Abstract
The DNA-dependent protein kinase (DNA-PK) complex plays a crucial role in radiation-induced DNA damage recognition. The complex includes the ku heterodimer, which comprises ku 70 and ku 80 subunits, that binds DNA termini of breaks without sequence specificity, and the catalytic subunit DNA-PKcs. The activation of the DNA-PK complex was studied in X-irradiated peripheral blood mononuclear cells (PBMC) from subjects of different ages. Radiation-induced changes in the DNA-binding activity of the ku heterodimer, and in the concentrations of ku 70, ku 80, DNA-PKcs and phosphorylated ku 80 were determined in nuclear and cytoplasmic extracts. DNA-binding activity was increased by irradiation only in the nuclear extract of PBMC from young, but not from elderly subjects, whereas it was found unchanged in cytoplasmic extracts regardless of age. The radiation-induced activation of the DNA-PK complex may result from the increased concentrations of ku 80 and DNA-PKcs in the cytoplasm of PBMC from young, but not from elderly subjects, leading to a higher concentration of phosphorylated ku 80 which readily migrates to the nucleus where, after dimerization with ku 70, binds to DNA breaks. These findings suggest major steps involved in DNA-PK activation, and the intracellular and molecular changes that may account for the age-dependent impairment of DNA repair capacity in irradiated mammalian cells.
| Original language | English |
|---|---|
| Pages (from-to) | 791-797 |
| Number of pages | 7 |
| Journal | International Immunology |
| Volume | 13 |
| Issue number | 6 |
| State | Published - Jun 19 2001 |
| Externally published | Yes |
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Keywords
- DNA damage recognition
- DNA-dependent protein kinase
- Peripheral blood mononuclear cell
- X-rays
ASJC Scopus subject areas
- Immunology
Cite this
Role of DNA-dependent protein kinase in recognition of radiation-induced DNA damage in human peripheral blood mononuclear cells. / Frasca, Daniela; Barattini, Paola; Tocchi, Grazia; Guidi, Luisa; Pierelli, Luca; Doria, Gino.
In: International Immunology, Vol. 13, No. 6, 19.06.2001, p. 791-797.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Role of DNA-dependent protein kinase in recognition of radiation-induced DNA damage in human peripheral blood mononuclear cells
AU - Frasca, Daniela
AU - Barattini, Paola
AU - Tocchi, Grazia
AU - Guidi, Luisa
AU - Pierelli, Luca
AU - Doria, Gino
PY - 2001/6/19
Y1 - 2001/6/19
N2 - The DNA-dependent protein kinase (DNA-PK) complex plays a crucial role in radiation-induced DNA damage recognition. The complex includes the ku heterodimer, which comprises ku 70 and ku 80 subunits, that binds DNA termini of breaks without sequence specificity, and the catalytic subunit DNA-PKcs. The activation of the DNA-PK complex was studied in X-irradiated peripheral blood mononuclear cells (PBMC) from subjects of different ages. Radiation-induced changes in the DNA-binding activity of the ku heterodimer, and in the concentrations of ku 70, ku 80, DNA-PKcs and phosphorylated ku 80 were determined in nuclear and cytoplasmic extracts. DNA-binding activity was increased by irradiation only in the nuclear extract of PBMC from young, but not from elderly subjects, whereas it was found unchanged in cytoplasmic extracts regardless of age. The radiation-induced activation of the DNA-PK complex may result from the increased concentrations of ku 80 and DNA-PKcs in the cytoplasm of PBMC from young, but not from elderly subjects, leading to a higher concentration of phosphorylated ku 80 which readily migrates to the nucleus where, after dimerization with ku 70, binds to DNA breaks. These findings suggest major steps involved in DNA-PK activation, and the intracellular and molecular changes that may account for the age-dependent impairment of DNA repair capacity in irradiated mammalian cells.
AB - The DNA-dependent protein kinase (DNA-PK) complex plays a crucial role in radiation-induced DNA damage recognition. The complex includes the ku heterodimer, which comprises ku 70 and ku 80 subunits, that binds DNA termini of breaks without sequence specificity, and the catalytic subunit DNA-PKcs. The activation of the DNA-PK complex was studied in X-irradiated peripheral blood mononuclear cells (PBMC) from subjects of different ages. Radiation-induced changes in the DNA-binding activity of the ku heterodimer, and in the concentrations of ku 70, ku 80, DNA-PKcs and phosphorylated ku 80 were determined in nuclear and cytoplasmic extracts. DNA-binding activity was increased by irradiation only in the nuclear extract of PBMC from young, but not from elderly subjects, whereas it was found unchanged in cytoplasmic extracts regardless of age. The radiation-induced activation of the DNA-PK complex may result from the increased concentrations of ku 80 and DNA-PKcs in the cytoplasm of PBMC from young, but not from elderly subjects, leading to a higher concentration of phosphorylated ku 80 which readily migrates to the nucleus where, after dimerization with ku 70, binds to DNA breaks. These findings suggest major steps involved in DNA-PK activation, and the intracellular and molecular changes that may account for the age-dependent impairment of DNA repair capacity in irradiated mammalian cells.
KW - DNA damage recognition
KW - DNA-dependent protein kinase
KW - Peripheral blood mononuclear cell
KW - X-rays
UR - http://www.scopus.com/inward/record.url?scp=0034990322&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0034990322&partnerID=8YFLogxK
M3 - Article
C2 - 11369707
AN - SCOPUS:0034990322
VL - 13
SP - 791
EP - 797
JO - International Immunology
JF - International Immunology
SN - 0953-8178
IS - 6
ER -