scholarly journals A Heterochromatin-Specific RNA Export Pathway Facilitates piRNA Production

Cell ◽  
2019 ◽  
Vol 178 (4) ◽  
pp. 964-979.e20 ◽  
Author(s):  
Mostafa F. ElMaghraby ◽  
Peter Refsing Andersen ◽  
Florian Pühringer ◽  
Ulrich Hohmann ◽  
Katharina Meixner ◽  
...  
Keyword(s):  
Export Pathway ◽  
Rna Export

scholarly journals Roles for RNA export factor, Nxt1, in ensuring muscle integrity and normal RNA expression in Drosophila

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Kevin van der Graaf ◽  
Katia Jindrich ◽  
Robert Mitchell ◽  
Helen White-Cooper
Keyword(s):  
Mrna Export ◽  
Rna Stability ◽  
Muscle Degeneration ◽  
Loss Of Function ◽  
Cellular Functions ◽  
Partial Loss ◽  
Export Pathway ◽  
Pathway Gene ◽  
Rna Export

Abstract The mRNA export pathway is responsible for the transport of mRNAs from the nucleus to the cytoplasm, and thus is essential for protein production and normal cellular functions. A partial loss of function allele of the mRNA export factor Nxt1 in Drosophila shows reduced viability and sterility. A previous study has shown that the male fertility defect is due to a defect in transcription and RNA stability, indicating the potential for this pathway to be implicated in processes beyond the known mRNA transport function. Here we investigate the reduced viability of Nxt1 partial loss of function mutants, and describe a defect in growth and maintenance of the larval muscles, leading to muscle degeneration. RNA-seq revealed reduced expression of a set of mRNAs, particularly from genes with long introns in Nxt1 mutant carcass. We detected differential expression of circRNA, and significantly fewer distinct circRNAs expressed in the mutants. Despite the widespread defects in gene expression, muscle degeneration was rescued by increased expression of the costamere component tn (abba) in muscles. This is the first report of a role for the RNA export pathway gene Nxt1 in the maintenance of muscle integrity. Our data also links the mRNA export pathway to a specific role in the expression of mRNA and circRNA from common precursor genes, in vivo.

scholarly journals RNA length defines RNA export pathway

2004 ◽  
Vol 18 (17) ◽  
pp. 2074-2085 ◽  
Author(s):  
K. Masuyama
Keyword(s):  
Export Pathway ◽  
Rna Export

scholarly journals The prototype γ-2 herpesvirus nucleocytoplasmic shuttling protein, ORF 57, transports viral RNA through the cellular mRNA export pathway

2005 ◽  
Vol 387 (2) ◽  
pp. 295-308 ◽  
Author(s):  
Ben J. L. WILLIAMS ◽  
James R. BOYNE ◽  
Delyth J. GOODWIN ◽  
Louise ROADEN ◽  
Guillaume M. HAUTBERGUE ◽  
...  
Keyword(s):  
Nuclear Export ◽  
Mammalian Cells ◽  
Mrna Export ◽  
Dominant Negative ◽  
Viral Rna ◽  
Exon Junction Complex ◽  
Independent Manner ◽  
Exon Junction ◽  
Export Pathway ◽  
Rna Export

HVS (herpesvirus saimiri) is the prototype γ-2 herpesvirus. This is a subfamily of herpesviruses gaining importance since the identification of the first human γ-2 herpesvirus, Kaposi's sarcoma-associated herpesvirus. The HVS ORF 57 (open reading frame 57) protein is a multifunctional transregulatory protein homologous with genes identified in all classes of herpesviruses. Recent work has demonstrated that ORF 57 has the ability to bind viral RNA, shuttles between the nucleus and cytoplasm and promotes the nuclear export of viral transcripts. In the present study, we show that ORF 57 shuttles between the nucleus and cytoplasm in a CRM-1 (chromosomal region maintenance 1)-independent manner. ORF 57 interacts with the mRNA export factor REF (RNA export factor) and two other components of the exon junction complex, Y14 and Magoh. The association of ORF 57 with REF stimulates recruitment of the cellular mRNA export factor TAP (Tip-associated protein), and HVS infection triggers the relocalization of REF and TAP from the nuclear speckles to several large clumps within the cell. Using a dominant-negative form of TAP and RNA interference to deplete TAP, we show that it is essential for bulk mRNA export in mammalian cells and is required for ORF 57-mediated viral RNA export. Furthermore, we show that the disruption of TAP reduces viral replication. These results indicate that HVS utilizes ORF 57 to recruit components of the exon junction complex and subsequently TAP to promote viral RNA export through the cellular mRNA export pathway.

