Identification of human cytomegalovirus target sequences in the human immunodeficiency virus long terminal repeat. Potential role of IE2-86 binding to sequences between -120 and -20 in promoter transactivation.
OBJECTIVE
Because of the important medical consequences of human cytomegalovirus (HCMV) infection in human immunodeficiency virus (HIV)-infected individuals, we wanted to understand the molecular interactions that occur during co-infection. Specifically, in this study, we wanted to identify the transactivating target sequences on the HIV long terminal repeat (LTR) that responded to HCMV infection.


METHODS
In this study, we transfected the HIV-LTR into human fibroblasts and then mapped the regulation of this promoter following HCMV infection and co-transfection with the HCMV immediate-early (IE) gene product IE2-86. In addition, we examined IE2-86 binding to specific sequences in the HIV-LTR by electrophoretic mobility shift assay.


RESULTS
Our results documented that HCMV and IE2-86 could transactivate the HIV-LTR. In mapping the regions of the HIV-LTR that IE2-86 transactivates, we identified discrete target sequences between -120 and -20 that are the major transactivating regions for the IE2-86-mediated effects and determined that IE2-86 could specifically bind to several discrete sequences within this region of the HIV-LTR.


CONCLUSIONS
Our discovery of the binding of IE2-86 to the HIV-LTR, coupled with its ability to transactivate the HIV-LTR and induce cellular transcription factors, points to potential molecular mechanisms used by HCMV to upregulate the HIV life cycle and, consequently, exacerbate the conditions observed in individuals co-infected with HCMV and HIV.
Yurochko
A D
AD
Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill 27599-7295, USA. yurochko@med.unc.edu
Huong
S M
SM
Huang
E S
ES
D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D003587:Cytomegalovirus / Q000235:genetics / Q000378:metabolism*; D004279:DNA, Viral / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D015967:Gene Expression Regulation, Viral; D016325:HIV Long Terminal Repeat / Q000235:genetics*; D006367:HeLa Cells; D006801:Humans; D017874:Immediate-Early Proteins / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D008562:Membrane Glycoproteins; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism; D020218:Response Elements / Q000235:genetics; D017384:Sequence Deletion; D016385:TATA Box / Q000235:genetics; D015534:Trans-Activators / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D015533:Transcriptional Activation; D014162:Transfection; D014759:Viral Envelope Proteins; D014764:Viral Proteins
D004279:DNA, Viral; D004268:DNA-Binding Proteins; C069186:IE2 protein, Cytomegalovirus; D017874:Immediate-Early Proteins; D008562:Membrane Glycoproteins; D011993:Recombinant Fusion Proteins; D015534:Trans-Activators; C077406:UL115 protein, Human herpesvirus 5; D014759:Viral Envelope Proteins; D014764:Viral Proteins; C071440:glycoprotein H, Cytomegalovirus; C499358:glycoprotein H, Human cytomegalovirus; C439068:glycoprotein O, cytomegalovirus