| First Author | Myung K | Year | 1997 |
| Journal | EMBO J | Volume | 16 |
| Issue | 11 | Pages | 3172-84 |
| PubMed ID | 9214634 | Mgi Jnum | J:41122 |
| Mgi Id | MGI:892876 | Doi | 10.1093/emboj/16.11.3172 |
| Citation | Myung K, et al. (1997) KARP-1: a novel leucine zipper protein expressed from the Ku86 autoantigen locus is implicated in the control of DNA-dependent protein kinase activity. EMBO J 16(11):3172-84 |
| abstractText | The Ku autoantigen plays an integral role in mammalian DNA double-strand break repair as the DNA binding component of the DNA-dependent protein kinase (DNA-PK) complex. Here, we demonstrate that a second gene, KARP-1 (Ku86 Autoantigen Related Protein-1), is expressed from the Ku86 locus. The KARP-1 gene utilizes an upstream promoter and additional exons which results in an extra 9 kDa of protein appended onto the normal Ku86 polypeptide. The KARP-1-specific domain encodes interdigitating hexa- and penta-heptad repeats of leucine residues flanked by a very basic region. Intriguingly, the catalytic subunit of DNA-PK also contains a hexa-heptad repeat of leucines. Consistent with this observation, we observed that human cell lines stably expressing dominant-negative constructs of KARP-1 resulted in diminished DNA-PK activity and X-ray hypersensitivity and that a KARP-1 antibody significantly neutralized DNA-PK activity in vitro. Finally, we present data which suggests that KARP-1 may be primate-specific. These observations have important repercussions for mammalian DNA double-strand break repair. |
