Ras Small Molecules and Peptides

The Ras proteins (H-Ras, N-Ras, and two splice variants of K-Ras) define a closely related family of 21 kDa GTPases that cycle between GTP-bound active and GDP-bound inactive states at the cytoplasmic face of the plasma membrane. Receptor tyrosine kinases and G-protein coupled receptors activate Ras, and effectors include Raf and PI 3-kinase. Activating mutations of Ras, which impair GTPase activity and stabilize the active state, are found in nearly one-third of all human cancers.