Analysis of the promoter and cis-acting elements regulating expression of herpes simplex virus type 2 latency-associated transcripts.
In latently infected neurons, herpes simplex virus type 2 (HSV-2) expresses one abundant family of transcripts, the latency-associated transcripts (LATs). We demonstrate here that the sequence lying about 700 bp upstream of the 5' end of the HSV-2 major LAT acts as a very strong promoter in transient expression assays in both neuronal and nonneuronal cells. Transcription starts about 27 to 32 bp downstream of a functional TATA box. The proximal fragment from -102 to +34 includes the basal promoter and accounts for constitutive transcriptional activity in various cell lines. The distal region from -392 to -103 contributes to particularly strong promoter activity in neuronal cell lines and involves multiple cis-acting elements. A functional activating transcription factor/cyclic AMP (cAMP) response element binding protein motif lies just upstream of the TATA. By DNase I footprint and methylation protection assays, we identified several additional protein-binding sites upstream of the activating transcription factor/cAMP response element binding protein motif. A GC-rich element, termed LAT-3, was located between bases -128 to -102. A 2-bp substitution in LAT-3 markedly reduced promoter activity and abolished protein-binding ability in vitro. Gel retardation assay showed no competition for protein binding to LAT-3 by other GC-rich elements. LAT-3 appears to be a novel cis-acting element that may contribute to the neuronal responsiveness of the HSV-2 LAT promoter.
Wang
K
K
Medical Virology Section, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland 20892, USA.
Krause
P R
PR
Straus
S E
SE
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D004279:DNA, Viral / Q000235:genetics; D015967:Gene Expression Regulation, Viral; D005814:Genes, Viral; D006367:HeLa Cells; D018258:Herpesvirus 2, Human / Q000235:genetics* / Q000472:pathogenicity; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D009474:Neurons / Q000821:virology; D016716:PC12 Cells; D011401:Promoter Regions, Genetic; D051381:Rats; D016385:TATA Box; D014158:Transcription, Genetic; D017735:Virus Latency / Q000235:genetics
D004279:DNA, Viral