Coordinated expression and activity of 3-hydroxy-3-methylglutaryl coenzyme A synthase and reductase in the fat body of Blattella germanica (L.) during vitellogenesis.
Levels of mRNA for the two 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) synthases, (HMG-S1 and HMG-S2), and for HMG-CoA reductase (HMG-R) of Blattella germanica were analyzed in the fat body during the first gonadotrophic cycle. HMG-S2 and HMG-R showed the highest mRNA levels on day 0 and decreased thereafter, whereas HMG-S1, showed faint expression. Western blot using specific antibodies for HMG-S1 and HMG-S2 showed no detectable levels for HMG-S1 but a clear pattern for HMG-S2. Both results point to a very limited role for HMG-CoA synthase-1 in B. germanica fat body that the functional enzyme in this organ is HMG-CoA synthase-2. HMG-CoA reductase and synthase proteins shared a cyclic pattern (maximum levels at day 4 and minimum levels on days 0 and 8), which was coincident with the pattern of activity. The delay between gene transcription and protein synthesis suggests a finely regulated translation mechanism. Moreover, the pattern of mevalonate synthesis parallels that of vitellogenin production, suggesting a coordinate mechanism between the mevalonate pathway and the production of vitellogenin.
Casals
N
N
Unit of Biochemistry, University of Barcelona, School of Pharmacy, Spain.
Buesa
C
C
Piulachs
M D
MD
Cabañó
J
J
Marrero
P F
PF
Bellés
X
X
Hegardt
F G
FG
D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies; D003058:Cockroaches / Q000201:enzymology*; D005216:Fat Body / Q000201:enzymology; D005260:Female; D006903:Hydroxymethylglutaryl CoA Reductases / Q000235:genetics / Q000378:metabolism*; D006904:Hydroxymethylglutaryl-CoA Synthase / Q000235:genetics / Q000378:metabolism*; D025782:Hydroxymethylglutaryl-CoA-Reductases, NADP-dependent; D008969:Molecular Sequence Data; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014818:Vitellogenesis / Q000502:physiology*
D000906:Antibodies; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D006903:Hydroxymethylglutaryl CoA Reductases; D025782:Hydroxymethylglutaryl-CoA-Reductases, NADP-dependent; D006904:Hydroxymethylglutaryl-CoA Synthase