Simplified sterol biosynthetic pathway in Arabidopsis and yeast.

Sterol biosynthesis starts preferentially with cycloartenol in plants and lanosterol in animals and fungi. Main biosynthetic steps and sterols accumulating in the mutant lines considered in this study are indicated in colors: red, ste1; green, dwarf5; blue, dim1. The major observed enzymatic activity of the YFP-fused enzymes generated is also indicated by the same color code. LAS1 = lanosterol synthase, CAS1 = cycloartenol synthase. The dashed arrows are indicating more than one enzymatic step. Accurate sterol nomenclature can be found at IUPAC http://www.iupac.org/