title: Identification and functional characterization of the CYP51 gene from the yeast Xanthophyllomyces dendrorhous that is involved in ergosterol biosynthesis.
abstract: BACKGROUND
  Xanthophyllomyces dendrorhous is a basidiomycetous yeast that synthesizes astaxanthin, a carotenoid with great biotechnological impact. The ergosterol and carotenoid synthetic pathways derive from the mevalonate pathway and involve cytochrome P450 enzymes. Among these enzymes, the CYP51 family, which is involved in ergosterol biosynthesis, is one of the most remarkable that has C14-demethylase activity.
  
  
  RESULTS
  In this study, the CYP51 gene from X. dendrorhous was isolated and its function was analyzed. The gene is composed of ten exons and encodes a predicted 550 amino acid polypeptide that exhibits conserved cytochrome P450 structural characteristics and shares significant identity with the sterol C14-demethylase from other fungi. The functionality of this gene was confirmed by heterologous complementation in S. cerevisiae. Furthermore, a CYP51 gene mutation in X. dendrorhous reduced sterol production by approximately 40% and enhanced total carotenoid production by approximately 90% compared to the wild-type strain after 48 and 120 h of culture, respectively. Additionally, the CYP51 gene mutation in X. dendrorhous increased HMGR (hydroxy-methylglutaryl-CoA reductase, involved in the mevalonate pathway) and crtR (cytochrome P450 reductase) transcript levels, which could be associated with reduced ergosterol production.
  
  
  CONCLUSIONS
  These results suggest that the CYP51 gene identified in X. dendrorhous encodes a functional sterol C14-demethylase that is involved in ergosterol biosynthesis.
authors.affiliation: Departamento de Ciencias Ecológicas y Centro de Biotecnología, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Casilla 653, Ñuñoa, Santiago, Chile. kritsye@gmail.com.
authors.forename: Kritsye
authors.initials: K
authors.lastname: Leiva
authors.affiliation: Departamento de Ciencias Ecológicas y Centro de Biotecnología, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Casilla 653, Ñuñoa, Santiago, Chile. nwerner@ug.uchile.cl.
authors.forename: Nicole
authors.initials: N
authors.lastname: Werner
authors.affiliation: Departamento de Ciencias Ecológicas y Centro de Biotecnología, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Casilla 653, Ñuñoa, Santiago, Chile. dony@uchile.cl.
authors.forename: Dionisia
authors.initials: D
authors.lastname: Sepúlveda
authors.affiliation: Departamento de Ciencias Ecológicas y Centro de Biotecnología, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Casilla 653, Ñuñoa, Santiago, Chile. barahona.salvador@gmail.com.
authors.forename: Salvador
authors.initials: S
authors.lastname: Barahona
authors.affiliation: Departamento de Ciencias Ecológicas y Centro de Biotecnología, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Casilla 653, Ñuñoa, Santiago, Chile. mbaeza@u.uchile.cl.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Baeza
authors.affiliation: Departamento de Ciencias Ecológicas y Centro de Biotecnología, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Casilla 653, Ñuñoa, Santiago, Chile. vcifuentes@uchile.cl.
authors.forename: Víctor
authors.initials: V
authors.lastname: Cifuentes
authors.affiliation: Departamento de Ciencias Ecológicas y Centro de Biotecnología, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Casilla 653, Ñuñoa, Santiago, Chile. jalcainog@u.uchile.cl.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Alcaíno
mesh_terms: D001487:Basidiomycota / Q000235:genetics* / Q000378:metabolism*; D002338:Carotenoids / Q000096:biosynthesis; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D004875:Ergosterol / Q000096:biosynthesis*; D005091:Exons; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D058886:Sterol 14-Demethylase / Q000235:genetics* / Q000378:metabolism*
chemical_list: D004271:DNA, Fungal; D002338:Carotenoids; D058886:Sterol 14-Demethylase; D004875:Ergosterol