id: O75822
gene_symbol: EIF3J
product_type: PROTEIN
status: COMPLETE
taxon:
  id: NCBITaxon:9606
  label: Homo sapiens
description: EIF3J (eukaryotic translation initiation factor 3 subunit J) is a cytoplasmic accessory subunit of the 13-subunit eIF-3 complex, the largest eukaryotic translation initiation factor. eIF-3 associates with the 40S ribosomal subunit and orchestrates several steps of cap-dependent translation initiation, promoting recruitment of eIF-1, eIF-1A, the eIF-2-GTP-Met-tRNAi ternary complex and eIF-5 to form the 43S pre-initiation complex, stimulating mRNA recruitment and scanning to the AUG start codon, and contributing to disassembly/recycling of post-termination ribosomal complexes while preventing premature 40S-60S subunit joining. EIF3J is a loosely associated, sub-stoichiometric ("labile") subunit that docks onto the complex through EIF3B; it positions near the 40S mRNA entry channel/decoding region and is required for stable binding of eIF-3 (and its subcomplexes) to the 40S subunit, thereby modulating mRNA loading and 40S availability. It is a non-catalytic accessory factor (its initiation-factor activity is contributed in the context of the assembled complex) and is phosphorylated in a serum-stimulation-dependent manner.
alternative_products:
- name: '1'
  id: O75822-1
- name: '2'
  id: O75822-2
  sequence_note: VSP_054593
- name: '3'
  id: O75822-3
  sequence_note: VSP_054776
existing_annotations:
- term:
    id: GO:0005852
    label: eukaryotic translation initiation factor 3 complex
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: part_of
  review:
    summary: EIF3J is a (labile) subunit of the eIF-3 complex, well supported across eukaryotes and by direct human evidence. This is the core cellular-component annotation.
    action: ACCEPT
    reason: EIF3J is documented as a component of the 13-subunit eIF-3 complex, binding via EIF3B; the IBA is corroborated by IDA/IPI evidence.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-uniprot.txt
      supporting_text: Component of the eukaryotic translation initiation factor 3 (eIF-3) complex
- term:
    id: GO:0001732
    label: formation of cytoplasmic translation initiation complex
  evidence_type: IEA
  original_reference_id: GO_REF:0000104
  qualifier: involved_in
  review:
    summary: As part of eIF-3, EIF3J participates in assembly of the 43S/48S translation initiation complexes on the 40S subunit. A genuine core process annotation.
    action: ACCEPT
    reason: eIF-3 facilitates recruitment of initiation factors and ternary complex to form the 43S PIC; EIF3J contributes to this assembly.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-uniprot.txt
      supporting_text: facilitates the recruitment of eIF-1, eIF-1A, eIF-2:GTP:methionyl-tRNAi and eIF-5 to
- term:
    id: GO:0002183
    label: cytoplasmic translational initiation
  evidence_type: IEA
  original_reference_id: GO_REF:0000104
  qualifier: involved_in
  review:
    summary: EIF3J participates in cytoplasmic translation initiation as an eIF-3 subunit. This is the core biological process.
    action: ACCEPT
    reason: eIF-3 is required for several steps in initiation of protein synthesis; this is EIF3J's central biological role.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-uniprot.txt
      supporting_text: required for several steps in the initiation of protein synthesis
- term:
    id: GO:0003743
    label: translation initiation factor activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000120
  qualifier: enables
  review:
    summary: EIF3J contributes translation initiation factor activity as an accessory subunit of eIF-3. The activity is exerted in the context of the assembled complex rather than by EIF3J alone.
    action: ACCEPT
    reason: The core molecular function of EIF3J is translation initiation factor activity via the eIF-3 complex; note the curated experimental annotations use the contributes_to qualifier, reflecting its accessory role.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-goa.tsv
      supporting_text: GO:0003743 translation initiation factor activity molecular_function ECO:0000501 IEA
- term:
    id: GO:0005737
    label: cytoplasm
  evidence_type: IEA
  original_reference_id: GO_REF:0000120
  qualifier: located_in
  review:
    summary: EIF3J is cytoplasmic, consistent with its role in cytoplasmic translation initiation.
