The bursicon gene in mosquitoes: an unusual example of mRNA trans-splicing.
Ontology highlight
ABSTRACT:
SUBMITTER: Robertson HM
PROVIDER: S-EPMC1894596 | biostudies-literature | 2007 Jun
REPOSITORIES: biostudies-literature
Publications
The bursicon gene in mosquitoes: an unusual example of mRNA trans-splicing.
Robertson Hugh M HM Navik Julia A JA Walden Kimberly K O KK Honegger Hans-Willi HW
Genetics 20070415 2
The bursicon gene in Anopheles gambiae is encoded by two loci. Burs124 on chromosome arm 2L contains exons 1, 2, and 4, while burs3 on arm 2R contains exon 3. Exon 3 is efficiently spliced into position in the mature transcript. This unusual gene arrangement is ancient within mosquitoes, being shared by Aedes aegypti and Culex pipiens. ...[more]
Similar Datasets
Project description:Ocular gene therapy with recombinant adeno-associated virus (AAV) has shown vector-mediated gene augmentation to be safe and efficacious in the retina in one set of diseases (retinitis pigmentosa and Leber congenital amaurosis (LCA) caused by RPE65 deficiency), with excellent safety profiles to date and potential for efficacy in several additional diseases. However, size constraints imposed by the packaging capacity of the AAV genome restrict application to diseases with coding sequence lengths that are less than 5,000 nt. The most prevalent retinal diseases with monogenic inheritance are caused by mutations in genes that exceed this capacity. Here, we designed a spliceosome mediated pre-mRNA trans-splicing strategy to rescue expression of CEP290, which is associated with Leber congenital amaurosis type 10 (LCA10) and several syndromic diseases including Joubert syndrome. We used this reagent to demonstrate editing of CEP290 in cell lines in vitro and in vivo in a mini-gene mouse model. This study is the first to show broad editing of CEP290 transcripts and in vivo proof of concept for editing of CEP290 transcripts in photoreceptors and paves the way for future studies evaluating therapeutic effects.
| S-EPMC6023944 | biostudies-literature
Project description:We report the discovery of mRNA 5'-leader trans-splicing (SL trans-splicing) in the chordates. In the ascidian protochordate Ciona intestinalis, the mRNAs of at least seven genes undergo trans-splicing of a 16-nucleotide 5'-leader apparently derived from a 46-nucleotide RNA that shares features with previously characterized splice donor SL RNAs. SL trans-splicing was known previously to occur in several protist and metazoan phyla, however, this is the first report of SL trans-splicing within the deuterostome division of the metazoa. SL trans-splicing is not known to occur in the vertebrates. However, because ascidians are primitive chordates related to vertebrate ancestors, our findings raise the possibility of ancestral SL trans-splicing in the vertebrate lineage.
| S-EPMC312621 | biostudies-literature
Project description:The expression of functional T cell receptor-beta (TCR-beta) transcripts requires the activation of programmed DNA rearrangement events. It is not clear whether other mechanisms dictate TCR-beta mRNA levels during thymic ontogeny. We examined the potential role of RNA splicing as a regulatory mechanism. As a model system, we used an immature T cell clone, SL12.4, that transcribes a fully rearranged TCR-beta gene but essentially lacks mature 1.3-kb TCR-beta transcripts in the cytoplasm. Abundant TCR-beta splicing intermediates accumulate in the nucleus of this cell clone. These splicing intermediates result from inefficient or inhibited excision of four of the five TCR-beta introns; the only intron that is efficiently spliced is the most 5' intron, IVSL. The focal point for the regulation appears to be IVS1C beta 1 and IVS2C beta 1, since unusual splicing intermediates that have cleaved the 5' splice site but not the 3' splice site of these two introns accumulate in vivo. The block in 3' splice site cleavage is of interest since sequence analysis reveals that these two introns possess canonical splice sites. A repressional mechanism involving a labile repressor protein may be responsible for the inhibition of RNA splicing since treatment of SL12.4 cells with the protein synthesis inhibitor cycloheximide reversibly induces a rapid and dramatic accumulation of fully spliced TCR-beta transcripts in the cytoplasm, concomitant with a decline in TCR-beta pre-mRNAs in the nucleus. This inducible system may be useful for future studies analyzing the underlying molecular mechanisms that regulate RNA splicing.
