scholarly journals Alternative processing of RNA transcribed from NMYC.

1987 ◽  
Vol 7 (12) ◽  
pp. 4266-4272 ◽  
Author(s):  
L W Stanton ◽  
J M Bishop

NMYC is a gene whose amplification and overexpression have been implicated in the generation of certain human malignancies. Little is known of how the expression of NMYC is normally controlled. We have therefore characterized transcription from the gene and the structure and stability of the resulting mRNAs. Transcription from NMYC is exceptionally complex: it initiates at numerous sites that may be grouped under the control of two promoters, and the multiplicity of initiation sites combines with alternative splicing to engender two forms of mRNA. The mRNAs have different 5' leader sequences (alternative first exons of the gene) but identical bodies (the second and third exons of the gene). Both forms of mRNA are unstable, with half-lives of ca. 15 min. Both encode the previously identified 65,000 and 67,000-dalton products of NMYC. However, the alternative first exons contain distinctive open reading frames that may diversify the coding potential of NMYC. The complexities in transcription of NMYC expand the means by which expression of the gene might be controlled.

1987 ◽  
Vol 7 (12) ◽  
pp. 4266-4272
Author(s):  
L W Stanton ◽  
J M Bishop

NMYC is a gene whose amplification and overexpression have been implicated in the generation of certain human malignancies. Little is known of how the expression of NMYC is normally controlled. We have therefore characterized transcription from the gene and the structure and stability of the resulting mRNAs. Transcription from NMYC is exceptionally complex: it initiates at numerous sites that may be grouped under the control of two promoters, and the multiplicity of initiation sites combines with alternative splicing to engender two forms of mRNA. The mRNAs have different 5' leader sequences (alternative first exons of the gene) but identical bodies (the second and third exons of the gene). Both forms of mRNA are unstable, with half-lives of ca. 15 min. Both encode the previously identified 65,000 and 67,000-dalton products of NMYC. However, the alternative first exons contain distinctive open reading frames that may diversify the coding potential of NMYC. The complexities in transcription of NMYC expand the means by which expression of the gene might be controlled.


2006 ◽  
Vol 80 (8) ◽  
pp. 4179-4182 ◽  
Author(s):  
Pierre Rivailler ◽  
Amitinder Kaur ◽  
R. Paul Johnson ◽  
Fred Wang

ABSTRACT A pathogenic isolate of rhesus cytomegalovirus (rhCMV 180.92) was cloned, sequenced, and annotated. Comparisons with the published rhCMV 68.1 genome revealed 8 open reading frames (ORFs) in isolate 180.92 that are absent in 68.1, 10 ORFs in 68.1 that are absent in 180.92, and 34 additional ORFs that were not previously annotated. Most of the differences appear to be due to genetic rearrangements in both isolates from a region that is frequently altered in human CMV (hCMV) during in vitro passage. These results indicate that the rhCMV ORF repertoire is larger than previously recognized. Like hCMV, understanding of the complete coding capacity of rhCMV is complicated by genomic instability and may require comparisons with additional isolates in vitro and in vivo.


2021 ◽  
Author(s):  
Yanyi Jiang ◽  
Xiaofan Chen ◽  
Wei Zhang

AbstractIn RNA field, the demarcation between coding and non-coding has been negotiated by the recent discovery of occasionally translated circular RNAs (circRNAs). Although absent of 5’ cap structure, circRNAs can be translated cap-independently. Complementary intron-mediated overexpression is one of the most utilized methodologies for circRNA research but not without bearing echoing skepticism for its poorly defined mechanism and latent coexistent side products. In this study, leveraging such circRNA overexpression system, we have interrogated the protein-coding potential of 30 human circRNAs containing infinite open reading frames in HEK293T cells. Surprisingly, pervasive translation signals are detected by immunoblotting. However, intensive mutagenesis reveals that numerous translation signals are generated independently of circRNA synthesis. We have developed a dual tag strategy to isolate translation noise and directly demonstrate that the fallacious translation signals originate from cryptically spliced linear transcripts. The concomitant linear RNA byproducts, presumably concatemers, can be translated to allow pseudo rolling circle translation signals, and can involve backsplicing junction (BSJ) to disqualify the BSJ-based evidence for circRNA translation. We also find non-AUG start codons may engage in the translation initiation of circRNAs. Taken together, our systematic evaluation sheds light on heterogeneous translational outputs from circRNA overexpression vector and comes with a caveat that ectopic overexpression technique necessitates extremely rigorous control setup in circRNA translation and functional investigation.


2020 ◽  
Vol 40 (6) ◽  
Author(s):  
Corrine Corrina R. Hartford ◽  
Ashish Lal

ABSTRACT Recent advancements in genetic and proteomic technologies have revealed that more of the genome encodes proteins than originally thought possible. Specifically, some putative long noncoding RNAs (lncRNAs) have been misannotated as noncoding. Numerous lncRNAs have been found to contain short open reading frames (sORFs) which have been overlooked because of their small size. Many of these sORFs encode small proteins or micropeptides with fundamental biological importance. These micropeptides can aid in diverse processes, including cell division, transcription regulation, and cell signaling. Here we discuss strategies for establishing the coding potential of putative lncRNAs and describe various functions of known micropeptides.