    action: ACCEPT
    reason: Cytoplasm is the documented subcellular location and the site of translation initiation.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-uniprot.txt
      supporting_text: 'SUBCELLULAR LOCATION: Cytoplasm'
- term:
    id: GO:0005852
    label: eukaryotic translation initiation factor 3 complex
  evidence_type: IEA
  original_reference_id: GO_REF:0000120
  qualifier: part_of
  review:
    summary: Electronic transfer of eIF-3 complex membership, redundant with the IBA/IDA/IPI evidence.
    action: ACCEPT
    reason: Correct core cellular component, corroborated by stronger evidence.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-goa.tsv
      supporting_text: GO:0005852 eukaryotic translation initiation factor 3 complex cellular_component ECO:0000501 IEA
- term:
    id: GO:0016282
    label: eukaryotic 43S preinitiation complex
  evidence_type: IEA
  original_reference_id: GO_REF:0000104
  qualifier: part_of
  review:
    summary: Via eIF-3, EIF3J is part of the transient 43S pre-initiation complex on the 40S subunit. A genuine but transient assembly intermediate.
    action: KEEP_AS_NON_CORE
    reason: The 43S PIC is a transient initiation intermediate that contains eIF-3; a real but non-core localization relative to the stable eIF-3 complex membership.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-uniprot.txt
      supporting_text: to form the 43S pre-initiation complex (43S PIC)
- term:
    id: GO:0033290
    label: eukaryotic 48S preinitiation complex
  evidence_type: IEA
  original_reference_id: GO_REF:0000104
  qualifier: part_of
  review:
    summary: Via eIF-3, EIF3J is part of the transient 48S pre-initiation complex (after mRNA recruitment and start-codon scanning). A transient assembly intermediate.
    action: KEEP_AS_NON_CORE
    reason: The 48S PIC is a transient initiation intermediate; real but non-core relative to stable eIF-3 complex membership.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-uniprot.txt
      supporting_text: stimulates mRNA recruitment to the 43S PIC and scanning of the mRNA for
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:14688252
  qualifier: enables
  review:
    summary: Interaction with EIF3B (P55884), the subunit through which EIF3J docks onto eIF-3; this study shows EIF3J is required for stable binding of eIF-3 to 40S subunits. Deep-research synthesis further localizes EIF3J binding to the 40S near the mRNA entry channel and A-site, where it binds anti-cooperatively with mRNA and acts as a gatekeeper for mRNA accommodation. Bare protein binding is uninformative, but the interaction is biologically central.
    action: KEEP_AS_NON_CORE
    reason: Records the functionally important EIF3J-EIF3B interaction, but the term is uninformative; the informative function (eIF-3 membership and 40S/mRNA-entry-channel binding) is captured by complex/initiation annotations and core_functions.
    supported_by:
    - reference_id: PMID:14688252
      supporting_text: j-subunit of human translation initiation factor eIF3 is required for the stable binding of eIF3 and its subcomplexes to 40 S ribosomal subunits in vitro
    - reference_id: file:human/EIF3J/EIF3J-deep-research-falcon.md
      supporting_text: Binds the 40S small subunit near the mRNA entry channel and A-site; competes anti-cooperatively with accommodated mRNA
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:16932749
  qualifier: enables
  review:
    summary: Interaction reported in a study of the ribosome-associated factor p97/DAP5. Bare protein binding is uninformative.
    action: KEEP_AS_NON_CORE
    reason: Records a real interaction but uninformative term; not core to EIF3J's function.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-goa.tsv
      supporting_text: GO:0005515 protein binding molecular_function ECO:0000353 IPI PMID:16932749 UniProtKB:Q04637
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:18628297
  qualifier: enables
  review:
    summary: Interaction with EIF4G1 (Q04637) in a study of DDX3 in translation and eIF3. Bare protein binding is uninformative.
    action: KEEP_AS_NON_CORE
    reason: Records a real translation-related interaction but uninformative term; not core.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-goa.tsv
      supporting_text: GO:0005515 protein binding molecular_function ECO:0000353 IPI PMID:18628297 UniProtKB:P55884
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:22113938
  qualifier: enables
  review:
    summary: Interaction with the casein kinase 2 catalytic subunit CSNK2A1 (P68400) from a kinase-substrate screen; consistent with EIF3J being phosphorylated. Bare protein binding is uninformative.
