The histone-interacting domain of nuclear factor I activates simian virus 40 DNA replication in vivo.
Efficient initiation of SV40 DNA replication requires transcription factors that bind auxiliary sequences flanking the minimally required origin. To evaluate the possibility that transcription factors may activate SV40 replication by acting on the chromatin structure of the origin, we used an in vivo replication system in which we targeted GAL4 fusion proteins to the minimally required origin. We found that the proline-rich transcriptional activation domain of nuclear factor I (NF-I), which has been previously shown to interact with histone H3, specifically activates replication. Evaluation of a series of deletion and point mutants of NF-I indicates that the H3-binding domain and the replication activity coincide perfectly. Assays with other transcription factors, such as Sp1, confirmed the correlation between the interaction with H3 and the activation of replication. These findings imply that transcription factors such as NF-I can activate SV40 replication via direct interaction with chromatin components, thereby contributing to the relief of nucleosomal repression at the SV40 origin.
Müller
K
K
Laboratory for Molecular Biotechnology, Institute of Animal Biology and Center for Biotechnology UNIL-EPFL, University of Lausanne, 1015 Lausanne, Switzerland.
Mermod
N
N
D000818:Animals; D022762:CCAAT-Enhancer-Binding Proteins; D019556:COS Cells; D002352:Carrier Proteins / Q000378:metabolism; D002843:Chromatin / Q000378:metabolism; D004261:DNA Replication; D004279:DNA, Viral / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D006657:Histones / Q000378:metabolism*; D051839:NFI Transcription Factors; D027701:Organic Cation Transport Proteins; D000075102:Organic Cation Transporter 2; D010957:Plasmids / Q000378:metabolism; D017354:Point Mutation; D017434:Protein Structure, Tertiary; D013539:Simian virus 40 / Q000235:genetics* / Q000378:metabolism*; D016329:Sp1 Transcription Factor / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D015533:Transcriptional Activation; D051840:Y-Box-Binding Protein 1
D022762:CCAAT-Enhancer-Binding Proteins; D002352:Carrier Proteins; D002843:Chromatin; D004279:DNA, Viral; D004268:DNA-Binding Proteins; D006657:Histones; D051839:NFI Transcription Factors; D027701:Organic Cation Transport Proteins; D000075102:Organic Cation Transporter 2; C491013:SLC22A2 protein, human; D016329:Sp1 Transcription Factor; D014157:Transcription Factors; D051840:Y-Box-Binding Protein 1; C486169:Ybx1 protein, rat