trans-activation of the HIV promoter by a cDNA and its genomic clones of human herpesvirus-6.
Human herpesvirus 6 (HHV-6) is a lymphotropic herpesvirus, and in vitro, it can productively infect human CD4+ T cells as HIV-1. Co-infection of T cells by HIV-1 and HHV-6 can lead to both activation of the HIV-1 promoter and acceleration of the cytopathic effects. An HHV-6 (GS) cDNA clone, pCD41, encoding for a 41-kDa nuclear protein was identified and characterized previously (Chang and Balachandran, J. Virol. 65, 2884-2894 and 7085, 1991). Sequence analyses show that this protein has significant homology with the human cytomegalovirus UL44 gene coding for the ICP36 family of early-late-class phosphoprotein. Using this cDNA as the probe, a 3.8-kb EcoRI genomic fragment encoding the HHV-6(GS)P41 was cloned and designated as pGD41. When cotransfected with the HIV LTR CAT into CV-1 cells, both the pCD41 and pGD41 clones trans-activated the HIV LTR. Sequence analyses of pCD41 indicate that there are two potential open reading frames (ORFs), A and B, which are homologous to the ORFs found in the genomic clone pGD41. Deletion constructs of the pCD41 clone demonstrated that ORF-A was critical for the HIV LTR activation. Deletion analyses of the pCD41 ORF-A and the use of promoter constructs further mapped an internal functional promoter within the pCD41 sequence that can direct the synthesis of the trans-activating protein. By using HIV LTR deletion mutants, the NF-kappa B binding sites were found to be critical for response to the pCD41 trans-activation.
Zhou
Y
Y
Department of Neurology and Microbiology, University of Miami School of Medicine, Florida 33101.
Chang
C K
CK
Qian
G
G
Chandran
B
B
Wood
C
C
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics / Q000502:physiology*; D004268:DNA-Binding Proteins; D015967:Gene Expression Regulation, Viral / Q000502:physiology; D016325:HIV Long Terminal Repeat / Q000502:physiology*; D015497:HIV-1; D015654:Herpesvirus 6, Human / Q000235:genetics / Q000502:physiology*; D006801:Humans; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000502:physiology; D016366:Open Reading Frames / Q000502:physiology; D010750:Phosphoproteins / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics / Q000502:physiology; D013601:T-Lymphocytes; D015533:Transcriptional Activation / Q000235:genetics / Q000502:physiology*; D014764:Viral Proteins / Q000235:genetics*
D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D016328:NF-kappa B; D010750:Phosphoproteins; D014764:Viral Proteins; C081690:p41 protein, Human herpesvirus 6