module: dmel_muvb_complexes
title: MuvB-containing transcription complexes in Drosophila melanogaster
label: MuvB complexes
module_type: PROTEIN_COMPLEX
description: >-
  MuvB is a conserved core of five proteins (Mip130, Mip120, Mip40, Lin-52
  and Caf1-55) that assembles with different partners to repress or activate
  cell-cycle and differentiation genes. With E2F2, Dp and the
  retinoblastoma-family proteins Rbf or Rbf2 it forms dREAM, which represses
  E2F target genes and developmentally regulated genes. With the Myb
  transcription factor it forms the Myb-MuvB complex (MMB), which activates
  G2/M genes and also controls site-specific chorion gene amplification. In
  spermatocytes a testis-specific relative, tMAC, which contains Aly, Comr,
  Tomb and Topi with Mip40 and Caf1-55, activates the meiotic and
  spermatid differentiation gene program.
summary: >-
  MuvB core and the dREAM, Myb-MuvB and testis-specific tMAC complexes built
  on it.
concepts:
  - {id: GO:0070176, label: DRM complex}
cellular_components:
  - {id: GO:0000785, label: chromatin}
parts:
  - id: muvb_core
    label: MuvB core
    role: shared core of dREAM and Myb-MuvB
    group: MUVB
  - id: muvb_assemblies
    label: MuvB-containing complexes
    role: partner-specific repressor and activator complexes
    variant_sets:
      - id: muvb_complex_forms
        label: dREAM, Myb-MuvB or tMAC
        selection: ONE_OR_MORE
        variants:
          - id: dream_rbf
            label: dREAM complex, Rbf variant
            group: DRM-R
            complex_term: {id: GO:0070176, label: DRM complex}
          - id: dream_rbf2
            label: dREAM complex, Rbf2 variant
            group: DRM-R2
            complex_term: {id: GO:0070176, label: DRM complex}
          - id: myb_muvb
            label: Myb-MuvB complex
            group: MMC
            complex_term: {id: GO:0031523, label: Myb complex}
          - id: tmac
            label: Testis-specific meiotic arrest complex
            group: TMAC
connections:
  - source: muvb_core
    target: muvb_assemblies
    connection_type: PROVIDES_INPUT_FOR
    description: The MuvB core is incorporated into dREAM and Myb-MuvB assemblies.
notes: >-
  The MuvB core is modelled as its own part (FlyBase group MUVB) and also
  appears within each assembly variant, which list full FlyBase memberships.
  FlyBase places the dREAM Rbf group (DRM-R) membership to include both Rbf
  and Rbf2. tMAC is listed under MuvB complexes by FlyBase; it shares Mip40
  and Caf1-55 with MuvB and contains testis-specific paralogs (Aly, Tomb) of
  other MuvB subunits. tMAC has no GO cellular-component term.
function_note: >-
  No molecular function is assigned in this version. The MuvB core has no
  established catalytic activity; the DNA-binding transcription factors that
  join it (Myb in the Myb-MuvB complex, E2f2-Dp in dREAM) carry DNA-binding
  transcription factor activity terms in GOA but are not yet given annoton
  functions here.