Function of DNA-protein kinase catalytic subunit during the early meiotic prophase without Ku70 and Ku86.
Biol Reprod
; 68(3): 717-21, 2003 Mar.
Article
em En
| MEDLINE
| ID: mdl-12604618
ABSTRACT
All components of the double-stranded DNA break (DSB) repair complex DNA-dependent protein kinase (DNA-PK), including Ku70, Ku86, and DNA-PK catalytic subunit (DNA-PKcs), were found in the radiosensitive spermatogonia. Although p53 induction was unaffected, spermatogonial apoptosis occurred faster in the irradiated DNA-PKcs-deficient scid testis. This finding suggests that spermatogonial DNA-PK functions in DNA damage repair rather than p53 induction. Despite the fact that early spermatocytes lack the Ku proteins, spontaneous apoptosis of these cells occurred in the scid testis. The majority of these apoptotic spermatocytes were found at stage IV of the cycle of the seminiferous epithelium where a meiotic checkpoint has been suggested to exist. Meiotic synapsis and recombination during the early meiotic prophase induce DSBs, which are apparently less accurately repaired in scid spermatocytes that then fail to pass the meiotic checkpoint. The role for DNA-PKcs during the meiotic prophase differs from that in mitotic cells; it is not influenced by ionizing radiation and is independent of the Ku heterodimer.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Epitélio Seminífero
/
Proteínas Serina-Treonina Quinases
/
DNA Helicases
/
Antígenos Nucleares
/
Proteínas de Ligação a DNA
/
Meiose
Limite:
Animals
Idioma:
En
Revista:
Biol Reprod
Ano de publicação:
2003
Tipo de documento:
Article
País de afiliação:
Holanda