Functions in lipid transport from the endoplasmic reticulum and is involved in a wide array of cellular functions probably through regulation of the biogenesis of lipid microdomains at the plasma membrane. Involved in the regulation of different receptors it plays a role in BDNF signaling and EGF signaling. Also regulates ion channels like the potassium channel and could modulate neurotransmitter release.

Plays a role in calcium signaling through modulation together with ANK2 of the ITP3R-dependent calcium efflux at the endoplasmic reticulum. Plays a role in several other cell functions including proliferation, survival and death. Originally identified for its ability to bind various psychoactive drugs it is involved in learning processes, memory and mood alteration (PubMed:16472803, PubMed:9341151).

Necessary for proper mitochondrial axonal transport in motor neurons, in particular the retrograde movement of mitochondria. Plays a role in protecting cells against oxidative stress-induced cell death via its interaction with RNF112 (By similarity)

Homotrimer (PubMed:27042935). Forms a ternary complex with ANK2 and ITPR3. The complex is disrupted by agonists.

Interacts with KCNA4. Interacts with KCNA2; cocaine consumption leads to increased interaction. Interacts with RNF112 in an oxidative stress-regulated manner (By similarity).

Interacts with the mu-type opioid receptor OPRM1 (By similarity)

Widely expressed with higher expression in liver, colon, prostate, placenta, small intestine, heart and pancreas. Expressed in the retina by retinal pigment epithelial cells. Expressed in alpha-motor neurons (PubMed:23314020)

The C-terminal helices form a flat, hydrophobic surface that is probably tightly associated with the cytosolic surface of the endoplasmic reticulum membrane

• Amyotrophic lateral sclerosis 16, juvenile (ALS16)

  A neurodegenerative disorder affecting upper motor neurons in the brain and lower motor neurons in the brain stem and spinal cord, resulting in fatal paralysis. Sensory abnormalities are absent. The pathologic hallmarks of the disease include pallor of the corticospinal tract due to loss of motor neurons, presence of ubiquitin-positive inclusions within surviving motor neurons, and deposition of pathologic aggregates.

  The etiology of amyotrophic lateral sclerosis is likely to be multifactorial, involving both genetic and environmental factors. The disease is inherited in 5-10% of the cases.

• Neuronopathy, distal hereditary motor, autosomal recessive 2 (HMNR2)

  A form of distal hereditary motor neuronopathy, a heterogeneous group of neuromuscular disorders caused by selective degeneration of motor neurons in the anterior horn of the spinal cord, without sensory deficit in the posterior horn. The overall clinical picture consists of a classical distal muscular atrophy syndrome in the legs without clinical sensory loss. The disease starts with weakness and wasting of distal muscles of the anterior tibial and peroneal compartments of the legs.

  Later on, weakness and atrophy may expand to the proximal muscles of the lower limbs and/or to the distal upper limbs. HMNR2 is characterized by onset of distal muscle weakness and wasting affecting the lower and upper limbs in the first decade.