Guanine nucleotide exchange factor

A Guanine Nucleotide Exchange Factor (GEF) is a specialized protein that helps activate certain cellular switch proteins called GTPases. GTPases control many cell functions, like growth and movement, by switching between active and inactive states. GEFs facilitate this by helping GTPases release their bound GDP (inactive form) so they can bind GTP (active form). This exchange turns the GTPase "on," allowing it to perform its role in cell processes. Essentially, GEFs act as regulators that trigger cellular activities by activating GTPases when needed.