scholarly journals Removal of Retained Introns Regulates Translation in the Rapidly Developing Gametophyte of Marsilea vestita

2013 ◽  
Vol 24 (5) ◽  
pp. 517-529 ◽  
Author(s):  
Thomas C. Boothby ◽  
Richard S. Zipper ◽  
Corine M. van der Weele ◽  
Stephen M. Wolniak
Keyword(s):  
Marsilea Vestita ◽  
Retained Introns

scholarly journals Full-length transcript characterization of SF3B1 mutation in chronic lymphocytic leukemia reveals downregulation of retained introns

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Alison D. Tang ◽  
Cameron M. Soulette ◽  
Marijke J. van Baren ◽  
Kevyn Hart ◽  
Eva Hrabeta-Robinson ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Lymphocytic Leukemia ◽  
Full Length ◽  
Full Length Transcript ◽  
Retained Introns

Effets d'un choc thermique sur le métabolisme des ARN et des protéines au cours de l'embryogenèse d'une fougère aquatique, le Marsilea vestita

1989 ◽  
Vol 67 (9) ◽  
pp. 2655-2662 ◽  
Author(s):  
Janine Kuligowski ◽  
Michèle Ferrand ◽  
Éliane Chenou
Keyword(s):  
Protein Synthesis ◽  
Temperature Stress ◽  
Cold Shock ◽  
Cold Temperature ◽  
Physiological Status ◽  
Main Stage ◽  
Globular Embryo ◽  
Cell Stage ◽  
Marsilea Vestita ◽  
Rna And Protein Synthesis

A mild, 2-h cold shock treatment, from 24 to 16 °C, was applied during the different stages of Marsilea vestita embryogenesis. For each main stage (proembryo, globular embryo, and completed embryo with a bilateral symmetry), cold-induced modifications in RNA and protein synthesis were studied by autoradiography of the cells after incorporation of [5-3H]uridine and [3H]leucine. In both controls and treated specimens, proembryogenesis was characterized by a lack of transcriptional activity and no labelling was detected in the cytoplasm until the 16-cell stage. Even in the absence of de novo RNA synthesis in cooled samples, proteins necessary for the first cleavages of the embryo were being synthesized, but always at a rate lower than in the reference material. These results lead us to postulate that long-lived mRNA is stored in the cytoplasm of young embryos. Transcription, slowed down by the cold treatment, starts at the 8- to 16-cell stage and increases during the globular embryo stage. In lowered temperature conditions, transport of new RNA transcripts to the cytoplasm, which was strongly inhibited during the transition from the 16- to the 64-cell stage, appears to be less sensitive to cold shock as the embryo gets older. Our results show a difference in the response to temperature between RNA and protein synthesis. However, in both cases, sensitivity to cold temperature stress decreases with age. It is the physiological status reached by the embryo when the cold temperature stress is applied that determines the intensity of the response. [Journal translation]

scholarly journals Intron retention as a new marker of the pre-disease state and its recovery to the normal state by a traditional Japanese multi-herbal medicine

2020 ◽  
Author(s):  
Norihiro Okada ◽  
Kenshiro Oshima ◽  
Yuki Iwasaki ◽  
Akiko Maruko ◽  
Erica Iioka ◽  
...  
Keyword(s):  
Herbal Medicine ◽  
Normal State ◽  
Molecular Mechanisms ◽  
Intron Retention ◽  
Disease State ◽  
Healthy State ◽  
Protein Functions ◽  
The Ancient Chinese ◽  
Retained Introns ◽  
Splicing Patterns

AbstractIntron retention (IR) is an important regulatory mechanism that affects gene expression and protein functions. Using klotho mice as a model, we proposed that retained introns are an excellent marker for the pre-disease state. Surprisingly, among widespread retained introns that accumulated during aging in the liver, a subset was recovered to the normal state by a Japanese traditional herbal medicine. IR-recovered genes fell into two categories: (1) those involved in the spliceosome and (2) those involved in liver-specific metabolism. By integrating data for splicing patterns, transcriptomes, and metabolomes, we hypothesize that this medicine-related IR recovery under the pre-disease state reflects the actual recovery of liver-specific function to the healthy state. Accordingly, the study provides proof-of-concept evidence related to the ancient Chinese statement proposing the medicine’s usefulness for treating the pre-disease state. This approach lays out a method for elucidating unknown molecular mechanisms of an herbal medicine with multiple ingredients.

