scholarly journals Identification of Distinct Inhibin and Transforming Growth Factor β-binding Sites on Betaglycan

2006 ◽  
Vol 281 (25) ◽  
pp. 17011-17022 ◽  
Author(s):  
Ezra Wiater ◽  
Craig A. Harrison ◽  
Kathy A. Lewis ◽  
Peter C. Gray ◽  
Wylie W. Vale
Keyword(s):  
Growth Factor ◽  
Binding Sites ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β

scholarly journals Multiple and Essential Sp1 Binding Sites in the Promoter for Transforming Growth Factor-β Type I Receptor

1997 ◽  
Vol 272 (34) ◽  
pp. 21260-21267 ◽  
Author(s):  
Changhua Ji ◽  
Sandra Casinghino ◽  
Thomas L. McCarthy ◽  
Michael Centrella
Keyword(s):  
Growth Factor ◽  
Binding Sites ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Type I

scholarly journals Betaglycan has multiple binding sites for transforming growth factor-β 1

1996 ◽  
Vol 315 (3) ◽  
pp. 815-820 ◽  
Author(s):  
Shinya KANAME ◽  
Erkki RUOSLAHTI
Keyword(s):  
Growth Factor ◽  
Binding Sites ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Extracellular Domain ◽  
Lung Epithelial Cells ◽  
Multiple Binding Sites ◽  
Lung Epithelial ◽  
Multiple Binding ◽  
Β Receptor

The transforming growth factor-β (TGF-β)-binding site in betaglycan, the type III TGF-β receptor, has been variously assigned to the C-terminal half and N-terminal one-third of the extracellular domain. In this study, we show that there are at least two TGF-β-binding sites in betaglycan. Bacterially expressed fragments bg1,2 and bg3, which represent the N-terminal two-thirds and C-terminal one-third of betaglycan extracellular domain, both competed for the binding of 125I-TGF-β to mink lung epithelial cells. 125I-bg1,2 bound to immobilized TGF-β with an affinity about 4-fold higher than bg3 had. Both bg3 and bg1,2 enhanced the bioactivity of TGF-β. The whole ectodomain of betaglycan was more active than either bg3 or bg1,2 in the assays. The binding of 125I-bg3 to TGF-β was inhibited by bg1,2, and vice versa. The binding of 125I-bg3 and 125I-bg1,2 to TGF-β was also inhibited by the small decorin family of proteoglycans. These results indicate that there are at least two binding sites for TGF-β in betaglycan and that these sites recognize the same or overlapping sites in TGF-β.

scholarly journals NFI-Ski Interactions Mediate Transforming Growth Factor β Modulation of Human Papillomavirus Type 16 Early Gene Expression

2004 ◽  
Vol 78 (8) ◽  
pp. 3953-3964 ◽  
Author(s):  
Amy Baldwin ◽  
Lucia Pirisi ◽  
Kim E. Creek
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Growth Factor ◽  
Binding Sites ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Early Gene ◽  
Early Gene Expression ◽  
Nuclear Extracts ◽  
E6 And E7

ABSTRACT Human papillomaviruses (HPVs) are present in virtually all cervical cancers. An important step in the development of malignant disease, including cervical cancer, involves a loss of sensitivity to transforming growth factor β (TGF-β). HPV type 16 (HPV16) early gene expression, including that of the E6 and E7 oncoprotein genes, is under the control of the upstream regulatory region (URR), and E6 and E7 expression in HPV16-immortalized human epithelial cells is inhibited at the transcriptional level by TGF-β. While the URR contains a myriad of transcription factor binding sites, including seven binding sites for nuclear factor I (NFI), the specific sequences within the URR or the transcription factors responsible for TGF-β modulation of the URR remain unknown. To identify potential transcription factors and binding sites involved in TGF-β modulation of the URR, we performed DNase I footprint analysis on the HPV16 URR using nuclear extracts from TGF-β-sensitive HPV16-immortalized human keratinocytes (HKc/HPV16) treated with and without TGF-β. Differentially protected regions were found to be located around NFI binding sites. Electrophoretic mobility shift assays, using the NFI binding sites as probes, showed decreased binding upon TGF-β treatment. This decrease in binding was not due to reduced NFI protein or NFI mRNA levels. Mutational analysis of individual and multiple NFI binding sites in the URR defined their role in TGF-β sensitivity of the promoter. Overexpression of the NFI family members in HKc/HPV16 decreased the ability of TGF-β to inhibit the URR. Since the oncoprotein Ski has been shown to interact with and increase the transcriptional activity of NFI and since cellular Ski levels are decreased by TGF-β treatment, we explored the possibility that Ski may provide a link between TGF-β signaling and NFI activity. Anti-NFI antibodies coimmunoprecipitated endogenous Ski in nuclear extracts from HKc/HPV16, confirming that NFI and Ski interact in these cells. Ski levels dramatically decreased upon TGF-β treatment of HKc/HPV16, and overexpression of Ski eliminated the ability of TGF-β to inhibit the URR. Based on these studies, we propose that TGF-β inhibition of HPV16 early gene expression is mediated by a decrease in Ski levels, which in turn dramatically reduces NFI activity.

