Very-long-chain fatty acid biosynthesis is controlled through the expression and specificity of the condensing enzyme
Article first published online: 6 FEB 2003
The Plant Journal
Volume 12, Issue 1, pages 121–131, July 1997
How to Cite
Millar, A. A. and Kunst, L. (1997), Very-long-chain fatty acid biosynthesis is controlled through the expression and specificity of the condensing enzyme. The Plant Journal, 12: 121–131. doi: 10.1046/j.1365-313X.1997.12010121.x
- Issue published online: 6 FEB 2003
- Article first published online: 6 FEB 2003
- Received 7 November 1996; revised 13 February 1997; accepted 3 March 1997.
- Cited By
The Arabidopsis FATTY ACID ELONGATION1 (FAE1) gene encodes a putative seed-specific condensing enzyme. It is the first of four enzyme activities that comprise the microsomal fatty acid elongase (FAE) involved in the biosynthesis of very-long-chain fatty acids (VLCFAs). FAE1 has been expressed in yeast and in tissues of Arabidopsis and tobacco, where significant quantities of VLCFAs are not found. The introduction of FAE1 alone in these systems is sufficient for the production of VLCFAs, for wherever FAE1 was expressed, VLCFAs accumulated. These results indicate that FAE1 is the rate-limiting enzyme for VLCFA biosynthesis in Arabidopsis seed, because introduction of extra copies of FAE1 resulted in higher levels of the VLCFAs. Furthermore, the condensing enzyme is the activity of the elongase that determines the acyl chain length of the VLCFAs produced. In contrast, it appears that the other three enzyme activities of the elongase are found ubiquitously throughout the plant, are not rate-limiting and play no role in the control of VLCFA synthesis. The ability of yeast containing FAE1 to synthesize VLCFAs suggests that the expression and the acyl chain length specificity of the condensing enzyme, along with the apparent broad specificities of the other three FAE activities, may be a universal eukaryotic mechanism for regulating the amounts and acyl chain length of VLCFAs synthesized.