This view shows enzymes only for those organisms listed below, in the list of taxa known to possess the pathway. If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.
Synonyms: xanthophyll cycle
|Superclasses:||Activation/Inactivation/Interconversion → Interconversions|
|Biosynthesis → Secondary Metabolites Biosynthesis → Terpenoids Biosynthesis → Carotenoids Biosynthesis|
|Biosynthesis → Secondary Metabolites Biosynthesis → Terpenoids Biosynthesis → Tetraterpenoids Biosynthesis|
Some taxa known to possess this pathway include : Arabidopsis thaliana col , Capsicum annuum , Chlamydomonas reinhardtii [Niyogi97], Lactuca sativa romaine , Nicotiana plumbaginifolia , Solanum lycopersicum , Solanum tuberosum , Xanthophyllomyces dendrorhous
Carotenoids with cyclic ends are integral constituents of plants, algae and cyanobacteria photosynthetic reaction centers [Goodwin80, Young93]. Animals, including humans, cannot synthesize carotenoids, although they are an essential source of retinoids and vitamin A. These isoprenoids pigments are lipid-soluble and are involved in a variety of functions including: protection against photooxidative stress through energy-dissipation of excess light absorbed by the antenna pigments; light-harvest for photosynthesis; the prominent lutein, as well as zeaxanthin, are involved in the reduction of cataract and macular degeneration; others are exploited as coloring agents in flowers and fruits to attract pollinators (and in industry as food colorant) and agents of seed dispersal; finally they are precursors for the plant growth hormone abscisic acid and vitamin A (for a succinct review of the applications of carotenoids, see [Cunningham98]).
Carotenoids are C40 isoprenoids which consist of eight isoprene units and can be divided in two major groups: carotene and xanthophylls. Carotenes are linear or cyclized hydrocarbons such as lycopene, α-carotene and β-carotene. Xanthophylls are oxygenated derivatives (epoxy, keto or hydroxyl groups) of carotenes; for example: lutein, zeaxanthin. The carotenoid composition varies from species to species; the concentration and composition of xanthophylls are affected by light intensity and the accumulation of specific carotenoids in fruit and flower chromoplasts is a highly, developmentally regulated process [Fraser94, Giuliano93]. Important carotenoids variations are observed during fruit ripening (for review, see [Ronen99]). Higher plant chloroplasts typically accumulate lutein, β-carotene, violaxanthin and neoxanthin in the thylakoid membrane-bound photosystems [Peter91, Ryberg93]. β-Carotene is generally found in the reaction center where it plays a critical photoprotective role by quenching triplet chlorophyll and singlet oxygen, and can undergo rapid degradation during photooxidation [Young93a]. Adjacent to the reaction centers, in the core complex proteins, β-carotene and lutein can be found [Peter91, Bassi93]. Finally, the surrounding antenna complexes contain xanthophylls (lutein, violaxanthin and neoxanthin) [Peter91, Bassi93]. In the chromoplasts of ripening fruits and flower petals, and in the chloroplasts of senescing leaves, the carotenoids are found in membranes or in oil bodies or other structures within the stroma.
About This Pathway
The epoxidation reaction of the xanthophyll cycle consists of the conversion of zeaxanthin to antheraxanthin and violaxanthin and is carried out by the zeaxanthin epoxidase. The isolated cDNA for this enzyme from tobacco was used to identify potential epoxidases of other plants. It has been demonstrated that in Arabidopsis plants defective in osmotic stress-regulated gene induction the LOS6/ABA1 gene encodes a zeaxanthin epoxidase that functions in ABA biosynthesis [Xiong02].
Superpathways: superpathway of carotenoid biosynthesis
Fraser94: Fraser PD, Truesdale MR, Bird CR, Schuch W, Bramley PM (1994). "Carotenoid Biosynthesis during Tomato Fruit Development (Evidence for Tissue-Specific Gene Expression)." Plant Physiol 105(1);405-413. PMID: 12232210
Niyogi97: Niyogi KK, Bjorkman O, Grossman AR (1997). "Chlamydomonas Xanthophyll Cycle Mutants Identified by Video Imaging of Chlorophyll Fluorescence Quenching." Plant Cell 9(8);1369-1380. PMID: 12237386
Ronen99: Ronen G, Cohen M, Zamir D, Hirschberg J (1999). "Regulation of carotenoid biosynthesis during tomato fruit development: expression of the gene for lycopene epsilon-cyclase is down-regulated during ripening and is elevated in the mutant Delta." Plant J 17(4);341-51. PMID: 10205893
Ryberg93: Ryberg, H., Ryberg, M., Sundqvist, C. (1993). "Plastid ultrastructure and development." In "Pigment-protein complexes in plastids: synthesis and assembly', C.Sundqvist and M. Ryberg, eds, London: Academic Press, pp. 25-62.
Young93a: Young AJ (1993). "Factors that affect the carotenoid composition of higer plants and algae." In 'Carotenoids in photosynthesis' A.J. Young and G. Britton, eds, London: Chapman and Hall, pp. 161-205.