scholarly journals A heterochromatin-specific RNA export pathway facilitates piRNA production

2019 ◽  
Author(s):  
Mostafa F. ElMaghraby ◽  
Peter Refsing Andersen ◽  
Florian Pühringer ◽  
Katharina Meixner ◽  
Thomas Lendl ◽  
...  
Keyword(s):  
Nuclear Export ◽  
Mrna Export ◽  
Surveillance Systems ◽  
Rna Surveillance ◽  
Export Pathway ◽  
Transposon Silencing ◽  
Nuclear Rna ◽  
Rna Export ◽  
Non Coding Rnas ◽  
Pirna Pathway

PIWI-interacting RNAs (piRNAs) guide transposon silencing in animals. The 22-30nt piRNAs are processed in the cytoplasm from long non-coding RNAs. How piRNA precursors, which often lack RNA processing hallmarks of export-competent transcripts, achieve nuclear export is unknown. Here, we uncover the RNA export pathway specific for piRNA precursors in theDrosophilagermline. This pathway requires Nxf3-Nxt1, a variant of the hetero-dimeric mRNA export receptor Nxf1-Nxt1. Nxf3 interacts with UAP56, a nuclear RNA helicase essential for mRNA export, and CG13741/Bootlegger, which recruits Nxf3-Nxt1 and UAP56 to heterochromatic piRNA source loci. Upon RNA cargo binding, Nxf3 achieves nuclear export via the exportin Crm1, and accumulates together with Bootlegger in peri-nuclear nuage, suggesting that after export, Nxf3-Bootlegger delivers precursor transcripts to the piRNA processing sites. Our findings indicate that the piRNA pathway bypasses nuclear RNA surveillance systems to achieve export of heterochromatic, unprocessed transcripts to the cytoplasm, a strategy also exploited by retroviruses.

scholarly journals Adenovirus Late Gene Expression Does Not Require a Rev-Like Nuclear RNA Export Pathway

2000 ◽  
Vol 74 (14) ◽  
pp. 6684-6688 ◽  
Author(s):  
Claudia Rabino ◽  
Anders Aspegren ◽  
Kara Corbin-Lickfett ◽  
Eileen Bridge
Keyword(s):  
Nuclear Export ◽  
Nuclear Export Signal ◽  
Late Gene Expression ◽  
Export Pathway ◽  
Early Proteins ◽  
Immunodeficiency Virus ◽  
Rna Export ◽  
Nuclear Rna Export ◽  
Export Signal

ABSTRACT Adenovirus late mRNA export is facilitated by viral early proteins of 55 and 34 kDa. The 34-kDa protein contains a leucine-rich nuclear export signal (NES) similar to that of the human immunodeficiency virus Rev protein. It was proposed that the 34-kDa protein might facilitate the export of adenovirus late mRNA through a Rev-like NES-mediated export pathway. We have tested the role of NES-mediated RNA export during adenovirus infection, and we find that it is not essential for the expression of adenovirus late genes.

scholarly journals HIV-1 Rev protein specifies the viral RNA export pathway by suppressing TAP/NXF1 recruitment

2014 ◽  
Vol 42 (10) ◽  
pp. 6645-6658 ◽  
Author(s):  
Ichiro Taniguchi ◽  
Naoto Mabuchi ◽  
Mutsuhito Ohno
Keyword(s):  
Viral Rna ◽  
Export Pathway ◽  
Rna Export ◽  
Hiv 1 ◽  
Rev Protein

scholarly journals Loss of function of the RNA export factor, Nxt1, in Drosophila causes muscle degeneration and reduced expression of genes with long introns

