Caffeic acid O-methyltransferase

Marita, J. M. Ralph, J. Lapierre, C. Jouanin, L. Boerjan, W. NMR characterization of lignins from transgenic poplars with suppressed caffeic acid O-methyltransferase activity. J. Chem. Soc., Perkin Trans. 2001, 1, 2939-2945. 

Morreel, K. Ralph, J. Lu, F Goeminne, G. Busson, R. Herdewijn, P. Goeman, J. L. Van der Eycken, J. Boeijan, W. Messens, E. Phenolic profiling of caffeic acid O-methyltransferase-dehcient poplar reveals novel benzodioxane oligolignols. Plant Physiol. 2004, 136, 4023 1036. 

The chemical and physical evidence for the presence of lignin in the material deposited at wound margins is supported by biochemical studies on the enzymes involved in phenylpropanoid metabolism. Thus, the extractable activities of phenylalanine ammonia-lyase, tyrosine ammonia-lyase, cinnamate-4-hydroxylase, caffeic acid O-methyltransferase,... 

Bout, S., and Vermerris, W., 2003, A candidate gene-approach to clone the sorghum Brown midrib gene encoding caffeic acid O-methyltransferase, Mol. Genet. Genomics 269 205-214. 

MENG, H., CAMPBELL, W.H., Substrate profiles and expression of caffeoyl coenzyme A and caffeic acid O-methyltransferases in secondary xylem of aspen during seasonal development, Plant Mol. Biol., 1998, 38, 513-520. 

Chen, L., Auh, C.K., Dowling, R, Bell, ]., Lehmann, D. and Wang, Z.Y (2004) Transgenic down-regulation of caffeic acid O-methyltransferase (COMT) led to improved digestibility in tall fescue Festuca arundinacea). Fund. Plant Biol, 31,235-45. 

Do, G.T., Pollet, B., Thevenin, ]., Sibout, R., Denoue, D., Barriere, Y., Lapierre, C. and Jouanin, L. (2007) Both caffeoyl coenzyme A 3-O-methyltransferase 1 and caffeic acid O-methyltransferase 1 are involved in redundant functions for lignin, flavonoids and sinapoyl malate biosynthesis in Arabidopsis. Planta, 226,1117-29. 

Jouanin, L., Goujon, T., De Nadai, V., Martin, M.T., Mila, I., Vallet, C., Pollet, B., Yoshinaga, A., Chabbert, B., Petit-Gonil, M. and Lapierre, C. (2000) Lignification in transgenic poplars with extremely reduced caffeic acid O-methyltransferase activity. Plant Physiol., 123,1363-73. 

Li, H.M., Rotter, D., Hartman, T.G., Pak, F.E., Havkin-Frenkel, D. and Belanger, F.C. (2006) Evolution of novel O-methyltransferases from the Vanilla planifolia caffeic acid O-methyltransferase. Plant Mol. Biol, 61, 537-52. 

L Jouanin, T Goujon, V de Nadai, M-T Martin, I Mila, C VaUef B Pollef A Yoshinaga, B Chabbert, M Petit-ConU, C Lapierre. Lignification in transgenic poplars with exhemely reduced caffeic acid O-methyltransferase activity. Plant physiol 123 1363-1373, 2000. 

Ni, W., Paiva, N. L., and Dixon, R. A. (1994) Reduced ligniu in transgenic plants containing a caffeic acid O-methyltransferase antisense gene. Transgenic Res 3(2), 120-126. 

Figure 4 Current view of the phenylpropanoid pathway to the monolignols 19-23. 4CL, 4-hydroxycinnamate coenzyme Aligases pC3H , p-coumarate 3-hydroxylase C4H, cinnamate 4-hydroxylase CAD, cinnamyl alcohol dehydrogenases CCOMT, hydroxycinnamoyl CoA O-methyltransferases CCR, cinnamoyl-CoA oxidoreductases COMT, caffeic acid O-methyltransferases F5H , ferulate 5-hydroxylase HCT, hydroxycinnamoyl-CoA shikimate hydroxycinnamoyltransferase HOT, hydroxycinnamoyl-CoA quinate hydroxycinnamoyltransferase PAL, phenylalanine ammonia lyase TAL, tyrosine ammonia lyase.

Fiber Fescue grass [13] (animal feed) Suppression of an intrinsic enzyme (cafFeic acid O-methyltransferase) involved with the biosynthesis of lignin (decrease in lignin and increase of lignin digestibility)... 

