Functional Characterization of Splicing Regulatory Elements

Functional Characterization of Splicing Regulatory Elements PDF Author: Scott Adamson
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
Alternative splicing is a key process in higher eukaryotes in which different introns in pre-mRNA are removed to generate diversity in mature RNA products. Changes in alternative splicing are important under normal conditions for expanding the proteome and regulating RNA species, however splicing dysregulation can underlie monogenic and polygenic diseases. Understanding the connection between genetic variants and phenotypes is a major goal of personalized medicine and is key to understanding the underlying biological processes. Here I develop a novel highthroughput splicing reporter assay to elucidate the impact of genetic variants on pre-mRNA splicing efficiency called variant exon sequencing (Vex-seq). The utility of Vex-seq is first demonstrated in the context of thousands of variants found in the human population across 110 exons, then it is applied to understand the sequence determinants of splicing regulatory elements. These splicing regulatory elements were identified by examining ENCODE data which monitors RNA-protein interactions, and changes in splicing upon RNA binding protein (RBP) knockdown. Vex-seq is used to identify sequence features associated with RBP-specific splicing regulation and contribute to our understanding of a key, understudied mechanistic link between sequence variation and splicing regulation.

Functional Characterization of Splicing Regulatory Elements

Functional Characterization of Splicing Regulatory Elements PDF Author: Scott Adamson
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
Alternative splicing is a key process in higher eukaryotes in which different introns in pre-mRNA are removed to generate diversity in mature RNA products. Changes in alternative splicing are important under normal conditions for expanding the proteome and regulating RNA species, however splicing dysregulation can underlie monogenic and polygenic diseases. Understanding the connection between genetic variants and phenotypes is a major goal of personalized medicine and is key to understanding the underlying biological processes. Here I develop a novel highthroughput splicing reporter assay to elucidate the impact of genetic variants on pre-mRNA splicing efficiency called variant exon sequencing (Vex-seq). The utility of Vex-seq is first demonstrated in the context of thousands of variants found in the human population across 110 exons, then it is applied to understand the sequence determinants of splicing regulatory elements. These splicing regulatory elements were identified by examining ENCODE data which monitors RNA-protein interactions, and changes in splicing upon RNA binding protein (RBP) knockdown. Vex-seq is used to identify sequence features associated with RBP-specific splicing regulation and contribute to our understanding of a key, understudied mechanistic link between sequence variation and splicing regulation.

Isolation and Characterization of Splicing Regulatory Elements from the C-src Pre-messenger RNA

Isolation and Characterization of Splicing Regulatory Elements from the C-src Pre-messenger RNA PDF Author: Edward Frank Modafferi
Publisher:
ISBN:
Category :
Languages : en
Pages : 238

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RNA Splicing Regulation in Drosophila Melanogaster

RNA Splicing Regulation in Drosophila Melanogaster PDF Author: Angela Norie Brooks
Publisher:
ISBN:
Category :
Languages : en
Pages : 236

