title: Transcriptional Auto-Regulation of RUNX1 P1 Promoter.
abstract: RUNX1 a member of the family of runt related transcription factors (RUNX), is essential for hematopoiesis. The expression of RUNX1 gene is controlled by two promoters; the distal P1 promoter and the proximal P2 promoter. Several isoforms of RUNX1 mRNA are generated through the use of both promoters and alternative splicing. These isoforms not only differs in their temporal expression pattern but also exhibit differences in tissue specificity. The RUNX1 isoforms derived from P2 are expressed in a variety of tissues, but expression of P1-derived isoform is restricted to cells of hematopoietic lineage. However, the control of hematopoietic-cell specific expression is poorly understood. Here we report regulation of P1-derived RUNX1 mRNA by RUNX1 protein. In silico analysis of P1 promoter revealed presence of two evolutionary conserved RUNX motifs, 0.6kb upstream of the transcription start site, and three RUNX motifs within 170bp of the 5'UTR. Transcriptional contribution of these RUNX motifs was studied in myeloid and T-cells. RUNX1 genomic fragment containing all sites show very low basal activity in both cell types. Mutation or deletion of RUNX motifs in the UTR enhances basal activity of the RUNX1 promoter. Chromatin immunoprecipitation revealed that RUNX1 protein is recruited to these sites. Overexpression of RUNX1 in non-hematopoietic cells results in a dose dependent activation of the RUNX1 P1 promoter. We also demonstrate that RUNX1 protein regulates transcription of endogenous RUNX1 mRNA in T-cell. Finally we show that SCL transcription factor is recruited to regions containing RUNX motifs in the promoter and the UTR and regulates activity of the RUNX1 P1 promoter in vitro. Thus, multiple lines of evidence show that RUNX1 protein regulates its own gene transcription.
authors.affiliation: Departamento de Bioquimica y Biologia Molecular, Facultad de Ciencias Biologicas, Universidad de Concepcion, Concepcion, Chile.
authors.forename: Milka
authors.initials: M
authors.lastname: Martinez
authors.affiliation: Departamento de Bioquimica y Biologia Molecular, Facultad de Ciencias Biologicas, Universidad de Concepcion, Concepcion, Chile.
authors.forename: Marcela
authors.initials: M
authors.lastname: Hinojosa
authors.affiliation: Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, 01655, Massachusetts, United States of America.
authors.forename: Daniel
authors.initials: D
authors.lastname: Trombly
authors.affiliation: Departamento de Bioquimica y Biologia Molecular, Facultad de Ciencias Biologicas, Universidad de Concepcion, Concepcion, Chile.
authors.forename: Violeta
authors.initials: V
authors.lastname: Morin
authors.affiliation: Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, 01655, Massachusetts, United States of America.|Department of Biochemistry and Vermont Cancer Center, University of Vermont College of Medicine, 89 Beaumont Avenue, Burlington 05405, Vermont, United States of America.
authors.forename: Janet
authors.initials: J
authors.lastname: Stein
authors.affiliation: Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, 01655, Massachusetts, United States of America.|Department of Biochemistry and Vermont Cancer Center, University of Vermont College of Medicine, 89 Beaumont Avenue, Burlington 05405, Vermont, United States of America.
authors.forename: Gary
authors.initials: G
authors.lastname: Stein
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dentistry, University of Alabama at Birmingham, Alabama, United States of America.
authors.forename: Amjad
authors.initials: A
authors.lastname: Javed
authors.affiliation: Departamento de Bioquimica y Biologia Molecular, Facultad de Ciencias Biologicas, Universidad de Concepcion, Concepcion, Chile.
authors.forename: Soraya E
authors.initials: SE
authors.lastname: Gutierrez
mesh_terms: D020121:5' Untranslated Regions; D001483:Base Sequence; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism; D001665:Binding Sites; D045744:Cell Line, Tumor; D050676:Core Binding Factor Alpha 2 Subunit / Q000235:genetics* / Q000378:metabolism*; D005786:Gene Expression Regulation; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D059372:Nucleotide Motifs; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D012333:RNA, Messenger; D016415:Sequence Alignment; D000073942:T-Cell Acute Lymphocytic Leukemia Protein 1; D014158:Transcription, Genetic; D015533:Transcriptional Activation
chemical_list: D020121:5' Untranslated Regions; D051792:Basic Helix-Loop-Helix Proteins; D050676:Core Binding Factor Alpha 2 Subunit; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D000073942:T-Cell Acute Lymphocytic Leukemia Protein 1; C067143:TAL1 protein, human