Human DES1 expressed in sur2-deficient yeast produces delta-4-unsaturated sphingolipids; the assay measures hydrolyzed cellular products. Minor hydroxylated products accompany predominant desaturation, preventing an absolute exclusion of hydroxylase side activity.

Mouse-liver serine palmitoyltransferase, 3-dehydrosphinganine reductase and sphinganine N-acyltransferase activities were localized to the cytosolic face of the ER. These are upstream sphingolipid-pathway findings, not an independently verified human DEGS1 topology measurement.

SERINC proteins facilitate serine incorporation into membrane lipids; rat SERINC1 colocalizes with lipid biosynthetic enzymes in the ER. This provides pathway and compartment context without establishing which DEGS1-specific experiment underlies the imported annotation.

Myristoylation targets part of recombinant DES1 to mitochondria in COS-7 cells; native desaturase activity is detected in both ER and mitochondria of rat hepatocytes. Myristoylatable and unmyristoylatable constructs differ in the reported apoptotic response.

Human DES1 expression increases retinol isomerization in 293T-cell homogenates and partially rescues the retinoid/visual phenotype of Rpe65-deficient mice. Purified-enzyme and Müller-cell knockdown experiments use chicken DES1.

OSBP couples ER–Golgi tethering and sterol transfer to PI(4)P countertransport and Sac1-dependent hydrolysis. This is lipid-contact-site context; the specific DEGS1 sphingomyelin result remains unresolved.

Human DEGS1 deficiency increases dihydroceramide relative to ceramide and causes hypomyelinating leukodystrophy. Zebrafish knockdown links disturbed lipid ratios to reduced myelinating oligodendrocytes and locomotor defects.

Human A280V DEGS1 has reduced cellular activity and stability. WT and mutant constructs predominantly overlap ER markers, and patient fibroblasts and DEGS1-null HAP1 cells accumulate dihydrosphingolipids.

The human binary interaction map contains DEGS1 pairs with ARLN and SEMA4G in validated two-hybrid records. These physical positives do not establish a physiological signaling or enzymatic role for DEGS1 in those partnerships.

Ceramide supplies the substrate for glucosylceramide and galactosylceramide synthesis, while UGCG and UGT8 perform sugar transfer. DEGS1 contributes precursor chemistry rather than the glycosyltransferase reaction.

Human MLD/DEGS1 is a detergent-extractable membrane protein with conserved histidine motifs and ER localization. Its overexpression selectively reduces EGF-receptor biosynthesis relative to the tested PDGF-receptor comparison.

The DEGS1-catalyzed conversion of dihydroceramide to ceramide is placed on the cytosolic face of the ER; detailed stoichiometry and cofactor requirements incorporate evidence from rat microsomes.

DEGS1 is included in a specific-granule membrane protein set transported to the plasma membrane during exocytosis, providing a context-specific localization model.

UniProt records the core catalytic activity (EC 1.14.19.17; N-acylsphinganine plus O2 plus Fe(II)-cytochrome b5 giving N-acylsphing-4-enine), ER and mitochondrion membrane localization, DEGS-subfamily membership, and causation of HLD18.

DEGS1 is enriched at ER–mitochondrial contact domains in human fibroblasts and human brain fractions. Its deficiency alters lipid composition, contact geometry and downstream MAM functions without establishing additional DEGS1 catalytic reactions.

Conditional deletion of Des1 in mouse Müller cells preserves cone sensitivity and rapid dark adaptation under the tested conditions, limiting an obligatory role in cone pigment regeneration.

Zebrafish degs1 knockout does not eliminate the tested larval photopic visual responses, limiting claims of universal visual-cycle essentiality.