scholarly journals Chromatin Immunoprecipitation on Microarray Analysis of Smad2/3 Binding Sites Reveals Roles of ETS1 and TFAP2A in Transforming Growth Factor β Signaling

2008 ◽  
Vol 29 (1) ◽  
pp. 172-186 ◽  
Author(s):  
Daizo Koinuma ◽  
Shuichi Tsutsumi ◽  
Naoko Kamimura ◽  
Hirokazu Taniguchi ◽  
Keiji Miyazawa ◽  
...  
Keyword(s):  
Growth Factor ◽  
Chromatin Immunoprecipitation ◽  
Binding Sites ◽  
Target Genes ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Hacat Keratinocytes ◽  
Small Interfering Rnas ◽  
Promoter Regions ◽  
Essential Resource

ABSTRACT The Smad2 and Smad3 (Smad2/3) proteins are principally involved in the transmission of transforming growth factor β (TGF-β) signaling from the plasma membrane to the nucleus. Many transcription factors have been shown to cooperate with the Smad2/3 proteins in regulating the transcription of target genes, enabling appropriate gene expression by cells. Here we identified 1,787 Smad2/3 binding sites in the promoter regions of over 25,500 genes by chromatin immunoprecipitation on microarray in HaCaT keratinocytes. Binding elements for the v-ets erythroblastosis virus E26 oncogene homolog (ETS) and transcription factor AP-2 (TFAP2) were significantly enriched in Smad2/3 binding sites, and knockdown of either ETS1 or TFAP2A resulted in overall alteration of TGF-β-induced transcription, suggesting general roles for ETS1 and TFAP2A in the transcription induced by TGF-β-Smad pathways. We identified novel Smad binding sites in the CDKN1A gene where Smad2/3 binding was regulated by ETS1 and TFAP2A. Moreover, we showed that small interfering RNAs for ETS1 and TFAP2A affected TGF-β-induced cytostasis. We also analyzed Smad2- or Smad3-specific target genes regulated by TGF-β and found that their specificity did not appear to be solely determined by the amounts of the Smad2/3 proteins bound to the promoters. These findings reveal novel regulatory mechanisms of Smad2/3-induced transcription and provide an essential resource for understanding their roles.

scholarly journals Transforming Growth Factor β Stimulates the Human Immunodeficiency Virus 1 Enhancer and Requires NF-κB Activity

1998 ◽  
Vol 18 (1) ◽  
pp. 110-121 ◽  
Author(s):  
Jian-Ming Li ◽  
Xing Shen ◽  
Patrick Pei-Chih Hu ◽  
Xiao-Fan Wang
Keyword(s):  
Human Immunodeficiency Virus ◽  
Growth Factor ◽  
Binding Sites ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Luciferase Reporter ◽  
Hacat Cells ◽  
Immunodeficiency Virus ◽  
Ltr Promoter ◽  
Hiv 1

ABSTRACT Transforming growth factor β (TGF-β) is the prototype of a large superfamily of signaling molecules involved in the regulation of cell growth and differentiation. In certain patients infected with human immunodeficiency virus type 1 (HIV-1), increased levels of TGF-β promoted the production of virus and also impaired the host immune system. In an effort to understand the signaling events linking TGF-β action and HIV production, we show here that TGF-β can stimulate transcription from the HIV-1 long terminal repeat (LTR) promoter through NF-κB binding sites in both HaCaT and 300.19 pre-B cells. When introduced into a minimal promoter, NF-κB binding sites supported nearly 30-fold activation from the luciferase reporter upon TGF-β treatment. Electrophoretic mobility shift assay indicated that a major factor binding to the NF-κB site is the p50-p65 heterodimeric NF-κB in HaCaT cells. Coexpression of Gal4-p65 chimeric proteins supported TGF-β ligand-dependent gene expression from a luciferase reporter gene driven by Gal4 DNA binding sites. NF-κB activity present in HaCaT cells was not affected by TGF-β treatment as judged by the unchanged DNA binding activity and concentrations of p50 and p65 proteins. Consistently, steady-state levels of IκBα and IκBβ proteins were not changed by TGF-β treatment. Our results demonstrate that TGF-β is able to stimulate transcription from the HIV-1 LTR promoter by activating NF-κB through a mechanism distinct from the classic NF-κB activation mechanism involving the degradation of IκB proteins.

Sign in / Sign up

Export Citation Format

Share Document