    action: KEEP_AS_NON_CORE
    reason: Records a kinase-substrate interaction (EIF3J is phosphorylated) but uninformative term; not a core function.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-goa.tsv
      supporting_text: GO:0005515 protein binding molecular_function ECO:0000353 IPI PMID:22113938 UniProtKB:P68400
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:25852190
  qualifier: enables
  review:
    summary: Interaction with CSNK2A1 (P68400) from a kinase-network apoptosis study. Bare protein binding is uninformative.
    action: KEEP_AS_NON_CORE
    reason: Records a kinase interaction but uninformative term; not core.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-goa.tsv
      supporting_text: GO:0005515 protein binding molecular_function ECO:0000353 IPI PMID:25852190 UniProtKB:P68400
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:32296183
  qualifier: enables
  review:
    summary: HuRI binary interactome capturing an EIF3J-ABCE1 (P61221) interaction. ABCE1 is the ribosome-recycling ATPase; deep-research synthesis indicates EIF3J specifically (not merely the eIF-3 holo-complex) functionally couples to ABCE1/RLI1 and enhances post-termination ribosome recycling, so this interaction is biologically meaningful even though the bare term is uninformative.
    action: KEEP_AS_NON_CORE
    reason: Records a recycling-relevant interaction (ABCE1) with EIF3J-subunit-specific functional support in the recycling literature, but the term itself is uninformative; the recycling role is captured at the complex level.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-goa.tsv
      supporting_text: GO:0005515 protein binding molecular_function ECO:0000353 IPI PMID:32296183 UniProtKB:P61221
    - reference_id: file:human/EIF3J/EIF3J-deep-research-falcon.md
      supporting_text: physically/ functionally associates with ABCE1/RLI1, the ATPase required for post-termination ribosome recycling
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:32707033
  qualifier: enables
  review:
    summary: Interaction with CSNK2A1 (P68400) from a kinase-interaction-network study. Bare protein binding is uninformative.
    action: KEEP_AS_NON_CORE
    reason: Records a kinase interaction but uninformative term; not core.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-goa.tsv
      supporting_text: GO:0005515 protein binding molecular_function ECO:0000353 IPI PMID:32707033 UniProtKB:P68400
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:32911434
  qualifier: enables
  review:
    summary: Interaction with NFE2L2/NRF2 (Q16236) from an NRF2-interactome screen. Bare protein binding is uninformative and likely peripheral.
    action: KEEP_AS_NON_CORE
    reason: Records a real interaction but uninformative term and peripheral to translation initiation; not core.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-goa.tsv
      supporting_text: GO:0005515 protein binding molecular_function ECO:0000353 IPI PMID:32911434 UniProtKB:Q16236
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:33961781
  qualifier: enables
  review:
    summary: BioPlex affinity-purification capturing an EIF3J-CSNK2A1 (P68400) interaction. Bare protein binding is uninformative.
    action: KEEP_AS_NON_CORE
    reason: Records a kinase interaction but uninformative term; not core.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-goa.tsv
      supporting_text: GO:0005515 protein binding molecular_function ECO:0000353 IPI PMID:33961781 UniProtKB:P68400
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:35271311
  qualifier: enables
  review:
    summary: OpenCell endogenous-tagging interactome capturing EIF3J interactions with EIF3B (P55884) and ABCE1 (P61221), consistent with eIF-3 docking and recycling roles. Bare protein binding is uninformative.
    action: KEEP_AS_NON_CORE
    reason: Records biologically consistent interactions (EIF3B, ABCE1) but uninformative term; captured by complex/initiation annotations.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-goa.tsv
      supporting_text: GO:0005515 protein binding molecular_function ECO:0000353 IPI PMID:35271311 UniProtKB:P55884
- term:
    id: GO:0042802
    label: identical protein binding
  evidence_type: IPI
  original_reference_id: PMID:32296183
  qualifier: enables
  review:
    summary: EIF3J self-interaction reported in the HuRI binary interactome (consistent with the EIF3J-EIF3J IntAct entry). A real homotypic interaction but not a core function.
