RAB3GAP2 : RAB3 GTPase activating non-catalytic protein subunit 2

Description

The RAB3GAP2 (RAB3 GTPase activating non-catalytic protein subunit 2) is a protein-coding gene located on chromosome 1.

The RAB3GAP2 gene provides instructions for making a protein that helps regulate the activity of specialized proteins called GTPases, which control a variety of functions in cells. To perform its function, the RAB3GAP2 protein interacts with another protein called RAB3GAP1 (produced from the RAB3GAP1 gene) to form the RAB3GAP complex.Often referred to as molecular switches, GTPases can be turned on and off. They are turned on (active) when they are attached (bound) to a molecule called GTP and are turned off (inactive) when they are bound to another molecule called GDP. The RAB3GAP complex turns on a GTPase known as RAB18 by exchanging GTP for the attached GDP. When active, RAB18 is involved in a process called vesicle trafficking, which moves proteins and other molecules within cells in sac-like structures called vesicles. RAB18 regulates the movement of substances between compartments in cells and the storage and release of fats (lipids) by structures called lipid droplets. The protein also appears to play a role in a process called autophagy, which helps clear unneeded materials from cells. RAB18 is important for the organization of a cell structure called the endoplasmic reticulum, which is involved in protein processing and transport.The RAB3GAP complex is also thought to inactivate another GTPase known as RAB3 by stimulating a reaction that turns the attached GTP into GDP. RAB3 plays a role in the release of hormones and brain chemicals (neurotransmitters) from cells.

RAB3GAP2 is a regulatory subunit of the Rab3 GTPase-activating (Rab3GAP) complex, which is composed of RAB3GAP1 and RAB3GAP2. The Rab3GAP complex functions as a GTPase-activating protein (GAP) for various Rab3 subfamily members (RAB3A, RAB3B, RAB3C and RAB3D), RAB5A and RAB43, and as a guanine nucleotide exchange factor (GEF) for RAB18. As a GAP, the complex converts active RAB3-GTP to the inactive form RAB3-GDP, regulating the exocytosis of neurotransmitters and hormones. As a GEF, the complex promotes the conversion of inactive RAB18-GDP to the active form RAB18-GTP, which is required for recruiting and activating RAB18 at the endoplasmic reticulum (ER) membrane, maintaining proper ER structure. RAB3GAP2 is essential for normal eye and brain development and may participate in neurodevelopmental processes such as proliferation, migration, and differentiation before synapse formation, and non-synaptic vesicular release of neurotransmitters.

RAB3GAP2 is also known as MARTS1, RAB3-GAP150, RAB3GAP150, SPG69, WARBM2, p150.

Associated Diseases

• Micro syndrome
• Autosomal recessive spastic paraplegia type 69
• Martsolf syndrome 1
• Cataract-intellectual disability-hypogonadism syndrome
• Warburg micro syndrome 2
• Coloboma
• RAB18 deficiency