Levels of translatable mRNA coding for rat liver glucokinase.
Changes in the level of translatable mRNA coding for glucokinase under different physiological conditions were determined using a reticulocyte lysate translation system and immunoprecipitation. Poly(A+) RNA isolated from livers of rats fed a high carbohydrate diet displayed a 10-fold increase in glucokinase template activity when compared to starved rats. Livers from streptozotocin-induced diabetic rats had only 9% of the glucokinase template activity displayed by controls. Administration of insulin to diabetic rats produced an increase in the level of mRNA coding for glucokinase within 20 min and reached a maximum 13-fold increase 1 h following insulin treatment. Under all experimental conditions examined, changes in the level of glucokinase mRNA were accompanied by similar changes in direction and magnitude of enzyme activity and the relative rate of synthesis of the enzyme in vivo. In addition, the developmental appearance of glucokinase activity at the 16th day following birth was accompanied by a corresponding increase in the amount of glucokinase mRNA. Thus, it appears that dietary, hormonal, and developmental changes in the activity of glucokinase arise as the result of changes in the amount of functional mRNA coding for the enzyme.
D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000201:enzymology; D004040:Dietary Carbohydrates / Q000008:administration & dosage; D005260:Female; D005941:Glucokinase / Q000235:genetics*; D008099:Liver / Q000201:enzymology*; D008297:Male; D011061:Poly A / Q000378:metabolism; D011247:Pregnancy; D014176:Protein Biosynthesis; D012313:RNA / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D004040:Dietary Carbohydrates; D012333:RNA, Messenger; D011061:Poly A; D012313:RNA; D005941:Glucokinase