title: A short cis-acting motif in the M112-113 promoter region is essential for IE3 to activate M112-113 gene expression and is important for murine cytomegalovirus replication.
abstract: Immediate-early 3 (IE3) gene products are required to activate early (E)-stage gene expression of murine cytomegaloviruses (MCMV). The first early gene activated by IE3 is the M112-113 gene (also called E1), although a complete understanding of the activation mechanism is still lacking. In this paper, we identify a 10-bp cis-regulating motif upstream of the M112-113 TATA box as important for IE3 activation of M112-113 expression. Results from DNA affinity assays and chromatin immunoprecipitation assays show that the association of IE3 with the M112-113 gene promoter was eliminated by deletion of the 10-bp DNA sequence, now named IE3AM (for IE3 activating motif). In addition, IE3 interacts with TATA box binding protein (TBP), a core protein of TFIID (transcription initiation) complexes. Finally, we created an IE3AM-deleted MCMV (MCMVdIE3AM) using a bacterial artificial chromosome system. The mutant virus can still replicate in NIH 3T3 cells but at a significantly lower level. The defectiveness of the MCMVdIE3AM infection can be rescued in an M112-113-complemented cell line. Our results suggest that the interactions of IE3 with IE3AM and with TBP stabilize the TFIID complex at the M112-113 promoter such that M112-113 gene expression can be activated and/or enhanced.
authors.affiliation: Department of Microbiology/RCMI Program, Ponce School of Medicine and Health Sciences, Ponce, Puerto Rico.
authors.forename: Kareni J
authors.initials: KJ
authors.lastname: Perez
authors.forename: Francisco Puerta
authors.initials: FP
authors.lastname: Martínez
authors.forename: Ruth
authors.initials: R
authors.lastname: Cosme-Cruz
authors.forename: Neysa M
authors.initials: NM
authors.lastname: Perez-Crespo
authors.forename: Qiyi
authors.initials: Q
authors.lastname: Tang
mesh_terms: D000818:Animals; D002460:Cell Line; D004279:DNA, Viral / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D015967:Gene Expression Regulation, Viral; D006566:Herpesviridae Infections / Q000821:virology; D017874:Immediate-Early Proteins / Q000235:genetics* / Q000378:metabolism*; D051379:Mice; D018146:Muromegalovirus / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D041681:NIH 3T3 Cells; D011401:Promoter Regions, Genetic; D017384:Sequence Deletion; D035181:TATA-Box Binding Protein / Q000235:genetics / Q000378:metabolism; D014764:Viral Proteins / Q000235:genetics* / Q000378:metabolism; D014779:Virus Replication
chemical_list: D004279:DNA, Viral; D017874:Immediate-Early Proteins; D035181:TATA-Box Binding Protein; D014764:Viral Proteins