文献类型：期刊文献

英文题名：4-Coumaroyl and Caffeoyl Shikimic Acids Inhibit 4-Coumaric Acid: Coenzyme A Ligases and Modulate Metabolic Flux for 3-Hydroxylation in Monolignol Biosynthesis of Populus trichocarpa

作者：Lin, Chien-Yuan[1,2] Wang, Jack P.[1,2] Li, Quanzi[1,3] Chen, Hsi-Chuan[2] Liu, Jie[2] Loziuk, Philip[4] Song, Jina[5] Williams, Cranos[5] Muddiman, David C.[4] Sederoff, Ronald R.[2] Chiang, Vincent L.[1,2]

第一作者：Lin, Chien-Yuan

通信作者：Sederoff, RR[1]

机构：[1]Northeast Forestry Univ, State Key Lab Tree Genet & Breeding, Harbin 150040, Peoples R China;[2]N Carolina State Univ, Dept Forestry & Environm Resources, Forest Biotechnol Grp, Raleigh, NC 27695 USA;[3]Chinese Acad Forestry, State Key Lab Tree Genet & Breeding, Beijing 100091, Peoples R China;[4]N Carolina State Univ, Dept Chem, WM Keck FT ICR Mass Spectrometry Lab, Raleigh, NC 27695 USA;[5]N Carolina State Univ, Dept Elect & Comp Engn, Raleigh, NC 27695 USA

年份：2015

卷号：8

期号：1

起止页码：176-187

外文期刊名：MOLECULAR PLANT

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000350812900016)】；

基金：The National Science Foundation (USA), Plant Genome Research Program grant DBI-0922391 (to V.L.C.), the NC State University Jordan Family Endowment, and the NC State University Forest Biotechnology Industrial Research Consortium supported this work.

语种：英文

外文关键词：monolignol biosynthesis; Populus trichocarpa; metabolic flux; reaction and inhibition kinetics; LC-MS/MS; 4-coumaroyl and caffeoyl shikimic acids

摘要：Downregulation of 4-coumaric acid: coenzyme A ligase (4CL) can reduce lignin content in a number of plant species. In lignin precursor (monolignol) biosynthesis during stem wood formation in Populus trichocarpa, two enzymes, Ptr4CL3 and Ptr4CL5, catalyze the coenzyme A (CoA) ligation of 4-coumaric acid to 4-coumaroyl-CoA and caffeic acid to caffeoyl-CoA. CoA ligation of 4-coumaric acid is essential for the 3-hydroxylation of 4-coumaroyl shikimic acid. This hydroxylation results from sequential reactions of 4-hydroxycinnamoyl-CoA: shikimic acid hydroxycinnamoyl transferases (PtrHCT1 and PtrHCT6) and 4-coumaric acid 3-hydroxylase 3 (PtrC3H3). Alternatively, 3-hydroxylation of 4-coumaric acid to caffeic acid may occur through an enzyme complex of cinnamic acid 4-hydroxylase 1 and 2 (PtrC4H1 and PtrC4H2) and PtrC3H3. We found that 4-coumaroyl and caffeoyl shikimic acids are inhibitors of Ptr4CL3 and Ptr4CL5. 4-Coumaroyl shikimic acid strongly inhibits the formation of 4-coumaroyl-CoA and caffeoyl-CoA. Caffeoyl shikimic acid inhibits only the formation of 4-coumaroyl-CoA. 4-Coumaroyl and caffeoyl shikimic acids both act as competitive and uncompetitive inhibitors. Metabolic flux in wild-type and PtrC3H3 downregulated P. trichocarpa transgenics has been estimated by absolute protein and metabolite quantification based on liquid chromatography-tandem mass spectrometry, mass action kinetics, and inhibition equations. Inhibition by 4-coumaroyl and caffeoyl shikimic acids may play significant regulatory roles when these inhibitors accumulate.