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Book Description
A majority of metazoan genes contain introns in their primary transcripts (pre-mRNA) that require removal by the spliceosome--a cellular complex composed of protein and RNA. Upon removal of introns from the primary transcript, the remaining exonic portion of the transcript is spliced together. It is essential to remove the correct intronic portion of a primary transcript in order to produce the desired product, typically a protein-coding mRNA. Pre-mRNAs are alternatively spliced when different intron boundaries are used by the spliceosome, thus creating different mRNA products. Alternative splicing allows for an additional step of gene regulation by producing transcript isoforms that can be differentially processed in a particular tissue or developmental time point. Alternative splicing is primarily regulated by RNA binding proteins that bind to pre-mRNA and act to recruit or inhibit the spliceosome at specific splice sites. A central aim of this work is to gain a better understanding of splicing regulation by the identification and characterization of protein regulators of splicing and cis-acting splicing regulatory sequences in the model organism, Drosophila melanogaster. To identify splicing regulatory elements, many previous studies in vertebrate genomes have used computational methods. In collaboration with Anna I. Podgornaia, I applied such an approach to predict splicing regulatory elements in Drosophila melanogaster and compared them with elements found in vertebrates. I identified 330 putative splicing enhancer sequences enriched near weak 5' and 3' splice sites of constitutively spliced introns. I found that a significant proportion (58%) of D. melanogaster enhancers were previously reported as splicing enhancers in vertebrates. To provide additional evidence for the function of the intronic splicing enhancers (ISEs), I identified intronic hexamers significantly enriched within sequences phylogenetically conserved among 15 insect species. This analysis uncovered 73 putative ISEs that are also enriched in conserved regions of the D. melanogaster genome. The functions of nine enhancer sequences were verified in a heterologous splicing reporter by Julie L. Aspden, demonstrating that these sequences are sufficient to enhance splicing in vivo. Taken together, these data identify a set of predicted positive-acting splicing regulatory motifs in the Drosophila genome and highlight those regulatory sequences that are present in distant metazoan genomes. To identify and characterize splicing regulators, collaborators and I have combined RNAi and RNA-Seq to identify exons that are regulated by 58 known or putative splicing regulators. To identify and quantify alternative splicing events from RNA-Seq data, I developed the JuncBASE (Junction Based Analysis of Splicing Events) software package. For a pilot study, I identified 404 splicing events significantly affected upon depletion of pasilla. Preliminary analysis showed 879 splicing events affected by at least one of the 57 other proteins. The sequence regions upstream and within Pasilla-repressed exons and downstream of Pasilla-activated exons are enriched for YCAY repeats, which is consistent with the location of these motifs near regulated exons of the mammalian ortholog, Nova. Thus, the RNA regulatory map of Pasilla and Nova is highly conserved between insects and mammals despite the fact that the pre-mRNAs that are regulated by Pasilla and Nova are almost entirely non-overlapping. This observation strongly suggests that the regulatory codes of individual RNA binding proteins are nearly immutable, yet the regulatory modules controlled by these proteins are highly evolvable. I also present RNA regulatory maps for the four hnRNP proteins: hrp36, hrp38, hrp40, and hrp48. Lastly, I examine splicing regulation throughout the life cycle of D. melanogaster. Using transcriptome data from 30 developmental time points produced by collaborators from the modENCODE Consortium, I identified a total of 23,859 alternative splicing events in Drosophila, taking into account all transcript information from D. melanogaster annotations, short sequenced reads (Illumina RNA-Seq), sequenced cDNA, long RNA-Seq reads (454 RNA-Seq) from adult flies, and short read sequences of rRNA-depleted RNA from embryonic time points. I observed that 60.7% of intron-containing genes in D. melanogaster are alternatively spliced. Using only the Illumina RNA-Seq reads throughout development, 21,216 splicing events were expressed and 13,951 events were differentially spliced in at least one time point. I also observed exons with similar patterns of splicing changes throughout development as well as sex-biased alternative splicing. Integrating information from our pasilla study, I also observed correlations of pasilla gene expression with alternative splicing changes of its target exons throughout development.

Systematic Functional Analyses of Spliceosomal Components Reveal Novel Mechanisme of Alternative Splicing Regulation

Systematic Functional Analyses of Spliceosomal Components Reveal Novel Mechanisme of Alternative Splicing Regulation PDF Author: Juan Ramón Tejedor Vaquero
Publisher:
ISBN:
Category :
Languages : en
Pages : 233

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Book Description
Alternative splicing is an essential regulatory layer of gene expression that expands the coding potential of the genome in multicellular organisms. The spliceosome -the sophisticated machinery involved in intron removal- allows versatile regulation of gene expression programs. The splicing process relies on the dynamic interplay between hundreds of components of the spliceosome, and the steps at which the complex process of the splicing reaction can be regulated remain largely unknown. The main objective of this thesis has been to develop high- throughput approaches to systematically identify novel regulators of alternative splicing, as well as to study the mechanisms by which they modulate splice site choice. We have identified a variety of regulators of Fas/CD95 alternative splicing within and outside of the splicing machinery and provide novel insights into connections between iron homeostasis and alternative splicing regulation. Using computational networks, we carried out a systematic functional analysis of the spliceosome components and their regulatory potential. Our results reveal the extensive regulatory plasticity of core spliceosome components throughout its assembly process. They also identified links between alternative splicing and iron homeostasis, providing a mechanism by which iron modulates alternative splicing through regulation of the RNA binding properties of a Zinc knuckle domain in the SR regulatory protein SRSF7. The results of this thesis highlight the value of high throughput technologies and network analyses to study complex molecular mechanisms, and unveils novel functional connections between the splicing machinery and other cellular processes.

