Browsing by Subject "RNA processing"

Now showing 1 - 3 of 3
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    HNRNPC haploinsufficiency affects alternative splicing of intellectual disability-associated genes and causes a neurodevelopmental disorder
    (Elsevier, 2023) Niggl, Eva; Bouman, Arjan; Briere, Lauren C.; Hoogenboezem, Remco M.; Wallaard, Ilse; Park, Joohyun; Admard, Jakob; Wilke, Martina; Harris-Mostert, Emilio D. R. O.; Elgersma, Minetta; Bain, Jennifer; Balasubramanian, Meena; Banka, Siddharth; Benke, Paul J.; Bertrand, Miriam; Blesson, Alyssa E.; Clayton-Smith, Jill; Ellingford, Jamie M.; Gillentine, Madelyn A.; Goodloe, Dana H.; Haack, Tobias B.; Jain, Mahim; Krantz, Ian; Luu, Sharon M.; McPheron, Molly; Muss, Candace L.; Raible, Sarah E.; Robin, Nathaniel H.; Spiller, Michael; Starling, Susan; Sweetser, David A.; Thiffault, Isabelle; Vetrini, Francesco; Witt, Dennis; Woods, Emily; Zhou, Dihong; Genomics England Research Consortium; Undiagnosed Diseases Network; Elgersma, Ype; van Esbroeck, Annelot C. M.; Medical and Molecular Genetics, School of Medicine
    Heterogeneous nuclear ribonucleoprotein C (HNRNPC) is an essential, ubiquitously abundant protein involved in mRNA processing. Genetic variants in other members of the HNRNP family have been associated with neurodevelopmental disorders. Here, we describe 13 individuals with global developmental delay, intellectual disability, behavioral abnormalities, and subtle facial dysmorphology with heterozygous HNRNPC germline variants. Five of them bear an identical in-frame deletion of nine amino acids in the extreme C terminus. To study the effect of this recurrent variant as well as HNRNPC haploinsufficiency, we used induced pluripotent stem cells (iPSCs) and fibroblasts obtained from affected individuals. While protein localization and oligomerization were unaffected by the recurrent C-terminal deletion variant, total HNRNPC levels were decreased. Previously, reduced HNRNPC levels have been associated with changes in alternative splicing. Therefore, we performed a meta-analysis on published RNA-seq datasets of three different cell lines to identify a ubiquitous HNRNPC-dependent signature of alternative spliced exons. The identified signature was not only confirmed in fibroblasts obtained from an affected individual but also showed a significant enrichment for genes associated with intellectual disability. Hence, we assessed the effect of decreased and increased levels of HNRNPC on neuronal arborization and neuronal migration and found that either condition affects neuronal function. Taken together, our data indicate that HNRNPC haploinsufficiency affects alternative splicing of multiple intellectual disability-associated genes and that the developing brain is sensitive to aberrant levels of HNRNPC. Hence, our data strongly support the inclusion of HNRNPC to the family of HNRNP-related neurodevelopmental disorders.
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    SARS-CoV-2 Selectively Induces the Expression of Unproductive Splicing Isoforms of Interferon, Class I MHC, and Splicing Machinery Genes
    (MDPI, 2024-05-23) Dias, Thomaz Lüscher; Mamede, Izabela; de Toledo, Nayara Evelin; Queiroz, Lúcio Rezende; Castro, Ícaro; Polidoro, Rafael; Del-Bem, Luiz Eduardo; Nakaya, Helder; Franco, Glória Regina; Pediatrics, School of Medicine
    RNA processing is a highly conserved mechanism that serves as a pivotal regulator of gene expression. Alternative processing generates transcripts that can still be translated but lead to potentially nonfunctional proteins. A plethora of respiratory viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), strategically manipulate the host’s RNA processing machinery to circumvent antiviral responses. We integrated publicly available omics datasets to systematically analyze isoform-level expression and delineate the nascent peptide landscape of SARS-CoV-2-infected human cells. Our findings explore a suggested but uncharacterized mechanism, whereby SARS-CoV-2 infection induces the predominant expression of unproductive splicing isoforms in key IFN signaling, interferon-stimulated (ISGs), class I MHC, and splicing machinery genes, including IRF7, HLA-B, and HNRNPH1. In stark contrast, cytokine and chemokine genes, such as IL6 and TNF, predominantly express productive (protein-coding) splicing isoforms in response to SARS-CoV-2 infection. We postulate that SARS-CoV-2 employs an unreported tactic of exploiting the host splicing machinery to bolster viral replication and subvert the immune response by selectively upregulating unproductive splicing isoforms from antigen presentation and antiviral response genes. Our study sheds new light on the molecular interplay between SARS-CoV-2 and the host immune system, offering a foundation for the development of novel therapeutic strategies to combat COVID-19.
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    Writing a wrong: Coupled RNA polymerase II transcription and RNA quality control
    (Wiley, 2019-07) Peck, Sarah A.; Hughes, Katlyn D.; Victorino, Jose F.; Mosley, Amber L.; Biochemistry and Molecular Biology, School of Medicine
    Processing and maturation of precursor RNA species is coupled to RNA polymerase II transcription. Co-transcriptional RNA processing helps to ensure efficient and proper capping, splicing, and 3' end processing of different RNA species to help ensure quality control of the transcriptome. Many improperly processed transcripts are not exported from the nucleus, are restricted to the site of transcription, and are in some cases degraded, which helps to limit any possibility of aberrant RNA causing harm to cellular health. These critical quality control pathways are regulated by the highly dynamic protein-protein interaction network at the site of transcription. Recent work has further revealed the extent to which the processes of transcription and RNA processing and quality control are integrated, and how critically their coupling relies upon the dynamic protein interactions that take place co-transcriptionally. This review focuses specifically on the intricate balance between 3' end processing and RNA decay during transcription termination. This article is categorized under: RNA Turnover and Surveillance > Turnover/Surveillance Mechanisms RNA Processing > 3' End Processing RNA Processing > Splicing Mechanisms RNA Processing > Capping and 5' End Modifications.