The regulation of the human tumor necrosis factor alpha promoter region in macrophage, T cell, and B cell lines.
The 1311-base pair human tumor necrosis factor (TNF) alpha promoter region was fused to the luciferase (Luc) reporter gene and studied in a transient transfection system in three TNF producing cell lines, the U937 macrophage cell line, the MLA 144 T cell line, and the 729-6 B cell line. This full length promoter construct can be induced by phorbol 13-myristate acetate (PMA) in each of these cell types. Analysis of a series of 5'-truncations showed several peaks of basal and PMA induced activity suggesting the presence of several positive and negative regulatory elements. A PMA responsive element was localized to a region between -95 and -36 bp relative to the transcription start site. Within this region, single AP-2- and AP-1-like consensus sequences were noted. These AP-2 and AP-1 sites were each modified with a double point mutation. A modest (20-50%) reduction in TNF promoter activity was observed with the AP-2 site mutation. However, mutation of the AP-1 site markedly diminished both the basal and PMA-activated promoter activity. Also co-transfections of the wild-type promoter construct with an AP-1/c-jun expression vector resulted in augmented basal and PMA-induced promoter activity.
Rhoades
K L
KL
Department of Microbiology and Immunology, UCLA School of Medicine 90024.
Golub
S H
SH
Economou
J S
JS
D001402:B-Lymphocytes / Q000502:physiology*; D001483:Base Sequence; D005786:Gene Expression Regulation; D006801:Humans; D066298:In Vitro Techniques; D008264:Macrophages / Q000502:physiology*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011401:Promoter Regions, Genetic; D017384:Sequence Deletion; D013601:T-Lymphocytes / Q000502:physiology*; D014157:Transcription Factors / Q000502:physiology; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*
D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha