FADS2

FADS2
Identifiers
AliasesFADS2, D6D, DES6, FADSD6, LLCDL2, SLL0262, TU13, fatty acid desaturase 2
External IDsOMIM: 606149; MGI: 1930079; HomoloGene: 3149; GeneCards: FADS2; OMA:FADS2 - orthologs
Orthologs
SpeciesHumanMouse
Entrez

9415

56473

Ensembl

ENSG00000134824

ENSMUSG00000024665

UniProt

O95864

Q9Z0R9

RefSeq (mRNA)

NM_001281501
NM_001281502
NM_004265

NM_019699

RefSeq (protein)

NP_001268430
NP_001268431
NP_004256

NP_062673

Location (UCSC)Chr 11: 61.79 – 61.87 MbChr 19: 10.04 – 10.08 Mb
PubMed search[3][4]
Wikidata
View/Edit HumanView/Edit Mouse

Fatty acid desaturase 2 (FADS2) is an enzyme that in humans is encoded by the FADS2 gene.[5][6]

Function

Desaturation

The protein encoded by the FADS2 gene is a member of the fatty acid desaturase (FADS) gene family. It has three catalytic activities acting on fatty-acid-CoA:[7]

  • As a Delta 6 desaturase, it desaturates omega-3 and omega-6 polyunsaturated fatty acids at the delta-6 position, catalyzing the first and rate-limiting step in the formation of tetracosapentaenoic acid and tetracosahexaenoic acid.
  • As a Delta 8 desaturase, desaturation at the delta-8 position.
  • As a Delta 4 desaturase, desaturation at the delta-4 position.[8]

Desaturase enzymes (such as those encoded by FADS2) cause desaturation of fatty acids through the introduction of double bonds between defined carbons of the fatty acyl chain. FADS family members are considered fusion products composed of an N-terminal cytochrome b5-like domain and a C-terminal multiple membrane-spanning desaturase portion, both of which are characterized by conserved histidine motifs. This gene is clustered with family members FADS1 and FADS2 at 11q12-q13.1; this cluster is thought to have arisen evolutionarily from gene duplication based on its similar exon/intron organization.[5]

Re-esterification

Separately from its function in synthesizing EPA and DHA, D6D plays a contributory role in fatty acid re-esterification,[9] required for the return of unoxidized free fatty acids into white adipose tissue as triglycerides.

Agonists and inhibiting factors

D6D is upregulated by estrogen,[10] low levels of omega-3s, and moderate food restriction (up to 300%) .

D6D activity slows with age, suggested by reductions in GLA and subsequent metabolites.[11][12] Other inhibiting factors include alcohol, radiation, and diabetes .

The conversion rate of ALA into DHA is vulnerable to suppression by dietary fatty acids. ALA intake greater than 1% and total polyunsaturated intake above 3% were found to drastically limit synthesis of EPA and DHA.[13]

Clinical significance

D6D deficiency can result in deficiencies in DHA, and in GLA and its metabolites dihomo-gamma-linolenic acid (DGLA) and prostaglandin E1 (PGE1).

Sperm quality

It is implicated in abnormal sperm production due to deficiency in DHA[14] and atopic dermatitis due to deficiencies in GLA and PGE1.[15]

Intelligence in brease-fed children

It was reported the FADS2 interacts with breastfeeding such that breast-fed children with the rs174575 "C" version of the gene appear about 7 intelligence quotient (IQ) points higher than those with the less common rs174575 "G" version (less than this when adjusted for maternal IQ).[16][17]

An attempt to replicate this study in 5934 8-year-old children failed: No relationship of the common rs174575 C allele to negative effects of formula feeding was apparent, and contra to the original report, the rare rs174575 GG homozygote children performed worse when formula fed than other children on formula milk.[18] A study of over 700 families recently found no evidence for either main or moderating effects of the original SNP (rs174575), nor of two additional FADS2 polymorphisms (rs1535 and rs174583), nor any effect of maternal FADS2 status on offspring IQ.[19]

