Biosynthesis of Polyunsaturated Fatty Acids in Octopus vulgaris: Molecular Cloning and Functional Characterisation of a Stearoyl-CoA Desaturase and an Elongation of Very Long-Chain Fatty Acid 4 Protein.
Polyunsaturated fatty acids (PUFAs) have been acknowledged as essential nutrients for cephalopods but the specific PUFAs that satisfy the physiological requirements are unknown. To expand our previous investigations on characterisation of desaturases and elongases involved in the biosynthesis of PUFAs and hence determine the dietary PUFA requirements in cephalopods, this study aimed to investigate the roles that a stearoyl-CoA desaturase (Scd) and an elongation of very long-chain fatty acid 4 (Elovl4) protein play in the biosynthesis of essential fatty acids (FAs). Our results confirmed theOctopus vulgarisScd is a ∆9 desaturase with relatively high affinity towards saturated FAs with ≥ C18chain lengths. Scd was unable to desaturate 20:1n-15 (∆520:1) suggesting that its role in the biosynthesis of non-methylene interrupted FAs (NMI FAs) is limited to the introduction of the first unsaturation at ∆9 position. Interestingly, the previously characterised ∆5 fatty acyl desaturase was indeed able to convert 20:1n-9 (∆1120:1) to∆5,1120:2, an NMI FA previously detected in octopus nephridium. Additionally, Elovl4 was able to mediate the production of 24:5n-3 and thus can contribute to docosahexaenoic acid (DHA) biosynthesis through the Sprecher pathway. Moreover, the octopus Elovl4 was confirmed to play a key role in the biosynthesis of very long-chain (>C24) PUFAs.
Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling FK9 4LA, Scotland, UK. oscar.monroig@stir.ac.uk.
Óscar
Ó
Monroig
School of Applied Sciences, Edinburgh Napier University, Edinburgh EH11 4BN, Scotland, UK. R.DeLlanos@napier.ac.uk.|Instituto de Agroquímica y Tecnología de Alimentos (IATA-CSIC), Paterna, Valencia 46980, Spain. R.DeLlanos@napier.ac.uk.
Rosa
R
de Llanos
Instituto de Acuicultura Torre de la Sal (IATS-CSIC), Ribera de Cabanes, Castellón 12595, Spain. inma@iats.csic.es.
Inmaculada
I
Varó
Instituto de Acuicultura Torre de la Sal (IATS-CSIC), Ribera de Cabanes, Castellón 12595, Spain. hontoria@iats.csic.es.
Francisco
F
Hontoria
Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling FK9 4LA, Scotland, UK. d.r.tocher@stir.ac.uk.
Douglas R
DR
Tocher
Instituto de Agroquímica y Tecnología de Alimentos (IATA-CSIC), Paterna, Valencia 46980, Spain. spuig@iata.csic.es.
Sergi
S
Puig
Instituto de Acuicultura Torre de la Sal (IATS-CSIC), Ribera de Cabanes, Castellón 12595, Spain. jcnavarro@iats.csic.es.
Juan C
JC
Navarro
D000123:Acetyltransferases / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D044943:Fatty Acid Desaturases / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000096:biosynthesis*; D029941:Fish Proteins / Q000378:metabolism; D049831:Octopodiformes / Q000378:metabolism*; D016415:Sequence Alignment; D013230:Stearoyl-CoA Desaturase / Q000378:metabolism*
D005231:Fatty Acids, Unsaturated; D029941:Fish Proteins; D044943:Fatty Acid Desaturases; D013230:Stearoyl-CoA Desaturase; D000123:Acetyltransferases
Octopus vulgaris; biosynthesis; elongation of very long-chain fatty acids 4 protein; non-methylene-interrupted fatty acids; polyunsaturated fatty acids; stearoyl-CoA desaturase