico prediction of the effect of the IVS14+5G>A mutation on splicing showed a score reduction for the mutant splice site and indicated the possible activation of a newly-created deep-intronic acceptor splice site. The second mutation is a synonymous transition (c.2139G>A, p.K713K) involving the last nucleotide of exon 20. This mutation was found in a young African albino patient in compound heterozygosity with a previously-reported OCA2 missense mutation (p.T404M). In-silico analysis predicted that the mutant c.2139G>A allele would result in the abolition of the splice donor site. The effects on splicing of these two novel mutations were investigated using an in-vitro hybrid-minigene approach that led to the demonstration of the causal role of the two mutations and to the identification of aberrant transcript variants. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Congenital analbuminemia caused by a novel aberrant splicing in the albumin gene.

    Science.gov (United States)

    Caridi, Gianluca; Dagnino, Monica; Erdeve, Omer; Di Duca, Marco; Yildiz, Duran; Alan, Serdar; Atasay, Begum; Arsan, Saadet; Campagnoli, Monica; Galliano, Monica; Minchiotti, Lorenzo

    2014-01-01

    Congenital analbuminemia is a rare autosomal recessive disorder manifested by the presence of a very low amount of circulating serum albumin. It is an allelic heterogeneous defect, caused by variety of mutations within the albumin gene in homozygous or compound heterozygous state. Herein we report the clinical and molecular characterization of a new case of congenital analbuminemia diagnosed in a female newborn of consanguineous (first degree cousins) parents from Ankara, Turkey, who presented with a low albumin concentration (A transition at position c.1652+1, the first base of intron 12, which inactivates the strongly conserved GT dinucleotide at the 5' splice site consensus sequence of this intron. The splicing defect results in the complete skipping of the preceding exon (exon 12) and in a frame-shift within exon 13 with a premature stop codon after the translation of three mutant amino acid residues. Our results confirm the clinical diagnosis of congenital analbuminemia in the proband and the inheritance of the trait and contribute to shed light on the molecular genetics of analbuminemia.

  10. Molecular analysis of alternative transcripts of equine AXL receptor tyrosine kinase gene

    Directory of Open Access Journals (Sweden)

    Jeong-Woong Park

    2017-10-01

    Full Text Available Objective Since athletic performance is a most importance trait in horses, most research focused on physiological and physical studies of horse athletic abilities. In contrast, the molecular analysis as well as the regulatory pathway studies remain insufficient for evaluation and prediction of horse athletic abilities. In our previous study, we identified AXL receptor tyrosine kinase (AXL gene which was expressed as alternative spliced isoforms in skeletal muscle during exercise. In the present study, we validated two AXL alternative splicing transcripts (named as AXLa for long form and AXLb for short form in equine skeletal muscle to gain insight(s into the role of each alternative transcript during exercise. Methods We validated two isoforms of AXL transcripts in horse tissues by reverse transcriptase polymerase chain reaction (RT-PCR, and then cloned the transcripts to confirm the alternative locus and its sequences. Additionally, we examined the expression patterns of AXLa and AXLb transcripts in horse tissues by quantitative RT-PCR (qRT-PCR. Results Both of AXLa and AXLb transcripts were expressed in horse skeletal muscle and the expression levels were significantly increased after exercise. The sequencing analysis showed that there was an alternative splicing event at exon 11 between AXLa and AXLb transcripts. 3-dimentional (3D prediction of the alternative protein structures revealed that the structural distance of the connective region between fibronectin type 3 (FN3 and immunoglobin (Ig domain was different between two alternative isoforms. Conclusion It is assumed that the expression patterns of AXLa and AXLb transcripts would be involved in regulation of exercise-induced stress in horse muscle possibly through an NF-κB signaling pathway. Further study is necessary to uncover biological function(s and significance of the alternative splicing isoforms in race horse skeletal muscle.

  11. Molecular analysis of alternative transcripts of equine AXL receptor tyrosine kinase gene.

    Science.gov (United States)

    Park, Jeong-Woong; Song, Ki-Duk; Kim, Nam Young; Choi, Jae-Young; Hong, Seul A; Oh, Jin Hyeog; Kim, Si Won; Lee, Jeong Hyo; Park, Tae Sub; Kim, Jin-Kyoo; Kim, Jong Geun; Cho, Byung-Wook

    2017-10-01

    Since athletic performance is a most importance trait in horses, most research focused on physiological and physical studies of horse athletic abilities. In contrast, the molecular analysis as well as the regulatory pathway studies remain insufficient for evaluation and prediction of horse athletic abilities. In our previous study, we identified AXL receptor tyrosine kinase ( AXL ) gene which was expressed as alternative spliced isoforms in skeletal muscle during exercise. In the present study, we validated two AXL alternative splicing transcripts (named as AXLa for long form and AXLb for short form) in equine skeletal muscle to gain insight(s) into the role of each alternative transcript during exercise. We validated two isoforms of AXL transcripts in horse tissues by reverse transcriptase polymerase chain reaction (RT-PCR), and then cloned the transcripts to confirm the alternative locus and its sequences. Additionally, we examined the expression patterns of AXLa and AXLb transcripts in horse tissues by quantitative RT-PCR (qRT-PCR). Both of AXLa and AXLb transcripts were expressed in horse skeletal muscle and the expression levels were significantly increased after exercise. The sequencing analysis showed that there was an alternative splicing event at exon 11 between AXLa and AXLb transcripts. 3-dimentional (3D) prediction of the alternative protein structures revealed that the structural distance of the connective region between fibronectin type 3 (FN3) and immunoglobin (Ig) domain was different between two alternative isoforms. It is assumed that the expression patterns of AXLa and AXLb transcripts would be involved in regulation of exercise-induced stress in horse muscle possibly through an NF-κB signaling pathway. Further study is necessary to uncover biological function(s) and significance of the alternative splicing isoforms in race horse skeletal muscle.

  12. Evaluation of MYBPC3 trans-Splicing and Gene Replacement as Therapeutic Options in Human iPSC-Derived Cardiomyocytes

    Directory of Open Access Journals (Sweden)

    Maksymilian Prondzynski

    2017-06-01

    Full Text Available Gene therapy is a promising option for severe forms of genetic diseases. We previously provided evidence for the feasibility of trans-splicing, exon skipping, and gene replacement in a mouse model of hypertrophic cardiomyopathy (HCM carrying a mutation in MYBPC3, encoding cardiac myosin-binding protein C (cMyBP-C. Here we used human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs from an HCM patient carrying a heterozygous c.1358-1359insC MYBPC3 mutation and from a healthy donor. HCM hiPSC-CMs exhibited ∼50% lower MYBPC3 mRNA and cMyBP-C protein levels than control, no truncated cMyBP-C, larger cell size, and altered gene expression, thus reproducing human HCM features. We evaluated RNA trans-splicing and gene replacement after transducing hiPSC-CMs with adeno-associated virus. trans-splicing with 5′ or 3′ pre-trans-splicing molecules represented ∼1% of total MYBPC3 transcripts in healthy hiPSC-CMs. In contrast, gene replacement with the full-length MYBPC3 cDNA resulted in ∼2.5-fold higher MYBPC3 mRNA levels in HCM and control hiPSC-CMs. This restored the cMyBP-C level to 81% of the control level, suppressed hypertrophy, and partially restored gene expression to control level in HCM cells. This study provides evidence for (1 the feasibility of trans-splicing, although with low efficiency, and (2 efficient gene replacement in hiPSC-CMs with a MYBPC3 mutation.

  13. Identification and functional analysis of two alternatively spliced transcripts of ABSCISIC ACID INSENSITIVE3 (ABI3) in linseed flax (Linum usitatissimum L.).

    Science.gov (United States)

    Wang, Yanyan; Zhang, Tianbao; Song, Xiaxia; Zhang, Jianping; Dang, Zhanhai; Pei, Xinwu; Long, Yan

    2018-01-01

    Alternative splicing is a popular phenomenon in different types of plants. It can produce alternative spliced transcripts that encode proteins with altered functions. Previous studies have shown that one transcription factor, ABSCISIC ACID INSENSITIVE3 (ABI3), which encodes an important component in abscisic acid (ABA) signaling, is subjected to alternative splicing in both mono- and dicotyledons. In the current study, we identified two homologs of ABI3 in the genome of linseed flax. We screened two alternatively spliced flax LuABI3 transcripts, LuABI3-2 and LuABI3-3, and one normal flax LuABI3 transcript, LuABI3-1. Sequence analysis revealed that one of the alternatively spliced transcripts, LuABI3-3, retained a 6 bp intron. RNA accumulation analysis showed that all three transcripts were expressed during seed development, while subcellular localization and transgene experiments showed that LuABI3-3 had no biological function. The two normal transcripts, LuABI3-1 and LuABI3-2, are the important functional isoforms in flax and play significant roles in the ABA regulatory pathway during seed development, germination, and maturation.

  14. Identification and functional analysis of two alternatively spliced transcripts of ABSCISIC ACID INSENSITIVE3 (ABI3 in linseed flax (Linum usitatissimum L..

    Directory of Open Access Journals (Sweden)

    Yanyan Wang

    Full Text Available Alternative splicing is a popular phenomenon in different types of plants. It can produce alternative spliced transcripts that encode proteins with altered functions. Previous studies have shown that one transcription factor, ABSCISIC ACID INSENSITIVE3 (ABI3, which encodes an important component in abscisic acid (ABA signaling, is subjected to alternative splicing in both mono- and dicotyledons. In the current study, we identified two homologs of ABI3 in the genome of linseed flax. We screened two alternatively spliced flax LuABI3 transcripts, LuABI3-2 and LuABI3-3, and one normal flax LuABI3 transcript, LuABI3-1. Sequence analysis revealed that one of the alternatively spliced transcripts, LuABI3-3, retained a 6 bp intron. RNA accumulation analysis showed that all three transcripts were expressed during seed development, while subcellular localization and transgene experiments showed that LuABI3-3 had no biological function. The two normal transcripts, LuABI3-1 and LuABI3-2, are the important functional isoforms in flax and play significant roles in the ABA regulatory pathway during seed development, germination, and maturation.

  15. Targeted modulation of alternative splicing by TALE-directed chromatin editing

    Czech Academy of Sciences Publication Activity Database

    Bieberstein, Nicole; Staněk, David

    2015-01-01

    Roč. 282, SI (2015), s. 210-210 ISSN 1742-464X. [40th Congress of the Federation-of-European-Biochemical-Societies (FEBS) - The Biochemical Basis of Life. 04.07.2015-09.07.2015, Berlín] R&D Projects: GA ČR(CZ) GBP305/12/G034 Institutional support: RVO:68378050 Keywords : histone methylation * pre-mRNA splicing * TALEN Subject RIV: EB - Genetics ; Molecular Biology

  16. spliceR

    DEFF Research Database (Denmark)

    Vitting-Seerup, Kristoffer; Porse, Bo Torben; Sandelin, Albin

    2014-01-01

    RNA-seq data is currently underutilized, in part because it is difficult to predict the functional impact of alternate transcription events. Recent software improvements in full-length transcript deconvolution prompted us to develop spliceR, an R package for classification of alternative splicing...

  17. Differential splicing of oncogenes and tumor suppressor genes in African and Caucasian American populations: contributing factor in prostate cancer disparities

    Science.gov (United States)

    2017-12-01

    populations: contributing factor in prostate cancer disparities? PRINCIPAL INVESTIGATOR: Norman H Lee, PhD CONTRACTING ORGANIZATION: George Washington...splicing of oncogenes and tumor suppressor genes in African and Caucasian American populations: contributing factor in prostate cancer disparities? 5b...American (AA) versus Caucasian American (CA) prostate cancer (PCa). We focused our efforts on two oncogenes, phosphatidylinositol-4,5-bisphosphate 3

  18. Differential expression of splicing variants of the human caldesmon gene (CALD1) in glioma neovascularization versus normal brain microvasculature

    NARCIS (Netherlands)

    P.P. Zheng (Pingpin); A.M. Sieuwerts (Anieta); T.M. Luider (Theo); M.M. van der Weiden (Marcel); J.M. Kros (Johan); P.A.E. Sillevis Smitt (Peter)

    2004-01-01

    textabstractCaldesmon is a cytoskeleton-associated protein which has not yet been related to neoplastic angiogenesis. In this study we investigated the expression of the caldesmon gene (CALD1) splicing variants and the protein expression level in glioma microvessels versus normal

  19. A novel splice mutation in the TP53 gene associated with Leydig cell tumor and primitive neuroectodermal tumor

    DEFF Research Database (Denmark)

    Stecher, Chalotte Willemann; Grønbaek, Kirsten; Hasle, Henrik

    2008-01-01

    A 20-month-old boy presented with precocious puberty due to a Leydig cell tumor, and at the age of 6 years with a primitive neuroectodermal brain-tumor (PNET). A novel splice site mutation of the TP53-gene, likely to be associated with a nonfunctional protein, was found in the proband, his father...

  20. MDS shows a higher expression of hTERT and alternative splice variants in unactivated T-cells.

    Science.gov (United States)

    Dong, Wen; Wu, Lei; Sun, Houfang; Ren, Xiubao; Epling-Burnette, Pearlie K; Yang, Lili

    2016-11-01

    Telomere instability and telomerase reactivation are believed to play an important role in the development of myelodysplastic syndromes (MDS). Abnormal enzymatic activity of human telomerase reverse transcriptase (hTERT), and its alternative splice variants have been reported to account for deregulated telomerase function in many cancers. In this study, we aim to compare the differences in expression of hTERT and hTERT splice variants, as well as telomere length and telomerase activity in unstimulated T-cells between MDS subgroups and healthy controls. Telomere length in MDS cases was significantly shorter than controls (n = 20, pMDS using World Health Organization classification (WHO subgroups versus control: RARS, p= 0.009; RCMD, p=0.0002; RAEB1/2, p=0.004, respectively) and the International Prognostic Scoring System (IPSS subgroups: Low+Int-1, pMDS patients (n=20) had significantly higher telomerase activity (p=0.002), higher total hTERT mRNA levels (p=0.001) and hTERT α+β- splice variant expression (pMDS (r=0.58, p=0.007). This data is in sharp contrast to data published previously by our group showing a reduction in telomerase and hTERT mRNA in MDS T-cells after activation. In conclusion, this study provides additional insight into hTERT transcript patterns and activity in peripheral T-cells of MDS patients. Additional studies are necessary to better understand the role of this pathway in MDS development and progression.

  1. Human thyroid peroxidase: complete cDNA and protein sequence, chromosome mapping, and identification of two alternately spliced mRNAs

    International Nuclear Information System (INIS)

    Kimura, S.; Kotani, T.; McBride, O.W.; Umeki, K.; Hirai, K.; Nakayama, T.; Ohtaki, S.

    1987-01-01

    Two forms of human thyroid peroxidase cDNAs were isolated from a λgt11 cDNA library, prepared from Graves disease thyroid tissue mRNA, by use of oligonucleotides. The longest complete cDNA, designated phTPO-1, has 3048 nucleotides and an open reading frame consisting of 933 amino acids, which would encode a protein with a molecular weight of 103,026. Five potential asparagine-linked glycosylation sites are found in the deduced amino acid sequence. The second peroxidase cDNA, designated phTPO-2, is almost identical to phTPO-1 beginning 605 base pairs downstream except that it contains 1-base-pair difference and lacks 171 base pairs in the middle of the sequence. This results in a loss of 57 amino acids corresponding to a molecular weight of 6282. Interestingly, this 171-nucleotide sequence has GT and AG at its 5' and 3' boundaries, respectively, that are in good agreement with donor and acceptor splice site consensus sequences. Using specific oligonucleotide probes for the mRNAs derived from the cDNA sequences hTOP-1 and hTOP-2, the authors show that both are expressed in all thyroid tissues examined and the relative level of two mRNAs is different in each sample. The results suggest that two thyroid peroxidase proteins might be generated through alternate splicing of the same gene. By using somatic cell hybrid lines, the thyroid peroxidase gene was mapped to the short arm of human chromosome 2

  2. Conservation and Sex-Specific Splicing of the transformer Gene in the Calliphorids Cochliomyia hominivorax, Cochliomyia macellaria and Lucilia sericata

    Science.gov (United States)

    Li, Fang; Vensko, Steven P.; Belikoff, Esther J.; Scott, Maxwell J.

