title: Two Sp1/Sp3 binding sites in the major immediate-early proximal enhancer of human cytomegalovirus have a significant role in viral replication.
abstract: We previously demonstrated that the major immediate early (MIE) proximal enhancer containing one GC box and the TATA box containing promoter are minimal elements required for transcription and viral replication in human fibroblast cells (H. Isomura, T. Tsurumi, M. F. Stinski, J. Virol. 78:12788-12799, 2004). After infection, the level of Sp1 increased while Sp3 remained constant. Here we report that either Sp1 or Sp3 transcription factors bind to the GC boxes located at approximately positions -55 and -75 relative to the transcription start site (+1). Both the Sp1 and Sp3 binding sites have a positive and synergistic effect on the human cytomegalovirus (HCMV) major immediate-early (MIE) promoter. There was little to no change in MIE transcription or viral replication for recombinant viruses with one or the other Sp1 or Sp3 binding site mutated. In contrast, mutation of both the Sp1 and Sp3 binding sites caused inefficient MIE transcription and viral replication. These data indicate that the Sp1 and Sp3 binding sites have a significant role in HCMV replication in human fibroblast cells.
authors: Division of Virology, Aichi Cancer Center Research Institute, Chikusa-ku, Nagoya, Japan.
authors: Hiroki
authors: H
authors: Isomura
authors: Mark F
authors: MF
authors: Stinski
authors: Ayumi
authors: A
authors: Kudoh
authors: Tohru
authors: T
authors: Daikoku
authors: Noriko
authors: N
authors: Shirata
authors: Tatsuya
authors: T
authors: Tsurumi
mesh_terms: D001665:Binding Sites / Q000502:physiology*; D003587:Cytomegalovirus / Q000235:genetics*; D005347:Fibroblasts; D015967:Gene Expression Regulation, Viral; D017781:Genes, Immediate-Early / Q000502:physiology*; D006801:Humans; D011401:Promoter Regions, Genetic / Q000502:physiology*; D011485:Protein Binding; D014157:Transcription Factors / Q000378:metabolism / Q000502:physiology*; D014779:Virus Replication
chemical_list: D014157:Transcription Factors