Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Translation initiation at a non-AUG start codon for mouse and human NELF-B

ABSTRACT: Negative elongation factor (NELF), a four-subunit protein complex in metazoan, plays an important role in regulating promoter-proximal pausing of RNA polymerase II (RNAPII). Genetic studies demonstrate that the B subunit of mouse NELF (NELF-B) is critical for embryonic development and homeostasis in adult tissue. We report here that both human and mouse NELF-B proteins are translated from a non-AUG codon upstream of the annotated AUG. This non-AUG codon sequence is conserved in mammalian NELF-B but not NELF-B orthologs of lower metazoan. The full-length and a truncated NELF-B that starts at the first AUG codon interact with the other three NELF subunits with comparable efficiency. Furthermore, these two forms of NELF-B have a similar impact on the transcriptomics and proliferation of mouse embryonic fibroblasts. These results strongly suggest that additional amino acid sequence upstream of the annotated AUG is dispensable for the essential function of NELF in supporting cell growth in vitro. While the majority of mouse adult tissues surveyed exclusively express the full-length NELF-B protein, mouse kidney only contains a truncated NELF-B protein with the same apparent size as the AUG-initiated version. This result raises the distinct possibility that translational initiation of mouse NELF-B is regulated in a tissue-dependent manner.

ORGANISM(S): Mus musculus

PROVIDER: GSE62248 | GEO | 2014/10/11

SECONDARY ACCESSION(S): PRJNA263581

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Similar Datasets

Translation initiation at a non-AUG start codon for mouse and human NELF-B

Project description:Negative elongation factor (NELF), a four-subunit protein complex in metazoan, plays an important role in regulating promoter-proximal pausing of RNA polymerase II (RNAPII). Genetic studies demonstrate that the B subunit of mouse NELF (NELF-B) is critical for embryonic development and homeostasis in adult tissue. We report here that both human and mouse NELF-B proteins are translated from a non-AUG codon upstream of the annotated AUG. This non-AUG codon sequence is conserved in mammalian NELF-B but not NELF-B orthologs of lower metazoan. The full-length and a truncated NELF-B that starts at the first AUG codon interact with the other three NELF subunits with comparable efficiency. Furthermore, these two forms of NELF-B have a similar impact on the transcriptomics and proliferation of mouse embryonic fibroblasts. These results strongly suggest that additional amino acid sequence upstream of the annotated AUG is dispensable for the essential function of NELF in supporting cell growth in vitro. While the majority of mouse adult tissues surveyed exclusively express the full-length NELF-B protein, mouse kidney only contains a truncated NELF-B protein with the same apparent size as the AUG-initiated version. This result raises the distinct possibility that translational initiation of mouse NELF-B is regulated in a tissue-dependent manner. triplicates for ATG-Nelf-B, triplicates for FL-Nelf-B

2014-10-11 | E-GEOD-62248 | biostudies-arrayexpress

Evolutionarily Conserved Inhibitory uORFs Sensitize Hox mRNA Translation to Start Codon Selection Stringency

Project description:Translation start site selection in eukaryotes is influenced by context nucleotides flanking the AUG codon and by levels of the eukaryotic translation initiation factors eIF1 and eIF5. In a search of human genes, we identified 5 Hox gene paralogs initiated by AUG codons in conserved suboptimal context as well as 13 Hox genes that contain evolutionarily conserved upstream open reading frames (uORFs) that initiate at AUG codons in poor sequence context. We analyzed published CAGE-seq data and generated CAGE-seq data from mRNAs from mouse somites. These data demonstrate that the 5’ leaders of Hox mRNAs of interest contain conserved uORFs, are much shorter than reported, and lack previously proposed IRES elements. We show that the conserved uORFs inhibit Hox reporter expression and that altering the stringency of start codon selection by overexpressing eIF1 or eIF5 modulates the expression of Hox reporters. We also show that modifying ribosome homeostasis by depleting a large ribosomal subunit protein or treating cells with sublethal concentrations of puromycin leads to lower stringency of start codon selection. Thus, altering global translation can confer gene-specific effects through altered start codon selection stringency.

