Cleavage and phosphorylation of XRCC4 protein induced by X-irradiation.
We report the p35 and p60 forms of XRCC4 protein, appearing in human leukemia MOLT-4 or U937 cells following X-irradiation or hyperthermia. p35 appeared in conjunction with the cleavage of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) and the fragmentation of internucleosomal DNA, and was suppressed by Ac-DEVD-CHO. p35 was also produced in vitro by treating MOLT-4 cell lysate with recombinant caspases, suggesting that p35 was a caspase-cleaved fragment of XRCC4 in apoptotic cell death. p60 was sensitive to treatment with phosphatase or wortmannin and was undetectable in M059J cells deficient in DNA-PKcs. However, p60 was found in ataxia-telangiectasia cells after irradiation. These results indicated p60 as a phosphorylated form of XRCC4, requiring DNA-PKcs but not ataxia-telangiectasia mutated (ATM).
Matsumoto
Y
Y
Department of Radiation Oncology, Faculty of Medicine, University of Tokyo, Japan.
Suzuki
N
N
Namba
N
N
Umeda
N
N
Ma
X J
XJ
Morita
A
A
Tomita
M
M
Enomoto
A
A
Serizawa
S
S
Hirano
K
K
Sakaia
K
K
Yasuda
H
H
Hosoi
Y
Y
D000730:Androstadienes / Q000494:pharmacology; D064007:Ataxia Telangiectasia Mutated Proteins; D015153:Blotting, Western; D053148:Caspase 3; D053179:Caspase 7; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism; D018797:Cell Cycle Proteins; D051747:DNA-Activated Protein Kinase; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism* / Q000528:radiation effects*; D006358:Hot Temperature; D006801:Humans; D008970:Molecular Weight; D009687:Nuclear Proteins; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism / Q000528:radiation effects; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010766:Phosphorylation / Q000528:radiation effects; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D014407:Tumor Cells, Cultured; D025521:Tumor Suppressor Proteins; D020298:U937 Cells; D000077191:Wortmannin
D000730:Androstadienes; D064007:Ataxia Telangiectasia Mutated Proteins; D053148:Caspase 3; D053179:Caspase 7; D061945:Caspase Inhibitors; D020169:Caspases; D018797:Cell Cycle Proteins; D051747:DNA-Activated Protein Kinase; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D010446:Peptide Fragments; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D017346:Protein Serine-Threonine Kinases; D011994:Recombinant Proteins; D025521:Tumor Suppressor Proteins; D000077191:Wortmannin; C101467:XRCC4 protein, human; C576324:ATM protein, human; C497263:PRKDC protein, human; C505407:CASP3 protein, human; C505520:CASP7 protein, human