SELENOI
Function
Ethanolaminephosphotransferase that catalyzes the transfer of phosphoethanolamine (PE) from CDP-ethanolamine to lipid acceptors, the final step in the synthesis of PE via the 'Kennedy' pathway (PubMed:17132865, PubMed:28052917, PubMed:29500230). PE is the second most abundant phospholipid of membranes in mammals and is involved in various membrane-related cellular processes (PubMed:17132865). The enzyme is critical for the synthesis of several PE species and also catalyzes the synthesis of plasmanyl-PE, a lipid required for proper myelination and neurodevelopment, from 1-alkyl-2-acylglycerol (PubMed:29500230).
Involvement in disease
Spastic paraplegia 81, autosomal recessive
SPG81
A form of spastic paraplegia, a neurodegenerative disorder characterized by a slow, gradual, progressive weakness and spasticity of the lower limbs. Rate of progression and the severity of symptoms are quite variable. Initial symptoms may include difficulty with balance, weakness and stiffness in the legs, muscle spasms, and dragging the toes when walking. In some forms of the disorder, bladder symptoms (such as incontinence) may appear, or the weakness and stiffness may spread to other parts of the body. SPG81 is a complicated form characterized by white matter abnormalities, hypomyelination with progressive white matter loss, delayed motor development, progressive spasticity, and impaired intellectual development and speech delay. Additional features may include bifid uvula, microcephaly, seizures, and variable ocular anomalies.
None
The disease is caused by variants affecting the gene represented in this entry.
Pathway
Phospholipid metabolism; phosphatidylethanolamine biosynthesis; phosphatidylethanolamine from ethanolamine: step 3/3.
Sequence Similarities
Belongs to the CDP-alcohol phosphatidyltransferase class-I family.
Tissue Specificity
Widely expressed. Abundant in brain, placenta, liver and pancreas, followed by heart, skeletal muscle, lung and kidney. In brain it is strongly expressed in cerebellum, followed by the occipital pole and the frontal lobe.
Cellular localization
- Endoplasmic reticulum membrane
- Multi-pass membrane protein
Alternative names
EPT1, KIAA1724, SELI, SELENOI, Ethanolaminephosphotransferase 1, hEPT1, Selenoprotein I, SelI