Related Experiment Videos
Regulation of p21ras activity
D R Lowy1, K Zhang, J E DeClue
1Laboratory of Cellular Oncology, National Cancer Institute, Bethesda, MD 20892.
Trends in Genetics : TIG
|November 1, 1991
Summary
Ras genes produce GTP/GDP-binding proteins crucial for cell signaling. Their activity, regulated by GTP-p21ras levels, involves positive and negative control mechanisms like GAP and NF1, influencing mitogenic signals.
Area of Science:
- Molecular Biology
- Cell Signaling
- Oncogenes
Background:
- Ras genes encode GTP/GDP-binding proteins essential for signal transduction.
- These proteins mediate mitogenic signals from membrane tyrosine kinases to cellular targets.
- The activity of p21ras is regulated by the concentration of its GTP-bound form.
Purpose of the Study:
- To elucidate the regulatory mechanisms controlling p21ras activity.
- To identify factors involved in the positive and negative regulation of ras signaling pathways.
Main Methods:
- Analysis of ras gene function in cellular signaling pathways.
- Investigation of protein-protein interactions involving ras proteins.
- Biochemical assays to measure GTP/GDP binding and hydrolysis rates.
Main Results:
- p21ras activity is tightly controlled by GTP-p21ras concentration.
- GTPase-activating protein (GAP) and Neurofibromin 1 (NF1) negatively regulate p21ras by promoting GTP hydrolysis.
- Other cellular factors positively regulate p21ras by facilitating GDP/GTP exchange.
Conclusions:
- Ras signaling is modulated by a complex interplay of positive and negative regulators.
- GAP and NF1 are key negative regulators of ras activity.
- Understanding these regulatory mechanisms is vital for comprehending cell growth and disease states.