2022-02-21 | GSE184515 | GEO

Mus musculus

Project description:Translation initiation at a non-AUG start codon for mouse and human NELF-B

| PRJNA263581 | ENA

eIF1 discriminates against suboptimal initiation sites to prevent excessive uORF translation genome-wide

Project description:The translation pre-initiation complex (PIC) scans the mRNA for an AUG codon in favorable context. Previous findings suggest that the factor eIF1 discriminates against non-AUG start codons by impeding full accommodation of Met-tRNAi in the P site of the 40S ribosomal subunit, necessitating eIF1 dissociation for start codon selection. Consistent with this, yeast eIF1 substitutions that weaken its binding to the PIC increase initiation at UUG codons on a mutant his4 mRNA and particular synthetic mRNA reporters; and also at the AUG start codon of the mRNA for eIF1 itself owing to its poor Kozak context. It was not known however whether such eIF1 mutants increase initiation at suboptimal start codons genome-wide. By ribosome profiling, we show that the eIF1-L96P variant confers increased translation of numerous upstream open reading frames (uORFs) initiating with either near-cognate codons (NCCs) or AUGs in poor context. The increased uORF translation is frequently associated with reduced translation of the downstream main coding sequences (CDS). Initiation is also elevated at the NCCs initiating N-terminal extensions on GRS1 and ALA1 mRNAs, and at a small set of main CDS AUG codons with especially poor context, including that of eIF1 itself. Thus, eIF1 acts throughout the yeast translatome to discriminate against NCC start codons and AUGs in poor context; and impairing this function enhances the repressive effects of uORFs on CDS translation and alters the ratios of protein isoforms translated from near-cognate versus AUG start codons.

2019-10-18 | GSE138599 | GEO

Regulation of Mammalian Cell Growth and Survival By an RNA Polymerase II-Pausing Factor (ChIP-seq)

Project description:Many mammalian genes are occupied by paused RNA polymerase II (pol II) at promoter-proximal regions on both sides of transcription start sites (TSSs). However, the consequences of pol II pausing on gene expression and cell biology are not fully understood. Here we report that genetic ablation of the b subunit of mouse negative elongation factor (Nelf-b), a key pol II-pausing factor, results in slower progression at multiple cell cycle stages and increased apoptosis. Consistently, a whole-genome analysis indicates that growth and cell death-related genes are highly enriched among the direct target genes of Nelf-b. In particular, Nelf-b deletion increases pol II density in the promoter-distal region of stress response genes and their overall expression levels in the absence of any external stress signals. In addition, our work also reveals a previously unappreciated role of Nelf-b role in curbing TSS-upstream transcription of many mammalian genes. We suggest that Nelf-mediated pol II pausing balances the cellular needs for growth/survival and stress response by preventing excessive basal transcription of stress-induced genes. Examination of Nelf-b bindings sites on chromosomes in mouse embryonic fibroblasts

2011-08-17 | E-GEOD-24113 | biostudies-arrayexpress

Direct epitranscriptomic regulation of mammalian translation initiation through N4-acetylcytidine

Project description:mRNA function is influenced by modifications that modulate canonical nucleobase behavior. We show that a single modification mediates distinct impacts on mRNA translation in a position-dependent manner. While cytidine acetylation (ac4C) within protein-coding sequences stimulates translation, ac4C within 5’UTRs impacts protein synthesis at the level of initiation. 5’UTR acetylation promotes initiation at upstream sequences, competitively inhibiting annotated start codons. Acetylation further directly impedes initiation at optimal AUG contexts: ac4C within AUG-flanking Kozak sequences reduced initiation in base-resolved transcriptome-wide HeLa results, and in vitro utilizing substrates with site-specific ac4C incorporation. Cryo-EM of mammalian 80S initiation complexes revealed ac4C in the -1-position adjacent to an AUG start codon disrupts an interaction between C and hypermodified t6A at nucleotide 37 of the initiator tRNA. These findings demonstrate the impact of RNA modifications on nucleobase function at a molecular level and introduce mRNA acetylation as a factor regulating translation in a location-specific manner.