| S-EPMC359481 | biostudies-other
Project description:Cytochrome oxidase subunit 3 (Cox3) is a mitochondrion-encoded core membrane protein of complex IV of the mitochondrial respiratory chain, and consists of seven trans-membrane helices. Here we show that in diverse later-branching dinoflagellates, cox3 is consistently split into two exons in the mitochondrial genome between helices six and seven. Gene exons are transcribed as two discrete oligoadenylated precursor RNAs, and these are subsequently trans-spliced to form a complete coding mRNA. This trans-splicing is highly unusual in that some of the oligoadenylated tail is incorporated at the splice site, such that a short string of adenosines links the two coding exons. This feature is consistently represented in diverse dinoflagellates, however the number of adenosines added varies according to the size of the coding gap between the two exons. Thus we observed between zero (Amphidinium carterae) and 10 (Symbiodinium sp.) adenosines added in different taxa, but the final coding sequence length is identical with the reading frame maintained. Northern analyses show that precursor cox3 transcripts are approximately equally abundant as mature cox3 mRNAs, suggesting a slow or regulated maturation process. These data indicate that the splicing mechanism in dinoflagellate mitochondria is tolerant of variations in the length of the precursor coding sequence, and implicates the use of a splicing template, or guide molecule, during splicing that controls mature mRNA length.
| S-EPMC3577742 | biostudies-literature
Project description:Dynamin 2 (DNM2) is a large GTPase, ubiquitously expressed, involved in membrane trafficking and regulation of actin and microtubule cytoskeletons. DNM2 mutations cause autosomal dominant centronuclear myopathy which is a rare congenital myopathy characterized by skeletal muscle weakness and histopathological features including nuclear centralization in absence of regeneration. No curative treatment is currently available for the DNM2-related autosomal dominant centronuclear myopathy. In order to develop therapeutic strategy, we evaluated here the potential of Spliceosome-Mediated RNA Trans-splicing technology to reprogram the Dnm2-mRNA in vitro and in vivo in mice. We show that classical 3'-trans-splicing strategy cannot be considered as accurate therapeutic strategy regarding toxicity of the pre-trans-splicing molecules leading to low rate of trans-splicing in vivo. Thus, we tested alternative strategies devoted to prevent this toxicity and enhance frequency of trans-splicing events. We succeeded to overcome the toxicity through a 5'-trans-splicing strategy which also allows detection of trans-splicing events at mRNA and protein levels in vitro and in vivo. These results suggest that the Spliceosome-Mediated RNA Trans-splicing strategy may be used to reprogram mutated Dnm2-mRNA but highlight the potential toxicity linked to the molecular tools which have to be carefully investigated during preclinical development.
| S-EPMC5056991 | biostudies-literature
Project description:Although spliced leader (SL) trans-splicing in the chordates was discovered in the tunicate Ciona intestinalis there has been no genomic overview analysis of the extent of trans-splicing or the make-up of the trans-spliced and non-trans-spliced gene populations of this model organism. Here we report such an analysis for Ciona based on the oligo-capping full-length cDNA approach. We randomly sampled 2078 5'-full-length ESTs representing 668 genes, or 4.2% of the entire genome. Our results indicate that Ciona contains a single major SL, which is efficiently trans-spliced to mRNAs transcribed from a specific set of genes representing approximately 50% of the total number of expressed genes, and that individual trans-spliced mRNA species are, on average, 2-3-fold less abundant than non-trans-spliced mRNA species. Our results also identify a relationship between trans-splicing status and gene functional classification; ribosomal protein genes fall predominantly into the non-trans-spliced category. In addition, our data provide the first evidence for the occurrence of polycistronic transcription in Ciona. An interesting feature of the Ciona polycistronic transcription units is that the great majority entirely lack intercistronic sequences.
