Ras signalling and apoptosis

Area of Science:

• Molecular Biology
• Cell Biology
• Biochemistry

Background:

• Ras proteins play a dual role in regulating apoptosis, with effects varying by cell type.
• Ras controls multiple effector pathways, including PI3-kinase (survival) and Raf (survival inhibition).
• Mechanisms underlying Ras's influence on apoptosis, particularly Raf's role, require further elucidation.

Purpose of the Study:

• To investigate the complex mechanisms by which Ras proteins regulate apoptosis.
• To clarify the specific roles of effector pathways like PI3-kinase and Raf in Ras-mediated apoptosis.
• To understand how Ras activation influences cell survival and death signaling.

Main Methods:

• Analysis of Ras protein activation and its downstream signaling.
• Investigating the impact of PI3-kinase and Raf pathways on apoptosis.
• Utilizing cell-based assays to monitor apoptosis regulation.
• Examining the activation of PKB/Akt and NF-kappa B in response to Ras signaling.

Main Results:

• Ras proteins can either promote or inhibit apoptosis, contingent on cellular context.
• PI3-kinase activation by Ras leads to a survival signal via PKB/Akt.
• Raf activation by Ras can contribute to the inhibition of survival pathways.
• Ras signaling can protect cells from apoptosis through PKB/Akt or NF-kappa B activation.

Conclusions:

• Ras proteins exert complex, context-dependent control over apoptosis.
• Multiple Ras effector pathways, including PI3-kinase/PKB/Akt and Raf, are critical for this regulation.
• Ras-mediated protection from apoptosis can occur via PI3-kinase/PKB/Akt or NF-kappa B activation pathways.