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First published online April 8, 2005; 10.1104/pp.104.054528 Plant Physiology 138:402-408 (2005) © 2005 American Society of Plant Biologists Identification of a Long-Chain Polyunsaturated Fatty Acid Acyl-Coenzyme A Synthetase from the Diatom Thalassiosira pseudonana1CNAP, Department of Biology, University of York, York YO10 5YW, United Kingdom
The draft genome of the diatom Thalassiosira pseudonana was searched for DNA sequences showing homology with long-chain acyl-coenzyme A synthetases (LACSs), since the corresponding enzyme may play a key role in the accumulation of health-beneficial polyunsaturated fatty acids (PUFAs) in triacylglycerol. Among the candidate genes identified, an open reading frame named TplacsA was found to be full length and constitutively expressed during cell cultivation. The predicted amino acid sequence of the corresponding protein, TpLACSA, exhibited typical features of acyl-coenzyme A (acyl-CoA) synthetases involved in the activation of long-chain fatty acids. Feeding experiments carried out in yeast (Saccharomyces cerevisiae) transformed with the algal gene showed that TpLACSA was able to activate a number of PUFAs, including eicosapentaenoic acid and docosahexaenoic acid (DHA). Determination of acyl-CoA synthetase activities by direct measurement of acyl-CoAs produced in the presence of different PUFA substrates showed that TpLACSA was most active toward DHA. Heterologous expression also revealed that TplacsA transformants were able to incorporate more DHA in triacylglycerols than the control yeast.
1 This work was supported by the Department for Environment, Food and Rural Affairs (grant no. NF 0507). R.Q. is a visiting scholar from Sichuan University of China, supported by the China Scholarship Council (grant no. CSC22851086). 2 These authors contributed equally to the paper. 3 Present address: UMR 7139 (CNRS-GOEMAR-UPMC), Station Biologique, BP 74, 29682 Roscoff cedex, France. 4 Present address: College of Life Science, Sichuan University, Chengdu, China. Article, publication date, and citation information can be found at www.plantphysiol.org/cgi/doi/10.1104/pp.104.054528. * Corresponding author; e-mail iag1{at}york.ac.uk; fax 441904328762. Received October 11, 2004; returned for revision January 21, 2005; accepted January 24, 2005. This article has been cited by other articles:
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