Regulation of the Integrin Subunit α5 Gene Promoter by the Transcription Factors Sp1/Sp3 Is Influenced by the Cell Density in Rabbit Corneal Epithelial Cells

Abstract

These results provide support to the hypothesis that the strong reduction in the activity of the alpha5 promoter when RCECs reach a high cell density is the consequence of a reduced expression of Sp1/Sp3 under such cell culture conditions.

Rescue of the Transcription Factors Sp1 and NFI in Human Skin Keratinocytes through a Feeder-Layer-Dependent Suppression of the Proteasome Activity

“…The labeling was revealed using a detection kit (Amersham, Baie d'Urfé, Canada) as described previously. 91,92 Nuclear extracts and EMSA Except when indicated otherwise, all crude nuclear extracts were consistently prepared from all cell types when they reached 80 ± 5% confluence as described previously. 93 The protein concentration of each extract was determined by the Bradford procedure and precisely validated through Coomassie blue staining on SDS-PAGE.…”

Tandem Sp1/Sp3 sites together with an Ets-1 site cooperate to mediate α11 integrin chain expression in mesenchymal cells

“…fibroblasts in the intervertebral disc, a5 and a11 are both highly expressed (Hayes et al, 1999;Tiger et al, 2001). It has been reported that binding of fibronectin to a5h1 integrin induces a ligand-dependent ERK phosphorylation of Sp1 which in turn regulates a5 transcription (Gingras et al, 2003). Similarly, phosphorylation of Sp1 affects its ability to bind the integrin a2 core promoter (Zutter et al, 1997).…”

Fibronectin Increases Survival of Rat Hepatic Stellate Cells - A Novel Profibrogenic Mechanism of Fibronectin

“…*, p <0.01 as compared with control. has been shown that the binding of FN to 5 1 integrin activates 5 gene transcription through phosphorylation of Sp1 by ERK [34]. Silencing gene expression of 5 integrin resulted in a loss of the protective effect of FN against apoptosis (Fig.…”