scholarly journals AnNXF1mRNA with a retained intron is expressed in hippocampal and neocortical neurons and is translated into a protein that functions as an Nxf1 cofactor

2016 ◽  
Vol 27 (24) ◽  
pp. 3903-3912 ◽  
Author(s):  
Ying Li ◽  
Yeou-cherng Bor ◽  
Mark P. Fitzgerald ◽  
Kevin S. Lee ◽  
David Rekosh ◽  
...  
Keyword(s):  
Nuclear Export ◽  
Neuroblastoma Cells ◽  
Nonsense Mediated Decay ◽  
Rna Granules ◽  
Neocortical Neurons ◽  
Mouse Neuroblastoma ◽  
Dendritic Mrna ◽  
Mrna Trafficking ◽  
Nuclear Export Receptor ◽  
Retained Introns

The Nxf1 protein is a major nuclear export receptor for the transport of mRNA, and it also is essential for export of retroviral mRNAs with retained introns. In the latter case, it binds to RNA elements known as constitutive transport elements (CTEs) and functions in conjunction with a cofactor known as Nxt1. The NXF1 gene also regulates expression of its own intron-containing RNA through the use of a functional CTE within intron 10. mRNA containing this intron is exported to the cytoplasm, where it can be translated into the 356–amino acid short Nxf1(sNxf1) protein, despite the fact that it is a prime candidate for nonsense-mediated decay (NMD). Here we demonstrate that sNxf1 is highly expressed in nuclei and dendrites of hippocampal and neocortical neurons in rodent brain. Additionally, we show that sNxf1 localizes in RNA granules in neurites of differentiated N2a mouse neuroblastoma cells, where it shows partial colocalization with Staufen2 isoform SS, a protein known to play a role in dendritic mRNA trafficking. We also show that sNxf1 forms heterodimers in conjunction with the full-length Nxf1 and that sNxf1 can replace Nxt1 to enhance the expression of CTE-containing mRNA and promote its association with polyribosomes.

Binding of Tetrahymena dynein to axonemes of Marsilea vestita lacking the outer dynein arm

1985 ◽  
Vol 73 (1) ◽  
pp. 299-310
Author(s):  
J.S. Hyams
Keyword(s):  
Electron Microscopy ◽  
Polyacrylamide Gel Electrophoresis ◽  
Valuable Insight ◽  
Marsilea Vestita ◽  
Thin Section Electron Microscopy ◽  
Section Electron ◽  
And Function ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Axonemes from the heterosporous water fern Marsilea vestita were fixed in the presence of tannic acid and examined by thin-section electron microscopy. Transverse sections revealed the normal 9+2 configuration except for the absence of the outer of the two dynein arms. Both arms were normally preserved in parallel preparations of Chlamydomonas axonemes. Isolated dynein from the ciliated protozoon Tetrahymena bound to Marsilea axonemes at the site normally occupied by the outer arm. Dynein binding was partially reversed by ATP as judged by both electron microscopy and polyacrylamide gel electrophoresis. This system should provide a valuable insight into the biochemistry and function of the inner dynein arm and the relationship of the two arms to motility in more conventionally equipped axonemes.

An ultrastructural study of the spermatozoid of the fern, Marsilea vestita

1975 ◽  
Vol 17 (3) ◽  
pp. 633-645
Author(s):  
D.G. Myles
Keyword(s):  
Nuclear Envelope ◽  
Ultrastructural Study ◽  
Spiral Structure ◽  
Multilayered Structure ◽  
Condensed Chromatin ◽  
Posterior Region ◽  
Cytoplasmic Vesicle ◽  
Marsilea Vestita ◽  
Shaped Cell ◽  
Dense Band

The ultrastructure of the mature spermatozoid of Marsilea vestita was studied after its release from the microspore and prior to its penetration of the egg. The psermatozoid is a pear-shaped cell with a complex spiral structure coiled around the edge in the narrow anterior end. This coil is composed of a large mitochondrion, elongated nucleus with highly condensed chromatin, a ribbon of microtubules, and a dense band of material (flagellated band) into which the flagella are inserted. There are over a hundred flagella protruding from each spermatozoid along the length of the coil. At the anterior tip of the coil is a short multilayered structure. It is not known what maintains the helical shape of the coil. The microtubular ribbon could be involved, but it is also possible that either the flagellated band, the condensed chromatin, or both, are sufficiently rigid to retain their shpaes unaided. When the spermatozoid is first released from the microspore it includes a cytoplasmic vesicle in the posterior region containing plastids, mitochondria, and other organelles. This vesicle is shed, taking the nuclear envelope with it, before the spermatozoid reaches the egg.

