A NF-κB/Sp1 Region Is Essential for Chromatin Remodeling and Correct Transcription of a Human Granulocyte- Macrophage Colony-Stimulating Factor Transgene

Abstract

The GM-CSF gene is expressed following activation of T cells. The proximal promoter and an upstream enhancer have previously been characterized using transfection and reporter assays in T cell lines in culture. A 10.5-kb transgene containing the entire human GM-CSF gene has also been shown to display inducible, position-independent, copy number-dependent transcription in mouse splenocytes. To determine the role of individual promoter elements in transgene function, mutations were introduced into the proximal promoter and activity assessed following the generation of transgenic mice. Of four mutations introduced into the transgene promoter, only one, in an NF-κB/Sp1 region, led to decreased induction of the transgene in splenocytes or bone marrow-derived macrophages. This mutation also affected the activity of reporter gene constructs stably transfected into T cell lines in culture, but not when transiently transfected into the same cell lines. The mutation alters the NF-κB family members that bind to the NF-κB site as well as reducing the binding of Sp1 to an adjacent element. A DNase I hypersensitive site that is normally generated at the promoter following T cell activation on the wild-type transgene does not appear in the mutant transgene. These results suggest that the NF-κB/Sp1 region plays a critical role in chromatin remodeling and transcription on the GM-CSF promoter in primary T cells.

PKC and PKC differentially regulate Legionella pneumophila-induced GM-CSF

“…A complex signaling network regulates the expression of inducible GM-CSF [24,25]. In L. pneumophila-infected lung epithelial cells, we noted a TLR2 and TLR5 dependent activation of PKC.…”

“…Activation of the transcription factors NF-kB and AP-1 is considered to significantly contribute to GM-CSF expression [24,25]. We therefore demonstrated that L. pneumophila induced GM-CSF was controlled by NF-kB and AP-1 (c-Jun).…”

“…Furthermore, AMs from GM-CSF -/-mice were defective for Escherichia coli phagocytosis [18] as well as in the production of tumour necrosis factor (TNF)-a [22] and IFN-c [23]. The expression of GM-CSF is controlled by a tight regulatory network involving the transcription-factors nuclear factor (NF)-kB and the activator protein (AP)-1 [24,25]. These transcription factors are activated by complex signalling pathways, including protein kinase C (PKC) [26,27].…”

The Sp1 transcription factor contributes to the tumor necrosis factor-induced expression of the angiogenic factor thymidine phosphorylase in human colon carcinoma cells

“…Response elements that were not found by sequence analysis in the 1.4-kb 5'-region of the TP gene included AP1, NF-kB, HIF1 and Egr1. In addition to their individual roles in regulating transcription, reports suggest that there is cross-talk between transcription factors, including evidence that gene activation by Sp1 can be modulated by positive and negative interactions with other transcription factors (Hirano et al, 1998;Krehan et al, 2000;Cakouros et al, 2001). Experiments with constructs containing 5'-truncations of the TP promoter revealed that the transcriptional activity dramatically decreased with deletion of sequence spanning 7368 to 7155 and 7155 to 764.…”

CBP Mediates NF-κB-Dependent Histone Acetylation and Estrogen Receptor Recruitment to an Estrogen Response Element in the BIRC3 Promoter

“…NF-B has previously been shown to enhance DNA accessibility around the NF-B-RE to which it binds. For example, at the granulocyte-macrophage colonystimulating factor gene (GM-CSF) promoter, NF-B causes increase in chromatin accessibility via remodeling through recruitment of the ATPase component of the SWI/SNF chromatin remodeling complex, BRG1 (4,22). More recently, constitutive activation of NF-B along with AP1 has been associated with increased accessibility of the IL-6 promoter in highly invasive breast cancer cells (40).…”