title: The chromatin remodeling factor SMARCB1 forms a complex with human cytomegalovirus proteins UL114 and UL44.
abstract: BACKGROUND
  Human cytomegalovirus (HCMV) uracil DNA glycosylase, UL114, is required for efficient viral DNA replication. Presumably, UL114 functions as a structural partner to other factors of the DNA-replication machinery and not as a DNA repair protein. UL114 binds UL44 (HCMV processivity factor) and UL54 (HCMV-DNA-polymerase). In the present study we have searched for cellular partners of UL114.
  
  
  RESULTS
  In a yeast two-hybrid screen SMARCB1, a factor of the SWI/SNF chromatin remodeling complex, was found to be an interacting partner of UL114. This interaction was confirmed in vitro by co-immunoprecipitation and pull-down. Immunofluorescence microscopy revealed that SMARCB1 along with BRG-1, BAF170 and BAF155, which are the core SWI/SNF components required for efficient chromatin remodeling, were present in virus replication foci 24-48 hours post infection (hpi). Furthermore a direct interaction was also demonstrated for SMARCB1 and UL44.
  
  
  CONCLUSIONS
  The core SWI/SNF factors required for efficient chromatin remodeling are present in the HCMV replication foci throughout infection. The proteins UL44 and UL114 interact with SMARCB1 and may participate in the recruitment of the SWI/SNF complex to the chromatinized virus DNA. Thus, the presence of the SWI/SNF chromatin remodeling complex in replication foci and its association with UL114 and with UL44 might imply its involvement in different DNA transactions.
authors.affiliation: Department of Microbiology, University of Oslo and Oslo University Hospital HF, Oslo, Norway.
authors.forename: Toril
authors.initials: T
authors.lastname: Ranneberg-Nilsen
authors.forename: Halvor
authors.initials: H
authors.lastname: Rollag
authors.forename: Ragnhild
authors.initials: R
authors.lastname: Slettebakk
authors.forename: Paul Hoff
authors.initials: PH
authors.lastname: Backe
authors.forename: Øyvind
authors.initials: Ø
authors.lastname: Olsen
authors.forename: Luisa
authors.initials: L
authors.lastname: Luna
authors.forename: Magnar
authors.initials: M
authors.lastname: Bjørås
mesh_terms: D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D002843:Chromatin / Q000737:chemistry / Q000378:metabolism*; D042002:Chromatin Assembly and Disassembly; D002868:Chromosomal Proteins, Non-Histone / Q000737:chemistry / Q000378:metabolism*; D003587:Cytomegalovirus / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism; D020869:Gene Expression Profiling; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D008856:Microscopy, Fluorescence / Q000379:methods; D015530:Nuclear Matrix / Q000378:metabolism; D011485:Protein Binding; D000071796:SMARCB1 Protein; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*; D020798:Two-Hybrid System Techniques; D051981:Uracil-DNA Glycosidase / Q000737:chemistry* / Q000378:metabolism; D014764:Viral Proteins / Q000737:chemistry* / Q000378:metabolism
chemical_list: D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; C072217:ICP36 protein, Cytomegalovirus; D000071796:SMARCB1 Protein; C513266:SMARCB1 protein, human; D014157:Transcription Factors; D014764:Viral Proteins; D005982:Glutathione Transferase; D051981:Uracil-DNA Glycosidase