Ras-related protein Rab-8a (Rab8a)

Ras-related protein Rab-8a (most commonly referred to as Rab8 GTPase) is a member of the Rab subfamily within the Ras superfamily of small GTPases. It functions as a dynamic regulator of intracellular vesicle trafficking, coordinating the transport of proteins from the trans-Golgi network to the plasma membrane, as well as endocytic and recycling pathways. Rab8 is essential for multiple cell biological processes, including helping shape cell morphology, orchestrating polarity in epithelial and neuronal cells, and regulating the formation and maintenance of primary cilia. It operates as a molecular switch, cycling between GTP- and GDP-bound states—a process governed by guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs). Rab8 interacts with numerous effector proteins (such as optineurin and VAMP-3) to regulate trafficking of major proteins and receptors (e.g., AMPA receptor, transferrin receptor, Klotho). Dysregulation of Rab8 is implicated in the development and progression of various diseases including cancers (through effects on migration, invasion, and drug resistance), ciliopathies, and some neurodegenerative conditions. No approved therapeutic drugs currently directly modulate Rab8, though Rab8-mediated trafficking pathways are considered possible intervention points in disease.

Other names

Rab8Rab8aRab8b (isoforms)Ras-related protein Rab-8Rab8 GTPase

Agents affecting Rab8 would act via inhibition/activation of GTPase activity, modulation of its interaction with effectors (e.g., GEFs, GAPs, optineurin), or disruption of membrane trafficking