    2013-01-01

    Transformer (TRA) promotes female development in several dipteran species including the Australian sheep blowfly Lucilia cuprina, the Mediterranean fruit fly, housefly and Drosophila melanogaster. tra transcripts are sex-specifically spliced such that only the female form encodes full length functional protein. The presence of six predicted TRA/TRA2 binding sites in the sex-specific female intron of the L. cuprina gene suggested that tra splicing is auto-regulated as in medfly and housefly. With the aim of identifying conserved motifs that may play a role in tra sex-specific splicing, here we have isolated and characterized the tra gene from three additional blowfly species, L. sericata, Cochliomyia hominivorax and C. macellaria. The blowfly adult male and female transcripts differ in the choice of splice donor site in the first intron, with males using a site downstream of the site used in females. The tra genes all contain a single TRA/TRA2 site in the male exon and a cluster of four to five sites in the male intron. However, overall the sex-specific intron sequences are poorly conserved in closely related blowflies. The most conserved regions are around the exon/intron junctions, the 3′ end of the intron and near the cluster of TRA/TRA2 sites. We propose a model for sex specific regulation of tra splicing that incorporates the conserved features identified in this study. In L. sericata embryos, the male tra transcript was first detected at around the time of cellular blastoderm formation. RNAi experiments showed that tra is required for female development in L. sericata and C. macellaria. The isolation of the tra gene from the New World screwworm fly C. hominivorax, a major livestock pest, will facilitate the development of a “male-only” strain for genetic control programs. PMID:23409170

  3. Roles of viral and cellular proteins in the expression of alternatively spliced HTLV-1 pX mRNAs

    International Nuclear Information System (INIS)

    Princler, Gerald L.; Julias, John G.; Hughes, Stephen H.; Derse, David

    2003-01-01

    The human T cell leukemia virus type 1 (HTLV-1) genome contains a cluster of at least five open reading frames (ORFs) near the 3' terminus within the pX region. The pX ORFs are encoded by mono- or bicistronic mRNAs that are generated by alternative splicing. The various pX mRNAs result from skipping of the internal exon (2-exon versus 3-exon isofoms) or from the utilization of alternative splice acceptor sites in the terminal exon. The Rex and Tax proteins, encoded by ORFs X-III and X-IV, have been studied intensively and are encoded by the most abundant of the alternative 3-exon mRNAs. The protein products of the other pX ORFs have not been detected in HTLV-1-infected cell lines and the levels of the corresponding mRNAs have not been accurately established. We have used real-time RT-PCR with splice-site specific primers to accurately measure the levels of individual pX mRNA species in chronically infected T cell lines. We have asked whether virus regulatory proteins or ectopic expression of cellular factors influence pX mRNA splicing in cells that were transfected with HTLV-1 provirus clones. In chronically infected cell lines, the pX-tax/rex mRNA was present at 500- to 2500-fold higher levels than the pX-tax-orfII mRNA and at approximately 1000-fold higher levels than pX-rex-orfI mRNA. Chronically infected cell lines that contain numerous defective proviruses expressed 2-exon forms of pX mRNAs at significantly higher levels compared to cell lines that contain a single full-length provirus. Cells transfected with provirus expression plasmids expressed similar relative amounts of 3-exon pX mRNAs but lower levels of 2-exon mRNA forms compared to cells containing a single, full-length provirus. The pX mRNA expression patterns were nearly identical in cells transfected with wild-type, Tax-minus, or Rex-minus proviruses. Cotransfection of cells with HTLV-1 provirus in combination with SF2/ASF expression plasmid resulted in a relative increase in pX-tax/rex m

  4. Sequence, 'subtle' alternative splicing and expression of the CYYR1 (cysteine/tyrosine-rich 1) mRNA in human neuroendocrine tumors

    International Nuclear Information System (INIS)

    Vitale, Lorenza; Coppola, Domenico; Strippoli, Pierluigi; Frabetti, Flavia; Huntsman, Shane A; Canaider, Silvia; Casadei, Raffaella; Lenzi, Luca; Facchin, Federica; Carinci, Paolo; Zannotti, Maria

    2007-01-01

    CYYR1 is a recently identified gene located on human chromosome 21 whose product has no similarity to any known protein and is of unknown function. Analysis of expressed sequence tags (ESTs) have revealed high human CYYR1 expression in cells belonging to the diffuse neuroendocrine system (DNES). These cells may be the origin of neuroendocrine (NE) tumors. The aim of this study was to conduct an initial analysis of sequence, splicing and expression of the CYYR1 mRNA in human NE tumors. The CYYR1 mRNA coding sequence (CDS) was studied in 32 NE tumors by RT-PCR and sequence analysis. A subtle alternative splicing was identified generating two isoforms of CYYR1 mRNA differing in terms of the absence (CAG - isoform, the first described mRNA for CYYR1 locus) or the presence (CAG + isoform) of a CAG codon. When present, this specific codon determines the presence of an alanine residue, at the exon 3/exon 4 junction of the CYYR1 mRNA. The two mRNA isoform amounts were determined by quantitative relative RT-PCR in 29 NE tumors, 2 non-neuroendocrine tumors and 10 normal tissues. A bioinformatic analysis was performed to search for the existence of the two CYYR1 isoforms in other species. The CYYR1 CDS did not show differences compared to the reference sequence in any of the samples, with the exception of an NE tumor arising in the neck region. Sequence analysis of this tumor identified a change in the CDS 333 position (T instead of C), leading to the amino acid mutation P111S. NE tumor samples showed no significant difference in either CYYR1 CAG - or CAG + isoform expression compared to control tissues. CYYR1 CAG - isoform was significantly more expressed than CAG + isoform in NE tumors as well as in control samples investigated. Bioinformatic analysis revealed that only the genomic sequence of Pan troglodytes CYYR1 is consistent with the possible existence of the two described mRNA isoforms. A new 'subtle' splicing isoform (CAG + ) of CYYR1 mRNA, the sequence and

  5. Splicing factor SR34b mutation reduces cadmium tolerance in Arabidopsis by regulating iron-regulated transporter 1 gene

    International Nuclear Information System (INIS)

    Zhang, Wentao; Du, Bojing; Liu, Di; Qi, Xiaoting

    2014-01-01

    Highlights: • Arabidopsis splicing factor SR34b gene is cadmium-inducible. • SR34b T-DNA insertion mutant is sensitive to cadmium due to high cadmium uptake. • SR34b is a regulator of cadmium transporter IRT1 at the posttranscription level. • These results highlight the roles of splicing factors in cadmium tolerance of plant. - Abstract: Serine/arginine-rich (SR) proteins are important splicing factors. However, the biological functions of plant SR proteins remain unclear especially in abiotic stresses. Cadmium (Cd) is a non-essential element that negatively affects plant growth and development. In this study, we provided clear evidence for SR gene involved in Cd tolerance in planta. Systemic expression analysis of 17 Arabidopsis SR genes revealed that SR34b is the only SR gene upregulated by Cd, suggesting its potential roles in Arabidopsis Cd tolerance. Consistent with this, a SR34b T-DNA insertion mutant (sr34b) was moderately sensitive to Cd, which had higher Cd 2+ uptake rate and accumulated Cd in greater amounts than wild-type. This was due to the altered expression of iron-regulated transporter 1 (IRT1) gene in sr34b mutant. Under normal growth conditions, IRT1 mRNAs highly accumulated in sr34b mutant, which was a result of increased stability of IRT1 mRNA. Under Cd stress, however, sr34b mutant plants had a splicing defect in IRT1 gene, thus reducing the IRT1 mRNA accumulation. Despite of this, sr34b mutant plants still constitutively expressed IRT1 proteins under Cd stress, thereby resulting in Cd stress-sensitive phenotype. We therefore propose the essential roles of SR34b in posttranscriptional regulation of IRT1 expression and identify it as a regulator of Arabidopsis Cd tolerance

  6. Splicing factor SR34b mutation reduces cadmium tolerance in Arabidopsis by regulating iron-regulated transporter 1 gene

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wentao; Du, Bojing; Liu, Di; Qi, Xiaoting, E-mail: qixiaoting@cnu.edu.cn

    2014-12-12

    Highlights: • Arabidopsis splicing factor SR34b gene is cadmium-inducible. • SR34b T-DNA insertion mutant is sensitive to cadmium due to high cadmium uptake. • SR34b is a regulator of cadmium transporter IRT1 at the posttranscription level. • These results highlight the roles of splicing factors in cadmium tolerance of plant. - Abstract: Serine/arginine-rich (SR) proteins are important splicing factors. However, the biological functions of plant SR proteins remain unclear especially in abiotic stresses. Cadmium (Cd) is a non-essential element that negatively affects plant growth and development. In this study, we provided clear evidence for SR gene involved in Cd tolerance in planta. Systemic expression analysis of 17 Arabidopsis SR genes revealed that SR34b is the only SR gene upregulated by Cd, suggesting its potential roles in Arabidopsis Cd tolerance. Consistent with this, a SR34b T-DNA insertion mutant (sr34b) was moderately sensitive to Cd, which had higher Cd{sup 2+} uptake rate and accumulated Cd in greater amounts than wild-type. This was due to the altered expression of iron-regulated transporter 1 (IRT1) gene in sr34b mutant. Under normal growth conditions, IRT1 mRNAs highly accumulated in sr34b mutant, which was a result of increased stability of IRT1 mRNA. Under Cd stress, however, sr34b mutant plants had a splicing defect in IRT1 gene, thus reducing the IRT1 mRNA accumulation. Despite of this, sr34b mutant plants still constitutively expressed IRT1 proteins under Cd stress, thereby resulting in Cd stress-sensitive phenotype. We therefore propose the essential roles of SR34b in posttranscriptional regulation of IRT1 expression and identify it as a regulator of Arabidopsis Cd tolerance.

  7. Temperature regulates splicing efficiency of the cold-inducible RNA-binding protein gene Cirbp

    Science.gov (United States)

    Gotic, Ivana; Omidi, Saeed; Fleury-Olela, Fabienne; Molina, Nacho; Naef, Felix; Schibler, Ueli

    2016-01-01

    In mammals, body temperature fluctuates diurnally around a mean value of 36°C–37°C. Despite the small differences between minimal and maximal values, body temperature rhythms can drive robust cycles in gene expression in cultured cells and, likely, animals. Here we studied the mechanisms responsible for the temperature-dependent expression of cold-inducible RNA-binding protein (CIRBP). In NIH3T3 fibroblasts exposed to simulated mouse body temperature cycles, Cirbp mRNA oscillates about threefold in abundance, as it does in mouse livers. This daily mRNA accumulation cycle is directly controlled by temperature oscillations and does not depend on the cells’ circadian clocks. Here we show that the temperature-dependent accumulation of Cirbp mRNA is controlled primarily by the regulation of splicing efficiency, defined as the fraction of Cirbp pre-mRNA processed into mature mRNA. As revealed by genome-wide “approach to steady-state” kinetics, this post-transcriptional mechanism is widespread in the temperature-dependent control of gene expression. PMID:27633015

  8. Alternatively spliced CD44 isoforms containing exon v10 promote cellular adhesion through the recognition of chondroitin sulfate-modified CD44

    NARCIS (Netherlands)

    Chiu, R K; Droll, A; Dougherty, S T; Carpenito, C; Cooper, D L; Dougherty, G J

    1999-01-01

    Correlations have been noted between the expression of certain alternatively spliced CD44 isoforms and the metastatic propensity of various histologically distinct tumor cell types. The precise mechanism by which particular CD44 isoforms contribute to the metastatic process is, however, unclear. In

  9. Thermopriming Triggers Splicing Memory in Arabidopsis

    KAUST Repository

    Ling, Yu

    2018-02-20

    Abiotic and biotic stresses limit crop productivity. Exposure to a non-lethal stress, referred to as priming, can allow plants to survive subsequent and otherwise lethal conditions; the priming effect persists even after a prolonged stress-free period. However, the molecular mechanisms underlying priming are not fully understood. Here, we investigated the molecular basis of heat shock memory and the role of priming in Arabidopsisthaliana. Comprehensive analysis of transcriptome-wide changes in gene expression and alternative splicing in primed and non-primed plants revealed that alternative splicing functions as a novel component of heat shock memory. We show that priming of plants with a non-lethal heat stress results in de-repression of splicing after a second exposure to heat stress. By contrast, non-primed plants showed significant repression of splicing. These observations link ‘splicing memory’ to the ability of plants to survive subsequent and otherwise lethal heat stress. This newly discovered priming-induced splicing memory may represent a general feature of heat stress responses in plants and other organisms as many of the key components of heat shock responses are conserved among eukaryotes. Furthermore, this finding could facilitate the development of novel approaches to improve plant survival under extreme heat stress.

  10. Generation of iPSC line from desmin-related cardiomyopathy patient carrying splice site mutation of DES gene

    Directory of Open Access Journals (Sweden)

    Aleksandr Khudiakov

    2017-10-01

    Full Text Available Human iPSC line was generated from patient-specific adipose tissue-derived mesenchymal multipotent stromal cells carrying desmin (DES gene heterozygous splice site mutation using non-integrative reprogramming method. Reprogramming factors OCT4, KLF4, SOX2, CMYC were delivered using Sendai viruses. iPSCs were characterized by sequencing, karyotype analysis, STR analysis, immunocytochemistry, RT-PCR and teratoma formation.

  11. A statistical method for the detection of alternative splicing using RNA-seq.

    Directory of Open Access Journals (Sweden)

    Liguo Wang

    2010-01-01

    Full Text Available Deep sequencing of transcriptome (RNA-seq provides unprecedented opportunity to interrogate plausible mRNA splicing patterns by mapping RNA-seq reads to exon junctions (thereafter junction reads. In most previous studies, exon junctions were detected by using the quantitative information of junction reads. The quantitative criterion (e.g. minimum of two junction reads, although is straightforward and widely used, usually results in high false positive and false negative rates, owning to the complexity of transcriptome. Here, we introduced a new metric, namely Minimal Match on Either Side of exon junction (MMES, to measure the quality of each junction read, and subsequently implemented an empirical statistical model to detect exon junctions. When applied to a large dataset (>200M reads consisting of mouse brain, liver and muscle mRNA sequences, and using independent transcripts databases as positive control, our method was proved to be considerably more accurate than previous ones, especially for detecting junctions originated from low-abundance transcripts. Our results were also confirmed by real time RT-PCR assay. The MMES metric can be used either in this empirical statistical model or in other more sophisticated classifiers, such as logistic regression.

  12. Interplay between DMD point mutations and splicing signals in Dystrophinopathy phenotypes.

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    Jonàs Juan-Mateu

    Full Text Available DMD nonsense and frameshift mutations lead to severe Duchenne muscular dystrophy while in-frame mutations lead to milder Becker muscular dystrophy. Exceptions are found in 10% of cases and the production of alternatively spliced transcripts is considered a key modifier of disease severity. Several exonic mutations have been shown to induce exon-skipping, while splice site mutations result in exon-skipping or activation of cryptic splice sites. However, factors determining the splicing pathway are still unclear. Point mutations provide valuable information regarding the regulation of pre-mRNA splicing and elements defining exon identity in the DMD gene. Here we provide a comprehensive analysis of 98 point mutations related to clinical phenotype and their effect on muscle mRNA and dystrophin expression. Aberrant splicing was found in 27 mutations due to alteration of splice sites or splicing regulatory elements. Bioinformatics analysis was performed to test the ability of the available algorithms to predict consequences on mRNA and to investigate the major factors that determine the splicing pathway in mutations affecting splicing signals. Our findings suggest that the splicing pathway is highly dependent on the interplay between splice site strength and density of regulatory elements.

