title: Functional characterization of interferon regulatory factor 3a (IRF-3a), an alternative splice isoform of IRF-3.
abstract: Virus infection of numerous cell types results in the transcriptional induction of a subset of virus- and interferon (IFN)-stimulated genes. The beta IFN (IFN-beta) gene is one of these rapidly induced genes; it serves as a fundamental component of the cellular defense response in eliciting potent antiviral, immunomodulatory, and antiproliferative effects. One of the transcription factors involved in the stringent regulation of IFN-beta production following virus infection is interferon regulatory factor (IRF) 3 (IRF-3). We have characterized an alternatively spliced isoform of IRF-3 that we have called IRF-3a. IRF-3a can selectively and potently inhibit virus-induced activation of the IFN-beta promoter. IRF-3a lacks half of the DNA binding domain found in IRF-3 and is unable to bind to the classical IRF binding elements, IFN-stimulated response elements. These studies suggest that IRF-3a may act as a modulator of IRF-3.
authors.affiliation: Department of Pathology, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors.forename: A Y
authors.initials: AY
authors.lastname: Karpova
authors.forename: L V
authors.initials: LV
authors.lastname: Ronco
authors.forename: P M
authors.initials: PM
authors.lastname: Howley
mesh_terms: D017398:Alternative Splicing; D000595:Amino Acid Sequence; D001483:Base Sequence; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D019281:Dimerization; D005786:Gene Expression Regulation; D006801:Humans; D015151:Immunoblotting; D050838:Interferon Regulatory Factor-3; D016899:Interferon-beta / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D011233:Precipitin Tests; D011401:Promoter Regions, Genetic; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics; D017434:Protein Structure, Tertiary; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics*; D018108:Respirovirus / Q000502:physiology; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; C494232:IRF3 protein, human; D050838:Interferon Regulatory Factor-3; D020033:Protein Isoforms; D014157:Transcription Factors; D016899:Interferon-beta