| S-EPMC1488885 | biostudies-literature
Project description:Polyketide biosynthesis engages a series of well-timed biosynthetic operations to generate elaborate natural products from simple building blocks. Mimicry of these processes has offered practical means for total synthesis and provided a foundation for reaction discovery. We now report an unusual intramolecular trans-amidation reaction discovered while preparing stabilized probes for the study of actinorhodin biosynthesis. This rapid cyclization event offers insight into the natural cyclization process inherent to the biosynthesis of type II polyketide antibiotics.
| S-EPMC4917018 | biostudies-literature
Project description:The Drosophila BTB domain containing gene mod(mdg4) produces a large number of protein isoforms combining a common N-terminal region of 402 aa with different C termini. We have deduced the genomic structure of this complex locus and found that at least seven of the mod(mdg4) isoforms are encoded on both of its antiparallel DNA strands, suggesting the generation of mature mRNAs by trans-splicing. In transgenic assays, we demonstrate the ability of Drosophila to produce mod(mdg4) mRNAs by trans-splicing of pre-mRNAs generated from transgenes inserted at distant chromosomal positions. Furthermore, evidence is presented for occurring of trans-splicing of mod(mdg4)-specific exons encoded by the parallel DNA strand. The mod(mdg4) locus represents a new type of complex gene structure in which genetic complexity is resolved by extensive trans-splicing, giving important implications for genome sequencing projects. Demonstration of naturally occurring trans-splicing in the model organism Drosophila opens new experimental approaches toward an analysis of the underlying mechanisms.
| S-EPMC55520 | biostudies-literature
Project description:We present a plasmid-based system in which upstream trans-splicing efficiently generates mRNAs that encode head-to-tail protein multimers. In this system, trans-splicing occurs between one of two downstream splice donors in the sequence encoding a C-terminal V5 epitope tag and an upstream splice acceptor in the 5' region of the pCS2(+) host plasmid. Using deletion and fusion constructs of the DUX4 protein as an example, we found that this system produced trans-spliced mRNAs in which coding regions from independent transcripts were fused in phase such that covalent head-to-tail protein multimers were translated. For a cDNA of ~450?bp, about half of the expressed proteins were multimeric, with the efficiency of trans-splicing and extent of multimer expression decreasing as cDNA length increased. This system generated covalent heterodimeric proteins upon co-transfections of plasmids encoding separate proteins and did not require a long complementary binding domain to position mRNAs for trans-splicing. This plasmid-based trans-splicing system is adaptable to multiple gene delivery systems, and it presents new opportunities for investigating molecular mechanisms of trans-splicing, generating covalent protein multimers with novel functions within cells, and producing mRNAs encoding large proteins from split precursors.
| S-EPMC6381186 | biostudies-literature
Project description:RNA editing and splicing are the two major processes that dynamically regulate human transcriptome diversity. Despite growing evidence of crosstalk between RNA editing enzymes (mainly ADAR1) and splicing machineries, detailed mechanistic explanations and their biological importance in diseases, such as cancer are still lacking. Herein, we identify approximately a hundred high-confidence splicing events altered by ADAR1 and/or ADAR2, and ADAR1 or ADAR2 protein can regulate cassette exons in both directions. We unravel a binding tendency of ADARs to dsRNAs that involves GA-rich sequences for editing and splicing regulation. ADAR1 edits an intronic splicing silencer, leading to recruitment of SRSF7 and repression of exon inclusion. We also present a mechanism through which ADAR2 binds to dsRNA formed between GA-rich sequences and polypyrimidine (Py)-tract and precludes access of U2AF65 to 3' splice site. Furthermore, we find these ADARs-regulated splicing changes per se influence tumorigenesis, not merely byproducts of ADARs editing and binding.
| S-EPMC7005744 | biostudies-literature