title: ATM engages autodegradation of the E3 ubiquitin ligase COP1 after DNA damage.
abstract: The ataxia telangiectasia mutated (ATM) protein kinase is a critical component of a DNA-damage response network configured to maintain genomic integrity. The abundance of an essential downstream effecter of this pathway, the tumor suppressor protein p53, is tightly regulated by controlled degradation through COP1 and other E3 ubiquitin ligases, such as MDM2 and Pirh2; however, the signal transduction pathway that regulates the COP1-p53 axis following DNA damage remains enigmatic. We observed that in response to DNA damage, ATM phosphorylated COP1 on Ser(387) and stimulated a rapid autodegradation mechanism. Ionizing radiation triggered an ATM-dependent movement of COP1 from the nucleus to the cytoplasm, and ATM-dependent phosphorylation of COP1 on Ser(387) was both necessary and sufficient to disrupt the COP1-p53 complex and subsequently to abrogate the ubiquitination and degradation of p53. Furthermore, phosphorylation of COP1 on Ser(387) was required to permit p53 to become stabilized and to exert its tumor suppressor properties in response to DNA damage.
authors.affiliation: Department of Physiological Chemistry, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA.
authors.forename: David
authors.initials: D
authors.lastname: Dornan
authors.forename: Harumi
authors.initials: H
authors.lastname: Shimizu
authors.forename: Angie
authors.initials: A
authors.lastname: Mah
authors.forename: Tanay
authors.initials: T
authors.lastname: Dudhela
authors.forename: Michael
authors.initials: M
authors.lastname: Eby
authors.forename: Karen
authors.initials: K
authors.lastname: O'rourke
authors.forename: Somasekar
authors.initials: S
authors.lastname: Seshagiri
authors.forename: Vishva M
authors.initials: VM
authors.lastname: Dixit
mesh_terms: D064007:Ataxia Telangiectasia Mutated Proteins; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D004249:DNA Damage; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005047:Etoposide / Q000494:pharmacology; D006801:Humans; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D010768:Phosphoserine / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering; D011839:Radiation, Ionizing; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D014162:Transfection; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism*; D025801:Ubiquitin / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism*
chemical_list: D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D034741:RNA, Small Interfering; D011993:Recombinant Fusion Proteins; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins; D025801:Ubiquitin; D010768:Phosphoserine; D005047:Etoposide; C471981:COP1 protein, human; D044767:Ubiquitin-Protein Ligases; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; D017346:Protein Serine-Threonine Kinases; D046988:Proteasome Endopeptidase Complex