Related Experiment Videos
Platelet-derived growth factor enhances Sp1 binding to the LDL receptor gene
K Basheeruddin1, X Li, C Rechtoris
1Department of Medicine, Rush Medical College, Chicago, Ill 60612, USA.
Arteriosclerosis, Thrombosis, and Vascular Biology
|August 1, 1995
Summary
Platelet-derived growth factor (PDGF) activates Sp1 binding to the LDL receptor gene in quiescent cells. This enhanced Sp1 binding likely mediates PDGF
Area of Science:
- Molecular Biology
- Cellular Biology
- Gene Regulation
Background:
- Growth factors like platelet-derived growth factor (PDGF) influence cellular processes, including gene expression.
- The low-density lipoprotein (LDL) receptor gene's transcription is regulated by growth factors and sterol levels.
- A key regulatory region of the LDL receptor gene contains a sterol response element and an Sp1 binding site.
Purpose of the Study:
- To investigate the mechanism by which PDGF activates LDL receptor gene transcription.
- To determine the role of the Sp1 binding site in mediating the PDGF response.
Main Methods:
- Mobility shift assays to assess Sp1 binding to the LDL receptor gene.
- Transfection analyses using reporter genes to evaluate promoter activity.
- Western blot analysis to determine Sp1 protein levels.
Main Results:
- PDGF stimulation enhanced Sp1 binding to the LDL receptor gene in quiescent cells.
- The Sp1 binding site, but not the sterol response element, conferred PDGF responsiveness.
- Increased Sp1 binding was mediated by posttranslational modification, not increased Sp1 production.
Conclusions:
- PDGF induction of LDL receptor gene transcription involves enhanced Sp1 binding.
- Posttranslational activation of Sp1 is a key mechanism in growth factor-induced gene expression.