EDD mediates DNA damage-induced activation of CHK2.
EDD, the human orthologue of Drosophila melanogaster "hyperplastic discs," is overexpressed or mutated in a number of common human cancers. Although EDD has been implicated in DNA damage signaling, a definitive role has yet to be demonstrated. Here we report a novel interaction between EDD and the DNA damage checkpoint kinase CHK2. EDD and CHK2 associate through a phospho-dependent interaction involving the CHK2 Forkhead-associated domain and a region of EDD spanning a number of putative Forkhead-associated domain-binding threonines. Using RNA interference, we demonstrate a critical role for EDD upstream of CHK2 in the DNA damage signaling pathway. EDD is necessary for the efficient activating phosphorylation of CHK2 in response to DNA damage following exposure to ionizing radiation or the radiomimetic, phleomycin. Cells depleted of EDD display impaired CHK2 kinase activity and an inability to respond to DNA damage. These results identify EDD as a novel mediator in DNA damage signal transduction via CHK2 and emphasize the potential importance of EDD in cancer.
Henderson
Michelle J
MJ
Cancer Research Program, Garvan Institute of Medical Research, 384 Victoria St., Darlinghurst, New South Wales 2010, Australia.
Munoz
Marcia A
MA
Saunders
Darren N
DN
Clancy
Jennifer L
JL
Russell
Amanda J
AJ
Williams
Brandi
B
Pappin
Darryl
D
Khanna
Kum Kum
KK
Jackson
Stephen P
SP
Sutherland
Robert L
RL
Watts
Colin K W
CK
D002460:Cell Line; D045744:Cell Line, Tumor; D064447:Checkpoint Kinase 2; D004249:DNA Damage / Q000502:physiology*; D004789:Enzyme Activation / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D011485:Protein Binding / Q000235:genetics; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism / Q000502:physiology*
C117617:UBR5 protein, human; D044767:Ubiquitin-Protein Ligases; D064447:Checkpoint Kinase 2; C578634:CHEK2 protein, human; D017346:Protein Serine-Threonine Kinases