Regulation of Adenovirus Alternative Pre-mRNA Splicing

Regulation of Adenovirus Alternative Pre-mRNA Splicing PDF Author: Bai-Gong Yue
Publisher: Uppsala Universitet
ISBN: 9789155447120
Category : Medical
Languages : en
Pages : 55

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Eukaryotic MRNA Processing

Eukaryotic MRNA Processing PDF Author: Adrian Krainer
Publisher: IRL Press
ISBN:
Category : Language Arts & Disciplines
Languages : en
Pages : 408

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Book Description
This volume focuses on the major aspects of post-transcriptional mRNA processing in the nucleus of eukaryotic cells. Each of the described mRNA reactions is required for proper gene expression and can also serve as a control point for regulating the expression of many genes, for example duringembryonic development or in different cell types. The different chapters review the assembly of newly synthesized nuclear mRNA transcripts into hnRNP particles and catalytically active spliceosomes; the structure and mechanism of action of small nuclear ribonucleoprotein particles and proteinfactors that catalyse pre-mRNA splicing in mammalian cells and in yeast; the regulation of gene expression and generation of protein isoform diversity by alternative splicing; the mechanisms of 3' end cleavage and polyadenylation; the architecture of the cell nucleus in relation to these processesand to the localization of the relevant substrates and factors; the diverse mechanisms of RNA processing by ribozymes and their potential relevance for nuclear mRNA processing; the mechanism of spliced-leader addition by trans-splicing in nematodes and trypanosomes; and the process ofinsertion/deletion mRNA editing in kinetoplasmid protozoa. In each chapter, leading researchers have provided detailed, critical reviews of the history, experimental approaches, major advances, current ideas and models, as well as future directions, for each of these active areas of research.

Characterization of a Composite Exonic Regulatory Element of Splicing (CERES) in CFTR Exon 12

Characterization of a Composite Exonic Regulatory Element of Splicing (CERES) in CFTR Exon 12 PDF Author: Ariful Haque
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Nuclear pre-mRNA Processing in Plants

Nuclear pre-mRNA Processing in Plants PDF Author: A. S. N. Reddy
Publisher: Springer Science & Business Media
ISBN: 3540767762
Category : Science
Languages : en
Pages : 323

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Book Description
During the last few years, tremendous progress has been made in understanding various aspects of pre-mRNA processing. This book, with contributions from leading scientists in this area, summarizes recent advances in nuclear pre-mRNA processing in plants. It provides researchers in the field, as well as those in related areas, with an up-to-date and comprehensive, yet concise, overview of the current status and future potential of this research in understanding plant biology.

Tropomyosin

Tropomyosin PDF Author: Peter Gunning
Publisher: Springer Science & Business Media
ISBN: 0387857664
Category : Medical
Languages : en
Pages : 323

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Book Description
A recent review of one of my grant applications commented on the ‘rediscovery of tropomyosin’. I was tempted to write back in my rebuttal to the reviewer that I didn’t realise it had been lost. Uncharacteristic maturity prevailed and I resisted the temptation, but I was struck by the underlying observation that research on the str- ture and function of tropomyosin has been somewhat invisible, particularly in terms of the cytoskeleton isoforms. So, how can it be that one of the two major components of the actin filament has been so thoroughly overlooked? I suspect that the answer is disappointingly pedestrian. Whereas the biochemistry of the 1980s revealed the potential of tropomyosin isoforms to diversify the function of actin filaments, the subsequent disenchantment with isoform biology in general in the 1990s inhibited growth of this field. With the development of more sophisticated experimental - proaches we are now seeing a growing realisation of the importance of tropomyosin in regulating actin filaments beyond its pivotal role in muscle contraction. The opportunity to edit this book came at a time when we had written several reviews on different aspects of tropomyosin function and I had just finished the background reading for a comprehensive review of tropomyosin biology. I realised that the field was simply beyond the capacity of any one person to do the field j- tice.

Regulation of Alternative Splicing

Regulation of Alternative Splicing PDF Author: Philippe Jeanteur
Publisher:
ISBN: 9783662097298
Category :
Languages : en
Pages : 266

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Book Description