title: A novel disrupter of telomere silencing 1-like (DOT1L) interaction is required for signal transducer and activator of transcription 1 (STAT1)-activated gene expression.
abstract: JAK-STAT-activated gene expression is both rapid and transient and requires dynamic post-translational modification of the chromatin template. Previously, we showed that following IFN-γ treatment, trimethylation of histone H3 at lysine 79 (H3K79me3) is rapidly and highly induced in the 5'-end of the STAT1-dependent gene interferon regulatory factor 1 (IRF1), but the role of this histone modification was unexplored. Here we report that DOT1L, the non-SET domain containing methyltransferase that modifies Lys-79, is localized across IRF1 in the uninduced state and is not further recruited by IFN-γ induction. RNAi-mediated depletion of DOT1L prevents the induction of H3K79me3 and lowers the transcription of IRF1 2-fold, as expected. Surprisingly, STAT1 binding to its DNA recognition element near the IRF1 promoter is diminished 2-fold in the DOT1L-depleted cell line. In vivo and in vitro protein interaction assays reveal a DOT1L-STAT1 interaction. Domain mapping identifies the middle region of DOT1L (amino acids 580-1183) as the STAT1 interaction domain. Overexpression of the DOT1L STAT1 interaction domain represses IRF1 transcription (2-fold) and interferes with STAT1 DNA binding at IRF1 and endogenous DOT1L histone methyltransferase activity. Collectively, our findings reveal a novel STAT1-DOT1L interaction that is required for the regulation JAK-STAT-inducible gene expression.
authors: Department of Biology, The University of Virginia, Charlottesville, Virginia 22903.
authors: Shaili
authors: S
authors: Shah
authors: Department of Biology, The University of Virginia, Charlottesville, Virginia 22903. Electronic address: mah2hx@virginia.edu.
authors: Melissa A
authors: MA
authors: Henriksen
mesh_terms: D002460:Cell Line; D005786:Gene Expression Regulation / Q000502:physiology*; D011495:Histone-Lysine N-Methyltransferase; D006657:Histones / Q000235:genetics / Q000378:metabolism; D006801:Humans; D050856:Interferon Regulatory Factor-1 / Q000096:biosynthesis / Q000235:genetics; D008780:Methyltransferases / Q000235:genetics / Q000378:metabolism*; D010449:Peptide Mapping; D017434:Protein Structure, Tertiary; D020218:Response Elements / Q000502:physiology; D050794:STAT1 Transcription Factor / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic / Q000502:physiology*
chemical_list: D006657:Histones; C494257:IRF1 protein, human; D050856:Interferon Regulatory Factor-1; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; C473477:DOT1L protein, human; D008780:Methyltransferases; D011495:Histone-Lysine N-Methyltransferase