| Abstract: |
The Ku70/80 complex, known as Ku, constitutes the DNA end binding component of the DNA-dependent protein kinase (DNA-PK). We have characterized the promoter region of the mouse and human Ku80 genes to delineate transcriptional elements necessary for basal gene expression and proliferation-dependent regulation. Consensus Sp1 recognition elements were identified in both promoters, and were determined to be essential for basal expression. We further identified a near-perfect palindrome of 21 base pairs located immediately 5' to one Sp1 element. This sequence was present once within the mouse Ku80 promoter and seven times, in a head-to-tail tandem array, within the human Ku80 promoter. This sequence possessed homology with a methylationsensitive promoter element, Enh2, present in the LTR of mouse intractisternal A-particles. Promoter deletion studies and expression analysis of in-vitro methylated reporter gene constructs provided strong evidence that, in vivo, this repeat sequence regulates Ku80 gene expression in cis, through a mechanism involving CpG methylation. Evidence is also presented, suggesting that Ku is directly involved in this regulatory process. |
| Keywords: |
dna binding protein; human cell; promoter region; dna-binding proteins; sequence deletion; nonhuman; cell proliferation; mouse; animals; mice; dna repair; gene expression; cell line; hela cells; dna methylation; nuclear proteins; gene expression regulation; cloning, molecular; dna; molecular sequence data; recombinant fusion proteins; transcription; transcription factor sp1; sp1 transcription factor; reporter gene; base sequence; cell nucleus; sequence homology; sequence homology, nucleic acid; virus particle; repetitive sequences, nucleic acid; dna helicases; cell extracts; long terminal repeat; sequence analysis, dna; v(d)j recombination; antigens, nuclear; dinucleoside phosphates; promoter regions (genetics); palindromic dna; humans; human; priority journal; article; dna-dependent protein kinase
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