eRF1 is the Drosophila class I eukaryotic peptide chain release factor. In the ribosomal A site it recognizes all three stop codons (UAA, UAG, UGA) and, through its conserved GGQ motif, triggers hydrolysis of peptidyl-tRNA to release the nascent polypeptide. eRF1 is delivered to terminating ribosomes in a complex with the GTPase eRF3. Its GGQ glutamine is methylated by HemK2, which is needed for efficient protein synthesis and mRNA stability in the female germline, and eRF1 loss-of-function alleles cause maternal-effect nonsense suppression and larval lethality.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0002184 cytoplasmic translational termination | IBA GO_REF:0000033 | ACCEPT | Summary: eRF1 acts in cytoplasmic translational termination. Reason: Core process; Drosophila eRF1 mutations cause stop-codon readthrough. Propagation Review Root cause: NO FAILURE CORE Sources checked: PANTHER:PTN000012042 SUPPORTS TRANSFER eRF1 is a canonical, single-copy class I release factor inside the eukaryotic eRF1 clade; no evidence of divergence. Supporting Evidence: PMID:14573473 Mutations disrupting the Drosophila eRF1 and eRF3 show a strong maternal-effect nonsense suppression due to readthrough of stop codons and are zygotically lethal during larval stages |
| GO:0003747 translation release factor activity | IEA GO_REF:0000002 | MODIFY | Summary: Translation release factor activity from InterPro. Reason: Correct; eRF1 is the codon-specific class I release factor, so the more precise term is translation release factor activity, codon specific. Proposed replacements: translation release factor activity, codon specific Supporting Evidence: PMID:14573473 eRF1 and eRF3 comprise the translation termination complex that recognizes stop codons and catalyzes the release of nascent polypeptide chains from ribosomes |
| GO:0005737 cytoplasm | IEA GO_REF:0000044 | ACCEPT | Summary: eRF1 is cytoplasmic. Reason: eRF1 acts on cytoplasmic ribosomes; UniProt records a cytoplasmic location. Supporting Evidence: file:DROME/eRF1/eRF1-uniprot.txt SUBCELLULAR LOCATION: Cytoplasm |
| GO:0005737 cytoplasm | NAS PMID:31410471 eRF1 mediates codon usage effects on mRNA translation effici... | ACCEPT | Summary: eRF1 is cytoplasmic. Reason: eRF1 acts on cytoplasmic ribosomes; UniProt records a cytoplasmic location. Supporting Evidence: file:DROME/eRF1/eRF1-uniprot.txt SUBCELLULAR LOCATION: Cytoplasm |
| GO:0005829 cytosol | IBA GO_REF:0000033 | ACCEPT | Summary: eRF1 is cytosolic. Reason: eRF1 terminates translation on cytosolic ribosomes; UniProt records a cytoplasmic location, and a FlyBase IDA (PMID:38881530) places it in the cytosol. Propagation Review Root cause: NO FAILURE CORE Sources checked: PANTHER:PTN000012041 SUPPORTS TRANSFER eRF1 is a canonical, single-copy class I release factor inside the eukaryotic eRF1 clade; no evidence of divergence. Supporting Evidence: file:DROME/eRF1/eRF1-uniprot.txt SUBCELLULAR LOCATION: Cytoplasm |
| GO:0005829 cytosol | IDA PMID:38881530 HemK2 functions for sufficient protein synthesis and RNA sta... | ACCEPT | Summary: eRF1 is cytosolic. Reason: eRF1 terminates translation on cytosolic ribosomes. The IDA localization data are in the full text of PMID:38881530, which is not cached (abstract only), so the curator is deferred to; the quote is the UniProt cytoplasmic location. Supporting Evidence: file:DROME/eRF1/eRF1-uniprot.txt SUBCELLULAR LOCATION: Cytoplasm |
| GO:0005829 cytosol | IEA GO_REF:0000117 | ACCEPT | Summary: eRF1 is cytosolic. Reason: eRF1 terminates translation on cytosolic ribosomes; UniProt records a cytoplasmic location, and a FlyBase IDA (PMID:38881530) places it in the cytosol. Supporting Evidence: file:DROME/eRF1/eRF1-uniprot.txt SUBCELLULAR LOCATION: Cytoplasm |
| GO:0006415 translational termination | IEA GO_REF:0000120 | ACCEPT | Summary: eRF1 is required for translational termination. Reason: Genetic loss of eRF1 causes nonsense suppression in vivo; methylation-deficient eRF1 impairs protein synthesis in germline cells. Supporting Evidence: PMID:14573473 Mutations disrupting the Drosophila eRF1 and eRF3 show a strong maternal-effect nonsense suppression due to readthrough of stop codons and are zygotically lethal during larval stages PMID:38881530 disruptions in eRF1 methylation may provoke ribosomal stalling |
| GO:0006415 translational termination | IMP PMID:14573473 Mutations in eukaryotic release factors 1 and 3 act as gener... | ACCEPT | Summary: eRF1 is required for translational termination. Reason: Genetic loss of eRF1 causes nonsense suppression in vivo; methylation-deficient eRF1 impairs protein synthesis in germline cells. Supporting Evidence: PMID:14573473 Mutations disrupting the Drosophila eRF1 and eRF3 show a strong maternal-effect nonsense suppression due to readthrough of stop codons and are zygotically lethal during larval stages PMID:38881530 disruptions in eRF1 methylation may provoke ribosomal stalling |
