title: Enhancement of carotenoids biosynthesis in Chlamydomonas reinhardtii by nuclear transformation using a phytoene synthase gene isolated from Chlorella zofingiensis.
abstract: The isolation and characterization of the phytoene synthase gene from the green microalga Chlorella zofingiensis (CzPSY), involved in the first step of the carotenoids biosynthetic pathway, have been performed. CzPSY gene encodes a polypeptide of 420 amino acids. A single copy of CzPSY has been found in C. zofingiensis by Southern blot analysis. Heterologous genetic complementation in Escherichia coli showed the ability of the predicted protein to catalyze the condensation of two molecules of geranylgeranyl pyrophosphate (GGPP) to form phytoene. Phylogenetic analysis has shown that the deduced protein forms a cluster with the rest of the phytoene synthases (PSY) of the chlorophycean microalgae studied, being very closely related to PSY of plants. This new isolated gene has been adequately inserted in a vector and expressed in Chlamydomonas reinhardtii. The overexpression of CzPSY in C. reinhardtii, by nuclear transformation, has led to an increase in the corresponding CzPSY transcript level as well as in the content of the carotenoids violaxanthin and lutein which were 2.0- and 2.2-fold higher than in untransformed cells. This is an example of manipulation of the carotenogenic pathway in eukaryotic microalgae, which can open up the possibility of enhancing the productivity of commercial carotenoids by molecular engineering.
authors.affiliation: Instituto de Bioquímica Vegetal y Fotosíntesis, Centro de Investigaciones Científicas Isla de la Cartuja, University of Sevilla and Consejo Superior de Investigaciones Científicas, Avda. Américo Vespucio no 49, 41092 Sevilla, Spain.
authors.forename: Baldo F
authors.initials: BF
authors.lastname: Cordero
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Couso
authors.forename: Rosa
authors.initials: R
authors.lastname: León
authors.forename: Herminia
authors.initials: H
authors.lastname: Rodríguez
authors.forename: M Angeles
authors.initials: MA
authors.lastname: Vargas
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000235:genetics* / Q000302:isolation & purification* / Q000378:metabolism; D001709:Biotechnology / Q000379:methods*; D002338:Carotenoids / Q000096:biosynthesis*; D016825:Chlamydomonas reinhardtii / Q000235:genetics / Q000378:metabolism*; D002708:Chlorella / Q000145:classification / Q000201:enzymology* / Q000235:genetics; D005818:Genetic Engineering / Q000379:methods; D051232:Geranylgeranyl-Diphosphate Geranylgeranyltransferase; D008969:Molecular Sequence Data; D010802:Phylogeny; D011106:Polyisoprenyl Phosphates / Q000378:metabolism; D017422:Sequence Analysis, DNA; D014170:Transformation, Genetic
chemical_list: D011106:Polyisoprenyl Phosphates; D002338:Carotenoids; C100185:(all-E) phytoene; D019883:Alkyl and Aryl Transferases; D051232:Geranylgeranyl-Diphosphate Geranylgeranyltransferase; C002963:geranylgeranyl pyrophosphate