Dihydroceramide desaturase 1 (DES1) (DES1)

Dihydroceramide desaturase 1 (DES1), also known as DEGS1, is a membrane-bound enzyme localized to the endoplasmic reticulum and mitochondria-associated membranes that catalyzes the final step of the de novo ceramide synthesis pathway [1, 2, 19]. It is responsible for the conversion of dihydroceramide to ceramide by introducing a trans double bond at the C4-C5 position of the sphingoid base [1, 11]. This enzyme plays a critical role in regulating the balance between dihydroceramides and ceramides, which are essential for membrane structure and act as signaling molecules in processes such as apoptosis, autophagy, and cell proliferation [2, 9, 13]. Dysregulation of DES1 activity is associated with several diseases; its overactivity contributes to insulin resistance, hepatic steatosis, and cancer, while loss-of-function mutations lead to hypomyelinating leukodystrophy-18 (HLD18), a severe neurological disorder [8, 12, 16]. Pharmacological inhibitors like fenretinide and GT-11 are being investigated for their potential to treat metabolic and oncological conditions by modulating sphingolipid levels [2, 6, 10]. However, the risk of neurotoxicity and impaired myelin maintenance remains a significant therapeutic challenge when targeting this enzyme [13, 16].

Other names

DEGS1Degenerative spermatocyte homolog 1Sphingolipid delta(4)-desaturase 1Retinol isomeraseMLDFADS7Cell migration-inducing gene 15 protein

Inhibition of the enzyme leads to the accumulation of dihydroceramides and a reduction in ceramide levels, which modulates signaling pathways involved in cell death, autophagy, and insulin sensitivity.