Regulatory role of microsomal 3-hydroxy-3-methylglutaryl-coenzyme A reductase in a tobacco mutant that overproduces sterols.
In a tobacco mutant callus, containing up to tenfold more sterols than the wild-type genotype, HMG-CoA reductase activity is increased by a factor of approximately three, as is the case in mutant seedlings and plants. The rate of HMG-CoA synthesis from acetyl-CoA by the coupled enzyme system acetoacetyl-CoA thiolase/HMG-CoA synthase, as well as its conversion to acetyl-CoA plus acetoacetate by action of HMG-CoA lyase are not affected. These results confirm the key-regulating role of HMG-CoA reductase in sterol biosynthesis, which seems not to be confined only to the animal kingdom, but can also be extended to plants.
Gondet
L
L
Centre National de la Recherche Scientifique, Institut de Botanique, Strasbourg, France.
Weber
T
T
Maillot-Vernier
P
P
Benveniste
P
P
Bach
T J
TJ
D002462:Cell Membrane / Q000378:metabolism; D005838:Genotype; D006706:Homeostasis; D006903:Hydroxymethylglutaryl CoA Reductases / Q000378:metabolism*; D008861:Microsomes / Q000201:enzymology*; D009154:Mutation; D010947:Plants, Toxic; D013261:Sterols / Q000096:biosynthesis*; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism*
D013261:Sterols; D006903:Hydroxymethylglutaryl CoA Reductases