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: apocarotenoid biosynthesis
|Superclasses:||Degradation/Utilization/Assimilation → Secondary Metabolites Degradation → Terpenoids Degradation|
Note: This is a chimeric pathway, comprising reactions from multiple organisms, and typically will not occur in its entirety in a single organism. The taxa listed here are likely to catalyze only subsets of the reactions depicted in this pathway.
Carotenoid cleavage dioxygenases (CCD) catalyze the oxidative cleavage of C-C double-bonds in carotenoids forming apocarotenoids [Auldridge06, Vallabhaneni10]. Apocarotenoids is a diverse class of compounds that play important physiological roles. For example, vitamin A (retinol and retinal) is required for vision in animals, abscisic acid is required for seed development in plants, and many small volatile aroma compounds such as beta-ionone give the characteristic of fruits and flowers.
Some CCDs recognize specific carotenoid substrates, whereas others act upon a broad range of substrates. Some cleave specific double bonds while others can cleave double bonds at different positions. So far the best characterized plant CCDs include CCD1, CCD2, CCD4, CCD7, CCD8, ZCD and LCD.
CCD1 and CCD4 have been isolated from a number of plant species [Schwartz01, Huang09a, Simkin04, Ilg09, Rubio08]. They generally show promiscuity in choice of substrates. For example, the rice CCD1, like the Arabidopsis CCD1, cleaves both linear and cyclic carotenoids at the 9,10 and 9',10' positions. In addition, the rice CCD1 also cleaves 5',6' and 7',8' double bonds in combination with cleavage at the 9,10 double bond [Ilg09]. The Arabidopsis CCD7 catalyzes a specific asymmetric 9,10-cleavage of beta-carotene to produce beta-ionone (C13) and 10'-apo-beta-carotenal (C27) [Schwartz04]. 10'-apo-beta-carotenal is further cleaved by CCD8 [Schwartz04]. ZCD from Crocus sativus is a zeaxanthin-specific CCD that cleaves 7,8(7',8') double bonds [Bouvier03]. LCD from Bixa orellana is a lycopene-specific CCD that recognizes 5,6(5',6') double bonds [Bouvier03a].
Besides CCDs, Nine-cis-epoxy-carotenoid dioxygenases (NCEDs) is another enzyme class that catalyzes the oxidative cleavage of carotenoids. They specifically cleave the 11,12(11',12') double bond of 9-cis-violaxanthin or 9-cis-neoxanthin which leads to the synthesis of abscisic acid in plants [Iuchi01].
Bouvier03: Bouvier F, Suire C, Mutterer J, Camara B (2003). "Oxidative remodeling of chromoplast carotenoids: identification of the carotenoid dioxygenase CsCCD and CsZCD genes involved in Crocus secondary metabolite biogenesis." Plant Cell 15(1);47-62. PMID: 12509521
Huang09a: Huang FC, Horvath G, Molnar P, Turcsi E, Deli J, Schrader J, Sandmann G, Schmidt H, Schwab W (2009). "Substrate promiscuity of RdCCD1, a carotenoid cleavage oxygenase from Rosa damascena." Phytochemistry 70(4);457-64. PMID: 19264332
Iuchi01: Iuchi S, Kobayashi M, Taji T, Naramoto M, Seki M, Kato T, Tabata S, Kakubari Y, Yamaguchi-Shinozaki K, Shinozaki K (2001). "Regulation of drought tolerance by gene manipulation of 9-cis-epoxycarotenoid dioxygenase, a key enzyme in abscisic acid biosynthesis in Arabidopsis." Plant J 27(4);325-33. PMID: 11532178
Rubio08: Rubio A, Rambla JL, Santaella M, Gomez MD, Orzaez D, Granell A, Gomez-Gomez L (2008). "Cytosolic and plastoglobule-targeted carotenoid dioxygenases from Crocus sativus are both involved in beta-ionone release." J Biol Chem 283(36);24816-25. PMID: 18611853
Schwartz04: Schwartz SH, Qin X, Loewen MC (2004). "The biochemical characterization of two carotenoid cleavage enzymes from Arabidopsis indicates that a carotenoid-derived compound inhibits lateral branching." J Biol Chem 279(45);46940-5. PMID: 15342640
Simkin04: Simkin AJ, Schwartz SH, Auldridge M, Taylor MG, Klee HJ (2004). "The tomato carotenoid cleavage dioxygenase 1 genes contribute to the formation of the flavor volatiles beta-ionone, pseudoionone, and geranylacetone." Plant J 40(6);882-92. PMID: 15584954
Alder12: Alder A, Jamil M, Marzorati M, Bruno M, Vermathen M, Bigler P, Ghisla S, Bouwmeester H, Beyer P, Al-Babili S (2012). "The path from β-carotene to carlactone, a strigolactone-like plant hormone." Science 335(6074);1348-51. PMID: 22422982
Frusciante14: Frusciante S, Diretto G, Bruno M, Ferrante P, Pietrella M, Prado-Cabrero A, Rubio-Moraga A, Beyer P, Gomez-Gomez L, Al-Babili S, Giuliano G (2014). "Novel carotenoid cleavage dioxygenase catalyzes the first dedicated step in saffron crocin biosynthesis." Proc Natl Acad Sci U S A 111(33);12246-51. PMID: 25097262
Kiefer01: Kiefer C, Hessel S, Lampert JM, Vogt K, Lederer MO, Breithaupt DE, von Lintig J (2001). "Identification and characterization of a mammalian enzyme catalyzing the asymmetric oxidative cleavage of provitamin A." J Biol Chem 276(17);14110-6. PMID: 11278918
Sorefan03: Sorefan K, Booker J, Haurogne K, Goussot M, Bainbridge K, Foo E, Chatfield S, Ward S, Beveridge C, Rameau C, Leyser O (2003). "MAX4 and RMS1 are orthologous dioxygenase-like genes that regulate shoot branching in Arabidopsis and pea." Genes Dev 17(12);1469-74. PMID: 12815068
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