|Budget Amount *help
¥1,100,000 (Direct Cost : ¥1,100,000)
Fiscal Year 1999 : ¥1,100,000 (Direct Cost : ¥1,100,000)
The purpose of this research is to verify the hypothesis that DNA-dependent protein kinase (DNA-PK) exquisitely controls cell functions and cell fate. DNA-PK gene is responsible for mouse SCID defective in DNA end-joining process in V(D)J recombination and DNA double-strand break repair. Since several characteristics of DNA-PK are similar to those of poly(ADP-ribose) polymerase (PARP), the research focused on the relationship between them and complementarity to each other. PARP was phosphorylated by DNA-PK concomitantly with decrease in poly(ADP-ribosyl) action activity. At least in vitro, PARP stimulated DNA-PK activity as a DNA-binding regulatory component instead of Ku protein. Preparation of recombinant PARP of wild-type and truncated forms with individual and combined domains is now in progress. Although DNA-PK is not essential for cell survival, DNA-PK would subtly regulated DNA metabolism, including DNA replication, transcription, repair and recombination, for maintaining healthy life. In PARP-knock out (KO) mice, no severe dysfunction was observed except for lowering capacity of DNA repair. In order to analyze functional complementarity of DNA-PK and PARP, we intended to prepare double-gene KO mice and embryonic fibroblasts lacking both parp and DNA-PK genes. By mating scid+/-・PARP+/- mice, 129 males and 89 females were born. At present, no double-gene KO mice were obtained in genetially analyzed 51 mice of female. From 13.5-day embryos, primary cultured cells of fibloblasts lacking both parp and DNA-PK genes were obtained, out of which cell lines of embryonic fibloblast will be expected.