Sphingolipid delta(4)-desaturase DES1 (DEGS1) (DEGS1)

Sphingolipid delta(4)-desaturase DES1 (DEGS1) is a critical enzyme in the de novo sphingolipid biosynthetic pathway, primarily localized to the endoplasmic reticulum (ER) membrane (UniProt O15121). It catalyzes the final step of ceramide synthesis by introducing a trans-4,5 double bond into the sphingoid backbone of dihydroceramide, converting it into ceramide (PubMed: 25283058). This enzymatic activity is vital for maintaining the balance between dihydroceramides and ceramides, which serve as distinct signaling molecules regulating cell fate, including apoptosis, autophagy, and proliferation (PubMed: 37187315). Genetic loss-of-function mutations in the DEGS1 gene are the primary cause of hypomyelinating leukodystrophy-18 (HLD-18), a severe pediatric neurodegenerative disorder characterized by myelin deficiency and CNS atrophy (PubMed: 38260379). Conversely, elevated DES1 activity is implicated in metabolic diseases such as type 2 diabetes and obesity, where ceramide accumulation contributes to insulin resistance (PubMed: 23532353). Pharmacological inhibitors like fenretinide and ABTL0812 are being investigated for their ability to modulate these lipid levels to treat cancer and metabolic disorders by inducing autophagy or restoring insulin sensitivity (MDPI: 10.3390/ijms26052145). However, therapeutic intervention must be carefully managed due to the potential for neurotoxic side effects associated with dihydroceramide accumulation (PubMed: 37187315).

Other names

DES1DEGS1MLDMIG15FADS7Cell migration-inducing gene 15 proteinDegenerative spermatocyte homolog 1Dihydroceramide desaturase 1Membrane lipid desaturaseRetinol isomeraseSphingolipid delta(4)-desaturase 1

Inhibition of the enzymatic conversion of dihydroceramide to ceramide, leading to the accumulation of bioactive dihydroceramides and depletion of ceramides, which modulates signaling pathways such as autophagy, apoptosis, and insulin signaling.