    action: KEEP_AS_NON_CORE
    reason: Records a self-interaction; not part of the core translation-initiation function.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-goa.tsv
      supporting_text: GO:0042802 identical protein binding molecular_function ECO:0000353 IPI PMID:32296183 UniProtKB:O75822
- term:
    id: GO:0001732
    label: formation of cytoplasmic translation initiation complex
  evidence_type: NAS
  original_reference_id: PMID:16920360
  qualifier: involved_in
  review:
    summary: Author statement (eIF3 review) that eIF-3 serves as a scaffold for assembly of translation initiation complexes; EIF3J participates as a subunit.
    action: ACCEPT
    reason: Consistent with eIF-3's documented role in initiation-complex assembly; core process for EIF3J as a subunit.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-goa.tsv
      supporting_text: GO:0001732 formation of cytoplasmic translation initiation complex biological_process ECO:0005547 NAS PMID:16920360
- term:
    id: GO:0005852
    label: eukaryotic translation initiation factor 3 complex
  evidence_type: IPI
  original_reference_id: PMID:17322308
  qualifier: part_of
  review:
    summary: Direct (ComplexPortal/MS) evidence placing EIF3J in the eIF-3 complex. Core cellular component.
    action: ACCEPT
    reason: Mass-spectrometry characterization of human eIF-3 confirms EIF3J as a component.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-goa.tsv
      supporting_text: GO:0005852 eukaryotic translation initiation factor 3 complex cellular_component ECO:0000353 IPI PMID:17322308
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-156808
  qualifier: located_in
  review:
    summary: Reactome curated cytosolic localization for translation-initiation reactions.
    action: ACCEPT
    reason: Correct cytosolic localization, consistent with the cytoplasmic site of action.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-goa.tsv
      supporting_text: GO:0005829 cytosol cellular_component ECO:0000304 TAS Reactome:R-HSA-156808
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-156823
  qualifier: located_in
  review:
    summary: Reactome curated cytosolic localization, redundant with the other cytosol annotations.
    action: ACCEPT
    reason: Correct cytosolic localization.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-goa.tsv
      supporting_text: GO:0005829 cytosol cellular_component ECO:0000304 TAS Reactome:R-HSA-156823
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-157849
  qualifier: located_in
  review:
    summary: Reactome curated cytosolic localization, redundant with the other cytosol annotations.
    action: ACCEPT
    reason: Correct cytosolic localization.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-goa.tsv
      supporting_text: GO:0005829 cytosol cellular_component ECO:0000304 TAS Reactome:R-HSA-157849
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-72619
  qualifier: located_in
  review:
    summary: Reactome curated cytosolic localization, redundant with the other cytosol annotations.
    action: ACCEPT
    reason: Correct cytosolic localization.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-goa.tsv
      supporting_text: GO:0005829 cytosol cellular_component ECO:0000304 TAS Reactome:R-HSA-72619
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-72621
  qualifier: located_in
  review:
    summary: Reactome curated cytosolic localization, redundant with the other cytosol annotations.
    action: ACCEPT
    reason: Correct cytosolic localization.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-goa.tsv
      supporting_text: GO:0005829 cytosol cellular_component ECO:0000304 TAS Reactome:R-HSA-72621
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-72676
  qualifier: located_in
  review:
    summary: Reactome curated cytosolic localization, redundant with the other cytosol annotations.
    action: ACCEPT
    reason: Correct cytosolic localization.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-goa.tsv
      supporting_text: GO:0005829 cytosol cellular_component ECO:0000304 TAS Reactome:R-HSA-72676
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-72691
  qualifier: located_in
  review:
    summary: Reactome curated cytosolic localization, redundant with the other cytosol annotations.
    action: ACCEPT
    reason: Correct cytosolic localization.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-goa.tsv
      supporting_text: GO:0005829 cytosol cellular_component ECO:0000304 TAS Reactome:R-HSA-72691
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-72697
  qualifier: located_in
  review:
    summary: Reactome curated cytosolic localization, redundant with the other cytosol annotations.
    action: ACCEPT
    reason: Correct cytosolic localization.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-goa.tsv
      supporting_text: GO:0005829 cytosol cellular_component ECO:0000304 TAS Reactome:R-HSA-72697
- term:
    id: GO:0003743
    label: translation initiation factor activity
  evidence_type: IC
  original_reference_id: PMID:17322308
  qualifier: contributes_to
  review:
    summary: Curator-inferred (from eIF-3 complex membership) that EIF3J contributes to translation initiation factor activity. The contributes_to qualifier correctly reflects its accessory role within the complex.
