RAB39B is a small GTPase protein belonging to the Rab family of vesicle trafficking proteins[1]. Mutations in the RAB39B gene cause a rare form of autosomal recessive Parkinson's disease characterized by early-onset parkinsonism, intellectual disability, and sometimes autism spectrum disorder[2][3]. RAB39B plays critical roles in synaptic vesicle trafficking, autophagy, and mitochondrial function in dopaminergic neurons[4].
The RAB39B gene is located on chromosome Xq28 and encodes a 236-amino acid protein with characteristic Rab GTPase domains[1:1]. It is highly expressed in the brain, particularly in the substantia nigra, hippocampus, and cerebral cortex[5].
RAB39B regulates synaptic vesicle trafficking and neurotransmitter release through:
Pathogenic RAB39B mutations cause loss of RAB39B function, leading to:
RAB39B mutations cause:
RAB39B interacts genetically and biochemically with other Parkinson's disease genes:
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