| GO:0006415 translational termination | IMP PMID:38881530 HemK2 functions for sufficient protein synthesis and RNA sta... | ACCEPT | Summary: eRF1 is required for translational termination. Reason: Genetic loss of eRF1 causes nonsense suppression in vivo; methylation-deficient eRF1 impairs protein synthesis in germline cells. Supporting Evidence: PMID:14573473 Mutations disrupting the Drosophila eRF1 and eRF3 show a strong maternal-effect nonsense suppression due to readthrough of stop codons and are zygotically lethal during larval stages PMID:38881530 disruptions in eRF1 methylation may provoke ribosomal stalling |
| GO:0006415 translational termination | NAS PMID:31410471 eRF1 mediates codon usage effects on mRNA translation effici... | ACCEPT | Summary: eRF1 is required for translational termination. Reason: Genetic loss of eRF1 causes nonsense suppression in vivo; methylation-deficient eRF1 impairs protein synthesis in germline cells. Supporting Evidence: PMID:14573473 Mutations disrupting the Drosophila eRF1 and eRF3 show a strong maternal-effect nonsense suppression due to readthrough of stop codons and are zygotically lethal during larval stages PMID:38881530 disruptions in eRF1 methylation may provoke ribosomal stalling |
| GO:0016149 translation release factor activity, codon specific | IBA GO_REF:0000033 | ACCEPT | Summary: Codon-specific translation release factor activity. Reason: Core molecular activity of eRF1: stop codon recognition and peptidyl-tRNA hydrolysis. Propagation Review Root cause: NO FAILURE CORE Sources checked: PANTHER:PTN000012041 SUPPORTS TRANSFER eRF1 is a canonical, single-copy class I release factor inside the eukaryotic eRF1 clade; no evidence of divergence. Supporting Evidence: PMID:14573473 eRF1 and eRF3 comprise the translation termination complex that recognizes stop codons and catalyzes the release of nascent polypeptide chains from ribosomes file:DROME/eRF1/eRF1-uniprot.txt Directs the termination of nascent peptide synthesis (translation) in response to the termination codons UAA, UAG and UGA |
| GO:0018444 translation release factor complex | IBA GO_REF:0000033 | ACCEPT | Summary: eRF1 is part of the eRF1-eRF3 release factor complex. Reason: eRF1 and eRF3 form the termination complex. Propagation Review Root cause: NO FAILURE CORE Sources checked: PANTHER:PTN000012041 SUPPORTS TRANSFER eRF1 is a canonical, single-copy class I release factor inside the eukaryotic eRF1 clade; no evidence of divergence. Supporting Evidence: PMID:14573473 eRF1 and eRF3 comprise the translation termination complex that recognizes stop codons and catalyzes the release of nascent polypeptide chains from ribosomes |
| GO:0018444 translation release factor complex | NAS PMID:31410471 eRF1 mediates codon usage effects on mRNA translation effici... | ACCEPT | Summary: eRF1 is part of the eRF1-eRF3 release factor complex. Reason: eRF1 and eRF3 form the termination complex. Supporting Evidence: PMID:14573473 eRF1 and eRF3 comprise the translation termination complex that recognizes stop codons and catalyzes the release of nascent polypeptide chains from ribosomes |
| GO:1990825 sequence-specific mRNA binding | IBA GO_REF:0000033 | KEEP AS NON CORE | Summary: Sequence-specific mRNA binding inherited from the eRF1 family. Reason: eRF1 decodes stop codons in the ribosomal A site, which is a sequence-specific contact with the mRNA, but this contact only occurs in the context of the terminating ribosome and is captured more precisely by codon-specific release factor activity. Propagation Review Root cause: NO FAILURE NON CORE Failure modes: GRANULARITY MISMATCH Sources checked: PANTHER:PTN000012041 SUPPORTS TRANSFER Stop-codon decoding is conserved; the mRNA binding term is a less informative description of it. Supporting Evidence: file:DROME/eRF1/eRF1-uniprot.txt Directs the termination of nascent peptide synthesis (translation) in response to the termination codons UAA, UAG and UGA |
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Download this section (compressed HTML)Q: Does HemK2-mediated GGQ methylation alter eRF1 stop-codon specificity or only termination efficiency in Drosophila germline cells?
Experiment: Ribosome profiling and disome profiling of ovaries expressing GGQ-methylation-deficient eRF1, scoring stop-codon dwell time and 3' UTR readthrough.
Hypothesis: Unmethylated eRF1 slows termination and causes ribosome collisions at stop codons in germline cells.
Type: ribosome profiling
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