Publications

• Identification of neoxanthin synthase as a carotenoid cyclase paralog.

  Bouvier F., D'harlingue A., Backhaus R.A., Kumagai M.H., Camara B.

  Neoxanthin, a precursor of the plant hormone abscisic acid, is an allenic xanthophyll recognized as the last product of carotenoid synthesis in green plants. A cDNA for neoxanthin synthase (NSY) was isolated from tomato using a molecular approach based on the mechanistic and structural similaritie ... >> More

  Neoxanthin, a precursor of the plant hormone abscisic acid, is an allenic xanthophyll recognized as the last product of carotenoid synthesis in green plants. A cDNA for neoxanthin synthase (NSY) was isolated from tomato using a molecular approach based on the mechanistic and structural similarities of NSY to two other closely related carotenogenic enzymes, lycopene cyclase (LCY) and capsanthin-capsorubin synthase (CCS). The identified tomato NSY cDNA (T.NSY) encodes a 56-kDa plastid-targeted protein that when expressed in Escherichia coli, catalyzes the conversion of violaxanthin to neoxanthin. In tobacco leaves that transiently express T.NSY, an increase in neoxanthin content with a concomitant decrease in violaxanthin is observed. NSY is structurally similar to LCY and CCS. However, in Cyanobacteria, the generally accepted progenitor of plastids, both CCS and NSY are absent while LCY is present. LCY catalyzes a simplified version of the reaction catalyzed by NSY and CCS suggesting that these two enzymes were remodeled from LCY during higher plant evolution to create new forms of oxidized carotenoids. << Less

  Eur. J. Biochem. 267:6346-6352(2000) [PubMed] [EuropePMC]

• Identification of a novel gene coding for neoxanthin synthase from Solanum tuberosum.

  Al-Babili S., Hugueney P., Schledz M., Welsch R., Frohnmeyer H., Laule O., Beyer P.

  The polymerase chain reaction analysis of potato plants, transformed with capsanthin capsorubin synthase ccs, revealed the presence of a highly related gene. The cloned cDNA showed at the protein level 89.6% identity to CCS. This suggested that the novel enzyme catalyzes a mechanistically similar ... >> More

  The polymerase chain reaction analysis of potato plants, transformed with capsanthin capsorubin synthase ccs, revealed the presence of a highly related gene. The cloned cDNA showed at the protein level 89.6% identity to CCS. This suggested that the novel enzyme catalyzes a mechanistically similar reaction. Such a reaction is represented by neoxanthin synthase (NXS), forming the xanthophyll neoxanthin, a direct substrate for abscisic acid formation. The function of the novel enzyme could be proven by transient expression in plant protoplasts and high performance liquid chromatography analysis. The cloned NXS was imported in vitro into plastids, the compartment of carotenoid biosynthesis. << Less

  FEBS Lett. 485:168-172(2000) [PubMed] [EuropePMC]