Ras-related protein Rab-4B (RAB4B)

Ras-related protein Rab-4B (RAB4B) is a small GTPase in the Ras oncogene superfamily that regulates intracellular membrane trafficking, notably endocytic sorting and recycling of receptors such as transferrin and the glucose transporter GLUT4. Rab4B cycles between GDP- and GTP-bound forms, organizing the movement, docking, and fusion of transport vesicles with various cellular compartments. In adipocytes, Rab4B controls GLUT4 trafficking in response to insulin and is implicated in glucose homeostasis. Its deficiency or decreased expression in T cells of obese adipose tissue promotes an imbalance in immune cell populations, contributing to inflammation and systemic insulin resistance. Recently, Rab4B has also been identified as a host factor essential for Japanese encephalitis virus (JEV) replication, influencing multiple stages of the viral life cycle, which makes it a candidate for antiviral drug targeting. Overall, Rab4B connects membrane transport, metabolism, immunity, and infection biology in health and disease.

Other names

Ras-related protein Rab-4BRab4BRAB4B, member RAS oncogene familyRAB4B_HUMAN (protein name)

Potential inhibitors or modulators would act by disturbing Rab4B’s GTPase-dependent trafficking functions, which could affect receptor recycling, immune cell balance, and viral replication. In viral infection (e.g., Japanese encephalitis virus), targeting Rab4B could disrupt the endocytic pathway required for viral replication and release.