Lanosterol synthase in dicotyledonous plants

• Published in: Plant and cell physiology 2006-05, Vol.47 (5), p.565-571
• Main Authors: Suzuki, M.(Institute of Physical and Chemical Research, Yokohama (Japan). Plant Science Center), Xiang, T, Ohyama, K, Seki, H, Saito, K, Muranaka, T, Hayashi, H, Katsube, Y, Kushiro, T, Shibuya, M, Ebizuka, Y
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Arabidopsis; Arabidopsis - genetics; Arabidopsis - physiology; Arabidopsis Proteins - analysis; Arabidopsis Proteins - genetics; Arabidopsis Proteins - physiology; ARABIDOPSIS THALIANA; BIOSINTESIS; BIOSYNTHESE; BIOSYNTHESIS; CAS; CELL MEMBRANES; Cycloartenol; cycloartenol synthase; DNA, Plant - analysis; DNA, Plant - genetics; ESTEROIDES; FITOSTEROLES; gas chromatography–mass spectrometry; GC–MS; GENE; Gene Expression Regulation, Plant - physiology; GENES; Genes, Plant - genetics; hairy root; Intramolecular Transferases - analysis; Intramolecular Transferases - genetics; Intramolecular Transferases - physiology; Lanosterol; Lanosterol - biosynthesis; Magnoliopsida - genetics; Magnoliopsida - physiology; MEMBRANAS CELULARES; MEMBRANE CELLULAIRE; Molecular Sequence Data; NMR; nuclear magnetic resonance; Nuclear Proteins - analysis; Nuclear Proteins - genetics; Nuclear Proteins - physiology; OSC; Oxidosqualene cyclase; Panax; Panax - genetics; Panax - physiology; Phylogeny; PHYTOSTEROL; PHYTOSTEROLS; Phytosterols - analysis; Phytosterols - metabolism; reverse transcription–PCR; RT–PCR; Saccharomyces cerevisiae Proteins - analysis; Saccharomyces cerevisiae Proteins - genetics; Saccharomyces cerevisiae Proteins - physiology; Squalene - analogs & derivatives; Squalene - metabolism; STEROIDE; STEROIDS; wild type
• ISSN: 0032-0781; 1471-9053
• DOI: 10.1093/pcp/pcj031

Sterols are important as structural components of plasma membranes and precursors of steroidal hormones in both animals and plants. Plant sterols show a wide structural variety and significant structural differences from those of animals. To elucidate the origin of structural diversity in plant sterols, their biosynthesis has been extensively studied [Benveniste (2004) Annu. Rev. Plant. Biol. 55: 429, Schaller (2004) Plant Physiol. Biochem. 42: 465]. The differences in the biosynthesis of sterols between plants and animals begin at the step of cyclization of 2,3-oxidosqualene, which is cyclized to lanosterol in animals and to cycloartenol in plants. However, here we show that plants also have the ability to synthesize lanosterol directly from 2,3-oxidosqualene, which may lead to a new pathway to plant sterols. The Arabidopsis gene At3g45130, designated LAS1, encodes a functional lanosterol synthase in plants. A phylogenetic tree showed that LAS1 belongs to the previously uncharacterized branch of oxidosqualene cyclases, which differs from the cycloartenol synthase branch. Panax PNZ on the same branch was also shown to be a lanosterol synthase in a yeast heterologous expression system. The higher diversity of plant sterols may require two biosynthetic routes in steroidal backbone formation.