XR-C1, a new CHO cell mutant which is defective in DNA-PKcs, is impaired in both V(D)J coding and signal joint formation.
- Abstract:
- DNA-dependent protein kinase (DNA-PK) plays an important role in DNA double-strand break (DSB) repair and V(D)J recombination. We have isolated a new X-ray-sensitive CHO cell line, XR-C1, which is impaired in DSB repair and which was assigned to complementation group 7, the group that is defective in the XRCC7/SCID(Prkdc) gene encoding the catalytic subunit of DNA-PK (DNA-PKcs). Consistent with this complementation analysis, XR-C1 cells lacked detectable DNA-PKcs protein, did not display DNA-PK catalytic activity and were complemented by the introduction of a single human chromosome 8 (providing the Prkdc gene). The impact of the XR-C1 mutation on V(D)J recombination was quite different from that found in most rodent cells defective in DNA-PKcs, which are preferentially blocked in coding joint formation, whereas XR-C1 cells were defective in forming both coding and signal joints. These results suggest that DMA-PKcs is required for both coding and signal joint formation during V(D)J recombination and that the XR-C1 mutant cell line may prove to be a useful tool in understanding this pathway.
- Authors:
- A Errami, DM He, AA Friedl, WJ Overkamp, B Morolli, EA Hendrickson, F Eckardt-Schupp, M Oshimura, PH Lohman, SP Jackson, MZ Zdzienicka
- Journal:
- Nucleic Acids Research
- Citation info:
- 26(13):3146-3153
- Publication date:
- 1st Jul 1998
- Full text
- DOI