  13. Splicing regulatory factors, ageing and age-related disease.

    Science.gov (United States)

    Latorre, Eva; Harries, Lorna W

    2017-07-01

    Alternative splicing is a co-transcriptional process, which allows for the production of multiple transcripts from a single gene and is emerging as an important control point for gene expression. Alternatively expressed isoforms often have antagonistic function and differential temporal or spatial expression patterns, yielding enormous plasticity and adaptability to cells and increasing their ability to respond to environmental challenge. The regulation of alternative splicing is critical for numerous cellular functions in both pathological and physiological conditions, and deregulated alternative splicing is a key feature of common chronic diseases. Isoform choice is controlled by a battery of splicing regulatory proteins, which include the serine arginine rich (SRSF) proteins and the heterogeneous ribonucleoprotein (hnRNP) classes of genes. These important splicing regulators have been implicated in age-related disease, and in the ageing process itself. This review will outline the important contribution of splicing regulator proteins to ageing and age-related disease. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Systematic Analysis of Splice-Site-Creating Mutations in Cancer

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    Reyka G. Jayasinghe

    2018-04-01

    Full Text Available Summary: For the past decade, cancer genomic studies have focused on mutations leading to splice-site disruption, overlooking those having splice-creating potential. Here, we applied a bioinformatic tool, MiSplice, for the large-scale discovery of splice-site-creating mutations (SCMs across 8,656 TCGA tumors. We report 1,964 originally mis-annotated mutations having clear evidence of creating alternative splice junctions. TP53 and GATA3 have 26 and 18 SCMs, respectively, and ATRX has 5 from lower-grade gliomas. Mutations in 11 genes, including PARP1, BRCA1, and BAP1, were experimentally validated for splice-site-creating function. Notably, we found that neoantigens induced by SCMs are likely several folds more immunogenic compared to missense mutations, exemplified by the recurrent GATA3 SCM. Further, high expression of PD-1 and PD-L1 was observed in tumors with SCMs, suggesting candidates for immune blockade therapy. Our work highlights the importance of integrating DNA and RNA data for understanding the functional and the clinical implications of mutations in human diseases. : Jayasinghe et al. identify nearly 2,000 splice-site-creating mutations (SCMs from over 8,000 tumor samples across 33 cancer types. They provide a more accurate interpretation of previously mis-annotated mutations, highlighting the importance of integrating data types to understand the functional and the clinical implications of splicing mutations in human disease. Keywords: splicing, RNA, mutations of clinical relevance

  15. Alternative splicing of TIA-1 in human colon cancer regulates VEGF isoform expression, angiogenesis, tumour growth and bevacizumab resistance.

    Science.gov (United States)

    Hamdollah Zadeh, Maryam A; Amin, Elianna M; Hoareau-Aveilla, Coralie; Domingo, Enric; Symonds, Kirsty E; Ye, Xi; Heesom, Katherine J; Salmon, Andrew; D'Silva, Olivia; Betteridge, Kai B; Williams, Ann C; Kerr, David J; Salmon, Andrew H J; Oltean, Sebastian; Midgley, Rachel S; Ladomery, Michael R; Harper, Steven J; Varey, Alexander H R; Bates, David O

    2015-01-01

    The angiogenic capability of colorectal carcinomas (CRC), and their susceptibility to anti-angiogenic therapy, is determined by expression of vascular endothelial growth factor (VEGF) isoforms. The intracellular protein T-cell Intracellular Antigen (TIA-1) alters post-transcriptional RNA processing and binds VEGF-A mRNA. We therefore tested the hypothesis that TIA-1 could regulate VEGF-A isoform expression in colorectal cancers. TIA-1 and VEGF-A isoform expression was measured in colorectal cancers and cell lines. We discovered that an endogenous splice variant of TIA-1 encoding a truncated protein, short TIA-1 (sTIA-1) was expressed in CRC tissues and invasive K-Ras mutant colon cancer cells and tissues but not in adenoma cell lines. sTIA-1 was more highly expressed in CRC than in normal tissues and increased with tumour stage. Knockdown of sTIA-1 or over-expression of full length TIA-1 (flTIA-1) induced expression of the anti-angiogenic VEGF isoform VEGF-A165b. Whereas flTIA-1 selectively bound VEGF-A165 mRNA and increased translation of VEGF-A165b, sTIA-1 prevented this binding. In nude mice, xenografted colon cancer cells over-expressing flTIA-1 formed smaller, less vascular tumours than those expressing sTIA-1, but flTIA-1 expression inhibited the effect of anti-VEGF antibodies. These results indicate that alternative splicing of an RNA binding protein can regulate isoform specific expression of VEGF providing an added layer of complexity to the angiogenic profile of colorectal cancer and their resistance to anti-angiogenic therapy. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  16. Splicing analysis for exonic and intronic mismatch repair gene variants associated with Lynch syndrome confirms high concordance between minigene assays and patient RNA analyses

    Science.gov (United States)

    van der Klift, Heleen M; Jansen, Anne M L; van der Steenstraten, Niki; Bik, Elsa C; Tops, Carli M J; Devilee, Peter; Wijnen, Juul T

    2015-01-01

    A subset of DNA variants causes genetic disease through aberrant splicing. Experimental splicing assays, either RT-PCR analyses of patient RNA or functional splicing reporter minigene assays, are required to evaluate the molecular nature of the splice defect. Here, we present minigene assays performed for 17 variants in the consensus splice site regions, 14 exonic variants outside these regions, and two deep intronic variants, all in the DNA mismatch-repair (MMR) genes MLH1, MSH2, MSH6, and PMS2, associated with Lynch syndrome. We also included two deep intronic variants in APC and PKD2. For one variant (MLH1 c.122A>G), our minigene assay and patient RNA analysis could not confirm the previously reported aberrant splicing. The aim of our study was to further investigate the concordance between minigene splicing assays and patient RNA analyses. For 30 variants results from patient RNA analyses were available, either performed by our laboratory or presented in literature. Some variants were deliberately included in this study because they resulted in multiple aberrant transcripts in patient RNA analysis, or caused a splice effect other than the prevalent exon skip. While both methods were completely concordant in the assessment of splice effects, four variants exhibited major differences in aberrant splice patterns. Based on the present and earlier studies, together showing an almost 100% concordance of minigene assays with patient RNA analyses, we discuss the weight given to minigene splicing assays in the current criteria proposed by InSiGHT for clinical classification of MMR variants. PMID:26247049

  17. Alteration of the SETBP1 gene and splicing pathway genes SF3B1, U2AF1, and SRSF2 in childhood acute myeloid leukemia.

    Science.gov (United States)

    Choi, Hyun-Woo; Kim, Hye-Ran; Baek, Hee-Jo; Kook, Hoon; Cho, Duck; Shin, Jong-Hee; Suh, Soon-Pal; Ryang, Dong-Wook; Shin, Myung-Geun

    2015-01-01

    Recurrent somatic SET-binding protein 1 (SETBP1) and splicing pathway gene mutations have recently been found in atypical chronic myeloid leukemia and other hematologic malignancies. These mutations have been comprehensively analyzed in adult AML, but not in childhood AML. We investigated possible alteration of the SETBP1, splicing factor 3B subunit 1 (SF3B1), U2 small nuclear RNA auxiliary factor 1 (U2AF1), and serine/arginine-rich splicing factor 2 (SRSF2) genes in childhood AML. Cytogenetic and molecular analyses were performed to reveal chromosomal and genetic alterations. Sequence alterations in the SETBP1, SF3B1, U2AF1, and SRSF2 genes were examined by using direct sequencing in a cohort of 53 childhood AML patients. Childhood AML patients did not harbor any recurrent SETBP1 gene mutations, although our study did identify a synonymous mutation in one patient. None of the previously reported aberrations in the mutational hotspot of SF3B1, U2AF1, and SRSF2 were identified in any of the 53 patients. Alterations of the SETBP1 gene or SF3B1, U2AF1, and SRSF2 genes are not common genetic events in childhood AML, implying that the mutations are unlikely to exert a driver effect in myeloid leukemogenesis during childhood.

  18. Identification of a novel function of CX-4945 as a splicing regulator.

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    Hyeongki Kim

    Full Text Available Alternative splicing is a nearly ubiquitous versatile process that controls gene expression and creates numerous protein isoforms with different functions from a single gene. The significance of alternative splicing has been confirmed by the increasing number of human diseases that are caused by misregulation of splicing events. Very few compounds, however, have been reported to act as inhibitors of alternative splicing, and their potential clinical use needs to be evaluated. Here, we report that CX-4945, a previously well-characterized inhibitor of casein kinase 2 (CK2 and a molecule currently in clinical trials (Phase II for cancer treatment, regulates splicing in mammalian cells in a CK2-independent manner. Transcriptome-wide analysis using exon array also showed a widespread alteration in alternative splicing of numerous genes. We found that CX-4945 potently inhibits the Cdc2-like kinases (Clks in vitro and in turn, leads to suppression of the phosphorylation of serine/arginine-rich (SR proteins in mammalian cells. Surprisingly, the overall efficacy of CX-4945 on Clks (IC50 = 3-90 nM was stronger than that of TG-003, the strongest inhibitor reported to date. Of the Clks, Clk2 was most strongly inhibited by CX-4945 in an ATP-competitive manner. Our research revealed an unexpected activity of the drug candidate CX-4945 as a potent splicing modulator and also suggested a potential application for therapy of diseases caused by abnormal splicing.

  19. Regulatory mechanisms for 3'-end alternative splicing and polyadenylation of the Glial Fibrillary Acidic Protein, GFAP, transcript

    DEFF Research Database (Denmark)

    Blechingberg, Jenny; Lykke-Andersen, Søren; Jensen, Torben Heick

    2007-01-01

    (PTB) protein enhanced both exon 7a polyadenylation and exon 7a splicing. Finally, increasing transcription by the VP16 trans-activator did not affect the frequency of use of the exon 7a polyadenylation signal whereas the exon 7a splicing frequency was decreased. Our data suggest a model...

  20. An alternatively spliced heat shock transcription factor, OsHSFA2dI, functions in the heat stress-induced unfolded protein response in rice.

    Science.gov (United States)

    Cheng, Q; Zhou, Y; Liu, Z; Zhang, L; Song, G; Guo, Z; Wang, W; Qu, X; Zhu, Y; Yang, D

    2015-03-01

    As sessile organisms, plants have evolved a wide range of defence pathways to cope with environmental stress such as heat shock. However, the molecular mechanism of these defence pathways remains unclear in rice. In this study, we found that OsHSFA2d, a heat shock transcriptional factor, encodes two main splice variant proteins, OsHSFA2dI and OsHSFA2dII in rice. Under normal conditions, OsHSFA2dII is the dominant but transcriptionally inactive spliced form. However, when the plant suffers heat stress, OsHSFA2d is alternatively spliced into a transcriptionally active form, OsHSFA2dI, which participates in the heat stress response (HSR). Further study found that this alternative splicing was induced by heat shock rather than photoperiod. We found that OsHSFA2dI is localised to the nucleus, whereas OsHSFA2dII is localised to the nucleus and cytoplasm. Moreover, expression of the unfolded protein response (UNFOLDED PROTEIN RESPONSE) sensors, OsIRE1, OsbZIP39/OsbZIP60 and the UNFOLDED PROTEIN RESPONSE marker OsBiP1, was up-regulated. Interestingly, OsbZIP50 was also alternatively spliced under heat stress, indicating that UNFOLDED PROTEIN RESPONSE signalling pathways were activated by heat stress to re-establish cellular protein homeostasis. We further demonstrated that OsHSFA2dI participated in the unfolded protein response by regulating expression of OsBiP1. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  1. Multiple novel alternative splicing forms of FBXW7α have a translational modulatory function and show specific alteration in human cancer.

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    Yueyong Liu

    Full Text Available FBXW7 acts as a tumor suppressor through ubiquitination and degradation of multiple oncoproteins. Loss of FBXW7 expression, which could be partially attributed by the genomic deletion or mutation of FBXW7 locus, is frequently observed in various human cancers. However, the mechanisms regulating FBXW7 expression still remain poorly understood. Here we examined the 5' region of FBXW7 gene to investigate the regulation of FBXW7 expression. We identified seven alternative splicing (AS 5'-UTR forms of FBXW7α that are composed of multiple novel non-coding exons. A significant difference in translational efficiency among these 5'-UTRs variants was observed by in vivo Luciferase reporter assay and Western blot. Furthermore, we found that the mRNA level of the AS form with high translational efficiency was specifically reduced in more than 80% of breast cancer cell lines and in more than 50% of human primary cancers from various tissues. In addition, we also identified mutations of FBXW7 in prostate cancers (5.6%, kidney cancers (16.7%, and bladder cancers (18.8%. Our results suggest that in addition to mutation, differential expression of FBXW7α AS forms with different translational properties may serve as a novel mechanism for inactivation of FBXW7 in human cancer.

  2. The Mitochondrial Genome of the Prasinophyte Prasinoderma coloniale Reveals Two Trans-Spliced Group I Introns in the Large Subunit rRNA Gene

    Science.gov (United States)

    Pombert, Jean-François; Otis, Christian; Turmel, Monique; Lemieux, Claude

    2013-01-01

    Organelle genes are often interrupted by group I and or group II introns. Splicing of these mobile genetic occurs at the RNA level via serial transesterification steps catalyzed by the introns'own tertiary structures and, sometimes, with the help of external factors. These catalytic ribozymes can be found in cis or trans configuration, and although trans-arrayed group II introns have been known for decades, trans-spliced group I introns have been reported only recently. In the course of sequencing the complete mitochondrial genome of the prasinophyte picoplanktonic green alga Prasinoderma coloniale CCMP 1220 (Prasinococcales, clade VI), we uncovered two additional cases of trans-spliced group I introns. Here, we describe these introns and compare the 54,546 bp-long mitochondrial genome of Prasinoderma with those of four other prasinophytes (clades II, III and V). This comparison underscores the highly variable mitochondrial genome architecture in these ancient chlorophyte lineages. Both Prasinoderma trans-spliced introns reside within the large subunit rRNA gene (rnl) at positions where cis-spliced relatives, often containing homing endonuclease genes, have been found in other organelles. In contrast, all previously reported trans-spliced group I introns occur in different mitochondrial genes (rns or coxI). Each Prasinoderma intron is fragmented into two pieces, forming at the RNA level a secondary structure that resembles those of its cis-spliced counterparts. As observed for other trans-spliced group I introns, the breakpoint of the first intron maps to the variable loop L8, whereas that of the second is uniquely located downstream of P9.1. The breakpoint In each Prasinoderma intron corresponds to the same region where the open reading frame (ORF) occurs when present in cis-spliced orthologs. This correlation between the intron breakpoint and the ORF location in cis-spliced orthologs also holds for other trans-spliced introns; we discuss the possible implications

  3. The mitochondrial genome of the prasinophyte Prasinoderma coloniale reveals two trans-spliced group I introns in the large subunit rRNA gene.

