Diurnal rhythm of rat liver cytosolic 3-hydroxy-3-methylglutaryl-CoA synthase.
Rat liver cytosolic 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase exhibits a diurnal rhythm of enzyme activity which coincides with the diurnal rhythm of HMG-CoA synthase protein. The peaks of activity and protein (determined by SDS/PAGE and immunoblotting) both occur at D10 (the tenth hour of the daily 12 h dark cycle). The peak of mRNA levels (measured by slot-blot hybridization of liver RNA) is slightly advanced with respect to that of protein, by about 4 h, and shows a maximum at D6. Cytosolic HMG-CoA synthase activity and protein in rats fed on a normal diet were approx. 2-fold higher during the peak at D10 than in the nadir at D2. HMG-CoA synthase mRNA levels were approx. 4-fold higher during the peak at D6 than in the nadir at D2. These results point to a transcriptional and translational regulation of the cytosolic HMG-CoA synthase.
Royo
T
T
Unit of Biochemistry, University of Barcelona, School of Pharmacy, Spain.
Ayté
J
J
Albericio
F
F
Giralt
E
E
Haro
D
D
Hegardt
F G
FG
D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies; D015152:Blotting, Northern; D002940:Circadian Rhythm; D003600:Cytosol / Q000201:enzymology; D003624:Darkness; D006904:Hydroxymethylglutaryl-CoA Synthase / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D015151:Immunoblotting; D008027:Light; D008099:Liver / Q000201:enzymology* / Q000502:physiology; D008297:Male; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010455:Peptides / Q000138:chemical synthesis / Q000276:immunology; D012333:RNA, Messenger / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D000906:Antibodies; D010455:Peptides; D012333:RNA, Messenger; D006904:Hydroxymethylglutaryl-CoA Synthase