Figure 3.1 Primary flux of carbon through phenylpropanoid pathway in Arabidopsis. PAL, phenylalanine ammonia-lyase 4CL, 4-(hydroxy)cinnamoyl CoA ligase C4H, cinnamate 4-hydroxylase HCT, hydroxycinnamoyl-CoA shikimate/quinate hydroxycinnamoyltransferase C3 H, /7-coumaroylshikimate 3 -hydroxylase CCoAOMT, caffeoyl CoA O-methyltransferase F5H, ferulate 5-hydroxylase COMT, caffeic acid/5-hydroxyferulic acid o-methyltransferase CCR, cinnamoyl CoA reductase CAD, cinnamyl alcohol dehydrogenase. Not depicted is the HCT catalyzed synthesis of/r-coumaroyl quinate.

Figure 1.15 Schematic of the main pathways and key enzymes involved in the biosynthesis of hydro-lysable tannins, salicylic acid, hydroxycinnamates and 5-caffeoylquinic acid. Enzyme abbreviations PAL, phenylalanine ammonia-lyase BA2H, benzoic acid 2-hydroxylase C4H, cinnamate 4-hydroxylase COMT-1, caffeic/5-hydroxyfemlic acid O-methyltransferase 4CL, p-coumarate CoA ligase F5H, ferulate 5-hydroxylase CT, galloyltransferase ACoAC, acelylCoA carboxylase.

Marita, J. M. Ralph, J. Hatheld, R. D. Guo, D. Chen, F. Dixon, R. A. Structural and compositional modihcations in lignin of transgenic alfalfa down-regulated in caffeic acid 3-O-methyltransferase and caffeoyl coenzyme A 3-O-methyltransferase. 

Caffeic acid is metabolized by liver enzymes to give ferulic, vanillic acids and their glycine conjugates, which may be excreted into urine. In addition, dihydroferulic acid is produced by catechol o-methyltransferase in the liver. Because of the specificity of this enzyme, only ortho hydroxy-methoxy metabolites may be formed. These reactions may occur in rats as well in humans [15]. Fig. (2) shows the metabolic reactions of caffeic acid in body tissues. 

Caffeic Acid / 5-Hydroxyferulic Acid 3/5-O-Methyltransferase (COMT) 46... 

EDWARDS, R., DIXON, R.A., Purification and characterization of S-adenosyl-L-methionine caffeic acid 3-O-methyltransferase from suspension cultures of alfalfa (Medicago saliva L.), Arch Biochem Biophys, 1991, 287, 372-379. 

ZUBIETA, C., KOTA, P., FERRER, J.-L., DIXON, R.A., NOEL, J.P., Structural basis for the modulation of lignin monomer methylation by caffeic acid / 5-hydroxyferulic acid 3/5-O-methyltransferase, Plant Cell, 2002, 14, 1265-1277. 

INOUE, K., SEWALT, V.J., MURRAY, G.B., NI, W STURZER, C., DIXON, R.A., Developmental expression and substrate specificities of alfalfa caffeic acid 3-O-methyltransferase and caffeoyl coenzyme A 3-0-methyltransferase in relation to lignification, Plant Physiol., 1998, 117, 761-770. 

MAURY, S., GEOFFROY, P., LEGRAND, M., Tobacco O-methyltransferases involved in phenylpropanoid metabolism. The different caffeoyl-coenzyme A/5-hydroxyferuloyl-coenzyme A 3/5-O-methy (transferase and caffeic acid/5-hydroxyferulic acid 3/5-O-methyltransferase classes have distinct substrate specificities and expression patterns., Plant Physiol., 1999,121,215-223. 

Eckardt, N.A. (2002) Probing the mysteries of lignin biosynthesis The crystal structure of caffeic acid/5-hydroxyferulic acid 3/5-O-methyltransferase provides new insights. Plant Cell, 14,1185-9. 

Guo, D., Chen, R, Inoue, K., Blount, J.W. and Dixon, R.A. (2001) Downregulation of caffeic acid 3-O-methyltransferase and caffeoyl CoA 3-O-methyltransferase in transgenic alfalfa Impacts on lignin structure and implications for the biosynthesis of G and S lignin. Plant Cell, 13, 73-88. 

Kota, R, Guo, D., Zubieta, C., Noel, J. and Dixon, R.A. (2004) O-Methylation of ben-zaldehyde derivatives by lignin specific caffeic acid 3-O-methyltransferase. Phytochemistry, 65, 837-46. 

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