    Directory of Open Access Journals (Sweden)

    Jean-François Pombert

    Full Text Available Organelle genes are often interrupted by group I and or group II introns. Splicing of these mobile genetic occurs at the RNA level via serial transesterification steps catalyzed by the introns'own tertiary structures and, sometimes, with the help of external factors. These catalytic ribozymes can be found in cis or trans configuration, and although trans-arrayed group II introns have been known for decades, trans-spliced group I introns have been reported only recently. In the course of sequencing the complete mitochondrial genome of the prasinophyte picoplanktonic green alga Prasinoderma coloniale CCMP 1220 (Prasinococcales, clade VI, we uncovered two additional cases of trans-spliced group I introns. Here, we describe these introns and compare the 54,546 bp-long mitochondrial genome of Prasinoderma with those of four other prasinophytes (clades II, III and V. This comparison underscores the highly variable mitochondrial genome architecture in these ancient chlorophyte lineages. Both Prasinoderma trans-spliced introns reside within the large subunit rRNA gene (rnl at positions where cis-spliced relatives, often containing homing endonuclease genes, have been found in other organelles. In contrast, all previously reported trans-spliced group I introns occur in different mitochondrial genes (rns or coxI. Each Prasinoderma intron is fragmented into two pieces, forming at the RNA level a secondary structure that resembles those of its cis-spliced counterparts. As observed for other trans-spliced group I introns, the breakpoint of the first intron maps to the variable loop L8, whereas that of the second is uniquely located downstream of P9.1. The breakpoint In each Prasinoderma intron corresponds to the same region where the open reading frame (ORF occurs when present in cis-spliced orthologs. This correlation between the intron breakpoint and the ORF location in cis-spliced orthologs also holds for other trans-spliced introns; we discuss the

  4. Autosomal dominant pseudohypoaldosteronism type 1 with a novel splice site mutation in MR gene

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    Kaito Hiroshi

    2009-11-01

    Full Text Available Abstract Background Autosomal dominant pseudohypoaldosteronism type 1 (PHA1 is a rare inherited condition that is characterized by renal resistance to aldosterone as well as salt wasting, hyperkalemia, and metabolic acidosis. Renal PHA1 is caused by mutations of the human mineralcorticoid receptor gene (MR, but it is a matter of debate whether MR mutations cause mineralcorticoid resistance via haploinsufficiency or dominant negative mechanism. It was previously reported that in a case with nonsense mutation the mutant mRNA was absent in lymphocytes because of nonsense mediated mRNA decay (NMD and therefore postulated that haploinsufficiency alone can give rise to the PHA1 phenotype in patients with truncated mutations. Methods and Results We conducted genomic DNA analysis and mRNA analysis for familial PHA1 patients extracted from lymphocytes and urinary sediments and could detect one novel splice site mutation which leads to exon skipping and frame shift result in premature termination at the transcript level. The mRNA analysis showed evidence of wild type and exon-skipped RT-PCR products. Conclusion mRNA analysis have been rarely conducted for PHA1 because kidney tissues are unavailable for this disease. However, we conducted RT-PCR analysis using mRNA extracted from urinary sediments. We could demonstrate that NMD does not fully function in kidney cells and that haploinsufficiency due to NMD with premature termination is not sufficient to give rise to the PHA1 phenotype at least in this mutation of our patient. Additional studies including mRNA analysis will be needed to identify the exact mechanism of the phenotype of PHA.

  5. The Associations between RNA Splicing Complex Gene SF3A1 Polymorphisms and Colorectal Cancer Risk in a Chinese Population.

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    Xiaohua Chen

    Full Text Available Aberrant alternative splicing included alterations in components of the mRNA splicing machinery often occurred in colon cancer. However, the role of SF3A1, one key component of the mRNA splicing machinery, on colorectal cancer (CRC risk was still not elucidated.We performed a hospital-based case-control study containing 801 CRC patients and 817 cancer-free controls to examine the association between SF3A1 polymorphisms and CRC risk in a Chinese population. Four candidate SNPs (rs10376, rs5753073, rs2839998 and rs2074733 were selected based on bioinformatics analysis and previous findings. The results showed no significant associations between these SNPs and CRC risk (P > 0.05. Besides, the stratified analysis based on the smoking and alcohol use status obtained no statistically significant results.Our study was the first one to investigate the association between SF3A1 polymorphisms and CRC risk. The results suggested these four SNPs in SF3A1 were not associated with CRC risk in a Chinese population, however, further more studies are needed to confirm our findings.

  6. Major Roles for Pyrimidine Dimers, Nucleotide Excision Repair, and ATR in the Alternative Splicing Response to UV Irradiation

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    Manuel J. Muñoz

    2017-03-01

    Full Text Available We have previously found that UV irradiation promotes RNA polymerase II (RNAPII hyperphosphorylation and subsequent changes in alternative splicing (AS. We show now that UV-induced DNA damage is not only necessary but sufficient to trigger the AS response and that photolyase-mediated removal of the most abundant class of pyrimidine dimers (PDs abrogates the global response to UV. We demonstrate that, in keratinocytes, RNAPII is the target, but not a sensor, of the signaling cascade initiated by PDs. The UV effect is enhanced by inhibition of gap-filling DNA synthesis, the last step in the nucleotide excision repair pathway (NER, and reduced by the absence of XPE, the main NER sensor of PDs. The mechanism involves activation of the protein kinase ATR that mediates the UV-induced RNAPII hyperphosphorylation. Our results define the sequence UV-PDs-NER-ATR-RNAPII-AS as a pathway linking DNA damage repair to the control of both RNAPII phosphorylation and AS regulation.

  7. A Splice Defect in the EDA Gene in Dogs with an X-Linked Hypohidrotic Ectodermal Dysplasia (XLHED) Phenotype.

    Science.gov (United States)

    Waluk, Dominik P; Zur, Gila; Kaufmann, Ronnie; Welle, Monika M; Jagannathan, Vidhya; Drögemüller, Cord; Müller, Eliane J; Leeb, Tosso; Galichet, Arnaud

    2016-09-08

    X-linked hypohidrotic ectodermal dysplasia (XLHED) caused by variants in the EDA gene represents the most common ectodermal dysplasia in humans. We investigated three male mixed-breed dogs with an ectodermal dysplasia phenotype characterized by marked hypotrichosis and multifocal complete alopecia, almost complete absence of sweat and sebaceous glands, and altered dentition with missing and abnormally shaped teeth. Analysis of SNP chip genotypes and whole genome sequence data from the three affected dogs revealed that the affected dogs shared the same haplotype on a large segment of the X-chromosome, including the EDA gene. Unexpectedly, the whole genome sequence data did not reveal any nonsynonymous EDA variant in the affected dogs. We therefore performed an RNA-seq experiment on skin biopsies to search for changes in the transcriptome. This analysis revealed that the EDA transcript in the affected dogs lacked 103 nucleotides encoded by exon 2. We speculate that this exon skipping is caused by a genetic variant located in one of the large introns flanking this exon, which was missed by whole genome sequencing with the illumina short read technology. The altered EDA transcript splicing most likely causes the observed ectodermal dysplasia in the affected dogs. These dogs thus offer an excellent opportunity to gain insights into the complex splicing processes required for expression of the EDA gene, and other genes with large introns. Copyright © 2016 Waluk et al.

  8. Human intronless genes: Functional groups, associated diseases, evolution, and mRNA processing in absence of splicing

    International Nuclear Information System (INIS)

    Grzybowska, Ewa A.

    2012-01-01

    Highlights: ► Functional characteristics of intronless genes (IGs). ► Diseases associated with IGs. ► Origin and evolution of IGs. ► mRNA processing without splicing. -- Abstract: Intronless genes (IGs) constitute approximately 3% of the human genome. Human IGs are essentially different in evolution and functionality from the IGs of unicellular eukaryotes, which represent the majority in their genomes. Functional analysis of IGs has revealed a massive over-representation of signal transduction genes and genes encoding regulatory proteins important for growth, proliferation, and development. IGs also often display tissue-specific expression, usually in the nervous system and testis. These characteristics translate into IG-associated diseases, mainly neuropathies, developmental disorders, and cancer. IGs represent recent additions to the genome, created mostly by retroposition of processed mRNAs with retained functionality. Processing, nuclear export, and translation of these mRNAs should be hampered dramatically by the lack of splice factors, which normally tightly cover mature transcripts and govern their fate. However, natural IGs manage to maintain satisfactory expression levels. Different mechanisms by which IGs solve the problem of mRNA processing and nuclear export are discussed here, along with their possible impact on reporter studies.

  9. Characterisation of the legume SERK-NIK gene superfamily including splice variants: Implications for development and defence

    Directory of Open Access Journals (Sweden)

    Rose Ray J

    2011-03-01

    Full Text Available Abstract Background SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE (SERK genes are part of the regulation of diverse signalling events in plants. Current evidence shows SERK proteins function both in developmental and defence signalling pathways, which occur in response to both peptide and steroid ligands. SERKs are generally present as small gene families in plants, with five SERK genes in Arabidopsis. Knowledge gained primarily through work on Arabidopsis SERKs indicates that these proteins probably interact with a wide range of other receptor kinases and form a fundamental part of many essential signalling pathways. The SERK1 gene of the model legume, Medicago truncatula functions in somatic and zygotic embryogenesis, and during many phases of plant development, including nodule and lateral root formation. However, other SERK genes in M. truncatula and other legumes are largely unidentified and their functions unknown. Results To aid the understanding of signalling pathways in M. truncatula, we have identified and annotated the SERK genes in this species. Using degenerate PCR and database mining, eight more SERK-like genes have been identified and these have been shown to be expressed. The amplification and sequencing of several different PCR products from one of these genes is consistent with the presence of splice variants. Four of the eight additional genes identified are upregulated in cultured leaf tissue grown on embryogenic medium. The sequence information obtained from M. truncatula was used to identify SERK family genes in the recently sequenced soybean (Glycine max genome. Conclusions A total of nine SERK or SERK-like genes have been identified in M. truncatula and potentially 17 in soybean. Five M. truncatula SERK genes arose from duplication events not evident in soybean and Lotus. The presence of splice variants has not been previously reported in a SERK gene. Upregulation of four newly identified SERK genes (in addition to the

  10. Global analysis of aberrant pre-mRNA splicing in glioblastoma using exon expression arrays

    Directory of Open Access Journals (Sweden)

    Nixon Tamara J

    2008-05-01

    Full Text Available Abstract Background Tumor-predominant splice isoforms were identified during comparative in silico sequence analysis of EST clones, suggesting that global aberrant alternative pre-mRNA splicing may be an epigenetic phenomenon in cancer. We used an exon expression array to perform an objective, genome-wide survey of glioma-specific splicing in 24 GBM and 12 nontumor brain samples. Validation studies were performed using RT-PCR on glioma cell lines, patient tumor and nontumor brain samples. Results In total, we confirmed 14 genes with glioma-specific splicing; seven were novel events identified by the exon expression array (A2BP1, BCAS1, CACNA1G, CLTA, KCNC2, SNCB, and TPD52L2. Our data indicate that large changes (> 5-fold in alternative splicing are infrequent in gliomagenesis ( Conclusion While we observed some tumor-specific alternative splicing, the number of genes showing exclusive tumor-specific isoforms was on the order of tens, rather than the hundreds suggested previously by in silico mining. Given the important role of alternative splicing in neural differentiation, there may be selective pressure to maintain a majority of splicing events in order to retain glial-like characteristics of the tumor cells.

  11. Alternatively Spliced Methionine Synthase in SH-SY5Y Neuroblastoma Cells: Cobalamin and GSH Dependence and Inhibitory Effects of Neurotoxic Metals and Thimerosal

    Directory of Open Access Journals (Sweden)

    Mostafa Waly

    2016-01-01

    Full Text Available The folate and cobalamin (Cbl- dependent enzyme methionine synthase (MS is highly sensitive to oxidation and its activity affects all methylation reactions. Recent studies have revealed alternative splicing of MS mRNA in human brain and patient-derived fibroblasts. Here we show that MS mRNA in SH-SY5Y human neuroblastoma cells is alternatively spliced, resulting in three primary protein species, thus providing a useful model to examine cofactor dependence of these variant enzymes. MS activity was dependent upon methylcobalamin (MeCbl or the combination of hydroxocobalamin (OHCbl and S-adenosylmethionine (SAM. OHCbl-based activity was eliminated by depletion of the antioxidant glutathione (GSH but could be rescued by provision of either glutathionylcobalamin (GSCbl or MeCbl. Pretreatment of cells with lead, arsenic, aluminum, mercury, or the ethylmercury-containing preservative thimerosal lowered GSH levels and inhibited MS activity in association with decreased uptake of cysteine, which is rate-limiting for GSH synthesis. Thimerosal treatment decreased cellular levels of GSCbl and MeCbl. These findings indicate that the alternatively spliced form of MS expressed in SH-SY5Y human neuronal cells is sensitive to inhibition by thimerosal and neurotoxic metals, and lower GSH levels contribute to their inhibitory action.

  12. Molecular cloning, genomic organization, chromosome mapping, tissues expression pattern and identification of a novel splicing variant of porcine CIDEb gene

    International Nuclear Information System (INIS)

    Li, YanHua; Li, AiHua; Yang, Z.Q.

    2016-01-01

    Cell death-inducing DNA fragmentation factor-α-like effector b (CIDEb) is a member of the CIDE family of apoptosis-inducing factors, CIDEa and CIDEc have been reported to be Lipid droplets (LDs)-associated proteins that promote atypical LD fusion in adipocytes, and responsible for liver steatosis under fasting and obese conditions, whereas CIDEb promotes lipid storage under normal diet conditions [1], and promotes the formation of triacylglyceride-enriched VLDL particles in hepatocytes [2]. Here, we report the gene cloning, chromosome mapping, tissue distribution, genetic expression analysis, and identification of a novel splicing variant of the porcine CIDEb gene. Sequence analysis shows that the open reading frame of the normal porcine CIDEb isoform covers 660bp and encodes a 219-amino acid polypeptide, whereas its alternative splicing variant encodes a 142-amino acid polypeptide truncated at the fourth exon and comprised of the CIDE-N domain and part of the CIDE-C domain. The deduced amino acid sequence of normal porcine CIDEb shows an 85.8% similarity to the human protein and 80.0% to the mouse protein. The CIDEb genomic sequence spans approximately 6KB comprised of five exons and four introns. Radiation hybrid mapping demonstrated that porcine CIDEb is located at chromosome 7q21 and at a distance of 57cR from the most significantly linked marker, S0334, regions that are syntenic with the corresponding region in the human genome. Tissue expression analysis indicated that normal CIDEb mRNA is ubiquitously expressed in many porcine tissues. It was highly expressed in white adipose tissue and was observed at relatively high levels in the liver, lung, small intestine, lymphatic tissue and brain. The normal version of CIDEb was the predominant form in all tested tissues, whereas the splicing variant was expressed at low levels in all examined tissues except the lymphatic tissue. Furthermore, genetic expression analysis indicated that CIDEb mRNA levels were

  13. Molecular cloning, genomic organization, chromosome mapping, tissues expression pattern and identification of a novel splicing variant of porcine CIDEb gene

    Energy Technology Data Exchange (ETDEWEB)

    Li, YanHua, E-mail: liyanhua.1982@aliyun.com [Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Translational Medical Research in Cognitive Development and Learning and Memory Disorders, China International Science and Technology Cooperation base of Child development and Critical Disorders, Children’s Hospital of Chongqing Medical University, Chongqing 400014 (China); Li, AiHua [Chongqing Cancer Institute & Hospital & Cancer Center, Chongqing 404100 (China); Yang, Z.Q. [Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China)

    2016-09-09

    Cell death-inducing DNA fragmentation factor-α-like effector b (CIDEb) is a member of the CIDE family of apoptosis-inducing factors, CIDEa and CIDEc have been reported to be Lipid droplets (LDs)-associated proteins that promote atypical LD fusion in adipocytes, and responsible for liver steatosis under fasting and obese conditions, whereas CIDEb promotes lipid storage under normal diet conditions [1], and promotes the formation of triacylglyceride-enriched VLDL particles in hepatocytes [2]. Here, we report the gene cloning, chromosome mapping, tissue distribution, genetic expression analysis, and identification of a novel splicing variant of the porcine CIDEb gene. Sequence analysis shows that the open reading frame of the normal porcine CIDEb isoform covers 660bp and encodes a 219-amino acid polypeptide, whereas its alternative splicing variant encodes a 142-amino acid polypeptide truncated at the fourth exon and comprised of the CIDE-N domain and part of the CIDE-C domain. The deduced amino acid sequence of normal porcine CIDEb shows an 85.8% similarity to the human protein and 80.0% to the mouse protein. The CIDEb genomic sequence spans approximately 6KB comprised of five exons and four introns. Radiation hybrid mapping demonstrated that porcine CIDEb is located at chromosome 7q21 and at a distance of 57cR from the most significantly linked marker, S0334, regions that are syntenic with the corresponding region in the human genome. Tissue expression analysis indicated that normal CIDEb mRNA is ubiquitously expressed in many porcine tissues. It was highly expressed in white adipose tissue and was observed at relatively high levels in the liver, lung, small intestine, lymphatic tissue and brain. The normal version of CIDEb was the predominant form in all tested tissues, whereas the splicing variant was expressed at low levels in all examined tissues except the lymphatic tissue. Furthermore, genetic expression analysis indicated that CIDEb mRNA levels were

  14. Correction of a splice-site mutation in the beta-globin gene stimulated by triplex-forming peptide nucleic acids

    DEFF Research Database (Denmark)

    Chin, Joanna Y; Kuan, Jean Y; Lonkar, Pallavi S

    2008-01-01

    Splice-site mutations in the beta-globin gene can lead to aberrant transcripts and decreased functional beta-globin, causing beta-thalassemia. Triplex-forming DNA oligonucleotides (TFOs) and peptide nucleic acids (PNAs) have been shown to stimulate recombination in reporter gene loci in mammalian...... DNA fragments, can promote single base-pair modification at the start of the second intron of the beta-globin gene, the site of a common thalassemia-associated mutation. This single base pair change was detected by the restoration of proper splicing of transcripts produced from a green fluorescent...

