module: dmel_ciliary_transition_zone
title: Ciliary transition zone components in Drosophila melanogaster
label: Ciliary transition zone
module_type: PROTEIN_COMPLEX
description: >-
  The transition zone is the region at the base of the cilium, just above the basal
  body, where Y-shaped links connect the axoneme to the ciliary membrane and form a
  diffusion barrier that controls which proteins enter the cilium. Its components
  include the MKS module, a membrane-associated complex of B9-domain proteins (B9d1,
  B9d2, Mks1), Cc2d2a and Tectonic, and Cep290, which links the barrier to the
  axoneme. In Drosophila, transition zone proteins act in the cilia of sensory
  neurons and in the long transition-zone-like region of spermatocyte cilia. Cep290,
  Chibby, Dilatory (Cep131) and Unc localize to the transition zone or basal body
  and are needed to assemble it and the cilium.
summary: >-
  MKS module, Cep290 complex and other transition zone proteins that build the
  ciliary gate at the base of the cilium.
concepts:
  - {id: GO:0035869, label: ciliary transition zone}
parts:
  - id: mks_module
    label: MKS complex
    role: membrane-associated diffusion barrier module
    group: MKS
    complex_term: {id: GO:0036038, label: MKS complex}
    locations:
      - {id: GO:0035869, label: ciliary transition zone}
  - id: cep290_complex
    label: Cep290 complex
    role: axoneme-to-membrane linker
    group: CEP290C
    locations:
      - {id: GO:0035869, label: ciliary transition zone}
  - id: other_transition_zone_proteins
    label: Chibby, Dilatory and Unc
    role: transition zone assembly factors
    description: >-
      Basal body and transition zone proteins required for transition zone
      assembly and ciliogenesis; they are not known to form one complex.
    genes: [Cby, dila, unc]
    complex: false
    processes:
      - {id: GO:0060271, label: cilium assembly}
notes: >-
  FlyBase groups TZ (all transition zone components), MKS and CEP290C overlap; the
  MKS and Cep290 complexes are modelled as parts, and TZ members outside them (Cby,
  dila, unc) as a third part. CG4975 is an Ataxin-10 homolog placed with Cep290 by
  FlyBase. An NPHP module comparable to the vertebrate NPHP1-NPHP4-RPGRIP1L complex
  is not represented in the FlyBase groups and is not modelled.
groups: [TZ, MKS, CEP290C]
function_note: >-
  No molecular function is assigned: the transition zone proteins are
  structural and gating components with no established molecular activity in
  Drosophila, and most have only ND molecular function annotations in GOA.