Condensing enzyme that elongates saturated and monounsaturated very long chain fatty acids (VLCFAs). Elongates C24:0 and C26:0 acyl-CoAs. Seems to represent a photoreceptor-specific component of the fatty acid elongation system residing on the endoplasmic reticulum. May be implicated in docosahexaenoic acid (DHA) biosynthesis, which requires dietary consumption of the essential alpha-linolenic acid and a subsequent series of three elongation steps.
Expressed in the retina and at much lower level in the brain. Ubiquitous, highest expression in thymus, followed by testis, small intestine, ovary, and prostate. Little or no espression in heart, lung, liver, or leukocates.
Defects in ELOVL4 are the cause of Stargardt disease type 3 (STGD3) [MIM:600110]. STGD is one of the most frequent causes of macular degeneration in childhood. It is characterized by macular dystrophy with juvenile-onset, rapidly progressive course, alterations of the peripheral retina, and subretinal deposition of lipofuscin-like material. STGD3 inheritance is autosomal dominant.
Belongs to the ELO family.
The di-lysine motif may confer endoplasmic reticulum localization.