  15. Systematic Identification of Genes Required for Expression of Androgen Receptor Splice Variants

    Science.gov (United States)

    2016-08-01

    cells using a packaging system from SBI per the manufacturer’s protocol, as described previously [33]. For infection, exponentially growing cells were...30. Kashima T, Rao N, Manley JL. An intronic element con- tributes to splicing repression in spinal muscular atrophy. Proceedings of the National

  16. Herboxidiene triggers splicing repression and abiotic stress responses in plants

    KAUST Repository

    Alshareef, Sahar

    2017-03-27

    Background Constitutive and alternative splicing of pre-mRNAs from multiexonic genes controls the diversity of the proteome; these precisely regulated processes also fine-tune responses to cues related to growth, development, and stresses. Small-molecule inhibitors that perturb splicing provide invaluable tools for use as chemical probes to uncover the molecular underpinnings of splicing regulation and as potential anticancer compounds. Results Here, we show that herboxidiene (GEX1A) inhibits both constitutive and alternative splicing. Moreover, GEX1A activates genome-wide transcriptional patterns involved in abiotic stress responses in plants. GEX1A treatment -activated ABA-inducible promoters, and led to stomatal closure. Interestingly, GEX1A and pladienolide B (PB) elicited similar cellular changes, including alterations in the patterns of transcription and splicing, suggesting that these compounds might target the same spliceosome complex in plant cells. Conclusions Our study establishes GEX1A as a potent splicing inhibitor in plants that can be used to probe the assembly, dynamics, and molecular functions of the spliceosome and to study the interplay between splicing stress and abiotic stresses, as well as having potential biotechnological applications.

  17. NeuN/Rbfox3 nuclear and cytoplasmic isoforms differentially regulate alternative splicing and nonsense-mediated decay of Rbfox2.

    Directory of Open Access Journals (Sweden)

    B Kate Dredge

    Full Text Available Anti-NeuN (Neuronal Nuclei is a monoclonal antibody used extensively to specifically detect post-mitotic neurons. Anti-NeuN reactivity is predominantly nuclear; by western it detects multiple bands ranging in molecular weight from 45 kDa to >75 kDa. Expression screening putatively identified R3hdm2 as NeuN; however immunoprecipitation and mass spectrometry of the two major NeuN species at 45-50 kDa identified both as the RNA binding protein Rbfox3 (a member of the Fox family of alternative splicing factors, confirming and extending the identification of the 45 kDa band as Rbfox3 by Kim et al. Mapping of the anti-NeuN reactive epitopes in both R3hdm2 and Rbfox3 reveals a common proline- and glutamine-rich domain that lies at the N-terminus of the Rbfox3 protein. Our data suggests that alternative splicing of the Rbfox3 pre-mRNA itself leads to the production of four protein isoforms that migrate in the 45-50 kDa range, and that one of these splicing choices regulates Rbfox3/NeuN sub-cellular steady-state distribution, through the addition or removal of a short C-terminal extension containing the second half of a bipartite hydrophobic proline-tyrosine nuclear localization signal. Rbfox3 regulates alternative splicing of the Rbfox2 pre-mRNA, producing a message encoding a dominant negative form of the Rbfox2 protein. We show here that nuclear Rbfox3 isoforms can also enhance the inclusion of cryptic exons in the Rbfox2 mRNA, resulting in nonsense-mediated decay of the message, thereby contributing to the negative regulation of Rbfox2 by Rbfox3 through a novel mechanism.

  18. Unique features of Myf-5 in turtles: nucleotide deletion, alternative splicing, and unusual expression pattern.

    Science.gov (United States)

    Ohya, Yoshie Kawashima; Usuda, Ryo; Kuraku, Shigehiro; Nagashima, Hiroshi; Kuratani, Shigeru

    2006-01-01

    Turtles characteristically possess a bony shell and show an extensive reduction of the trunk muscles. To gain insight into the evolution of this animal group, we focused on the underlying mechanism of the turtle-specific developmental pattern associated with the somitic mesoderm, which differentiates into both skeleton and muscle. We isolated Myf-5, a member of the myogenic-transcription-factor-encoding gene family expressed in the myotome, from the Chinese soft-shelled turtle Pelodiscus sinensis. We detected a deletion of 12 sequential nucleotides in P. sinensis Myf-5 (PsMyf-5), which appears to be shared by the turtle group. The expression pattern of PsMyf-5 in P. sinensis embryos differed from those of its orthologs in other amniotes, especially in the hypaxial region of the flank. We also identified two isoforms of the PsMyf-5 protein, a normal form similar to those of other vertebrates, and a short form produced by a translational frameshift. The short PsMyf-5 showed weaker myogenic activity in cultured cells than that of the normal protein, although the tissue distribution of the two isoforms overlapped perfectly. We propose that the unusual features of PsMyf-5 may be related to the unique developmental patterns of this animal group, and constitute one of the molecular bases for their evolutionary origin.

  19. Concerted effects of heterogeneous nuclear ribonucleoprotein C1/C2 to control vitamin D-directed gene transcription and RNA splicing in human bone cells.

    Science.gov (United States)

    Zhou, Rui; Park, Juw Won; Chun, Rene F; Lisse, Thomas S; Garcia, Alejandro J; Zavala, Kathryn; Sea, Jessica L; Lu, Zhi-Xiang; Xu, Jianzhong; Adams, John S; Xing, Yi; Hewison, Martin

    2017-01-25

    Traditionally recognized as an RNA splicing regulator, heterogeneous nuclear ribonucleoprotein C1/C2 (hnRNPC1/C2) can also bind to double-stranded DNA and function in trans as a vitamin D response element (VDRE)-binding protein. As such, hnRNPC1/C2 may couple transcription induced by the active form of vitamin D, 1,25-dihydroxyvitamin D (1,25(OH) 2 D) with subsequent RNA splicing. In MG63 osteoblastic cells, increased expression of the 1,25(OH) 2 D target gene CYP24A1 involved immunoprecipitation of hnRNPC1/C2 with CYP24A1 chromatin and RNA. Knockdown of hnRNPC1/C2 suppressed expression of CYP24A1, but also increased expression of an exon 10-skipped CYP24A1 splice variant; in a minigene model the latter was attenuated by a functional VDRE in the CYP24A1 promoter. In genome-wide analyses, knockdown of hnRNPC1/C2 resulted in 3500 differentially expressed genes and 2232 differentially spliced genes, with significant commonality between groups. 1,25(OH) 2 D induced 324 differentially expressed genes, with 187 also observed following hnRNPC1/C2 knockdown, and a further 168 unique to hnRNPC1/C2 knockdown. However, 1,25(OH) 2 D induced only 10 differentially spliced genes, with no overlap with differentially expressed genes. These data indicate that hnRNPC1/C2 binds to both DNA and RNA and influences both gene expression and RNA splicing, but these actions do not appear to be linked through 1,25(OH) 2 D-mediated induction of transcription. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  20. Alternative Splicing and Caspase-Mediated Cleavage Generate Antagonistic Variants of the Stress Oncoprotein LEDGF/p75

    Science.gov (United States)

    Brown-Bryan, Terry A.; Leoh, Lai S.; Ganapathy, Vidya; Pacheco, Fabio J.; Mediavilla-Varela, Melanie; Filippova, Maria; Linkhart, Thomas A.; Gijsbers, Rik; Debyser, Zeger; Casiano, Carlos A.

    2009-01-01

    There is increasing evidence that an augmented state of cellular oxidative stress modulates the expression of stress genes implicated in diseases associated with health disparities such as certain cancers and diabetes. Lens epithelium–derived growth factor p75 (LEDGF/p75), also known as DFS70 autoantigen, is emerging as a survival oncoprotein that promotes resistance to oxidative stress–induced cell death and chemotherapy. We previously showed that LEDGF/p75 is targeted by autoantibodies in prostate cancer patients and is overexpressed in prostate tumors, and that its stress survival activity is abrogated during apoptosis. LEDGF/p75 has a COOH-terminally truncated splice variant, p52, whose role in stress survival and apoptosis has not been thoroughly investigated. We observed unbalanced expression of these proteins in a panel of tumor cell lines, with LEDGF/p75 generally expressed at higher levels. During apoptosis, caspase-3 cleaved p52 to generate a p38 fragment that lacked the NH2-terminal PWWP domain and failed to transactivate the Hsp27 promoter in reporter assays. However, p38 retained chromatin association properties and repressed the transactivation potential of LEDGF/p75. Overexpression of p52 or its variants with truncated PWWP domains in several tumor cell lines induced apoptosis, an activity that was linked to the presence of an intron-derived COOH-terminal sequence. These results implicate the PWWP domain of p52 in transcription function but not in chromatin association and proapoptotic activities. Consistent with their unbalanced expression in tumor cells, LEDGF/p75 and p52 seem to play antagonistic roles in the cellular stress response and could serve as targets for novel antitumor therapies. PMID:18708362

  1. The fission yeast RNA binding protein Mmi1 regulates meiotic genes by controlling intron specific splicing and polyadenylation coupled RNA turnover.

    Directory of Open Access Journals (Sweden)

    Huei-Mei Chen

    Full Text Available The polyA tails of mRNAs are monitored by the exosome as a quality control mechanism. We find that fission yeast, Schizosaccharomyces pombe, adopts this RNA quality control mechanism to regulate a group of 30 or more meiotic genes at the level of both splicing and RNA turnover. In vegetative cells the RNA binding protein Mmi1 binds to the primary transcripts of these genes. We find the novel motif U(U/C/GAAAC highly over-represented in targets of Mmi1. Mmi1 can specifically regulate the splicing of particular introns in a transcript: it inhibits the splicing of introns that are in the vicinity of putative Mmi1 binding sites, while allowing the splicing of other introns that are far from such sites. In addition, binding of Mmi1, particularly near the 3' end, alters 3' processing to promote extremely long polyA tails of up to a kilobase. The hyperadenylated transcripts are then targeted for degradation by the nuclear exonuclease Rrp6. The nuclear polyA binding protein Pab2 assists this hyperadenylation-mediated RNA decay. Rrp6 also targets other hyperadenylated transcripts, which become hyperadenylated in an unknown, but Mmi1-independent way. Thus, hyperadenylation may be a general signal for RNA degradation. In addition, binding of Mmi1 can affect the efficiency of 3' cleavage. Inactivation of Mmi1 in meiosis allows meiotic expression, through splicing and RNA stabilization, of at least 29 target genes, which are apparently constitutively transcribed.

  2. Temporal and tissue specific regulation of RP-associated splicing factor genes PRPF3, PRPF31 and PRPC8--implications in the pathogenesis of RP.

    Directory of Open Access Journals (Sweden)

    Huibi Cao

    2011-01-01

    Full Text Available Genetic mutations in several ubiquitously expressed RNA splicing genes such as PRPF3, PRP31 and PRPC8, have been found to cause retina-specific diseases in humans. To understand this intriguing phenomenon, most studies have been focused on testing two major hypotheses. One hypothesis assumes that these mutations interrupt retina-specific interactions that are important for RNA splicing, implying that there are specific components in the retina interacting with these splicing factors. The second hypothesis suggests that these mutations have only a mild effect on the protein function and thus affect only the metabolically highly active cells such as retinal photoreceptors.We examined the second hypothesis using the PRPF3 gene as an example. We analyzed the spatial and temporal expression of the PRPF3 gene in mice and found that it is highly expressed in retinal cells relative to other tissues and its expression is developmentally regulated. In addition, we also found that PRP31 and PRPC8 as well as snRNAs are highly expressed in retinal cells.Our data suggest that the retina requires a relatively high level of RNA splicing activity for optimal tissue-specific physiological function. Because the RP18 mutation has neither a debilitating nor acute effect on protein function, we suggest that retinal degeneration is the accumulative effect of decades of suboptimal RNA splicing due to the mildly impaired protein.

  3. Negative Regulation of Interferon-β Production by Alternative Splicing of Tumor Necrosis Factor Receptor-Associated Factor 3 in Ducks

    Directory of Open Access Journals (Sweden)

    Xiaoqin Wei

    2018-03-01

    Full Text Available Tumor necrosis factor receptor-associated factor 3 (TRAF3, an intracellular signal transducer, is identified as an important component of Toll-like receptors and RIG-I-like receptors induced type I interferon (IFN signaling pathways. Previous studies have clarified TRAF3 function in mammals, but little is known about the role of TRAF3 in ducks. Here, we cloned and characterized the full-length duck TRAF3 (duTRAF3 gene and an alternatively spliced isoform of duTRAF3 (duTRAF3-S lacking the fragment encoding amino acids 217–319, from duck embryo fibroblasts (DEFs. We found that duTRAF3 and duTRAF3-S played different roles in regulating IFN-β production in DEFs. duTRAF3 through its TRAF domain interacted with duMAVS or duTRIF, leading to the production of IFN-β. However, duTRAF3-S, containing the TRAF domain, was unable to bind duMAVS or duTRIF due to the intramolecular binding between the N- and C-terminal of duTRAF3-S that blocked the function of its TRAF domain. Further analysis identified that duTRAF3-S competed with duTRAF3 itself for binding to duTRAF3, perturbing duTRAF3 self-association, which impaired the assembly of duTRAF3-duMAVS/duTRIF complex, ultimately resulted in a reduced production of IFN-β. These findings suggest that duTRAF3 is an important regulator of duck innate immune signaling and reveal a novel mechanism for the negative regulation of IFN-β production via changing the formation of the homo-oligomerization of wild molecules, implying a novel regulatory role of truncated proteins.

  4. A temperature-sensitive allele of a putative mRNA splicing helicase down-regulates many cell wall genes and causes radial swelling in Arabidopsis thaliana.

    Science.gov (United States)

    Howles, Paul A; Gebbie, Leigh K; Collings, David A; Varsani, Arvind; Broad, Ronan C; Ohms, Stephen; Birch, Rosemary J; Cork, Ann H; Arioli, Tony; Williamson, Richard E

    2016-05-01

    The putative RNA helicase encoded by the Arabidopsis gene At1g32490 is a homolog of the yeast splicing RNA helicases Prp2 and Prp22. We isolated a temperature-sensitive allele (rsw12) of the gene in a screen for root radial swelling mutants. Plants containing this allele grown at the restrictive temperature showed weak radial swelling, were stunted with reduced root elongation, and contained reduced levels of cellulose. The role of the protein was further explored by microarray analysis. By using both fold change cutoffs and a weighted gene coexpression network analysis (WGCNA) to investigate coexpression of genes, we found that the radial swelling phenotype was not linked to genes usually associated with primary cell wall biosynthesis. Instead, the mutation has strong effects on expression of secondary cell wall related genes. Many genes potentially associated with secondary walls were present in the most significant WGCNA module, as were genes coding for arabinogalactans and proteins with GPI anchors. The proportion of up-regulated genes that possess introns in rsw12 was above that expected if splicing was unrelated to the activity of the RNA helicase, suggesting that the helicase does indeed play a role in splicing in Arabidopsis. The phenotype may be due to a change in the expression of one or more genes coding for cell wall proteins.

  5. Depletion of Arabidopsis SC35 and SC35-like serine/arginine-rich proteins affects the transcription and splicing of a subset of genes.