Baroli03: Baroli I, Do AD, Yamane T, Niyogi KK (2003). "Zeaxanthin accumulation in the absence of a functional xanthophyll cycle protects Chlamydomonas reinhardtii from photooxidative stress." Plant Cell 15(4);992-1008. PMID: 12671093
Bouvier96: Bouvier F, d'Harlingue A, Hugueney P, Marin E, Marion-Poll A, Camara B (1996). "Xanthophyll biosynthesis. Cloning, expression, functional reconstitution, and regulation of beta-cyclohexenyl carotenoid epoxidase from pepper (Capsicum annuum)." J Biol Chem 271(46);28861-7. PMID: 8910532
Chae11: Chae, Lee (2011). "The functional annotation of protein sequences was performed by the in-house Ensemble Enzyme Prediction Pipeline (E2P2, version 1.0). E2P2 systematically integrates results from three molecular function annotation algorithms using an ensemble classification scheme. For a given genome, all protein sequences are submitted as individual queries against the base-level annotation methods. The individual methods rely on homology transfer to annotate protein sequences, using single sequence (BLAST, E-value cutoff <= 1e-30, subset of SwissProt 15.3) and multiple sequence (Priam, November 2010; CatFam, version 2.0, 1% FDR profile library) models of enzymatic functions. The base-level predictions are then integrated into a final set of annotations using an average weighted integration algorithm, where the weight of each prediction from each individual method was determined via a 0.632 bootstrap process over 1000 rounds of testing. The training and testing data for E2P2 and the BLAST reference database were drawn from protein sequences with experimental support of existence, compiled from SwissProt release 15.3."
DestefanoBeltra06: Destefano-Beltran L, Knauber D, Huckle L, Suttle JC (2006). "Effects of postharvest storage and dormancy status on ABA content, metabolism, and expression of genes involved in ABA biosynthesis and metabolism in potato tuber tissues." Plant Mol Biol 61(4-5);687-97. PMID: 16897484
Frechilla99: Frechilla S, Zhu J, Talbott LD, Zeiger E (1999). "Stomata from npq1, a zeaxanthin-less Arabidopsis mutant, lack a specific response to blue light." Plant Cell Physiol 40(9);949-54. PMID: 10588066
Han10a: Han H, Gao S, Li B, Dong XC, Feng HL, Meng QW (2010). "Overexpression of violaxanthin de-epoxidase gene alleviates photoinhibition of PSII and PSI in tomato during high light and chilling stress." J Plant Physiol 167(3);176-83. PMID: 19767125
Hieber02: Hieber AD, Bugos RC, Verhoeven AS, Yamamoto HY (2002). "Overexpression of violaxanthin de-epoxidase: properties of C-terminal deletions on activity and pH-dependent lipid binding." Planta 214(3);476-83. PMID: 11855651
Marin96: Marin E, Nussaume L, Quesada A, Gonneau M, Sotta B, Hugueney P, Frey A, Marion-Poll A (1996). "Molecular identification of zeaxanthin epoxidase of Nicotiana plumbaginifolia, a gene involved in abscisic acid biosynthesis and corresponding to the ABA locus of Arabidopsis thaliana." EMBO J 15(10);2331-42. PMID: 8665840
Merchant07: Merchant SS, Prochnik SE, Vallon O, Harris EH, Karpowicz SJ, Witman GB, Terry A, Salamov A, Fritz-Laylin LK, Marechal-Drouard L, Marshall WF, Qu LH, Nelson DR, Sanderfoot AA, Spalding MH, Kapitonov VV, Ren Q, Ferris P, Lindquist E, Shapiro H, Lucas SM, Grimwood J, Schmutz J, Cardol P, Cerutti H, Chanfreau G, Chen CL, Cognat V, Croft MT, Dent R, Dutcher S, Fernandez E, Fukuzawa H, Gonzalez-Ballester D, Gonzalez-Halphen D, Hallmann A, Hanikenne M, Hippler M, Inwood W, Jabbari K, Kalanon M, Kuras R, Lefebvre PA, Lemaire SD, Lobanov AV, Lohr M, Manuell A, Meier I, Mets L, Mittag M, Mittelmeier T, Moroney JV, Moseley J, Napoli C, Nedelcu AM, Niyogi K, Novoselov SV, Paulsen IT, Pazour G, Purton S, Ral JP, Riano-Pachon DM, Riekhof W, Rymarquis L, Schroda M, Stern D, Umen J, Willows R, Wilson N, Zimmer SL, Allmer J, Balk J, Bisova K, Chen CJ, Elias M, Gendler K, Hauser C, Lamb MR, Ledford H, Long JC, Minagawa J, Page MD, Pan J, Pootakham W, Roje S, Rose A, Stahlberg E, Terauchi AM, Yang P, Ball S, Bowler C, Dieckmann CL, Gladyshev VN, Green P, Jorgensen R, Mayfield S, Mueller-Roeber B, Rajamani S, Sayre RT, Brokstein P, Dubchak I, Goodstein D, Hornick L, Huang YW, Jhaveri J, Luo Y, Martinez D, Ngau WC, Otillar B, Poliakov A, Porter A, Szajkowski L, Werner G, Zhou K, Grigoriev IV, Rokhsar DS, Grossman AR (2007). "The Chlamydomonas genome reveals the evolution of key animal and plant functions." Science 318(5848);245-50. PMID: 17932292
Niyogi98: Niyogi KK, Grossman AR, Bjorkman O (1998). "Arabidopsis mutants define a central role for the xanthophyll cycle in the regulation of photosynthetic energy conversion." Plant Cell 1998;10(7);1121-34. PMID: 9668132
Wang08d: Wang N, Fang W, Han H, Sui N, Li B, Meng QW (2008). "Overexpression of zeaxanthin epoxidase gene enhances the sensitivity of tomato PSII photoinhibition to high light and chilling stress." Physiol Plant 132(3);384-96. PMID: 18275469
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