    action: ACCEPT
    reason: This is the core molecular function annotation for EIF3J, appropriately qualified as contributes_to for a non-catalytic accessory subunit.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-goa.tsv
      supporting_text: GO:0003743 translation initiation factor activity molecular_function ECO:0000305 IC PMID:17322308
- term:
    id: GO:0003743
    label: translation initiation factor activity
  evidence_type: IC
  original_reference_id: PMID:18599441
  qualifier: contributes_to
  review:
    summary: Curator-inferred translation initiation factor activity from eIF-3 complex membership (subunit interaction map study). Redundant with the other IC annotation.
    action: ACCEPT
    reason: Core molecular function, appropriately qualified contributes_to.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-goa.tsv
      supporting_text: GO:0003743 translation initiation factor activity molecular_function ECO:0000305 IC PMID:18599441
- term:
    id: GO:0005852
    label: eukaryotic translation initiation factor 3 complex
  evidence_type: IDA
  original_reference_id: PMID:17322308
  qualifier: part_of
  review:
    summary: Direct MS-based evidence for EIF3J as an eIF-3 component. Core cellular component.
    action: ACCEPT
    reason: Directly demonstrated eIF-3 complex membership.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-goa.tsv
      supporting_text: GO:0005852 eukaryotic translation initiation factor 3 complex cellular_component ECO:0000314 IDA PMID:17322308
- term:
    id: GO:0005852
    label: eukaryotic translation initiation factor 3 complex
  evidence_type: IDA
  original_reference_id: PMID:18599441
  qualifier: part_of
  review:
    summary: Direct MS-based evidence for EIF3J as an eIF-3 component (subunit interaction map). Core cellular component.
    action: ACCEPT
    reason: Directly demonstrated eIF-3 complex membership.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-goa.tsv
      supporting_text: GO:0005852 eukaryotic translation initiation factor 3 complex cellular_component ECO:0000314 IDA PMID:18599441
- term:
    id: GO:0006413
    label: translational initiation
  evidence_type: IC
  original_reference_id: PMID:17322308
  qualifier: involved_in
  review:
    summary: Curator-inferred involvement in translational initiation from eIF-3 membership. Core biological process.
    action: ACCEPT
    reason: EIF3J participates in translation initiation as an eIF-3 subunit.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-goa.tsv
      supporting_text: GO:0006413 translational initiation biological_process ECO:0000305 IC PMID:17322308
- term:
    id: GO:0006413
    label: translational initiation
  evidence_type: IC
  original_reference_id: PMID:18599441
  qualifier: involved_in
  review:
    summary: Curator-inferred involvement in translational initiation from eIF-3 membership. Redundant with the other IC annotation.
    action: ACCEPT
    reason: Core biological process for EIF3J as an eIF-3 subunit.
    supported_by:
    - reference_id: file:human/EIF3J/EIF3J-goa.tsv
      supporting_text: GO:0006413 translational initiation biological_process ECO:0000305 IC PMID:18599441
references:
- id: GO_REF:0000033
  title: Annotation inferences using phylogenetic trees.
  findings: []
- id: GO_REF:0000104
  title: Automatic annotation of UniProtKB entries based on UniRule rules.
  findings: []
- id: GO_REF:0000120
  title: Combined Automated Annotation using Multiple IEA Methods.
  findings: []
- id: PMID:14688252
  title: The j-subunit of human translation initiation factor eIF3 is required for the stable binding of eIF3 and its subcomplexes to 40 S ribosomal subunits in vitro.
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: "Cached publications/PMID_14688252.md title matches YAML; directly establishes
      EIF3J's core function — required for stable binding of eIF-3 (and subcomplexes) to 40S
      ribosomal subunits. This is the primary experimental support cited in core_functions."
  findings:
  - statement: EIF3J (the j-subunit) is required for stable binding of eIF-3 and its subcomplexes to 40S ribosomal subunits.
    reference_section_type: RESULTS
- id: PMID:16920360
  title: 'eIF3: a versatile scaffold for translation initiation complexes.'
  findings:
  - statement: eIF-3 acts as a scaffold for assembly of translation initiation complexes.
    reference_section_type: RESULTS
- id: PMID:16932749
  title: p97/DAP5 is a ribosome-associated factor that facilitates protein synthesis and cell proliferation by modulating the synthesis of cell cycle proteins.
