The exon junction complex (EJC) deposited upstream of mRNA exon junctions shapes structure, composition, and fate of spliced mRNA ribonucleoprotein particles (mRNPs). To achieve this, the EJC core nucleates assembly of a dynamic shell of peripheral proteins that function in diverse post-transcriptional processes. To illuminate consequences of EJC composition change, we purified EJCs from human cells via peripheral proteins RNPS1 and CASC3. We show that the EJC originates as an SR-rich mega-dalton-sized RNP that contains RNPS1 but lacks CASC3. Sometime before or during translation, the EJC undergoes compositional and structural remodeling into an SR-devoid monomeric complex that contains CASC3. Surprisingly, RNPS1 is important for nonsense-mediated mRNA decay (NMD) in general, whereas CASC3 is needed for NMD of only select mRNAs. The switch to CASC3-EJC slows down NMD. Overall, the EJC compositional switch dramatically alters mRNP structure and specifies two distinct phases of EJC-dependent NMD.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6328047 | PMC |
| http://dx.doi.org/10.1016/j.celrep.2018.11.046 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Unlabelled: Pre-mRNA splicing, carried out in the nucleus by a large ribonucleoprotein machine known as the spliceosome, is functionally and physically coupled to the mRNA surveillance pathway in the cytoplasm called nonsense mediated mRNA decay (NMD). The NMD pathway monitors for premature translation termination signals, which can result from alternative splicing, by relying on the exon junction complex (EJC) deposited on exon-exon junctions by the spliceosome. Recently, multiple genetic screens in human cell lines have identified numerous spliceosome components as putative NMD factors.
View Article and Find Full Text PDFNovel variant alters splicing of in family with features of Loeys-Dietz syndrome.
Front Genet
December 2024
HudsonAlpha Institute for Biotechnology, Huntsville, AL, United States.
Loeys-Dietz syndrome (LDS) is a connective tissue disorder representing a wide spectrum of phenotypes, ranging from isolated thoracic aortic aneurysm or dissection to a more severe syndromic presentation with multisystemic involvement. Significant clinical variability has been noted for both related and unrelated individuals with the same pathogenic variant. We report a family of five affected individuals with notable phenotypic variability who appear to have two distinct molecular causes of LDS, one attributable to a missense variant in and the other an intronic variant 6 bp upstream from a splice junction in .
View Article and Find Full Text PDFTalin1 dysfunction is genetically linked to systemic capillary leak syndrome.
JCI Insight
December 2024
Institute of BioInnovation, Biomedical Sciences Research Centre "Alexander Fleming," Vari-Athens, Greece.
Systemic capillary leak syndrome (SCLS) is a rare life-threatening disorder due to profound vascular leak. The trigger and the cause of the disease are currently unknown and there is no specific treatment. Here, we identified a rare heterozygous splice-site variant in the TLN1 gene in a familial SCLS case, suggestive of autosomal dominant inheritance with incomplete penetrance.
View Article and Find Full Text PDFA Novel Compound Heterozygous Mutation in Progressive Familial Intrahepatic Cholestasis (PFIC) 4: A Rare Case Report With Literature Review.
Cureus
November 2024
Department of Gastroenterology, Topiwala National Medical College & BYL Nair Charitable Hospital, Mumbai, IND.
A 12-year-old female, resident of western India, presented with a history of pruritus associated with jaundice for two months. On presentation, she had icterus with mild palpable hepatomegaly. Investigations revealed direct hyperbilirubinemia and elevated transaminases, while gamma-glutamyl transferase levels were normal.
View Article and Find Full Text PDFProteoglycan 4 (Lubricin) and regulation of xanthine oxidase in synovial macrophage as a mechanism of controlling synovitis.
Arthritis Res Ther
December 2024
Department of Emergency Medicine, Rhode Island Hospital, Providence, RI, USA.
Background: Synovial macrophages (SMs) are important effectors of joint health and disease. A novel Cx3CR1 + TREM2 + SM population expressing the tight junction protein claudin-5, was recently discovered in synovial lining. Ablation of these SMs was associated with onset of arthritis.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!