Final answer:
The Rho family of Ras superfamily includes small GTPases like RAS, which regulate cellular activities through signal transduction pathways. In cancer, mutations in RAS that prevent GTP hydrolysis lead to persistent signaling for cellular growth and contribute to uncontrolled cell proliferation.
Step-by-step explanation:
The Rho family of Ras superfamily is part of a group of small GTPases that play a critical role in cellular signal transduction. The RAS protein is a well-known member of this group, acting as a molecular switch that controls various cellular processes, including proliferation, differentiation, and survival.
When RAS is bound to GTP, it is active and initiates signal transduction pathways, such as the MAPK kinase cascade. Activated RAS stimulates RAF, leading to the phosphorylation of MEK, which subsequently phosphorylates ERK. ERK then moves into the nucleus to trigger cellular responses.
In the context of cancer, mutations that impair the GTPase activity of RAS result in its inability to hydrolyze GTP to GDP. This leads to the RAS protein remaining persistently active, resulting in continuous signaling for cell growth and division, which can contribute to uncontrolled cell proliferation and the development of tumors.