Identification of p32 as a novel substrate for ATM in heart.
Chemotherapeutic agents to induce DNA damage have been limited to use due to severe side effects of cardiotoxicity. ATM (Ataxia-telangiectasia mutated) is an essential protein kinase in triggering DNA damage responses. However, it is unclear how the ATM-mediated DNA damage responses are involved in the cardiac cell damage. To elucidate these functions in heart, we searched for specific substrates of ATM from mouse heart homogenate. Combining an in vitro phosphorylation following anion-exchange chromatography with purification by reverse-phase high-performance liquid chromatography (HPLC), we successfully identified p32, an ASF/SF2-associated protein, as a novel substrate for ATM. An in vitro kinase assay using recombinant p32 revealed that ATM directly phosphorylated p32. Furthermore, we determined Ser 148 of p32 as an ATM phosphorylation site. Since p32 is known to regulate mRNA splicing and transcription, p32 phosphorylation by ATM might be a new transcriptional regulatory pathway for specific DNA damage responses in heart.
Kato
Hisakazu
H
Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
Takashima
Seiji
S
Asano
Yoshihiro
Y
Shintani
Yasunori
Y
Yamazaki
Satoru
S
Seguchi
Osamu
O
Yamamoto
Hiroyuki
H
Nakano
Atsushi
A
Higo
Shuichiro
S
Ogai
Akiko
A
Minamino
Tetsuo
T
Kitakaze
Masafumi
M
Hori
Masatsugu
M
D000595:Amino Acid Sequence; D000818:Animals; D064007:Ataxia Telangiectasia Mutated Proteins; D018797:Cell Cycle Proteins / Q000378:metabolism*; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006801:Humans; D018960:Hyaluronan Receptors / Q000737:chemistry / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D024101:Mitochondrial Proteins; D008969:Molecular Sequence Data; D009206:Myocardium / Q000201:enzymology*; D009687:Nuclear Proteins / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D010768:Phosphoserine / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D013379:Substrate Specificity; D025521:Tumor Suppressor Proteins / Q000378:metabolism*
C490193:C1qbp protein, mouse; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D018960:Hyaluronan Receptors; D024101:Mitochondrial Proteins; D009687:Nuclear Proteins; D025521:Tumor Suppressor Proteins; D010768:Phosphoserine; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; C576325:Atm protein, mouse; D017346:Protein Serine-Threonine Kinases