scholarly journals Structural disruption of exonic stem–loops immediately upstream of the intron regulates mammalian splicing

2020 ◽  
Vol 48 (11) ◽  
pp. 6294-6309 ◽  
Author(s):  
Kaushik Saha ◽  
Whitney England ◽  
Mike Minh Fernandez ◽  
Tapan Biswas ◽  
Robert C Spitale ◽  
...  
Keyword(s):  
Structural Information ◽  
Structural Features ◽  
Splicing Factors ◽  
Splice Sites ◽  
Exonic Splicing Enhancer ◽  
Stem Loop ◽  
The Core ◽  
Retained Introns ◽  
Splicing Enhancer ◽  
Structural Disruption

Abstract Recognition of highly degenerate mammalian splice sites by the core spliceosomal machinery is regulated by several protein factors that predominantly bind exonic splicing motifs. These are postulated to be single-stranded in order to be functional, yet knowledge of secondary structural features that regulate the exposure of exonic splicing motifs across the transcriptome is not currently available. Using transcriptome-wide RNA structural information we show that retained introns in mouse are commonly flanked by a short (≲70 nucleotide), highly base-paired segment upstream and a predominantly single-stranded exonic segment downstream. Splicing assays with select pre-mRNA substrates demonstrate that loops immediately upstream of the introns contain pre-mRNA-specific splicing enhancers, the substitution or hybridization of which impedes splicing. Additionally, the exonic segments flanking the retained introns appeared to be more enriched in a previously identified set of hexameric exonic splicing enhancer (ESE) sequences compared to their spliced counterparts, suggesting that base-pairing in the exonic segments upstream of retained introns could be a means for occlusion of ESEs. The upstream exonic loops of the test substrate promoted recruitment of splicing factors and consequent pre-mRNA structural remodeling, leading up to assembly of the early spliceosome. These results suggest that disruption of exonic stem–loop structures immediately upstream (but not downstream) of the introns regulate alternative splicing events, likely through modulating accessibility of splicing factors.

Molecular cloning of a centrin homolog from Marsilea vestita and evidence for its translational control during spermiogenesis

1999 ◽  
Vol 77 (2) ◽  
pp. 101-108 ◽  
Author(s):  
Peter E Hart ◽  
Stephen M Wolniak
Keyword(s):  
Translational Control ◽  
De Novo ◽  
Basal Bodies ◽  
Motile Cells ◽  
Marsilea Vestita ◽  
Stored Mrna ◽  
Eukaryotic Organisms ◽  
Alpha Amanitin ◽  
Made In

Spermiogenesis in the water fern Marsilea vestita is a process that reaches completion 11 h after dry microspores are immersed in an aqueous medium at 20°C. Each microspore produces 32 spermatozoids and each spermatozoid has a coiled cell body and approximately 140 cilia. The spermatids make basal bodies de novo, from a structure known as a blepharoplast. From the onset of development, the spores contain a large quantity of protein and stored mRNA. We have found previously that centrin, a protein involved in the function of microtubule organizing centers and present in association with basal bodies in motile cells, is made in large quantity approximately 4 h after the microspores are placed into liquid medium. In this paper, we show that a centrin cDNA (MvCen1) we isolated from M. vestita closely resembles centrin cDNAs from other eukaryotic organisms. MvCen1, synthesized in Escherichia coli as a GST-fusion protein, reacted with anti-centrin monoclonal antibodies on immunoblots. Northern blot analysis demonstrates that centrin mRNA is present in the dry microspore at the time of imbibition, at levels that remain constant over 10 h of development and are unaffected by treatment of spores with alpha-amanitin. The centrin transcripts, stored in dry microspores, cannot be translated in vitro for at least 30 min after imbibition.Key words: Marsilea vestita, spermatozoid, spermiogenesis, centrin, MTOC.

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