    Science.gov (United States)

    Yan, Qingqing; Xia, Xi; Sun, Zhenfei; Fang, Yuda

    2017-03-01

    Serine/arginine-rich (SR) proteins are important splicing factors which play significant roles in spliceosome assembly and splicing regulation. However, little is known regarding their biological functions in plants. Here, we analyzed the phenotypes of mutants upon depleting different subfamilies of Arabidopsis SR proteins. We found that loss of the functions of SC35 and SC35-like (SCL) proteins cause pleiotropic changes in plant morphology and development, including serrated leaves, late flowering, shorter roots and abnormal silique phyllotaxy. Using RNA-seq, we found that SC35 and SCL proteins play roles in the pre-mRNA splicing. Motif analysis revealed that SC35 and SCL proteins preferentially bind to a specific RNA sequence containing the AGAAGA motif. In addition, the transcriptions of a subset of genes are affected by the deletion of SC35 and SCL proteins which interact with NRPB4, a specific subunit of RNA polymerase II. The splicing of FLOWERING LOCUS C (FLC) intron1 and transcription of FLC were significantly regulated by SC35 and SCL proteins to control Arabidopsis flowering. Therefore, our findings provide mechanistic insight into the functions of plant SC35 and SCL proteins in the regulation of splicing and transcription in a direct or indirect manner to maintain the proper expression of genes and development.

  6. The nuclear receptor ERβ engages AGO2 in regulation of gene transcription, RNA splicing and RISC loading.

    Science.gov (United States)

    Tarallo, Roberta; Giurato, Giorgio; Bruno, Giuseppina; Ravo, Maria; Rizzo, Francesca; Salvati, Annamaria; Ricciardi, Luca; Marchese, Giovanna; Cordella, Angela; Rocco, Teresa; Gigantino, Valerio; Pierri, Biancamaria; Cimmino, Giovanni; Milanesi, Luciano; Ambrosino, Concetta; Nyman, Tuula A; Nassa, Giovanni; Weisz, Alessandro

    2017-10-06

    The RNA-binding protein Argonaute 2 (AGO2) is a key effector of RNA-silencing pathways It exerts a pivotal role in microRNA maturation and activity and can modulate chromatin remodeling, transcriptional gene regulation and RNA splicing. Estrogen receptor beta (ERβ) is endowed with oncosuppressive activities, antagonizing hormone-induced carcinogenesis and inhibiting growth and oncogenic functions in luminal-like breast cancers (BCs), where its expression correlates with a better prognosis of the disease. Applying interaction proteomics coupled to mass spectrometry to characterize nuclear factors cooperating with ERβ in gene regulation, we identify AGO2 as a novel partner of ERβ in human BC cells. ERβ-AGO2 association was confirmed in vitro and in vivo in both the nucleus and cytoplasm and is shown to be RNA-mediated. ChIP-Seq demonstrates AGO2 association with a large number of ERβ binding sites, and total and nascent RNA-Seq in ERβ + vs ERβ - cells, and before and after AGO2 knock-down in ERβ + cells, reveals a widespread involvement of this factor in ERβ-mediated regulation of gene transcription rate and RNA splicing. Moreover, isolation and sequencing by RIP-Seq of ERβ-associated long and small RNAs in the cytoplasm suggests involvement of the nuclear receptor in RISC loading, indicating that it may also be able to directly control mRNA translation efficiency and stability. These results demonstrate that AGO2 can act as a pleiotropic functional partner of ERβ, indicating that both factors are endowed with multiple roles in the control of key cellular functions.

  7. Identification and analysis of Eimeria nieschulzi gametocyte genes reveal splicing events of gam genes and conserved motifs in the wall-forming proteins within the genus Eimeria (Coccidia, Apicomplexa

    Directory of Open Access Journals (Sweden)

    Wiedmer Stefanie

    2017-01-01

    Full Text Available The genus Eimeria (Apicomplexa, Coccidia provides a wide range of different species with different hosts to study common and variable features within the genus and its species. A common characteristic of all known Eimeria species is the oocyst, the infectious stage where its life cycle starts and ends. In our study, we utilized Eimeria nieschulzi as a model organism. This rat-specific parasite has complex oocyst morphology and can be transfected and even cultivated in vitro up to the oocyst stage. We wanted to elucidate how the known oocyst wall-forming proteins are preserved in this rodent Eimeria species compared to other Eimeria. In newly obtained genomics data, we were able to identify different gametocyte genes that are orthologous to already known gam genes involved in the oocyst wall formation of avian Eimeria species. These genes appeared putatively as single exon genes, but cDNA analysis showed alternative splicing events in the transcripts. The analysis of the translated sequence revealed different conserved motifs but also dissimilar regions in GAM proteins, as well as polymorphic regions. The occurrence of an underrepresented gam56 gene version suggests the existence of a second distinct E. nieschulzi genotype within the E. nieschulzi Landers isolate that we maintain.

  8. Identification and analysis of Eimeria nieschulzi gametocyte genes reveal splicing events of gam genes and conserved motifs in the wall-forming proteins within the genus Eimeria (Coccidia, Apicomplexa)

    Science.gov (United States)

    Wiedmer, Stefanie; Erdbeer, Alexander; Volke, Beate; Randel, Stephanie; Kapplusch, Franz; Hanig, Sacha; Kurth, Michael

    2017-01-01

    The genus Eimeria (Apicomplexa, Coccidia) provides a wide range of different species with different hosts to study common and variable features within the genus and its species. A common characteristic of all known Eimeria species is the oocyst, the infectious stage where its life cycle starts and ends. In our study, we utilized Eimeria nieschulzi as a model organism. This rat-specific parasite has complex oocyst morphology and can be transfected and even cultivated in vitro up to the oocyst stage. We wanted to elucidate how the known oocyst wall-forming proteins are preserved in this rodent Eimeria species compared to other Eimeria. In newly obtained genomics data, we were able to identify different gametocyte genes that are orthologous to already known gam genes involved in the oocyst wall formation of avian Eimeria species. These genes appeared putatively as single exon genes, but cDNA analysis showed alternative splicing events in the transcripts. The analysis of the translated sequence revealed different conserved motifs but also dissimilar regions in GAM proteins, as well as polymorphic regions. The occurrence of an underrepresented gam56 gene version suggests the existence of a second distinct E. nieschulzi genotype within the E. nieschulzi Landers isolate that we maintain. PMID:29210668

  9. Cytokines interleukin-1beta and tumor necrosis factor-alpha regulate different transcriptional and alternative splicing networks in primary beta-cells

    DEFF Research Database (Denmark)

    Ortis, Fernanda; Naamane, Najib; Flamez, Daisy

    2010-01-01

    by the cytokines interleukin (IL)-1beta + interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha + IFN-gamma in primary rat beta-cells. RESEARCH DESIGN AND METHODS: Fluorescence-activated cell sorter-purified rat beta-cells were exposed to IL-1beta + IFN-gamma or TNF-alpha + IFN-gamma for 6 or 24 h......-cells, with temporal differences in the number of genes modulated by IL-1beta + IFNgamma or TNF-alpha + IFN-gamma. These cytokine combinations induced differential expression of inflammatory response genes, which is related to differential induction of IFN regulatory factor-7. Both treatments decreased the expression...... of genes involved in the maintenance of beta-cell phenotype and growth/regeneration. Cytokines induced hypoxia-inducible factor-alpha, which in this context has a proapoptotic role. Cytokines also modified the expression of >20 genes involved in RNA splicing, and exon array analysis showed cytokine...

  10. Clinical, in silico, and experimental evidence for pathogenicity of two novel splice site mutations in the SH3TC2 gene

    Czech Academy of Sciences Publication Activity Database

    Laššuthová, P.; Gregor, Martin; Sarnová, Lenka; Machalová, Eliška; Sedláček, Radislav; Seeman, P.

    2012-01-01

    Roč. 26, 3-4 (2012), s. 413-420 ISSN 0167-7063 R&D Projects: GA ČR GAP303/10/2044 Institutional support: RVO:68378050 Keywords : exon trapping * peripheral neuropathy * SH3TC2 gene * splice site mutation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.159, year: 2012

  11. Splice site mutations in mismatch repair genes and risk of cancer in the general population

    DEFF Research Database (Denmark)

    Thomsen, Mette; Nordestgaard, Børge G; Tybjærg-Hansen, Anne

    2013-01-01

    We tested the hypothesis that splice site variations in MSH2 and MLH1 are associated with increased risk of hereditary non-polyposis colorectal cancer (HNPCC) and of cancer in general in the general population. In a cohort of 154 HNPCC patients with sequenced MSH2 and MLH1, we identified four...... possible splice-site mutations, which we subsequently genotyped in more than 9,000 individuals from the general population. Allele frequencies in the general population were 0 % for 942+3A>T in MSH2, 0.05 % for 307-19A>G, 0.005 % for 1,667+(2-8)del(taaatca);ins(attt), and 4.4 % for 1039-8T>A in MLH1. Odds...... ratios for HNPCC in a case-control design were 419 (95 % CI: 53-18,900) for 942+3A>T in MSH2, 19 (5-72) for 307-19A>G, 194 (21-1,768) for 1,667+(2-8)del(taaatca); ins(attt), and 0.3 (0.1-0.7) for 1,039-8T>A in MLH1. In the general population, incidence rate ratios for 1,039-8T>A carriers versus...

  12. The E180splice mutation in the GHR gene causing Laron syndrome: witness of a Sephardic Jewish exodus from the Iberian Peninsula to the New World?

    Science.gov (United States)

    Gonçalves, Fernanda T; Fridman, Cintia; Pinto, Emília M; Guevara-Aguirre, Jaime; Shevah, Orit; Rosembloom, Arlan L; Hwa, Vivian; Cassorla, Fernando; Rosenfeld, Ron G; Lins, Theresa S S; Damiani, Durval; Arnhold, Ivo J P; Laron, Zvi; Jorge, Alexander A L

    2014-05-01

    Laron syndrome (LS) is a genetic disorder caused by mutations in the growth hormone receptor (GHR) gene. The most frequent GHR mutation is E180splice (rs121909360), which was initially found in an inbred population of Spanish descent in Ecuador and subsequently in Israel, Brazil, Chile, and the United States. The aim of the present study is to determine if the E180splice mutation arose from a common origin. We studied 22 patients with LS from Ecuador, Israel (of Moroccan origin), Brazil, Chile, and the United States (of Mexican origin) who were homozygous for the E180splice mutation and compared them to control individuals for markers surrounding the GHR, intragenic polymorphisms, and Y-chromosome STR. An identical haplotype was found in all but one of the subjects carrying the E180splice mutation: D5S665: 150/150; D5S2082: 192/192; D5S2087: 246/246; rs6179 G/G; and rs6180 C/C. One patient differed from the others only at D5S2082 (168/192). This haplotype is rare (~1%) in control individuals and confirmed that the E180splice-associated haplotype was not derived from independent origins but represented recombination from a common ancestor. The analysis of paternal lineage markers showed that 50% belong to haplogroup R1b (found in Portugal and Spain) and 40% to haplogroups J and E (typical in the Middle East and in Eastern European Jews). The germline E180Splice mutation appears to have originated from a single common ancestor. The presence of Y-chromosome markers associated with Sephardic populations in persons harboring the E180splice mutation provides genetic evidence in support of the historical tracking of the exodus of this specific population. © 2014 Wiley Periodicals, Inc.

  13. Mutations in the human adenosine deaminase gene that affect protein structure and RNA splicing

    International Nuclear Information System (INIS)

    Akeson, A.L.; Wiginton, D.A.; States, C.J.; Perme, C.M.; Dusing, M.R.; Hutton, J.J.

    1987-01-01

    Adenosine deaminase deficiency is one cause of the genetic disease severe combined immunodeficiency. To identify mutations responsible for ADA deficiency, the authors synthesized cDNAs to ADA mRNAs from two cell lines, GM2756 and GM2825A, derived from ADA-deficient immunodeficient patients. Sequence analysis of GM2756 cDNA clones revealed a different point mutation in each allele that causes amino acid changes of alanine to valine and arginine to histidine. One allele of GM2825A also has a point mutation that causes an alanine to valine substitution. The other allele of GM2825A was found to produce an mRNA in which exon 4 had been spliced out but had no other detrimental mutations. S1 nuclease mapping of GM2825A mRNA showed equal abundance of the full-length ADA mRNA and the ADA mRNA that was missing exon 4. Several of the ADA cDNA clones extended 5' of the major initiation start site, indicating multiple start sites for ADA transcription. The point mutations in GM2756 and GM2825A and the absence of exon 4 in GM2825A appear to be directly responsible for the ADA deficiency. Comparison of a number of normal and mutant ADA cDNA sequences showed a number of changes in the third base of codons. These change do not affect the amino acid sequence. Analyses of ADA cDNAs from different cell lines detected aberrant RNA species that either included intron 7 or excluded exon 7. Their presence is a result of aberrant splicing of pre-mRNAs and is not related to mutations that cause ADA deficiency

  14. Rhythmic Behavior Is Controlled by the SRm160 Splicing Factor in Drosophila melanogaster.

    Science.gov (United States)

    Beckwith, Esteban J; Hernando, Carlos E; Polcowñuk, Sofía; Bertolin, Agustina P; Mancini, Estefania; Ceriani, M Fernanda; Yanovsky, Marcelo J

    2017-10-01

    Circadian clocks organize the metabolism, physiology, and behavior of organisms throughout the day-night cycle by controlling daily rhythms in gene expression at the transcriptional and post-transcriptional levels. While many transcription factors underlying circadian oscillations are known, the splicing factors that modulate these rhythms remain largely unexplored. A genome-wide assessment of the alterations of gene expression in a null mutant of the alternative splicing regulator SR-related matrix protein of 160 kDa (SRm160) revealed the extent to which alternative splicing impacts on behavior-related genes. We show that SRm160 affects gene expression in pacemaker neurons of the Drosophila brain to ensure proper oscillations of the molecular clock. A reduced level of SRm160 in adult pacemaker neurons impairs circadian rhythms in locomotor behavior, and this phenotype is caused, at least in part, by a marked reduction in period ( per ) levels. Moreover, rhythmic accumulation of the neuropeptide PIGMENT DISPERSING FACTOR in the dorsal projections of these neurons is abolished after SRm160 depletion. The lack of rhythmicity in SRm160-downregulated flies is reversed by a fully spliced per construct, but not by an extra copy of the endogenous locus, showing that SRm160 positively regulates per levels in a splicing-dependent manner. Our findings highlight the significant effect of alternative splicing on the nervous system and particularly on brain function in an in vivo model. Copyright © 2017 by the Genetics Society of America.

  15. An intronic mutation c.6430-3C>G in the F8 gene causes splicing efficiency and premature termination in hemophilia A.

    Science.gov (United States)

    Xia, Zunjing; Lin, Jie; Lu, Lingping; Kim, Chol; Yu, Ping; Qi, Ming

    2018-06-01

    : Hemophilia A is a bleeding disorder caused by coagulation factor VIII protein deficiency or dysfunction, which is classified into severe, moderate, and mild according to factor clotting activity. An overwhelming majority of missense and nonsense mutations occur in exons of F8 gene, whereas mutations in introns can also be pathogenic. This study aimed to investigate the effect of an intronic mutation, c.6430-3C>G (IVS22-3C>G), on pre-mRNA splicing of the F8 gene. We applied DNA and cDNA sequencing in a Chinese boy with hemophilia A to search if any pathogenic mutation in the F8 gene. Functional analysis was performed to investigate the effect of an intronic mutation at the transcriptional level. Human Splicing Finder and PyMol were also used to predict its effect. We found the mutation c.6430-3C>G (IVS22-3C>G) in the F8 gene in the affected boy, with his mother being a carrier. cDNA from the mother and pSPL3 splicing assay showed that the mutation IVS22-3C>G results in a two-nucleotide AG inclusion at the 3' end of intron 22 and leads to a truncated coagulation factor VIII protein, with partial loss of the C1 domain and complete loss of the C2 domain. The in-silico tool predicted that the mutation induces altered pre-mRNA splicing by using a cryptic acceptor site in intron 22. The IVS22-3C>G mutation was confirmed to affect pre-mRNA splicing and produce a truncated protein, which reduces the stability of binding between the F8 protein and von Willebrand factor carrier protein due to the loss of an interaction domain.

