Open AccessFormation of two methylenedioxy bridges by a Sesamum CYP81Q protein yielding a furofuran lignan, (+)-sesamin
Author(s) -
Eiichiro Ono,
Michikazu Nakai,
Yûkô Fukui,
Namino Tomimori,
Masako Fukuchi-Mizutani,
Masayuki Saito,
Honoo Satake,
Takaharu Tanaka,
Masumi Katsuta,
Toshiaki Umezawa,
Yoshikazu Tanaka
Publication year - 2006
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.0603865103
Subject(s) - sesamin , lignan , sesamum , pinoresinol , methylenedioxy , biosynthesis , biochemistry , biology , chemistry , stereochemistry , gene , food science , organic chemistry , alkyl , halogen , horticulture
(+)-Sesamin, a furofuran class lignan, is widespread in vascular plants and represented bySesamum spp. (+)-Sesamin has been of rapidly growing interest because of its beneficial biological effects in mammals, but its biosynthesis and physiological roles in plants remain to be clarified. It is speculated to be synthesized from (+)-pinoresinol by means of (+)-piperitol by formation of two methylenedioxy bridges mediated by two distinctSesamum indicum cytochrome P450 (SiP450) proteins. Here, we report an SiP450, CYP81Q1, that alone catalyzes (+)-sesamin biosynthesis from (+)-pinoresinol by means of (+)-piperitol by forming two methylenedioxy bridges. The CYP81Q1 gene expression profile was temporally consistent with the accumulation pattern of (+)-sesamin during seed development. The CYP81Q1-GFP chimera protein was colocalized with an endoplasmic reticulum (ER)-targeting chimera protein, indicating that (+)-sesamin biosynthesis occurs on the ER cytoplasmic surface. Moreover, we isolated two CYP81Q1 homologs from otherSesamum spp.Sesamum radiatum CYP81Q2 showed dual (+)-piperitol/(+)-sesamin synthetic activity. CYP81Q2, as well as CYP81Q1, therefore, corresponds to a (+)-piperitol/(+)-sesamin synthase in lignan biosynthesis. In contrast,Sesamum alatum CYP81Q3 showed no activity, in accord with (+)-sesamin being deficient inS. alatum . Our findings not only provide insight into lignan biosynthesis but also unravel a unique mode of cytochrome P450 action.