The Nucleotide Exchange Cycle

The nucleotide exchange cycle involves proteins called GTPases that act as molecular switches inside cells. These proteins alternate between an active form bound to GTP (guanosine triphosphate) and an inactive form bound to GDP (guanosine diphosphate). When a GTPase releases GDP, it can then bind a new GTP, switching to the active state. This cycle is tightly controlled by other proteins that help remove GDP and add GTP, thus regulating various cellular processes like signaling and transport. The cycle ensures that GTPases are active only when needed, maintaining proper cell function.