Search results for "RNA Splicing"
showing 10 items of 109 documents
The mitochondrial genome of fission yeast: inability of all introns to splice autocatalytically, and construction and characterization of an intronle…
1991
In this paper we report the inability of four group I introns in the gene encoding subunit I of cytochrome c oxidase (cox1) and the group II intron in the apocytochrome b gene (cob) to splice autocatalytically. Furthermore we present the characterization of the first cox1 intron in the mutator strain anar-14 and the construction and characterization of strains with intronless mitochondrial genomes. We provide evidence that removal of introns at the DNA level (termed DNA splicing) is dependent on an active RNA maturase. Finally we demonstrate that the absence of introns does not abolish homologous mitochondrial recombination.
All-atom simulations disentangle the functional dynamics underlying gene maturation in the intron lariat spliceosome
2018
The spliceosome (SPL) is a majestic macromolecular machinery composed of five small nuclear RNAs and hundreds of proteins. SPL removes noncoding introns from precursor messenger RNAs (pre-mRNAs) and ligates coding exons, giving rise to functional mRNAs. Building on the first SPL structure solved at near–atomic-level resolution, here we elucidate the functional dynamics of the intron lariat spliceosome (ILS) complex through multi-microsecond-long molecular-dynamics simulations of ∼1,000,000 atoms models. The ILS essential dynamics unveils (i) the leading role of the Spp42 protein, which heads the gene maturation by tuning the motions of distinct SPL components, and (ii) the critical particip…
Assembly of a Filamin Four-domain Fragment and the Influence of Splicing Variant-1 on the Structure
2011
Filamins are scaffold proteins that bind to various proteins, including the actin cytoskeleton, integrin adhesion receptors, and adaptor proteins such as migfilin. Alternative splicing of filamin, largely constructed from 24 Ig-like domains, is thought to have a role in regulating its interactions with other proteins. The filamin A splice variant-1 (FLNa var-1) lacks 41 amino acids, including the last β-strand of domain 19, FLNa(19), and the first β-strand of FLNa(20) that was previously shown to mask a key binding site on FLNa(21). Here, we present a structural characterization of domains 18-21, FLNa(18-21), in the FLNa var-1 as well as its nonspliced counterpart. A model of nonspliced FLN…
Development of aDrosophila melanogasterspliceosensor system forin vivohigh-throughput screening in myotonic dystrophy type 1
2014
AbstractAlternative splicing of pre-mRNAs is an important mechanism that regulates cellular function in higher eukaryotes. A growing number of human genetic diseases involve splicing defects that are directly connected to their pathology. In myotonic dystrophy type 1 (DM1), several clinical manifestations have been proposed to be the consequence of tissue-specific missplicing of numerous genes. These events are triggered by an RNA gain-of-function and resultant deregulation of specific RNA-binding factors, such as the nuclear sequestration of muscleblind-like family factors (MBNL1-MBNL3). Thus, the identification of chemical modulators of splicing events could lead to the development of the…
Assembly of fluorescent chimeric virus-like particles of canine parvovirus in insect cells
2004
Canine parvovirus (CPV) is a small non-enveloped ssDNA virus composed of the viral proteins VP1, VP2, and VP3 with a T=1 icosahedral symmetry. VP2 is nested in VP1 and the two proteins are produced by differential splicing of a primary transcript of the right ORF of the viral genome. The VP2 protein can be further proteolytically cleaved to form VP3. Previous studies have shown that VP1 and VP3 are unnecessary for capsid formation and consequently, that VP2 alone is sufficient for assembly. We have hypothesized that insertion of the enhanced green fluorescent protein (EGFP) at the N-terminus of VP2 could be carried out without altering assembly. To investigate the possibility to develop flu…
BASE-SPECIFIC RIBONUCLEASES POTENTIALLY INVOLVED IN HETEROGENEOUS NUCLEAR-RNA PROCESSING AND POLY(A) METABOLISM
1984
Abstract Polyadenylation and splicing of heterogeneous nuclear RNA, two crucial steps in mRNA processing, are apparently enzymically mediated processes. This contribution summarizes the properties and the presumed functions of the known poly(A) catabolic enzymes (endoribonuclease IV and V, 2′,3′-exoribonuclease) as well as those of the pyrimidine-specific endoribonucleases associated with snRNP—hnRNP complexes (endoribonuclease VII, acidic p I 4.1 endoribonuclease and poly(U)-specific U1 snRNP-nuclease).
Noncanonical RNAs from transcripts of the Drosophila muscleblind gene.
2006
It has become increasingly evident that eukaryotic cells produce RNA molecules from coding genes with constitutions other than those of typically spliced mRNA transcripts. Here we describe new cDNAs from the Drosophila melanogaster muscleblind (mbl ) locus that identify two such atypical RNA molecules: RNAs containing an incomplete exon 2 tandem repetition (mblE2E2#) or having exons with a different order compared to the corresponding genomic DNA (mblE2E3#E2#; exon scrambling). The existence of exon duplications and rearrangements in the genomic locus that might explain such cDNAs was ruled out by genomic Southern blotting and in silico analysis of the Drosophila genome sequence. The incomp…
Homozygous familial hypobetalipoproteinemia: two novel mutations in the splicing sites of apolipoprotein B gene and review of the literature.
2015
Objective: Familial hypobetalipoproteinemia (FHBL) is autosomal codominant disorder of lipoprotein metabolism characterized by low plasma levels of total cholesterol (TC), low-density lipoproteincholesterol (LDL-C) and apolipoprotein B (apoB) below the 5 th percentile of the distribution in the population. Patients with the clinical diagnosis of homozygous FHBL (Ho-FHBL) are extremely rare and few patients have been characterized at the molecular level. Here we report the medical history and the molecular characterization of one paediatric patient with clinical features of Ho-FHBL. Methods: A one month old infant with failure to thrive, severe hypocholesterolemia and acanthocytosis was clin…
The interaction of recombinant subdomains of the procollagen C-proteinase with procollagen I provides a quantitative explanation for functional diffe…
2006
The procollagen C-proteinase (PCP) is a zinc peptidase of the astacin family and the metzincin superfamily. The enzyme removes the C-terminal propeptides of fibrillar procollagens and activates other matrix proteins. Besides its catalytic protease domain, the procollagen C-proteinase contains several C-terminal CUB modules (named after complement factors C1r and C1s, the sea urchin UEGF protein, and BMP-1) and EGF-like domains. The two major splice forms of the C-proteinase differ in their overall domain composition. The longer variant, termed mammalian tolloid (mTld, i.e., PCP-2), has the protease- CUB1-CUB2-EGF1-CUB3-EGF2-CUB4-CUB5 composition, whereas the shorter form termed bone morphog…
Expression and glycosylation studies of human FGF receptor 4
2001
Fibroblast growth factor receptor subtype 4 (FGFR4) has been shown to have special activation properties and just one splicing form, unlike the other FGFRs. FGFR4 overexpression is correlated with breast cancer and therefore FGFR4 is a target for drug design. Our aim is to overexpress high amounts of homogeneous FGFR4 extracellular domain (FGFR4ed) for structural studies. We show that baculovirus-insect cell-expressed FGFR4ed is glycosylated on three (N88, N234, and N266) of the six possible N-glycosylation sites but is not O-glycosylated. The deglycosylated triple mutant was expressed and had binding properties similar to those of glycosylated FGFR4ed, but was still heterogeneous. Large am…