module: dmel_cleavage_polyadenylation
title: mRNA 3' end cleavage and polyadenylation machinery in Drosophila melanogaster
label: mRNA cleavage and polyadenylation
module_type: PROTEIN_COMPLEX
description: >-
  Most eukaryotic mRNAs acquire their 3' end by endonucleolytic cleavage of the
  pre-mRNA followed by addition of a poly(A) tail. The cleavage and
  polyadenylation specificity factor (CPSF) recognizes the AAUAAA
  polyadenylation signal through Cpsf160, Wdr33 and Clp (CPSF30), and Fip1
  recruits poly(A) polymerase. The cleavage stimulation factor (CstF; CstF50,
  CstF64 and Su(f), the CstF77 homolog) binds GU-rich sequences downstream of the
  cleavage site. The core cleavage complex of Cpsf73, Cpsf100 and the scaffold
  Symplekin (Sym) carries out cleavage, with Cpsf73 as the endonuclease. Cpsf73,
  Cpsf100 and Sym are shared with the histone pre-mRNA processing machinery.
summary: >-
  CPSF, CstF and the Cpsf73-Cpsf100-Symplekin core cleavage complex, which
  cleave pre-mRNAs at the polyadenylation site.
concepts:
  - {id: GO:0005847, label: mRNA cleavage and polyadenylation specificity factor complex}
cellular_components:
  - {id: GO:0005634, label: nucleus}
parts:
  - id: cpsf_signal_recognition
    label: CPSF polyadenylation-signal recognition subcomplex
    role: AAUAAA recognition and poly(A) polymerase recruitment
    genes: [Cpsf160, Wdr33, Clp, Fip1]
    complex_term: {id: GO:0005847, label: mRNA cleavage and polyadenylation specificity factor complex}
    processes:
      - {id: GO:0180010, label: "co-transcriptional mRNA 3'-end processing, cleavage and polyadenylation pathway"}
  - id: core_cleavage_complex
    label: Core cleavage complex
    role: pre-mRNA endonucleolytic cleavage
    group: CCC
    unit_functions:
      Cpsf73: {id: GO:0004521, label: RNA endonuclease activity}
    processes:
      - {id: GO:0180010, label: "co-transcriptional mRNA 3'-end processing, cleavage and polyadenylation pathway"}
  - id: cstf
    label: Cleavage stimulation factor
    role: downstream element recognition
    genes: [CstF50, CstF64, su(f)]
    complex_term: {id: GO:0005848, label: mRNA cleavage stimulating factor complex}
    processes:
      - {id: GO:0180010, label: "co-transcriptional mRNA 3'-end processing, cleavage and polyadenylation pathway"}
notes: >-
  Boundary. FlyBase groups the polyadenylation factors (PF: CPSF signal
  recognition subunits plus CstF) separately from the core cleavage complex
  (CCC); this module splits PF into its CPSF and CstF subcomplexes. Poly(A)
  polymerase, the CFIm and CFIIm factors and poly(A)-binding proteins have no
  FlyBase group in this set and are not added. The histone pre-mRNA processing
  machinery that reuses the core cleavage complex is in
  dmel_histone_mrna_3prime_processing.