RAB18 Human

RAB18 is a gene that encodes a protein belonging to the Rab family of small GTPases. These proteins are key regulators of intracellular membrane trafficking, which includes the formation, movement, and fusion of transport vesicles within cells . The RAB18 protein is involved in various cellular processes, including vesicle trafficking, lipid droplet formation, and maintaining endoplasmic reticulum structure .

The RAB18 gene is located on chromosome 10 in humans . It produces a protein that is ubiquitously expressed, with particularly high expression levels in the brain . The protein encoded by RAB18 cycles between an inactive GDP-bound form and an active GTP-bound form, which allows it to recruit different sets of downstream effectors responsible for vesicle formation, movement, tethering, and fusion .

RAB18 plays a crucial role in several cellular functions:

• Vesicle Trafficking: RAB18 regulates the movement of proteins and other molecules within cells by controlling vesicle trafficking .
• Lipid Droplet Formation: It is required for the localization of ZFYVE1 to lipid droplets and mediates the formation of endoplasmic reticulum-lipid droplets (ER-LD) contacts .
• Endoplasmic Reticulum Structure: RAB18 is essential for maintaining the structure of the endoplasmic reticulum .
• Eye and Brain Development: It plays a key role in the development of the eye and brain, and its dysfunction is associated with neurodegeneration .

Mutations in the RAB18 gene are linked to Warburg Micro Syndrome, a rare genetic disorder characterized by developmental abnormalities of the eye and brain . This syndrome is caused by disruptions in the function of RAB18, which affects vesicle trafficking and other cellular processes .

Research on RAB18 has provided insights into its role in cellular processes and its association with diseases. Understanding the function of RAB18 and its pathways can help in developing therapeutic strategies for conditions like Warburg Micro Syndrome .