title: Astaxanthin accumulation in Haematococcus requires a cytochrome P450 hydroxylase and an active synthesis of fatty acids.
abstract: Astaxanthin accumulation by green microalgae is a natural phenomenon known as red snows and blood rains. The fact that astaxanthin synthesis requires oxygen, NADPH and Fe(2+) led Cunningham and Gantt [Annu. Rev. Plant Physiol. Plant Mol. Biol. 49 (1998) 557-583] to propose that a cytochrome P450-dependent enzyme might be involved in the transformation of beta-carotene to astaxanthin. In Haematococcus only esterified astaxanthin molecules accumulate, but it is not determined whether a fatty acid synthesis should occur simultaneously to allow pigment accumulation. The aim of this contribution was to answer these two questions using specific inhibitors of beta-carotene (norflurazon) and fatty acid (cerulenin) synthesis, and of cytochrome P450 enzyme activity (ellipticine).
authors.affiliation: Plant Cytophysiology and Phycology, UPRES CNRS 8013, University of Lille 1, Villenueve d'Ascq, France. benoit.schoefs@ujf-grenoble.fr
authors.forename: B
authors.initials: B
authors.lastname: Schoefs
authors.forename: N
authors.initials: N
authors.lastname: Rmiki
authors.forename: J
authors.initials: J
authors.lastname: Rachadi
authors.forename: Y
authors.initials: Y
authors.lastname: Lemoine
mesh_terms: D002569:Cerulenin / Q000494:pharmacology; D000460:Chlorophyta / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D004611:Ellipticines / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005227:Fatty Acids / Q000096:biosynthesis*; D008027:Light; D006899:Mixed Function Oxygenases / Q000378:metabolism*; D011724:Pyridazines / Q000494:pharmacology; D024341:Xanthophylls; D065146:Zeaxanthins; D019207:beta Carotene / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000378:metabolism
chemical_list: D004611:Ellipticines; D004791:Enzyme Inhibitors; D005227:Fatty Acids; D011724:Pyridazines; D024341:Xanthophylls; D065146:Zeaxanthins; D019207:beta Carotene; C034192:ellipticine; D002569:Cerulenin; C005948:astaxanthine; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; C008677:norflurazone