  16. Spliced leader-based analyses reveal the effects of polycyclic aromatic hydrocarbons on gene expression in the copepod Pseudodiaptomus poplesia.

    Science.gov (United States)

    Zhuang, Yunyun; Yang, Feifei; Xu, Donghui; Chen, Hongju; Zhang, Huan; Liu, Guangxing

    2017-02-01

    Polycyclic aromatic hydrocarbons (PAHs) are a group of toxic and carcinogenic pollutants that can adversely affect the development, growth and reproduction of marine organisms including copepods. However, knowledge on the molecular mechanisms regulating the response to PAH exposure in marine planktonic copepods is limited. In this study, we investigated the survival and gene expression of the calanoid copepod Pseudodiaptomus poplesia upon exposure to two PAHs, 1, 2-dimethylnaphthalene (1, 2-NAPH) and pyrene. Acute toxicity responses resulted in 96-h LC 50 of 788.98μgL -1 and 54.68μgL -1 for 1, 2-NAPH and pyrene, respectively. Using the recently discovered copepod spliced leader as a primer, we constructed full-length cDNA libraries from copepods exposed to sublethal concentrations and revealed 289 unique genes of diverse functions, including stress response genes and novel genes previously undocumented for this species. Eighty-three gene families were specifically expressed in PAH exposure libraries. We further analyzed the expression of seven target genes by reverse transcription-quantitative PCR in a time-course test with three sublethal concentrations. These target genes have primary roles in detoxification, oxidative defense, and signal transduction, and include different forms of glutathione S-transferase (GST), glutathione peroxidases (GPX), peroxiredoxin (PRDX), methylmalonate-semialdehyde dehydrogenase (MSDH) and ras-related C3 botulinum toxin substrate (RAC1). Expression stability of seven candidate reference genes were evaluated and the two most stable ones (RPL15 and RPS20 for 1, 2-NAPH exposure, RPL15 and EF1D for pyrene exposure) were used to normalize the expression levels of the target genes. Significant upregulation was detected in GST-T, GST-DE, GPX4, PRDX6 and RAC1 upon 1, 2-NAPH exposure, and GST-DE and MSDH upon pyrene exposure. These results indicated that the oxidative stress was induced and that signal transduction might be affected by PAH

  17. SPA: a probabilistic algorithm for spliced alignment.

    Directory of Open Access Journals (Sweden)

    2006-04-01

    Full Text Available Recent large-scale cDNA sequencing efforts show that elaborate patterns of splice variation are responsible for much of the proteome diversity in higher eukaryotes. To obtain an accurate account of the repertoire of splice variants, and to gain insight into the mechanisms of alternative splicing, it is essential that cDNAs are very accurately mapped to their respective genomes. Currently available algorithms for cDNA-to-genome alignment do not reach the necessary level of accuracy because they use ad hoc scoring models that cannot correctly trade off the likelihoods of various sequencing errors against the probabilities of different gene structures. Here we develop a Bayesian probabilistic approach to cDNA-to-genome alignment. Gene structures are assigned prior probabilities based on the lengths of their introns and exons, and based on the sequences at their splice boundaries. A likelihood model for sequencing errors takes into account the rates at which misincorporation, as well as insertions and deletions of different lengths, occurs during sequencing. The parameters of both the prior and likelihood model can be automatically estimated from a set of cDNAs, thus enabling our method to adapt itself to different organisms and experimental procedures. We implemented our method in a fast cDNA-to-genome alignment program, SPA, and applied it to the FANTOM3 dataset of over 100,000 full-length mouse cDNAs and a dataset of over 20,000 full-length human cDNAs. Comparison with the results of four other mapping programs shows that SPA produces alignments of significantly higher quality. In particular, the quality of the SPA alignments near splice boundaries and SPA's mapping of the 5' and 3' ends of the cDNAs are highly improved, allowing for more accurate identification of transcript starts and ends, and accurate identification of subtle splice variations. Finally, our splice boundary analysis on the human dataset suggests the existence of a novel non

  18. Requirement of a novel splicing variant of human histone deacetylase 6 for TGF-{beta}1-mediated gene activation

    Energy Technology Data Exchange (ETDEWEB)

    Zhuang, Yan [Department of Medicine, Tulane School of Medicine, New Orleans, LA 70112 (United States); Nguyen, Hong T. [Graduate Program in Biomedical Sciences, Tulane School of Medicine, New Orleans, LA 70112 (United States); Lasky, Joseph A. [Department of Medicine, Tulane School of Medicine, New Orleans, LA 70112 (United States); Cao, Subing [Graduate Program in Biomedical Sciences, Tulane School of Medicine, New Orleans, LA 70112 (United States); Li, Cui [Department of Medicine, Tulane School of Medicine, New Orleans, LA 70112 (United States); Xiangya Hospital, Central South University, Hunan 41008 (China); Hu, Jiyao; Guo, Xinyue; Burow, Matthew E. [Department of Medicine, Tulane School of Medicine, New Orleans, LA 70112 (United States); Shan, Bin, E-mail: bshan@tulane.edu [Department of Medicine, Tulane School of Medicine, New Orleans, LA 70112 (United States)

    2010-02-19

    Histone deacetylase 6 (HDAC6) belongs to the family of class IIb HDACs and predominantly deacetylates non-histone proteins in the cytoplasm via the C-terminal deacetylase domain of its two tandem deacetylase domains. HDAC6 modulates fundamental cellular processes via deacetylation of {alpha}-tubulin, cortactin, molecular chaperones, and other peptides. Our previous study indicates that HDAC6 mediates TGF-{beta}1-induced epithelial-mesenchymal transition (EMT) in A549 cells. In the current study, we identify a novel splicing variant of human HDAC6, hHDAC6p114. The hHDAC6p114 mRNA arises from incomplete splicing and encodes a truncated isoform of the hHDAC6p114 protein of 114 kDa when compared to the major isoform hHDAC6p131. The hHDAC6p114 protein lacks the first 152 amino acids from N-terminus in the hHDAC6p131 protein, which harbors a nuclear export signal peptide and 76 amino acids of the N-terminal deacetylase domain. hHDAC6p114 is intact in its deacetylase activity against {alpha}-tubulin. The expression hHDAC6p114 is elevated in a MCF-7 derivative that exhibits an EMT-like phenotype. Moreover, hHDAC6p114 is required for TGF-{beta}1-activated gene expression associated with EMT in A549 cells. Taken together, our results implicate that expression and function of hHDAC6p114 is differentially regulated when compared to hHDAC6p131.

  19. Tissue-specific splicing pattern of fibronectin messenger RNA precursor during development and aging in rat

    OpenAIRE

    1991-01-01

    Fibronectin isoforms are generated by the alternative splicing of a primary transcript derived from a single gene. In rat at least three regions of the molecule are involved: EIIIA, EIIIB, and V. This study investigated the splicing patterns of these regions during development and aging, by means of ribonuclease protection analysis. Between fetal and adult rat, the extent of inclusion of the EIIIA and/or EIIIB region in fibronectin mRNA varied according to the type of tissue analyzed; but the...

  20. The strength of intron donor splice sites in human genes displays a bell-shaped pattern

    DEFF Research Database (Denmark)

    Wang, Kai; Wernersson, Rasmus; Brunak, Søren

    2011-01-01

    introns. Interestingly, when analysing the intron containing gene pool from mouse consisting of >15 000 genes, we found the convex pattern to be conserved despite >75 million years of evolutionary divergence between the two organisms. We also analysed an interesting, novel class of chimeric genes which...

  1. Alternative Splicing of AMPA subunits in Prefrontal Cortical Fields of Cynomolgus Monkeys following Chronic Ethanol Self-Administration

    Directory of Open Access Journals (Sweden)

    Glen eAcosta

    2012-01-01

    Full Text Available Functional impairment of the orbital and medial prefrontal cortex underlies deficits in executive control that characterize addictive disorders, including alcohol addiction. Previous studies indicate that alcohol alters glutamate neurotransmission and one substrate of these effects may be through the reconfiguration of the subunits constituting ionotropic glutamate receptor (iGluR complexes. Glutamatergic transmission is integral to cortico-cortical and cortico-subcortical communication and alcohol-induced changes in the abundance of the receptor subunits and/or their splice variants may result in critical functional impairments of prefrontal cortex in alcohol dependence. To this end, the effects of chronic ethanol self-administration on glutamate receptor ionotropic AMPA (GRIA subunit variant and kainate (GRIK subunit mRNA expression were studied in the orbitofrontal cortex (OFC, dorsolateral prefrontal cortex (DLPFC and anterior cingulate cortex (ACC of male cynomolgus monkeys. In DLPFC, total AMPA splice variant expression and total kainate receptor subunit expression were significantly decreased in alcohol drinking monkeys. Expression levels of GRIA3 flip and flop and GRIA4 flop mRNAs in this region were positively correlated with daily ethanol intake and blood ethanol concentrations averaged over the six months prior to necropsy. In OFC, AMPA subunit splice variant expression was reduced in the alcohol treated group. GRIA2 flop mRNA levels in this region were positively correlated with daily ethanol intake and blood ethanol concentrations averaged over the six months prior to necropsy. Results from these studies provide further evidence of transcriptional regulation of iGluR subunits in the primate brain following chronic alcohol self-administration. Additional studies examining the cellular localization of such effects in the framework of primate prefrontal cortical circuitry are warranted.

  2. Altered Pre-mRNA Splicing Caused by a Novel Intronic Mutation c.1443+5G>A in the Dihydropyrimidinase (DPYS) Gene.

    Science.gov (United States)

    Nakajima, Yoko; Meijer, Judith; Zhang, Chunhua; Wang, Xu; Kondo, Tomomi; Ito, Tetsuya; Dobritzsch, Doreen; Van Kuilenburg, André B P

    2016-01-12

    Dihydropyrimidinase (DHP) deficiency is an autosomal recessive disease caused by mutations in the DPYS gene. Patients present with highly elevated levels of dihydrouracil and dihydrothymine in their urine, blood and cerebrospinal fluid. The analysis of the effect of mutations in DPYS on pre-mRNA splicing is hampered by the fact that DHP is primarily expressed in liver and kidney cells. The minigene approach can detect mRNA splicing aberrations using cells that do not express the endogenous mRNA. We have used a minigene-based approach to analyze the effects of a presumptive pre-mRNA splicing mutation in two newly identified Chinese pediatric patients with DHP deficiency. Mutation analysis of DPYS showed that both patients were compound heterozygous for a novel intronic mutation c.1443+5G>A in intron 8 and a previously described missense mutation c.1001A>G (p.Q334R) in exon 6. Wild-type and the mutated minigene constructs, containing exons 7, 8 and 9 of DPYS, yielded different splicing products after expression in HEK293 cells. The c.1443+5G>A mutation resulted in altered pre-mRNA splicing of the DPYS minigene construct with full skipping of exon 8. Analysis of the DHP crystal structure showed that the deletion of exon 8 severely affects folding, stability and homooligomerization of the enzyme as well as disruption of the catalytic site. Thus, the analysis suggests that the c.1443+5G>A mutation results in aberrant splicing of the pre-mRNA encoding DHP, underlying the DHP deficiency in two unrelated Chinese patients.

  3. Altered Pre-mRNA Splicing Caused by a Novel Intronic Mutation c.1443+5G>A in the Dihydropyrimidinase (DPYS Gene

    Directory of Open Access Journals (Sweden)

    Yoko Nakajima

    2016-01-01

    Full Text Available Dihydropyrimidinase (DHP deficiency is an autosomal recessive disease caused by mutations in the DPYS gene. Patients present with highly elevated levels of dihydrouracil and dihydrothymine in their urine, blood and cerebrospinal fluid. The analysis of the effect of mutations in DPYS on pre-mRNA splicing is hampered by the fact that DHP is primarily expressed in liver and kidney cells. The minigene approach can detect mRNA splicing aberrations using cells that do not express the endogenous mRNA. We have used a minigene-based approach to analyze the effects of a presumptive pre-mRNA splicing mutation in two newly identified Chinese pediatric patients with DHP deficiency. Mutation analysis of DPYS showed that both patients were compound heterozygous for a novel intronic mutation c.1443+5G>A in intron 8 and a previously described missense mutation c.1001A>G (p.Q334R in exon 6. Wild-type and the mutated minigene constructs, containing exons 7, 8 and 9 of DPYS, yielded different splicing products after expression in HEK293 cells. The c.1443+5G>A mutation resulted in altered pre-mRNA splicing of the DPYS minigene construct with full skipping of exon 8. Analysis of the DHP crystal structure showed that the deletion of exon 8 severely affects folding, stability and homooligomerization of the enzyme as well as disruption of the catalytic site. Thus, the analysis suggests that the c.1443+5G>A mutation results in aberrant splicing of the pre-mRNA encoding DHP, underlying the DHP deficiency in two unrelated Chinese patients.

  4. Missense mutation in GRN gene affecting RNA splicing and plasma progranulin level in a family affected by frontotemporal lobar degeneration.

    Science.gov (United States)

    Luzzi, Simona; Colleoni, Lara; Corbetta, Paola; Baldinelli, Sara; Fiori, Chiara; Girelli, Francesca; Silvestrini, Mauro; Caroppo, Paola; Giaccone, Giorgio; Tagliavini, Fabrizio; Rossi, Giacomina

    2017-06-01

    Gene coding for progranulin, GRN, is a major gene linked to frontotemporal lobar degeneration. While most of pathogenic GRN mutations are null mutations leading to haploinsufficiency, GRN missense mutations do not have an obvious pathogenicity, and only a few have been revealed to act through different pathogenetic mechanisms, such as cytoplasmic missorting, protein degradation, and abnormal cleavage by elastase. The aim of this study was to disclose the pathogenetic mechanisms of the GRN A199V missense mutation, which was previously reported not to alter physiological progranulin features but was associated with a reduced plasma progranulin level. After investigating the family pedigree, we performed genetic and biochemical analysis on its members and performed RNA expression studies. We found that the mutation segregates with the disease and discovered that its pathogenic feature is the alteration of GRN mRNA splicing, actually leading to haploinsufficiency. Thus, when facing with a missense GRN mutation, its pathogenetic effects should be investigated, especially if associated with low plasma progranulin levels, to determine its nature of either benign polymorphism or pathogenic mutation. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Systematic Analysis of Splice-Site-Creating Mutations in Cancer.

    Science.gov (United States)

    Jayasinghe, Reyka G; Cao, Song; Gao, Qingsong; Wendl, Michael C; Vo, Nam Sy; Reynolds, Sheila M; Zhao, Yanyan; Climente-González, Héctor; Chai, Shengjie; Wang, Fang; Varghese, Rajees; Huang, Mo; Liang, Wen-Wei; Wyczalkowski, Matthew A; Sengupta, Sohini; Li, Zhi; Payne, Samuel H; Fenyö, David; Miner, Jeffrey H; Walter, Matthew J; Vincent, Benjamin; Eyras, Eduardo; Chen, Ken; Shmulevich, Ilya; Chen, Feng; Ding, Li

    2018-04-03

    For the past decade, cancer genomic studies have focused on mutations leading to splice-site disruption, overlooking those having splice-creating potential. Here, we applied a bioinformatic tool, MiSplice, for the large-scale discovery of splice-site-creating mutations (SCMs) across 8,656 TCGA tumors. We report 1,964 originally mis-annotated mutations having clear evidence of creating alternative splice junctions. TP53 and GATA3 have 26 and 18 SCMs, respectively, and ATRX has 5 from lower-grade gliomas. Mutations in 11 genes, including PARP1, BRCA1, and BAP1, were experimentally validated for splice-site-creating function. Notably, we found that neoantigens induced by SCMs are likely several folds more immunogenic compared to missense mutations, exemplified by the recurrent GATA3 SCM. Further, high expression of PD-1 and PD-L1 was observed in tumors with SCMs, suggesting candidates for immune blockade therapy. Our work highlights the importance of integrating DNA and RNA data for understanding the functional and the clinical implications of mutations in human diseases. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  6. Feline immunodeficiency virus OrfA alters gene expression of splicing factors and proteasome-ubiquitination proteins

    International Nuclear Information System (INIS)

    Sundstrom, Magnus; Chatterji, Udayan; Schaffer, Lana; Rozieres, Sohela de; Elder, John H.

