ADP Ribosylation Factor (ARF) is a protein that plays a crucial role in intracellular vesicular trafficking, which is the process of transporting materials within a cell. ARF is a small GTPase protein that regulates the formation, budding, and fusion of vesicles, controlling the movement of proteins and lipids between different compartments of the cell.
ARF acts as a molecular switch, existing in two forms: an inactive GDP-bound form and an active GTP-bound form. When ARF is bound to GTP, it undergoes a conformational change, promoting its interaction with specific effector proteins that mediate vesicle formation and fusion. This activation process is regulated by guanine nucleotide exchange factors (GEFs) that catalyze the exchange of GDP with GTP, and GTPase-activating proteins (GAPs) that enhance the intrinsic GTPase activity of ARF, leading to its inactivation.
ARF is involved in various cellular processes, including protein sorting, vesicle budding, endocytosis, and recycling. It works in conjunction with other proteins, such as coat proteins (e.g., COPI and clathrin), to facilitate vesicle formation and cargo selection. By regulating the trafficking of proteins and lipids, ARF ensures their proper localization within the cell and influences various cellular functions.
The dysregulation of ARF function has been implicated in several diseases, including cancer, neurodegenerative disorders, and infectious diseases. Therefore, understanding the mechanisms underlying ARF activation and its interaction with effector proteins can provide valuable insights into the pathophysiology of these conditions and offer potential therapeutic targets.