2019 ◽  
Vol 36 (7) ◽  
pp. 2053-2059 ◽  
Author(s):  
Saket Choudhary ◽  
Wenzheng Li ◽  
Andrew D. Smith

Abstract Motivation Ribo-seq, a technique for deep-sequencing ribosome-protected mRNA fragments, has enabled transcriptome-wide monitoring of translation in vivo. It has opened avenues for re-evaluating the coding potential of open reading frames (ORFs), including many short ORFs that were previously presumed to be non-translating. However, the detection of translating ORFs, specifically short ORFs, from Ribo-seq data, remains challenging due to its high heterogeneity and noise. Results We present ribotricer, a method for detecting actively translating ORFs by directly leveraging the three-nucleotide periodicity of Ribo-seq data. Ribotricer demonstrates higher accuracy and robustness compared with other methods at detecting actively translating ORFs including short ORFs on multiple published datasets across species inclusive of Arabidopsis, Caenorhabditis elegans, Drosophila, human, mouse, rat, yeast and zebrafish. Availability and implementation Ribotricer is available at https://github.com/smithlabcode/ribotricer. All analysis scripts and results are available at https://github.com/smithlabcode/ribotricer-results. Supplementary information Supplementary data are available at Bioinformatics online.


2004 ◽  
Vol 78 (20) ◽  
pp. 11187-11197 ◽  
Author(s):  
Lisa M. Kattenhorn ◽  
Ryan Mills ◽  
Markus Wagner ◽  
Alexandre Lomsadze ◽  
Vsevolod Makeev ◽  
...  

ABSTRACT Proteins associated with the murine cytomegalovirus (MCMV) viral particle were identified by a combined approach of proteomic and genomic methods. Purified MCMV virions were dissociated by complete denaturation and subjected to either separation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and in-gel digestion or treated directly by in-solution tryptic digestion. Peptides were separated by nanoflow liquid chromatography and analyzed by tandem mass spectrometry (LC-MS/MS). The MS/MS spectra obtained were searched against a database of MCMV open reading frames (ORFs) predicted to be protein coding by an MCMV-specific version of the gene prediction algorithm GeneMarkS. We identified 38 proteins from the capsid, tegument, glycoprotein, replication, and immunomodulatory protein families, as well as 20 genes of unknown function. Observed irregularities in coding potential suggested possible sequence errors in the 3′-proximal ends of m20 and M31. These errors were experimentally confirmed by sequencing analysis. The MS data further indicated the presence of peptides derived from the unannotated ORFs ORFc225441-226898 (m166.5) and ORF105932-106072. Immunoblot experiments confirmed expression of m166.5 during viral infection.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Shraddha Puntambekar ◽  
Rachel Newhouse ◽  
Jaime San Miguel Navas ◽  
Ruchi Chauhan ◽  
Grégoire Vernaz ◽  
...  

AbstractNovel open reading frames (nORFs) with coding potential may arise from noncoding DNA. Not much is known about their emergence, functional role, fixation in a population or contribution to adaptive radiation. Cichlids fishes exhibit extensive phenotypic diversification and speciation. Encounters with new environments alone are not sufficient to explain this striking diversity of cichlid radiation because other taxa coexistent with the Cichlidae demonstrate lower species richness. Wagner et al. analyzed cichlid diversification in 46 African lakes and reported that both extrinsic environmental factors and intrinsic lineage-specific traits related to sexual selection have strongly influenced the cichlid radiation, which indicates the existence of unknown molecular mechanisms responsible for rapid phenotypic diversification, such as emergence of novel open reading frames (nORFs). In this study, we integrated transcriptomic and proteomic signatures from two tissues of two cichlids species, identified nORFs and performed evolutionary analysis on these nORF regions. Our results suggest that the time scale of speciation of the two species and evolutionary divergence of these nORF genomic regions are similar and indicate a potential role for these nORFs in speciation of the cichlid fishes.


Genetics ◽  
1993 ◽  
Vol 133 (4) ◽  
pp. 933-942
Author(s):  
J L Azevedo ◽  
B C Hyman

Abstract Complete nucleotide sequences, precise endpoints and coding potential of several 3.0-kilobase mitochondrial DNA (mtDNA) repeating units derived from two isofemale lineages of the mermithid nematode Romanomermis culicivorax have been determined. Endpoint analysis has allowed us to infer deletion and inversion events that most likely generated the present day repeat configuration. Each amplified unit contains the genes for NADH dehydrogenase subunits 3 and 6 (ND3 and ND6), an open reading frame (ORF 1) that represents a cytochrome P450-like gene, and three additional unidentified open reading frames. The primary nucleotide sequences of the R. culicivorax mt-repeat copies within individual haplotypes are highly conserved; three nearly complete copies of the repeat unit vary by 0.01% at the nucleotide level. These observations suggest that concerted evolution mechanisms may be active, resulting in sequence homogenation of these lengthy duplications.


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