title: In vivo regulation of murine granzyme B gene transcription in activated primary T cells.
abstract: A murine granzyme B promoter fragment that extends 243 base pairs upstream of the transcription start site confers high levels of luciferase reporter gene activity in transient transfection assays into T cells and mouse L cell fibroblasts. This promoter fragment contains canonical binding sites for the transcription factors AP-1, core binding factor (CBF), Ikaros, and the cyclic AMP responsive element binding protein (CREB). Oligonucleotides containing the granzyme B AP-1 or CBF elements form specific complexes with proteins present in nuclear extracts from activated CD8(+) splenocytes, MTL cells, EL4 T cells, and L cells. A strong DNase1 hypersensitive site that coincides with the closely associated AP-1, CBF, Ikaros, and CRE elements is present in activated CD8(+) T cells but not in resting T cells or L cells. Both in vitro and in vivo footprints are observed at these sequence elements in activated cytotoxic T cells (CTL) but not in resting T cells. The endogenous granzyme B gene is CTL-specific as no mRNA is detectable in EL4 or L cells. We propose that a condensed chromatin structure at the granzyme B promoter is responsible for transcription factor inaccessibility and repression of transcription in non-T cells.
authors.affiliation: Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada.
authors.forename: C K
authors.initials: CK
authors.lastname: Babichuk
authors.forename: B L
authors.initials: BL
authors.lastname: Duggan
authors.forename: R C
authors.initials: RC
authors.lastname: Bleackley
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D004247:DNA; D004789:Enzyme Activation; D017930:Genes, Reporter; D053804:Granzymes; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008808:Mice, Inbred CBA; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012697:Serine Endopeptidases / Q000235:genetics* / Q000378:metabolism; D013602:T-Lymphocytes, Cytotoxic / Q000201:enzymology* / Q000276:immunology; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic; D014162:Transfection; D014407:Tumor Cells, Cultured
chemical_list: D014157:Transcription Factors; D004247:DNA; D053804:Granzymes; C509214:Gzmb protein, mouse; D012697:Serine Endopeptidases