2019 ◽  
Author(s):  
Kevin van der Graaf ◽  
Helen White-Cooper
Keyword(s):  
Gene Expression ◽  
Protein Synthesis ◽  
Mrna Export ◽  
Circular Rnas ◽  
Specific Gene ◽  
Muscle Degeneration ◽  
Loss Of Function ◽  
Export Pathway ◽  
Expression Of Genes ◽  
Rna Export

AbstractThe RNA export pathway is essential for export-competent mRNAs to pass from the nucleus into the cytoplasm, and thus is essential for protein production and normal function of cells. Drosophila with partial loss of function of Nxt1, a core factor in the pathway, show reduced viability and male and female sterility. The male sterility has previously been shown to be caused by defects in testis-specific gene expression, particularly of genes without introns. Here we describe a specific defect in growth and maintenance of the larval muscles, leading to muscle degeneration in Nxt1 mutants. RNAseq revealed reduced expression of mRNAs of many genes in Nxt1 mutant muscles. Despite this, the degeneration was rescued by increased expression of a single gene, the costamere component tn (abba), in muscles. Genes under-expressed in the mutant typically have long introns, and most normally encode circular RNAs in addition to mRNAs. This is the first report of a specific role for the RNA export pathway gene Nxt1 in muscle integrity. Our data on Nxt1 links the mRNA export pathway to a global role in mRNA expression of genes that also produce circular RNAs, in vivo.Author summaryIn eukaryotic cells the DNA encoding instructions for protein synthesis is located in the nucleus, it is transcribed to generate pre-mRNA, which is processed at both ends and spliced to remove internal spacer regions (introns) to generate mRNA. This mRNA is then transported by the mRNA export pathway via nuclear pores to the cytoplasm for protein synthesis. We have previously shown that reduction in activity of a specific protein in the mRNA export pathway, Nxt1, has an additional role in testis-specific transcription. Here we describe a further role for this protein specifically in gene expression, particularly of genes with long introns, and in muscle maintenance. Drosophila larvae with reduced Nxt1 activity have normal muscle pattern when they are small, but show muscular atrophy and degeneration as they grow, resulting in significant defects in their movement speed. We discovered that expression of many genes is reduced in the mutant larvae, but that restoring the expression of just one of these, abba, the Drosophila homologue of Trim32 (a human gene involved in muscular dystrophy) is capable of preventing the muscle degeneration.

scholarly journals Rous Sarcoma Virus DR Posttranscriptional Elements Use a Novel RNA Export Pathway

2000 ◽  
Vol 74 (20) ◽  
pp. 9507-9514 ◽  
Author(s):  
Robert E. Paca ◽  
Robert A. Ogert ◽  
Catherine S. Hibbert ◽  
Elisa Izaurralde ◽  
Karen L. Beemon
Keyword(s):  
Rous Sarcoma Virus ◽  
Direct Repeat ◽  
Viral Rna ◽  
Export Pathway ◽  
Rous Sarcoma ◽  
Constitutive Transport Element ◽  
Rna Export ◽  
Sarcoma Virus ◽  
Nucleocytoplasmic Export ◽  
Hiv 1

ABSTRACT Rous sarcoma virus (RSV), a simple retrovirus, needs to export unspliced viral RNA from the nucleus to the cytoplasm, circumventing the host cell restriction on cytoplasmic expression of intron-containing RNA. The cytoplasmic accumulation of full-length viral RNA is promoted by two cis-acting direct repeat (DR) elements that flank the src gene; at least one copy of the DR sequence is necessary for viral replication. We show here that the DR mediates export of a reporter construct from the nucleus, suggesting it is a constitutive transport element (CTE). In contrast, human immunodeficiency virus type 1 (HIV-1) and other complex retroviruses encode accessory proteins, Rev or Rex, which promote export of incompletely spliced viral transcripts. This RNA export pathway is CRM1 dependent and can be blocked by the cytotoxic agent leptomycin B. We show here that DR-mediated export is CRM1 independent, suggesting that RSV uses a different export pathway from that of HIV-1 and other complex retroviruses. The simian retroviruses have a CTE which interacts with the cellular Tap export protein. However, we were unable to detect binding of the RSV DR RNA to Tap, suggesting it may use a different export pathway from that of the simian retroviruses. These data suggest that the RSV DR element uses a novel nucleocytoplasmic export pathway.

Sign in / Sign up

Export Citation Format

Share Document