Doan Thuy T P, Domergue Frédéric, Fournier Ashley E, Vishwanath Sollapura J, Rowland Owen, Moreau Patrick, Wood Craig C, Carlsson Anders S, Hamberg Mats, Hofvander Per
Department of Plant Breeding and Biotechnology, Swedish University of Agricultural Sciences, Alnarp, Sweden.
Biochim Biophys Acta. 2012 Sep;1821(9):1244-55. doi: 10.1016/j.bbalip.2011.10.019. Epub 2011 Nov 30.
Primary long-chain fatty alcohols are present in a variety of phyla. In eukaryotes, the production of fatty alcohols is catalyzed by fatty acyl-CoA reductase (FAR) enzymes that convert fatty acyl-CoAs or acyl-ACPs into fatty alcohols. Here, we report on the biochemical properties of a purified plant FAR, Arabidopsis FAR6 (AtFAR6). In vitro assays show that the enzyme preferentially uses 16 carbon acyl-chains as substrates and produces predominantly fatty alcohols. Free fatty acids and fatty aldehyde intermediates can be released from the enzyme, in particular with suboptimal chain lengths and concentrations of the substrates. Both acyl-CoA and acyl-ACP could serve as substrates. Transient expression experiments in Nicotiana tabacum showed that AtFAR6 is a chloroplast localized FAR. In addition, expression of full length AtFAR6 in Nicotiana benthamiana leaves resulted in the production of C16:0-alcohol within this organelle. Finally, a GUS reporter gene fusion with the AtFAR6 promoter showed that the AtFAR6 gene is expressed in various tissues of the plant with a distinct pattern compared to that of other Arabidopsis FARs, suggesting specialized functions in planta.
初级长链脂肪醇存在于多种生物门类中。在真核生物中，脂肪醇的产生由脂肪酰辅酶A还原酶（FAR）催化，该酶将脂肪酰辅酶A或酰基-ACP转化为脂肪醇。在此，我们报告了一种纯化的植物FAR——拟南芥FAR6（AtFAR6）的生化特性。体外实验表明，该酶优先使用16碳的酰基链作为底物，并主要产生脂肪醇。游离脂肪酸和脂肪醛中间体可从该酶中释放出来，特别是在底物链长度和浓度不理想的情况下。酰基辅酶A和酰基-ACP均可作为底物。在烟草中的瞬时表达实验表明，AtFAR6是一种定位于叶绿体的FAR。此外，在本氏烟草叶片中全长AtFAR6的表达导致该细胞器内产生了C16:0-醇。最后，一个与AtFAR6启动子融合的GUS报告基因显示，AtFAR6基因在植物的各种组织中表达，与其他拟南芥FARs相比具有独特的模式，表明其在植物中有特定功能。
