NRAS: Proteins and Enzymes

Ras (p21), a signal transducer, was first characterized as the transforming genes of Harvey & Kristen sarcoma virus (1). The Ras family (H-Ras, N-Ras, and K-Ras) regulates cell growth, differentiation and apoptosis (2). Switching from an active or resting state, Ras can either bind GTP or GDP respectively. In the triphosphate conformation, Ras will interact with GTPase activating protein (GAP) to increase its activity (3). Mutations in any of the three isoforms can convert these proteins into active oncogenes. Additionally, Ras mutations are found in 30% of all human cancer (4).