Transcription factor Sp1 is involved in the regulation of varicella-zoster virus glycoprotein E.
Varicella-zoster virus glycoprotein E (ORF 68) belongs to the group of late genes. It is a major component of the virion envelope and can be found complexed with glycoprotein I on the infected host cell surface. Glycoprotein E (gE) expression is activated by IE4 and IE62. Also, cellular transcription factors, like Sp1, are able to influence the gE expression. Performing quantitative reverse transcription-polymerase chain reaction, we found no decrease in Sp1 mRNA levels at different times post-infection, indicating that Sp1 mRNA evade virion host shutoff effects. In addition, the Sp1 protein was detectable in highly infected cells. Electrophoretic mobility shift assays have shown a binding of Sp1 to both GC elements within the gE-5'untranslated region (5'UTR). Additional shift assays have notified a binding of TATA box binding protein to the TATA box of the gE promoter, which is characterized by an untypical TATACA motif. Promoter-reporter constructs have been made using mutated variants of the gE-5'UTR as promoters. In transfection studies, we found that the TATA deletion, as well as inactivations of both GC boxes, reduced the basal activity of the promoter. A complete loss of activity did not become measurable until eliminating both GC elements and the TATA box, indicating that these cis-elements substitute for each other in initiation of transcription of the gE-5'UTR.
Rahaus
M
M
Institute of Microbiology and Virology, University of Witten/Herdecke, Stockumer Strasse 10, 58448 Witten, Germany.
Wolff
M H
MH
D020121:5' Untranslated Regions; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002478:Cells, Cultured; D017931:DNA Primers / Q000235:genetics; D004268:DNA-Binding Proteins / Q000378:metabolism; D014645:Herpesvirus 3, Human / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D012367:RNA, Viral / Q000032:analysis / Q000235:genetics; D016329:Sp1 Transcription Factor / Q000378:metabolism*; D016385:TATA Box; D035181:TATA-Box Binding Protein; D014157:Transcription Factors / Q000378:metabolism; D014759:Viral Envelope Proteins / Q000235:genetics / Q000378:metabolism*
D020121:5' Untranslated Regions; D017931:DNA Primers; D004268:DNA-Binding Proteins; D012333:RNA, Messenger; D012367:RNA, Viral; D016329:Sp1 Transcription Factor; D035181:TATA-Box Binding Protein; D014157:Transcription Factors; D014759:Viral Envelope Proteins; C056913:glycoprotein E, varicella-zoster virus