Receptor accessory protein 1 (REEP1)

Receptor accessory protein 1 (REEP1) is a membrane-associated protein found predominantly in neuronal cells of the brain and spinal cord. It plays a crucial role in shaping and maintaining the structure of the endoplasmic reticulum (ER), particularly the formation of tubular ER networks critical for axonal health and maintenance. REEP1 also enhances the trafficking and cell surface expression of certain G protein–coupled receptors, such as odorant and taste receptors, by facilitating their delivery through the ER. REEP1 localizes to both the ER and mitochondria, and may act at ER-mitochondria junctions to facilitate organelle communication and homeostasis. Mutations in REEP1 are causative for several neurodegenerative conditions, primarily hereditary spastic paraplegia type 31 (SPG31), which is characterized by progressive weakness and spasticity of the lower limbs due to degeneration of upper motor neurons. Pathogenic variants disrupt ER morphology, compromise axonal maintenance, and can negatively affect energy metabolism by altering the ER-mitochondria interface. REEP1 is not currently a direct therapeutic target, but it is central to the pathophysiology of these inherited neurodegenerative diseases.

Other names

Receptor expression-enhancing protein 1C2orf23SPG31FLJ13110Yip2aSpastic paraplegia 31 proteinDSMA6HMN5BHMND12HMNR6

Not applicable (REEP1 is not a target of drugs; it acts as an accessory/trafficking and membrane-shaping protein rather than as a direct mediator of pharmacological action)