  findings: []
- id: PMID:17322308
  title: Structural characterization of the human eukaryotic initiation factor 3 protein complex by mass spectrometry.
  findings:
  - statement: Mass-spectrometry characterization of human eIF-3 confirms EIF3J as a subunit of the complex.
    reference_section_type: RESULTS
- id: PMID:18599441
  title: Mass spectrometry reveals modularity and a complete subunit interaction map of the eukaryotic translation factor eIF3.
  findings:
  - statement: Subunit interaction map of eIF-3 places EIF3J as a labile subunit binding via EIF3B.
    reference_section_type: RESULTS
- id: PMID:18628297
  title: Human DDX3 functions in translation and interacts with the translation initiation factor eIF3.
  findings: []
- id: PMID:22113938
  title: A bead-based approach for large-scale identification of in vitro kinase substrates.
  findings: []
- id: PMID:25852190
  title: Integrative analysis of kinase networks in TRAIL-induced apoptosis provides a source of potential targets for combination therapy.
  findings: []
- id: PMID:32296183
  title: A reference map of the human binary protein interactome.
  findings: []
- id: PMID:32707033
  title: Kinase Interaction Network Expands Functional and Disease Roles of Human Kinases.
  findings: []
- id: PMID:32911434
  title: A functionally defined high-density NRF2 interactome reveals new conditional regulators of ARE transactivation.
  findings: []
- id: PMID:33961781
  title: Dual proteome-scale networks reveal cell-specific remodeling of the human interactome.
  findings: []
- id: PMID:35271311
  title: 'OpenCell: Endogenous tagging for the cartography of human cellular organization.'
  findings: []
- id: PMID:25849773
  title: eIF3 targets cell-proliferation messenger RNAs for translational activation or repression.
  findings:
  - statement: eIF-3 selectively targets a subset of cell-proliferation mRNAs for translational activation or repression via stem-loop binding.
    reference_section_type: RESULTS
- id: PMID:27462815
  title: eIF3d is an mRNA cap-binding protein that is required for specialized translation initiation.
  findings:
  - statement: eIF-3 (via eIF3d) mediates specialized cap-dependent translation initiation.
    reference_section_type: RESULTS
- id: Reactome:R-HSA-156808
  title: Reactome translation-initiation reaction (cytosolic).
  findings: []
- id: Reactome:R-HSA-156823
  title: Reactome translation-initiation reaction (cytosolic).
  findings: []
- id: Reactome:R-HSA-157849
  title: Reactome translation-initiation reaction (cytosolic).
  findings: []
- id: Reactome:R-HSA-72619
  title: Reactome translation-initiation reaction (cytosolic).
  findings: []
- id: Reactome:R-HSA-72621
  title: Reactome translation-initiation reaction (cytosolic).
  findings: []
- id: Reactome:R-HSA-72676
  title: Reactome translation-initiation reaction (cytosolic).
  findings: []
- id: Reactome:R-HSA-72691
  title: Reactome translation-initiation reaction (cytosolic).
  findings: []
- id: Reactome:R-HSA-72697
  title: Reactome translation-initiation reaction (cytosolic).
  findings: []
- id: file:human/EIF3J/EIF3J-deep-research-falcon.md
  title: Falcon deep research report for EIF3J
  reference_review:
    relevance: HIGH
    correctness: UNVERIFIED
    review_notes: "LLM-synthesized deep-research report (Edison/falcon); citations are author-year
      keys to reviews/primary papers, not independently re-verified here, hence UNVERIFIED.
      EIF3J-SUBUNIT-SPECIFIC claims that are well-anchored to primary literature and used below:
      (1) eIF3j binds the human 40S near the mRNA entry channel and A-site, anti-cooperatively with
      mRNA, acting as a gatekeeper for mRNA accommodation and being displaced upon mRNA recruitment
      in an ATP-dependent, helicase-independent manner (Sokabe & Fraser 2017, PNAS); (2) eIF3j
      functionally couples to ABCE1/RLI1 and enhances post-termination ribosome recycling (Young &
      Guydosh 2022, BioEssays); (3) eIF3j N-terminus contacts the eIF3b RRM (NMR) and its C-terminus
      mediates transcript-selective inhibition of a subset of circRNA translation (Song et al. 2022).