References

  1. ^ a b c GRCh38: Ensembl release 89: ENSG00000134824Ensembl, May 2017
  2. ^ a b c GRCm38: Ensembl release 89: ENSMUSG00000024665Ensembl, May 2017
  3. ^ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. ^ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. ^ a b "Entrez Gene: FADS1 fatty acid desaturase 1".
  6. ^ Marquardt A, Stöhr H, White K, Weber BH (June 2000). "cDNA cloning, genomic structure, and chromosomal localization of three members of the human fatty acid desaturase family". Genomics. 66 (2): 175–83. doi:10.1006/geno.2000.6196. PMID 10860662.
  7. ^ Brenna JT (June 2009). "An alternate pathway to long-chain polyunsaturates: the FADS2 gene product Δ8-desaturates 20:2n-6 and 20:3n-3". Journal of Lipid Research. 50 (6): 1195–202. doi:10.1194/jlr.M800630-JLR200. PMC 2681401. PMID 19202133.
  8. ^ Park HG, Park WJ, Kothapalli KS, Brenna JT (September 2015). "The fatty acid desaturase 2 (FADS2) gene product catalyzes Δ4 desaturation to yield n-3 docosahexaenoic acid and n-6 docosapentaenoic acid in human cells". FASEB Journal. 29 (9): 3911–9. doi:10.1096/fj.15-271783. PMC 4550368. PMID 26065859.
  9. ^ Wang C, Hucik B, Sarr O, Brown LH, Wells KR, Brunt KR, Nakamura MT, Harasim-Symbor E, Chabowski A, Mutch DM (2023). "Delta-6 desaturase (Fads2) deficiency alters triacylglycerol/fatty acid cycling in murine white adipose tissue". Journal of Lipid Research. 64 (6) 100376. doi:10.1016/j.jlr.2023.100376. PMC 10323924. PMID 37085033.
  10. ^ Giltay EJ, Gooren LJ, Toorians AW, Katan MB, Zock PL (2004). "Docosahexaenoic acid concentrations are higher in women than in men because of estrogenic effects". The American Journal of Clinical Nutrition. 80 (5): 1167–1174. doi:10.1093/ajcn/80.5.1167. ISSN 0002-9165. PMID 15531662.
  11. ^ Horrobin DF (1981). "Loss of delta-6-desaturase activity as a key factor in aging". Medical Hypotheses. 7 (9): 1211–1220. doi:10.1016/0306-9877(81)90064-5. ISSN 0306-9877. PMID 6270521.
  12. ^ Biagi PL, Bordoni A, Hrelia S, Celadon M, Horrobin DF (1991). "Gamma-linolenic acid dietary supplementation can reverse the aging influence on rat liver microsome delta 6-desaturase activity". Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism. 1083 (2): 187–192. doi:10.1016/0005-2760(91)90041-F. ISSN 0005-2760. PMID 1674661.
  13. ^ Gibson RA, Neumann MA, Lien EL, Boyd KA, Tu WC (2012). "Docosahexaenoic acid synthesis from alpha-linolenic acid is inhibited by diets high in polyunsaturated fatty acids". Prostaglandins, Leukotrienes, and Essential Fatty Acids. 88 (1): 139–146. doi:10.1016/j.plefa.2012.04.003. ISSN 0952-3278. PMID 22515943.
  14. ^ Roqueta-Rivera M, Stroud CK, Haschek WM, Akare SJ, Segre M, Brush RS, Agbaga MP, Anderson RE, Hess RA, Nakamura MT (February 2010). "Docosahexaenoic acid supplementation fully restores fertility and spermatogenesis in male delta-6 desaturase-null mice". Journal of Lipid Research. 51 (2): 360–367. doi:10.1194/jlr.M001180. PMC 2803238. PMID 19690334.
  15. ^ Chung BY, Park SY, Jung MJ, Kim HO, Park CW (2018). "Effect of Evening Primrose Oil on Korean Patients With Mild Atopic Dermatitis: A Randomized, Double-Blinded, Placebo-Controlled Clinical Study". Annals of Dermatology. 30 (4): 409–416. doi:10.5021/ad.2018.30.4.409. PMC 6029968. PMID 30065580.
  16. ^ Gene governs IQ boost from breastfeeding.
  17. ^ Caspi A, Williams B, Kim-Cohen J, Craig IW, Milne BJ, Poulton R, Schalkwyk LC, Taylor A, Werts H, Moffitt TE (November 2007). "Moderation of breastfeeding effects on the IQ by genetic variation in fatty acid metabolism". Proc. Natl. Acad. Sci. U.S.A. 104 (47): 18860–5. Bibcode:2007PNAS..10418860C. doi:10.1073/pnas.0704292104. PMC 2141867. PMID 17984066.
  18. ^ Steer CD, Davey Smith G, Emmett PM, Hibbeln JR, Golding J (2010). "FADS2 polymorphisms modify the effect of breastfeeding on child IQ". PLOS ONE. 5 (7) e11570. Bibcode:2010PLoSO...511570S. doi:10.1371/journal.pone.0011570. PMC 2903485. PMID 20644632.
  19. ^ Martin NW, Benyamin B, Hansell NK, Montgomery GW, Martin NG, Wright MJ, Bates TC (January 2011). "Cognitive function in adolescence: testing for interactions between breast-feeding and FADS2 polymorphisms". J Am Acad Child Adolesc Psychiatry. 50 (1): 55–62.e4. doi:10.1016/j.jaac.2010.10.010. PMID 21156270.

Further reading