High impact information on CYP98A3

• Recombinant CYP98A3 expressed in yeast did not metabolize free p-coumaric acid or its glucose or CoA esters, p-coumaraldehyde, or p-coumaryl alcohol, but very actively converted the 5-O-shikimate and 5-O-d-quinate esters of trans-p-coumaric acid into the corresponding caffeic acid conjugates [1].
• Taken together, these data show that CYP98A3 catalyzes the synthesis of chlorogenic acid and very likely also the 3-hydroxylation of lignin monomers [1].
• In this study, we show that the gene encoding CYP98A3, which was the best possible P450 candidate for a 3-hydroxylase in the Arabidopsis genome, is highly expressed in inflorescence stems and wounded tissues [1].
• We isolated a T-DNA insertion mutant in CYP98A3 and show that this mutation leads to a more drastic inhibition of plant development and inhibition of cell growth [2].
• The ref8 Arabidopsis (Arabidopsis thaliana) mutant, with a point mutation in the CYP98A3 gene, was previously described to show developmental defects, changes in lignin composition, and lack of soluble sinapoyl esters [2].

Biological context of CYP98A3

• In transgenic Arabidopsis, the promoters of CYP98A3 and C4H showed wound inducibility and a comparable developmental regulation throughout the life cycle, except in seeds, where the CYP98A3 promoter construct was inactive while remaining active in silique walls [3].
• Finally, the mutant displays developmental defects and is subject to fungal attack, suggesting that phenylpropanoid pathway products downstream of REF8 may be required for normal plant development and disease resistance [4].

Associations of CYP98A3 with chemical compounds

• This observation suggests that scopoletin and scopolin biosynthesis in A. thaliana are strongly dependent on the 3'-hydroxylation of p-coumarate units catalyzed by CYP98A3 [5].
• In order to gain insight into the biosynthetic pathway of coumarins in A. thaliana, we analyzed coumarins in the mutants obtained from the SALK Institute collection that carried a T-DNA insertion within the gene encoding the cytochrome P450, CYP98A3, which catalyzes 3'-hydroxylation of p-coumarate units in the phenylpropanoid pathway [5].
• We have found that Arabidopsis CYP98A3, also a P450, could hydroxylate p-coumaric acid to caffeic acid in vivo when expressed in yeast (Saccharomyces cerevisiae) cells, albeit very slowly [3].
• The ref8 mutant accumulates p-coumarate esters in place of the sinapoylmalate found in wild-type plants [4].

References