      DISTINGUISH from eIF3 HOLO-COMPLEX inference: the report repeatedly attributes whole-eIF3
      functions (43S/48S PIC formation, cap-dependent initiation, mRNA scanning, start-codon
      selectivity, NF-kB/IFN crosstalk) to the complex; these are NOT EIF3J-subunit-specific and were
      not used to strengthen subunit-level annotations. The eIF3j-specific, biochemically grounded
      roles are the mRNA-entry-channel/A-site gatekeeping and the ABCE1-coupled recycling role."
  findings:
  - statement: eIF3j binds the human 40S near the mRNA entry channel and A-site (anti-cooperatively with mRNA) as a gatekeeper for mRNA accommodation, and is displaced upon mRNA recruitment; it also functionally couples to ABCE1/RLI1 to enhance post-termination ribosome recycling.
    reference_section_type: RESULTS
- id: file:human/EIF3J/EIF3J-uniprot.txt
  title: UniProt entry O75822 (EIF3J_HUMAN), Eukaryotic translation initiation factor 3 subunit J.
  findings:
  - statement: EIF3J is a labile/loosely-associated subunit of the eIF-3 complex that binds via EIF3B; eIF-3 associates with the 40S subunit, drives 43S/48S pre-initiation complex formation, mRNA recruitment and scanning, and post-termination ribosome recycling; cytoplasmic; phosphorylated upon serum stimulation.
    reference_section_type: OTHER
core_functions:
- description: Accessory (labile) subunit of the eIF-3 complex that contributes translation initiation factor activity, helping eIF-3 assemble the 43S/48S pre-initiation complexes on the 40S ribosomal subunit and recruit/scan mRNA during cap-dependent translation initiation.
  molecular_function:
    id: GO:0003743
    label: translation initiation factor activity
  in_complex:
    id: GO:0005852
    label: eukaryotic translation initiation factor 3 complex
  locations:
  - id: GO:0005737
    label: cytoplasm
  supported_by:
  - reference_id: file:human/EIF3J/EIF3J-uniprot.txt
    supporting_text: required for several steps in the initiation of protein synthesis
  - reference_id: PMID:14688252
    supporting_text: j-subunit of human translation initiation factor eIF3 is required for the stable binding of eIF3 and its subcomplexes to 40 S ribosomal subunits in vitro
- description: Structural component of the eIF-3 complex; EIF3J docks onto eIF-3 through EIF3B and is required for stable association of eIF-3 with the 40S ribosomal subunit, positioning near the mRNA entry channel and modulating mRNA loading and 40S availability (including in ribosome recycling).
  molecular_function:
    id: GO:0003743
    label: translation initiation factor activity
  locations:
  - id: GO:0005737
    label: cytoplasm
  supported_by:
  - reference_id: file:human/EIF3J/EIF3J-uniprot.txt
    supporting_text: EIF3J is a labile subunit that binds to the eIF-3 complex via EIF3B
  - reference_id: file:human/EIF3J/EIF3J-deep-research-falcon.md
    supporting_text: Binds the 40S small subunit near the mRNA entry channel and A-site; competes anti-cooperatively with accommodated mRNA
  in_complex:
    id: GO:0005852
    label: eukaryotic translation initiation factor 3 complex
proposed_new_terms: []
suggested_questions:
- question: Does human EIF3J have a distinct, separable role in 40S ribosome recycling/availability (post-termination) versus initiation, as suggested by yeast Hcr1?
- question: How does the sub-stoichiometric/labile association of EIF3J with eIF-3 regulate switching between mRNA-entry-channel occupancy and mRNA loading?
- question: What is the functional consequence of serum-stimulated phosphorylation of EIF3J for its association with eIF-3 and selective mRNA translation?
suggested_experiments:
- description: Selective EIF3J depletion/rescue with ribosome profiling and 40S/80S subunit-availability assays to dissect its contribution to initiation versus post-termination recycling.
- description: Cryo-EM of 40S-eIF-3 complexes with and without EIF3J to define its occupancy of the mRNA entry channel and effect on mRNA accommodation.
- description: Phosphomutant (phospho-null/phospho-mimetic) EIF3J variants to test how serum-stimulated phosphorylation modulates eIF-3 binding and translational output.