Identification of two NF-kappa B sites in mouse CD95 ligand (Fas ligand) promoter: functional analysis in T cell hybridoma.
Fas ligand (FasL) gene expression is critically involved in peripheral T cell tolerance and lymphocyte homeostasis. Previous studies have suggested that nuclear translocation of NF-kappaB during T cell activation is a critical event for FasL gene activation. In the present study we have identified two NF-kappaB sites (designated FasL-kappaB1 and FasL-kappaB2) on the promoter (approximately 700 bp) of FasL. The NF-kappaB sites were identified by electrophoretic mobility shift assay. Transient transfection reporter analyses showed that the FasL promoter activity was comparable between a construct that contains both sites and a shorter construct (433 bp) that contains only the FasL-kappaB1 site. Furthermore, elimination of FasL-kappaB1 by site-directed mutagenesis significantly inhibited FasL promoter activity. These observations provide strong evidence that NF-kappaB directly binds to the FasL-kappaB1 site and up-regulates FasL gene expression.
Department of Pathology and Laboratory Medicine, Boston University School of Medicine, MA 02118, USA.
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K
Matsui
A
A
Fine
B
B
Zhu
A
A
Marshak-Rothstein
S T
ST
Ju
D000818:Animals; D017209:Apoptosis / Q000235:genetics / Q000276:immunology; D001665:Binding Sites / Q000235:genetics; D053222:Fas Ligand Protein; D005786:Gene Expression Regulation / Q000276:immunology; D006825:Hybridomas; D008024:Ligands; D008562:Membrane Glycoproteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D051379:Mice; D016513:Mice, SCID; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D016328:NF-kappa B / Q000302:isolation & purification / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D015533:Transcriptional Activation; D019014:fas Receptor / Q000378:metabolism*
D053222:Fas Ligand Protein; C505658:Fasl protein, mouse; D008024:Ligands; D008562:Membrane Glycoproteins; D016328:NF-kappa B; D019014:fas Receptor