The human immunodeficiency virus type 1 long terminal repeat is activated by monofunctional and bifunctional DNA alkylating agents in human lymphocytes.
The activation of the human immunodeficiency virus, type 1 (HIV-1) by the DNA alkylating agents ethyl methanesulfonate, methyl methanesulfonate, and mitomycin C was observed in human B lymphocytes transiently transfected with plasmids in which the HIV-1 long terminal repeat (LTR) directed the expression of the bacterial chloramphenicol acetyltransferase gene. Deletion of the two NF-kappa B-binding sites of LTR abolished the HIV-1 activation induced by the three mutagens, while deletion of the three Sp1-binding sites slightly reduced it. Electrophoretic mobility shift assays revealed an increased binding to the kappa B sites of HIV-1 LTR in the nuclear extracts of human B lymphocytes upon mutagen treatment, while binding to Sp1 sites was unaffected. The TAR region was also involved in the mutagen-mediated activation of HIV-1 LTR inasmuch as a small deletion in the TAR sequence (nucleotides +34 to +37) greatly decreased the induction of HIV-1 expression. Moreover, an enhanced binding activity to the TAR DNA sequence (nucleotides +24 to +47) was observed in nuclear extracts of mutagen-treated lymphocytes. Thus, both the enhancer and the 5'-untranslated region of HIV-1 functionally cooperate in the mutagen-mediated induction of HIV-1 expression.
Quinto
I
I
Dipartimento di Biochimica e Biotecnologie Mediche, Università degli Studi Federico II, Naples, Italy.
Ruocco
M R
MR
Baldassarre
F
F
Mallardo
M
M
Dragonetti
E
E
Scala
G
G
D000477:Alkylating Agents / Q000494:pharmacology*; D001483:Base Sequence; D002460:Cell Line; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics; D005020:Ethyl Methanesulfonate / Q000494:pharmacology; D016325:HIV Long Terminal Repeat / Q000187:drug effects* / Q000235:genetics*; D015497:HIV-1 / Q000187:drug effects / Q000235:genetics*; D006801:Humans; D008214:Lymphocytes / Q000382:microbiology*; D008741:Methyl Methanesulfonate / Q000494:pharmacology; D016685:Mitomycin / Q000494:pharmacology; D008969:Molecular Sequence Data; D009153:Mutagens / Q000494:pharmacology*; D016328:NF-kappa B / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D016329:Sp1 Transcription Factor / Q000378:metabolism; D014775:Virus Activation / Q000187:drug effects / Q000235:genetics
D000477:Alkylating Agents; D009153:Mutagens; D016328:NF-kappa B; D009687:Nuclear Proteins; D016329:Sp1 Transcription Factor; D016685:Mitomycin; D005020:Ethyl Methanesulfonate; D008741:Methyl Methanesulfonate; D015500:Chloramphenicol O-Acetyltransferase