module: dmel_integrator_complex
title: Integrator complex in Drosophila melanogaster
label: Integrator complex
module_type: PROTEIN_COMPLEX
description: >-
  Integrator is a multisubunit complex that binds promoter-proximal RNA
  polymerase II and cleaves nascent transcripts. Its endonuclease module, in
  which IntS11 is the catalytic subunit related to the cleavage and
  polyadenylation endonuclease Cpsf73, processes the 3' ends of snRNAs and
  terminates transcription of paused or non-productive polymerases at
  protein-coding genes, enhancers and long noncoding RNA loci. Integrator also
  recruits protein phosphatase 2A through IntS6 and IntS8, forming the
  Integrator-PP2A (INTAC) complex that dephosphorylates the polymerase C-terminal
  domain and Spt5 and opposes P-TEFb. In Drosophila, Integrator attenuates
  transcription at many genes and is required for snRNA processing.
summary: >-
  Promoter-proximal RNA polymerase II-associated endonuclease and PP2A
  phosphatase complex for snRNA processing and premature transcription
  termination.
concepts:
  - {id: GO:0032039, label: integrator complex}
  - {id: GO:0160232, label: INTAC complex}
cellular_components:
  - {id: GO:0005634, label: nucleus}
parts:
  - id: endonuclease_module
    label: Integrator endonuclease module
    role: nascent RNA cleavage
    description: IntS4, IntS9 and the catalytic endonuclease IntS11.
    genes: [IntS4, IntS9, IntS11]
    unit_functions:
      IntS11: {id: GO:0004521, label: RNA endonuclease activity}
    processes:
      - {id: GO:0034472, label: snRNA 3'-end processing}
  - id: core_scaffold
    label: Integrator backbone, shoulder and associated subunits
    role: structural core and polymerase binding
    description: >-
      IntS1, IntS2, IntS7 (defl), IntS5 (omd), IntS8, IntS3, IntS12 and IntS15
      (CG5274); IntS8 also contributes to PP2A binding.
    genes: [IntS1, IntS2, defl, omd, IntS8, IntS3, IntS12, CG5274]
  - id: tail_module
    label: IntS10-IntS13-IntS14 module
    role: auxiliary module
    description: IntS10, IntS13 (asun) and IntS14.
    genes: [IntS10, asun, IntS14]
  - id: phosphatase_module
    label: Integrator-associated PP2A phosphatase module
    role: RNA polymerase II dephosphorylation in INTAC
    description: IntS6 with the PP2A catalytic subunit mts and the A subunit Pp2A-29B.
    genes: [IntS6, mts, Pp2A-29B]
    unit_functions:
      mts: {id: GO:0004722, label: protein serine/threonine phosphatase activity}
notes: >-
  Boundary. FlyBase groups the core Integrator (INT) and Integrator-PP2A (INTAC);
  INTAC adds the PP2A catalytic (mts) and scaffolding (Pp2A-29B) subunits, which
  are general PP2A subunits that also act in many other complexes. The four-part
  decomposition follows the endonuclease, backbone/shoulder, IntS10-13-14 and
  phosphatase modules described for human Integrator; IntS3 and IntS12 are
  placed with the core scaffold for simplicity.