Formation of glucosylceramide and sterol glucoside by a UDP-glucose-dependent glucosylceramide synthase from cotton expressed in Pichia pastoris.
In plants, glucosylceramide (GlcCer) biosynthesis is poorly understood. Previous investigations suggested that sterol glucoside (SG) acts as the actual glucose donor for the plant GlcCer synthase (GCS). We addressed this question by generating a Pichia pastoris double mutant devoid of GlcCer and SG. This mutant was used for heterologous expression of the plant GCS. The activity of the GCS resulted in the accumulation of GlcCer and, surprisingly, a small proportion of SG. The synthesis of GlcCer in the transformed double mutant shows that the GCS is SG-independent, while the detection of SG suggests that in addition to the sterol glucosyltransferase, also the GCS may contribute in planta to SG biosynthesis.
Institut für Allgemeine Botanik, University of Hamburg, Ohnhorststr. 18, 22609 Hamburg, Germany.
Inga
I
Hillig
Martina
M
Leipelt
Claudia
C
Ott
Ulrich
U
Zähringer
Dirk
D
Warnecke
Ernst
E
Heinz
D002176:Candida albicans / Q000235:genetics / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D005960:Glucosides / Q000096:biosynthesis* / Q000737:chemistry; D005963:Glucosylceramides / Q000096:biosynthesis* / Q000737:chemistry; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism*; D003368:Gossypium / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D006868:Hydrolysis; D009154:Mutation / Q000235:genetics; D010843:Pichia / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013261:Sterols / Q000096:biosynthesis* / Q000737:chemistry; D014532:Uridine Diphosphate Glucose / Q000378:metabolism*
D005656:Fungal Proteins; D005960:Glucosides; D005963:Glucosylceramides; D011994:Recombinant Proteins; D013261:Sterols; D005964:Glucosyltransferases; C023256:UDPglucose-sterol glucosyltransferase; C023246:ceramide glucosyltransferase; D014532:Uridine Diphosphate Glucose