module: dmel_atr_atrip_complex
title: ATR-ATRIP checkpoint kinase complex in Drosophila melanogaster
label: ATR-ATRIP complex
module_type: PROTEIN_COMPLEX
description: >-
  ATR is a phosphatidylinositol 3-kinase-related protein kinase that responds
  to single-stranded DNA at stalled replication forks and processed DNA
  breaks. Its partner ATRIP binds RPA-coated single-stranded DNA and recruits
  ATR, which then phosphorylates checkpoint targets such as Chk1 to arrest the
  cell cycle and stabilize replication forks. In Drosophila ATR is encoded by
  mei-41 and ATRIP by mus304; mutants are sensitive to DNA damage and are
  defective in DNA damage checkpoints.
summary: >-
  ATR (Mei-41) checkpoint kinase with its ssDNA-recruitment partner ATRIP
  (Mus304).
concepts:
  - {id: GO:0070310, label: ATR-ATRIP complex}
cellular_components:
  - {id: GO:0005634, label: nucleus}
group: ATR-ATRIP
unit_functions:
  mei-41: {id: GO:0004674, label: protein serine/threonine kinase activity}
roles:
  mei-41: ATR catalytic kinase subunit
  mus304: ATRIP recruitment subunit
notes: >-
  Upstream activators (9-1-1 clamp, TopBP1) and downstream effectors (Chk1,
  encoded by grp) are outside the module; see dmel_9_1_1_checkpoint_clamp.