ECERIFERUM2-LIKE Proteins Have Unique Biochemical and Physiological Functions in Very-Long-Chain Fatty Acid Elongation  . Issue 3 (16th January 2015)

• Record Type: Journal Article
• Authors: Haslam, Tegan M.; Haslam, Richard; Thoraval, Didier; Pascal, Stéphanie; Delude, Camille; Domergue, Frédéric; Fernández, Aurora Mañas; Beaudoin, Frédéric; Napier, Johnathan A.; Kunst, Ljerka; Joubès, Jérôme
• Is Part Of: Plant physiology. Volume 167:Issue 3(2015)
• Page Start: 682
• Page End: 692
• Publication Date: 2015-01-16
• Subjects: Plant physiology -- Periodicals; Botany -- Periodicals; Periodicals; Electronic journals; 571.2
• DOI: 10.1104/pp.114.253195
• Languages: English
• ISSNs: 0032-0889

Abstract

Abstract : An Arabidopsis protein that lacks enzymatic activity in long-chain fatty-acid condensation nonetheless affects chain length specificity of very-long-chain fatty acid elongation, which is important for cuticle and pollen coat function. Abstract: The extension of very-long-chain fatty acids (VLCFA s) for the synthesis of specialized apoplastic lipids requires unique biochemical machinery. Condensing enzymes catalyze the first reaction in fatty acid elongation and determine the chain length of fatty acids accepted and produced by the fatty acid elongation complex. Although necessary for the elongation of all VLCFA s, known condensing enzymes cannot efficiently synthesize VLCFA s longer than 28 carbons, despite the prevalence of C28 to C34 acyl lipids in cuticular wax and the pollen coat. The eceriferum2 ( cer2 ) mutant of Arabidopsis ( Arabidopsis thaliana ) was previously shown to have a specific deficiency in cuticular waxes longer than 28 carbons, and heterologous expression of CER2 in yeast ( Saccharomyces cerevisiae ) demonstrated that it can modify the acyl chain length produced by a condensing enzyme from 28 to 30 carbon atoms. Here, we report the physiological functions and biochemical specificities of the CER2 homologs CER2-LIKE1 and CER2-LIKE2 by mutant analysis and heterologous expression in yeast. We demonstrate that all three CER2-LIKEs function with the same small subset of condensing enzymes, and that they have different effects on the substrate specificity of the same condensing enzyme. Finally, we show that the changes in acyl chain length caused by each CER2-LIKE protein are of substantial importance for cuticle formation and pollen coat function.