    2008-01-01

    Expression of the feline immunodeficiency virus (FIV) accessory protein OrfA (or Orf2) is critical for efficient viral replication in lymphocytes, both in vitro and in vivo. OrfA has been reported to exhibit functions in common with the human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) accessory proteins Vpr and Tat, although the function of OrfA has not been fully explained. Here, we use microarray analysis to characterize how OrfA modulates the gene expression profile of T-lymphocytes. The primary IL-2-dependent T-cell line 104-C1 was transduced to express OrfA. Functional expression of OrfA was demonstrated by trans complementation of the OrfA-defective clone, FIV-34TF10. OrfA-expressing cells had a slightly reduced cell proliferation rate but did not exhibit any significant alteration in cell cycle distribution. Reverse-transcribed RNA from cells expressing green fluorescent protein (GFP) or GFP + OrfA were hybridized to Affymetrix HU133 Plus 2.0 microarray chips representing more than 47,000 genome-wide transcripts. By using two statistical approaches, 461 (Rank Products) and 277 (ANOVA) genes were identified as modulated by OrfA expression. The functional relevance of the differentially expressed genes was explored by Ingenuity Pathway Analysis. The analyses revealed alterations in genes critical for RNA post-transcriptional modifications and protein ubiquitination as the two most significant functional outcomes of OrfA expression. In these two groups, several subunits of the spliceosome, cellular splicing factors and family members of the proteasome-ubiquitination system were identified. These findings provide novel information on the versatile function of OrfA during FIV infection and indicate a fine-tuning mechanism of the cellular environment by OrfA to facilitate efficient FIV replication

  7. Nanospan, an alternatively spliced isoform of sarcospan, localizes to the sarcoplasmic reticulum in skeletal muscle and is absent in limb girdle muscular dystrophy 2F.

    Science.gov (United States)

    Peter, Angela K; Miller, Gaynor; Capote, Joana; DiFranco, Marino; Solares-Pérez, Alhondra; Wang, Emily L; Heighway, Jim; Coral-Vázquez, Ramón M; Vergara, Julio; Crosbie-Watson, Rachelle H

    2017-06-06

    Sarcospan (SSPN) is a transmembrane protein that interacts with the sarcoglycans (SGs) to form a tight subcomplex within the dystrophin-glycoprotein complex that spans the sarcolemma and interacts with laminin in the extracellular matrix. Overexpression of SSPN ameliorates Duchenne muscular dystrophy in murine models. Standard cloning approaches were used to identify nanospan, and nanospan-specific polyclonal antibodies were generated and validated. Biochemical isolation of skeletal muscle membranes and two-photon laser scanning microscopy were used to analyze nanospan localization in muscle from multiple murine models. Duchenne muscular dystrophy biopsies were analyzed by immunoblot analysis of protein lysates as well as indirect immunofluorescence analysis of muscle cryosections. Nanospan is an alternatively spliced isoform of sarcospan. While SSPN has four transmembrane domains and is a core component of the sarcolemmal dystrophin-glycoprotein complex, nanospan is a type II transmembrane protein that does not associate with the dystrophin-glycoprotein complex. We demonstrate that nanospan is enriched in the sarcoplasmic reticulum (SR) fractions and is not present in the T-tubules. SR fractions contain membranes from three distinct structural regions: a region flanking the T-tubules (triadic SR), a SR region across the Z-line (ZSR), and a longitudinal SR region across the M-line (LSR). Analysis of isolated murine muscles reveals that nanospan is mostly associated with the ZSR and triadic SR, and only minimally with the LSR. Furthermore, nanospan is absent from the SR of δ-SG-null (Sgcd -/- ) skeletal muscle, a murine model for limb girdle muscular dystrophy 2F. Analysis of skeletal muscle biopsies from Duchenne muscular dystrophy patients reveals that nanospan is preferentially expressed in type I (slow) fibers in both control and Duchenne samples. Furthermore, nanospan is significantly reduced in Duchenne biopsies. Alternative splicing of proteins from the SG

  8. Differential Splicing of Oncogenes and Tumor Suppressor Genes in African- and Caucasian-American Populations: Contributing Factor in Prostate Cancer Disparities

    Science.gov (United States)

    2016-10-01

    for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data...Olender (PhD graduate student) 5d. PROJECT NUMBER 5e. TASK NUMBER E-Mail: nhlee@gwu. edu 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION...inhibitory effects of idelalisib. 15. SUBJECT TERMS prostate cancer, cancer health disparities, alternative splicing, African American, European

  9. Dynamic regulation of genome-wide pre-mRNA splicing and stress tolerance by the Sm-like protein LSm5 in Arabidopsis

    KAUST Repository

    Cui, Peng

    2014-01-07

    Background: Sm-like proteins are highly conserved proteins that form the core of the U6 ribonucleoprotein and function in several mRNA metabolism processes, including pre-mRNA splicing. Despite their wide occurrence in all eukaryotes, little is known about the roles of Sm-like proteins in the regulation of splicing.Results: Here, through comprehensive transcriptome analyses, we demonstrate that depletion of the Arabidopsis supersensitive to abscisic acid and drought 1 gene (SAD1), which encodes Sm-like protein 5 (LSm5), promotes an inaccurate selection of splice sites that leads to a genome-wide increase in alternative splicing. In contrast, overexpression of SAD1 strengthens the precision of splice-site recognition and globally inhibits alternative splicing. Further, SAD1 modulates the splicing of stress-responsive genes, particularly under salt-stress conditions. Finally, we find that overexpression of SAD1 in Arabidopsis improves salt tolerance in transgenic plants, which correlates with an increase in splicing accuracy and efficiency for stress-responsive genes.Conclusions: We conclude that SAD1 dynamically controls splicing efficiency and splice-site recognition in Arabidopsis, and propose that this may contribute to SAD1-mediated stress tolerance through the metabolism of transcripts expressed from stress-responsive genes. Our study not only provides novel insights into the function of Sm-like proteins in splicing, but also uncovers new means to improve splicing efficiency and to enhance stress tolerance in a higher eukaryote. 2014 Cui et al.; licensee BioMed Central Ltd.

  10. SplicePlot: a utility for visualizing splicing quantitative trait loci.

    Science.gov (United States)

    Wu, Eric; Nance, Tracy; Montgomery, Stephen B

    2014-04-01

    RNA sequencing has provided unprecedented resolution of alternative splicing and splicing quantitative trait loci (sQTL). However, there are few tools available for visualizing the genotype-dependent effects of splicing at a population level. SplicePlot is a simple command line utility that produces intuitive visualization of sQTLs and their effects. SplicePlot takes mapped RNA sequencing reads in BAM format and genotype data in VCF format as input and outputs publication-quality Sashimi plots, hive plots and structure plots, enabling better investigation and understanding of the role of genetics on alternative splicing and transcript structure. Source code and detailed documentation are available at http://montgomerylab.stanford.edu/spliceplot/index.html under Resources and at Github. SplicePlot is implemented in Python and is supported on Linux and Mac OS. A VirtualBox virtual machine running Ubuntu with SplicePlot already installed is also available.

  11. BAP1 missense mutation c.2054 A>T (p.E685V completely disrupts normal splicing through creation of a novel 5' splice site in a human mesothelioma cell line.

    Directory of Open Access Journals (Sweden)

    Arianne Morrison

    Full Text Available BAP1 is a tumor suppressor gene that is lost or deleted in diverse cancers, including uveal mela¬noma, malignant pleural mesothelioma (MPM, clear cell renal carcinoma, and cholangiocarcinoma. Recently, BAP1 germline mutations have been reported in families with combinations of these same cancers. A particular challenge for mutation screening is the classification of non-truncating BAP1 sequence variants because it is not known whether these subtle changes can affect the protein function sufficiently to predispose to cancer development. Here we report mRNA splicing analysis on a homozygous substitution mutation, BAP1 c. 2054 A&T (p.Glu685Val, identified in an MPM cell line derived from a mesothelioma patient. The mutation occurred at the 3rd nucleotide from the 3' end of exon 16. RT-PCR, cloning and subsequent sequencing revealed several aberrant splicing products not observed in the controls: 1 a 4 bp deletion at the end of exon 16 in all clones derived from the major splicing product. The BAP1 c. 2054 A&T mutation introduced a new 5' splice site (GU, which resulted in the deletion of 4 base pairs and presumably protein truncation; 2 a variety of alternative splicing products that led to retention of different introns: introns 14-16; introns 15-16; intron 14 and intron 16; 3 partial intron 14 and 15 retentions caused by activation of alternative 3' splice acceptor sites (AG in the introns. Taken together, we were unable to detect any correctly spliced mRNA transcripts in this cell line. These results suggest that aberrant splicing caused by this mutation is quite efficient as it completely abolishes normal splicing through creation of a novel 5' splice site and activation of cryptic splice sites. These data support the conclusion that BAP1 c.2054 A&T (p.E685V variant is a pathogenic mutation and contributes to MPM through disruption of normal splicing.

  12. Mutations in Splicing Factor Genes Are a Major Cause of Autosomal Dominant Retinitis Pigmentosa in Belgian Families

    Science.gov (United States)

    Coppieters, Frauke; Roels, Dimitri; De Jaegere, Sarah; Flipts, Helena; De Zaeytijd, Julie; Walraedt, Sophie; Claes, Charlotte; Fransen, Erik; Van Camp, Guy; Depasse, Fanny; Casteels, Ingele; de Ravel, Thomy

    2017-01-01

    Purpose Autosomal dominant retinitis pigmentosa (adRP) is characterized by an extensive genetic heterogeneity, implicating 27 genes, which account for 50 to 70% of cases. Here 86 Belgian probands with possible adRP underwent genetic testing to unravel the molecular basis and to assess the contribution of the genes underlying their condition. Methods Mutation detection methods evolved over the past ten years, including mutation specific methods (APEX chip analysis), linkage analysis, gene panel analysis (Sanger sequencing, targeted next-generation sequencing or whole exome sequencing), high-resolution copy number screening (customized microarray-based comparative genomic hybridization). Identified variants were classified following American College of Medical Genetics and Genomics (ACMG) recommendations. Results Molecular genetic screening revealed mutations in 48/86 cases (56%). In total, 17 novel pathogenic mutations were identified: four missense mutations in RHO, five frameshift mutations in RP1, six mutations in genes encoding spliceosome components (SNRNP200, PRPF8, and PRPF31), one frameshift mutation in PRPH2, and one frameshift mutation in TOPORS. The proportion of RHO mutations in our cohort (14%) is higher than reported in a French adRP population (10.3%), but lower than reported elsewhere (16.5–30%). The prevalence of RP1 mutations (10.5%) is comparable to other populations (3.5%-10%). The mutation frequency in genes encoding splicing factors is unexpectedly high (altogether 19.8%), with PRPF31 the second most prevalent mutated gene (10.5%). PRPH2 mutations were found in 4.7% of the Belgian cohort. Two families (2.3%) have the recurrent NR2E3 mutation p.(Gly56Arg). The prevalence of the recurrent PROM1 mutation p.(Arg373Cys) was higher than anticipated (3.5%). Conclusions Overall, we identified mutations in 48 of 86 Belgian adRP cases (56%), with the highest prevalence in RHO (14%), RP1 (10.5%) and PRPF31 (10.5%). Finally, we expanded the molecular

  13. FOX-2 Dependent Splicing of Ataxin-2 Transcript Is Affected by Ataxin-1 Overexpression

    Science.gov (United States)

    Welzel, Franziska; Kaehler, Christian; Isau, Melanie; Hallen, Linda; Lehrach, Hans; Krobitsch, Sylvia

    2012-01-01

    Alternative splicing is a fundamental posttranscriptional mechanism for controlling gene expression, and splicing defects have been linked to various human disorders. The splicing factor FOX-2 is part of a main protein interaction hub in a network related to human inherited ataxias, however, its impact remains to be elucidated. Here, we focused on the reported interaction between FOX-2 and ataxin-1, the disease-causing protein in spinocerebellar ataxia type 1. In this line, we further evaluated this interaction by yeast-2-hybrid analyses and co-immunoprecipitation experiments in mammalian cells. Interestingly, we discovered that FOX-2 localization and splicing activity is affected in the presence of nuclear ataxin-1 inclusions. Moreover, we observed that FOX-2 directly interacts with ataxin-2, a protein modulating spinocerebellar ataxia type 1 pathogenesis. Finally, we provide evidence that splicing of pre-mRNA of ataxin-2 depends on FOX-2 activity, since reduction of FOX-2 levels led to increased skipping of exon 18 in ataxin-2 transcripts. Most striking, we observed that ataxin-1 overexpression has an effect on this splicing event as well. Thus, our results demonstrate that FOX-2 is involved in splicing of ataxin-2 transcripts and that this splicing event is altered by overexpression of ataxin-1. PMID:22666429

  14. Long SAGE analysis of genes differentially expressed in the midgut ...

    African Journals Online (AJOL)

    USER

    identification of genes related to sexual disparity in silk protein production efficiency. ... Ysh, a yellow cocoon color sex-limited strain of the silkworm B. mori, ...... alternative splicing of human genes. ... Structure, function and evolution of.

  15. Conservation and sex-specific splicing of the doublesex gene in the ...

    Indian Academy of Sciences (India)

    2010-09-06

    Sep 6, 2010 ... Traditionally, industry has depended on chem- ical insecticides and good farming practices but with the increasing resistance to some commonly used insecticides, there is great interest in alternative control measures, includ- ing genetic approaches. Over 20 years ago, Foster and colleagues developed.

  16. Contradiction between plastid gene transcription and function due to complex posttranscriptional splicing: an exemplary study of ycf15 function and evolution in angiosperms.

    Directory of Open Access Journals (Sweden)

    Chao Shi

    Full Text Available Plant chloroplast genes are usually co-transcribed while its posttranscriptional splicing is fairly complex and remains largely unsolved. On basis of sequencing the three complete Camellia (Theaceae chloroplast genomes for the first time, we comprehensively analyzed the evolutionary patterns of ycf15, a plastid gene quite paradoxical in terms of its function and evolution, along the inferred angiosperm phylogeny. Although many species in separate lineages including the three species reported here contained an intact ycf15 gene in their chloroplast genomes, the phylogenetic mixture of both intact and obviously disabled ycf15 genes imply that they are all non-functional. Both intracellular gene transfer (IGT and horizontal gene transfer (HGT failed to explain such distributional anomalies. While, transcriptome analyses revealed that ycf15 was transcribed as precursor polycistronic transcript which contained ycf2, ycf15 and antisense trnL-CAA. The transcriptome assembly was surprisingly found to cover near the complete Camellia chloroplast genome. Many non-coding regions including pseudogenes were mapped by multiple transcripts, indicating the generality of pseudogene transcriptions. Our results suggest that plastid DNA posttranscriptional splicing may involve complex cleavage of non-functional genes.

  17. Splicing pattern - ASTRA | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available List Contact us ASTRA Splicing pattern Data detail Data name Splicing pattern DOI 10.18908/lsdba.nbdc00371-0...04 Description of data contents The patterns of alternative splicing/transcriptional initiation Data file Fi...le name: astra_splicing_pattern.zip File URL: ftp://ftp.biosciencedbc.jp/archive/astra/LATEST/astra_splicing_patt...ogodb/view/astra_splicing_pattern#en Data acquisition method For the five organisms (H. sapiens, M. musculus...apping data into bit arrays, detection of splicing patterns and distribution to t

  18. A novel aberrant splicing mutation of the PEX16 gene in two patients with Zellweger syndrome

    NARCIS (Netherlands)

    Shimozawa, Nobuyuki; Nagase, Tomoko; Takemoto, Yasuhiko; Suzuki, Yasuyu