title: Identification and purification of the enhancer-binding factor of human immunodeficiency virus-1. Multiple proteins and binding to other enhancers.
abstract: The enhancer-binding factor of human immunodeficiency virus (HIV)-1 was purified from human B cells by sequence-specific duplex oligonucleotide affinity chromatography. Gel retardation assay and footprint analysis showed that the purified factor bound specifically to the HIV-1 enhancer sequence, and protected both direct repeats in the HIV-1 enhancer. The purified factor consisted of four main polypeptides of the molecular weight of 36,000-42,000. At least three of them had enhancer-binding activity after elution from sodium dodecyl sulfate-polyacrylamide gel and renaturation. UV cross-linking analysis also showed that at least two of the polypeptides in purified fraction had a binding activity specific for the HIV-1 enhancer. The purified factor activated transcription from the HIV-1 promoter in vitro, confirming that it was indeed a transcription factor for HIV-1. The purified factor also recognized sequences in the immunoglobulin kappa gene enhancer and the major histocompatibility complex class I gene enhancer with almost the same affinity as the HIV-1 enhancer. These results suggested the existence of multiple proteins which recognize the kappa B-related sequences. This regulatory factor should help in the study of the biochemical pathway underlying HIV production from latently infected cells.
authors.affiliation: Tsukuba Life Science Center, Institute of Physical and Chemical Research (RIKEN), Ibaraki, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Maekawa
authors.forename: F
authors.initials: F
authors.lastname: Itoh
authors.forename: T
authors.initials: T
authors.lastname: Okamoto
authors.forename: M
authors.initials: M
authors.lastname: Kurimoto
authors.forename: F
authors.initials: F
authors.lastname: Imamoto
authors.forename: S
authors.initials: S
authors.lastname: Ishii
mesh_terms: D001483:Base Sequence; D002460:Cell Line; D002846:Chromatography, Affinity; D004742:Enhancer Elements, Genetic; D015696:Gene Products, tat; D015497:HIV-1 / Q000235:genetics*; D006801:Humans; D046911:Macromolecular Substances; D008970:Molecular Weight; D015345:Oligonucleotide Probes; D014157:Transcription Factors / Q000302:isolation & purification* / Q000378:metabolism; D014158:Transcription, Genetic; D054322:tat Gene Products, Human Immunodeficiency Virus
chemical_list: D015696:Gene Products, tat; D046911:Macromolecular Substances; D015345:Oligonucleotide Probes; D014157:Transcription Factors; D054322:tat Gene Products, Human Immunodeficiency Virus