Template activating factor-I remodels the chromatin structure and stimulates transcription from the chromatin template.
To study the mechanisms of replication and transcription on chromatin, we have been using the adenovirus DNA complexed with viral basic core proteins, called Ad core. We have identified template activating factor (TAF)-I from uninfected HeLa cells as the factor that stimulates replication and transcription from the Ad core. The nuclease sensitivity assays have revealed that TAF-I remodels the Ad core, thereby making transcription and replication apparatus accessible to the template DNA. To examine whether TAF-I remodels the chromatin consisting of histones, the chromatin structure was reconstituted on the DNA fragment with core histones by the salt dialysis method. The transcription from the reconstituted chromatin was completely repressed, while TAF-I remodeled the chromatin and stimulated the transcription. TAF-I was found to interact with histones. Furthermore, it was shown that TAF-I is capable not only of disrupting the chromatin structure but also of preventing the formation of DNA-histone aggregation and transferring histones to naked DNA. The possible function of TAF-I in conjunction with a histone chaperone activity is discussed.
Okuwaki
M
M
Department of Biomolecular Engineering, Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan.
Nagata
K
K
D000260:Adenoviruses, Human / Q000235:genetics*; D002474:Cell-Free System; D002843:Chromatin / Q000235:genetics* / Q000648:ultrastructure*; D002868:Chromosomal Proteins, Non-Histone; D004261:DNA Replication; D004279:DNA, Viral / Q000378:metabolism; D004268:DNA-Binding Proteins; D006367:HeLa Cells; D056488:Histone Chaperones; D006657:Histones / Q000378:metabolism; D006801:Humans; D009687:Nuclear Proteins / Q000378:metabolism*; D009707:Nucleosomes / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D013698:Templates, Genetic; D014157:Transcription Factors; D014158:Transcription, Genetic; D014758:Viral Core Proteins / Q000378:metabolism
D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D004279:DNA, Viral; D004268:DNA-Binding Proteins; D056488:Histone Chaperones; D006657:Histones; D009687:Nuclear Proteins; D009707:Nucleosomes; D011994:Recombinant Proteins; C513473:SET protein, human; D014157:Transcription Factors; D014758:Viral Core Proteins