ARF3

ADP-ribosylation factor 3 (ARF3) is a member of the ARF family of small GTPases that regulate vesicular trafficking in eukaryotic cells. In humans, ARF3 is encoded by the ARF3 gene and produces a protein of about 181 amino acids that localizes primarily to Golgi and endosomal membranes. The protein is N-terminally myristoylated, a modification that promotes membrane association, and it cycles between GDP-bound (inactive) and GTP-bound (active) states as part of its regulatory function.

Functionally, ARF3 acts as a molecular switch that coordinates the formation and trafficking of vesicles. In its GTP-bound form, ARF3 promotes recruitment of coat protein complexes to membranes and supports lipid remodeling during vesicle budding, contributing to trafficking within the Golgi and between the Golgi and endosomes. Activation is driven by guanine nucleotide exchange factors (GEFs) such as GBF1 and BIG family proteins, while inactivation is carried out by GTPase-activating proteins (GAPs). Through these cycles, ARF3 influences cargo sorting, membrane curvature, and lipid dynamics in the secretory pathway.

Localization and regulation of ARF3 reflect its role in intracellular transport. It operates on Golgi membranes and associated compartments, with activity modulated by cellular signals and the surrounding lipid environment. The protein’s function is integrated with other ARF family members to ensure proper trafficking and homeostasis of membrane systems.

In research contexts, ARF3 and related ARF proteins are studied for their roles in intracellular transport and how disruption of ARF-regulated pathways can affect cellular processes. While specific disease associations vary, alterations in vesicular trafficking involving ARF proteins are examined for potential relevance to development, cancer biology, and neurobiology.