module: dmel_eif4e_cup_complex
title: eIF4E-Cup translational repressor complex in Drosophila melanogaster
label: eIF4E-Cup complex
module_type: PROTEIN_COMPLEX
description: >-
  Cup is an ovary-enriched eIF4E-binding protein that represses translation of
  specific maternal mRNAs during oogenesis. Cup binds the cap-binding factor
  eIF4E1 through a motif resembling that of eIF4G, so that eIF4E1 bound to the
  mRNA cap cannot recruit eIF4G and the ribosome. Cup is recruited to target
  mRNAs such as oskar and nanos by sequence-specific RNA-binding repressors
  (Bruno and Smaug), so that these mRNAs stay silent until they are localized in
  the oocyte. Cup is also required for eIF4E localization to the oocyte.
summary: >-
  Cup-eIF4E1 complex that blocks cap-dependent translation initiation on
  localized maternal mRNAs.
concepts:
  - {id: GO:1990500, label: eif4e-cup complex}
notes: >-
  Two-subunit complex modelled one part per subunit. Bruno (aret) and Smaug
  (smg), which recruit the complex to target mRNAs, are not FlyBase members and
  are not modelled as parts. eIF4E1 also acts in general cap-dependent
  translation initiation with eIF4G, outside this module.
parts:
- id: eif4e1_subunit
  label: eIF4E1 subunit
  role: mRNA cap-binding subunit
  genes: [eIF4E1]
  function: {id: 'GO:0000340', label: RNA 7-methylguanosine cap binding}
- id: cup_subunit
  label: cup subunit
  role: eIF4E-binding translational repressor
  genes: [cup]
  function: {id: 'GO:0008190', label: eukaryotic initiation factor 4E binding}
group: ECUP