title: Myb protein binds to human immunodeficiency virus 1 long terminal repeat (LTR) sequences and transactivates LTR-mediated transcription.
abstract: The protooncogene c-myb encodes a nuclear transcription factor that binds to DNA in a sequence-specific manner and transactivates transcription of several viral and cellular genes. The expression of c-myb is induced in mitogen-stimulated peripheral blood lymphocytes and is constitutively expressed in several CD4+ T-cell and myeloid cell lines, all of which constitute excellent targets for human immunodeficiency virus (HIV) infection and replication. We looked for the presence of Myb-binding motifs in human retroviral long terminal repeats (LTRs) and tested for Myb binding to HIV-1 LTR sequences by using a highly purified recombinant Myb protein. Our results show that HIV-1 LTR contains one high-affinity Myb-binding site along with two or more low-affinity binding sites. DNase I protection analysis as well as oligonucleotide competition experiments indicate that this binding is sequence specific. Introduction of purified Myb protein directly into HeLa cells harboring HIV-1 LTR chloramphenicol acetyltransferase vectors indicates that Myb protein transactivates HIV-1 LTR-mediated transcription. Thus, Myb protein binding to HIV LTR sequences may constitute one of the signals that regulates HIV-1 transcription.
authors.affiliation: Wistar Institute of Anatomy and Biology, Philadelphia, PA 19104.
authors.forename: P
authors.initials: P
authors.lastname: Dasgupta
authors.forename: P
authors.initials: P
authors.lastname: Saikumar
authors.forename: C D
authors.initials: CD
authors.lastname: Reddy
authors.forename: E P
authors.initials: EP
authors.lastname: Reddy
mesh_terms: D001483:Base Sequence; D004279:DNA, Viral / Q000235:genetics / Q000378:metabolism; D005814:Genes, Viral; D015497:HIV-1 / Q000235:genetics*; D015498:HIV-2 / Q000235:genetics; D006367:HeLa Cells / Q000378:metabolism; D015368:Human T-lymphotropic virus 1 / Q000235:genetics; D015367:Human T-lymphotropic virus 2 / Q000235:genetics; D008969:Molecular Sequence Data; D020626:Oncogene Proteins v-myb; D009857:Oncogenes; D010957:Plasmids; D011485:Protein Binding; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D012091:Repetitive Sequences, Nucleic Acid; D015682:Retroviridae Proteins, Oncogenic / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation
chemical_list: D004279:DNA, Viral; D020626:Oncogene Proteins v-myb; D015682:Retroviridae Proteins, Oncogenic; D011505:Protein-Tyrosine Kinases