Sequence-specific DNA binding by Ku autoantigen and its effects on transcription.
DNA-dependent protein kinase (DNA-PK) has been implicated in several nuclear processes including transcription, DNA replication, double-stranded DNA break repair, and V(D)J recombination. Linkage of kinase and substrate on DNA in cis is required for efficient phosphorylation. Recruitment of DNA-PK to DNA is by Ku autoantigen, a DNA-end-binding protein required for DNA-PK catalytic activity. Although Ku is known to translocate along naked DNA, how DNA-end binding by Ku might lead to DNA-PK-mediated phosphorylation of sequence-specific DNA-binding proteins in vivo has not been obvious. Here we report the identification of Ku as a transcription factor that recruits DNA-PK directly to specific DNA sequences. NRE1 (negative regulatory element 1) is a DNA sequence element (-394/ -381) in the long terminal repeat of mouse mammary tumour virus (MMTV) that is important for repressing inappropriate viral expression. We show that direct binding of Ku/DNA-PK to NRE1 represses glucocorticoid-induced MMTV transcription.
Giffin
W
W
Department of Medicine, University of Ottawa, Loeb Institute for Medical Research, Ottawa Civic Hospital, Ontario, Canada.
Torrance
H
H
Rodda
D J
DJ
Préfontaine
G G
GG
Pope
L
L
Hache
R J
RJ
D000818:Animals; D034961:Antigens, Nuclear; D001324:Autoantigens / Q000378:metabolism*; D001483:Base Sequence; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D004265:DNA Helicases; D004279:DNA, Viral / Q000378:metabolism*; D051747:DNA-Activated Protein Kinase; D004268:DNA-Binding Proteins / Q000378:metabolism*; D000072200:Ku Autoantigen; D008324:Mammary Tumor Virus, Mouse / Q000235:genetics; D051379:Mice; D016513:Mice, SCID; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism*; D010766:Phosphorylation; D010957:Plasmids; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic
D034961:Antigens, Nuclear; D001324:Autoantigens; D004279:DNA, Viral; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D014157:Transcription Factors; D051747:DNA-Activated Protein Kinase; D017346:Protein Serine-Threonine Kinases; D004265:DNA Helicases; C106893:XRCC5 protein, human; C000606509:Xrcc6 protein, human; C000606510:Xrcc6 protein, mouse; D000072200:Ku Autoantigen