Abstract
Rare Ig and TCR coding joints can be isolated from mice that have a targeted deletion in the gene encoding the 86-kDa subunit of the Ku heterodimer, the regulatory subunit of the DNA-dependent protein kinase (DNA- PK). However in the coding joints isolated from Ku86(-/-) animals, there is an extreme paucity of N regions (the random nucleotides added during V(D)J recombination by the enzyme TdT). This finding is consistent with a decreased frequency of coding joints containing N regions isolated from C.B-17 SCID mice that express a truncated form of the catalytic subunit of the DNA-PK (DNA-PK(CS)). This finding suggests an unexpected role for DNA-PK in addition of N nucleotides to coding ends during V(D)J recombination. In this report, we establish that TdT forms a stable complex with DNA-PK. Furthermore, we show that DNA-PK modulates TdT activity in vitro by limiting both the length and composition of nucleotide additions.
Original language | English (US) |
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Pages (from-to) | 834-843 |
Number of pages | 10 |
Journal | Journal of Immunology |
Volume | 163 |
Issue number | 2 |
State | Published - Jul 15 1999 |
ASJC Scopus subject areas
- Immunology and Allergy
- Immunology