GDI3

GDI3, short for GDP dissociation inhibitor 3, is a member of the GDP dissociation inhibitor (GDI) family of proteins that regulate Rab GTPases, which are essential for vesicular trafficking within the cell. The GDI family binds Rab proteins in their GDP-bound state in the cytosol and helps shuttle them between membrane compartments, thereby controlling Rab activity and localization.

GDI3 interacts with a subset of Rab GTPases and functions to extract Rab proteins from membranes and maintain them soluble in the cytosol. Through this cycling, GDI3 contributes to the regulation of vesicle formation and trafficking between organelles such as the endoplasmic reticulum, Golgi apparatus, endosomes, and the plasma membrane, influencing trafficking efficiency and organelle morphology. The exact Rab partners and regulatory roles of GDI3 can vary among cell types and species.

In humans, the GDI3 gene encodes the GDI3 protein, and orthologs are found across diverse eukaryotes, indicating a conserved role in intracellular trafficking. The protein is generally localized to the cytosol, with recruitment to membranes expected when binding Rab GTPases.

Research on GDI3 is ongoing. Studies have explored its potential involvement in neuronal development and trafficking-related disease processes, but no widely accepted causal link to specific conditions has been established. GDI3 is typically discussed alongside other GDIs and Rab regulators in the broader context of vesicular transport and intracellular trafficking.