SCD5 Gene - Stearoyl-CoA Desaturase 5: Function, Expression, and Disease Associations

SCD5 encodes stearoyl-CoA desaturase 5, an enzyme that catalyzes the introduction of a cis-double bond at the delta-9 position of saturated fatty acyl-CoA substrates, primarily converting stearoyl-CoA (18:0) to oleoyl-CoA (18:1) and palmitoyl-CoA (16:0) to palmitoleoyl-CoA (16:1). This desaturation is a key step in fatty acid metabolism, influencing membrane fluidity, lipid signaling, and energy homeostasis. SCD5 is predominantly expressed in the brain and pancreas, with lower levels in other tissues. Its expression is regulated by dietary factors and hormonal signals, and dysregulation has been implicated in metabolic disorders and cancer progression.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• Fatty acid biosynthesis (Reactome: R-HSA-8978868)

• Stearoyl-CoA desaturase pathway (KEGG: hsa01040)

• PPAR signaling pathway (KEGG: hsa03320)

SCD5 is a 359-amino acid integral membrane protein localized to the endoplasmic reticulum. It contains a conserved fatty acid desaturase domain and four transmembrane helices. The enzyme uses molecular oxygen and NADH to introduce a cis-double bond at the delta-9 position of saturated fatty acids. SCD5 shares high sequence similarity with SCD1 but exhibits distinct tissue-specific expression, particularly in brain and pancreas. Its activity is critical for maintaining the balance of saturated and monounsaturated fatty acids in cellular membranes and lipid droplets.