2022-06-08 | GSE162043 | GEO

Regulation of Mammalian Cell Growth and Survival By an RNA Polymerase II-Pausing Factor (Gene expression)

Project description:Many mammalian genes are occupied by paused RNA polymerase II (pol II) at promoter-proximal regions on both sides of transcription start sites (TSSs). However, the consequences of pol II pausing on gene expression and cell biology are not fully understood. Here we report that genetic ablation of the b subunit of mouse negative elongation factor (Nelf-b), a key pol II-pausing factor, results in slower progression at multiple cell cycle stages and increased apoptosis. Consistently, a whole-genome analysis indicates that growth and cell death-related genes are highly enriched among the direct target genes of Nelf-b. In particular, Nelf-b deletion increases pol II density in the promoter-distal region of stress response genes and their overall expression levels in the absence of any external stress signals. In addition, our work also reveals a previously unappreciated role of Nelf-b role in curbing TSS-upstream transcription of many mammalian genes. We suggest that Nelf-mediated pol II pausing balances the cellular needs for growth/survival and stress response by preventing excessive basal transcription of stress-induced genes. Immortalized mouse embryonic fibroblasts derived from a Nelf-b flox/- embryo were infected with control or Cre-epxressing retrovirus. Gene expression profile of control and knockout MEF at 7 days after virus infection were compared by using Illumina's mouse whole-genome gene expression BeadChIPs. There are two replicates for both control and knockout MEF samples.

2011-08-16 | E-GEOD-24114 | biostudies-arrayexpress

Multiple cis acting polypyrimidine tract elements regulate a cooperative mechanism for Triticum mosaic virus internal ribosomal entry site activity=]

Project description:Diverse elements within the 5’ untranslated region of an mRNA can influence the translation efficiency at the main AUG codon. We previously identified a core picornaviral like Y16X11-AUG motif with 16-nt polypyrimidine CU-tract separated by an 11-nt spacer sequence from the 13th AUG codon recognized as the preferred initiation site within the Triticum mosaic virus (TriMV) internal ribosome entry site (IRES) element. The motif is proposed to function as an internal ribosomal landing site at the designated start codon. Here we exposed the cooperative role of multiple CU-rich segments flanking the TriMV YX-AUG motif to drive internal initiation of translation at the preferred start site. We propose that these auxiliary domains may enhance the ribosome capacity at proximity of the correct initiation site. These polypyrimidine tracts can be modulated with a cryptic AUG and in a position-dependent manner to replace the native YX-AUG motif and to reprogram translation to the upstream sites, and thus uncovering a new layer of control of the selection of the initiation site. In line with these observations, mass spec analysis of proteins directly interacting with translationally impaired TriMV IRES mutants that bear these motifs indicated an enrichment in 40S and 60S ribosomal related proteins, revealing a new function of polypyrimidine tracts to regulate IRES-driven translation. Accessibility of these RNA regions for in trans interaction was validated by SHAPE analysis of the entire TriMV leader sequence and supported by the ability of anti-sense oligonucleotides designed to block the CU-tracts accessibility to impair IRES activity. This is the first evidence that defines the core modular domains required for start codon selection in a complex, multi-AUG viral 5’UTR for translation in plants.

2022-05-04 | PXD031443 | Pride

Translation initiation site profiling reveals widespread synthesis of non-AUG-initiated protein isoforms in yeast

Project description:Genomic analyses in budding yeast have helped to define the foundational principles of eukaryotic gene expression, but have systematically excluded specific classes of potential coding regions, including those with non-AUG start codons. Without methods to define coding regions empirically, the prevalence of these non-canonical coding regions has been impossible to assess. Here, we applied an experimental approach to globally annotate translation initiation sites in yeast and identified a class of 149 genes that encode N-terminally extended alternate protein isoforms that result from translation initiation at non-AUG codons upstream of the annotated AUG start codon. These alternate isoforms are produced in concert with canonical isoforms and are translated with a high degree of specificity, resulting from initiation at only a small subset of possible start codons in 5’ leader regions. Their translation is enriched during meiosis, and is induced by low eIF5A levels, which are observed in this context. These findings reveal widespread production of non-canonical protein isoforms and, more generally, show unexpected complexity to the rules by which the budding yeast genome is decoded.

2020-07-24 | GSE150375 | GEO

Genome-wide map of RNA polymerase II, NELF, and DSIF in HeLa cells

Project description:Most metazoan promoters have RNA polymerase II (Pol II) paused slightly downstream of the transcription start site by NELF and DSIF. This pausing keeps these promoters available for rapid induction by P-TEFb, whose activity causes NELF to dissociate and Pol II and DSIF to elongate on the gene. ChIP-Seq data was generated for Pol II, NELF, and DSIF in HeLa cells and used to look at pausing downstream of unannotated promoters. 3x ChIP-Seq (Pol II, NELF, DSIF) in HeLa cells

2014-02-01 | E-GEOD-53008 | biostudies-arrayexpress

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data