Regulation of 3-hydroxy-3-methylglutaryl coenzyme a reductase in minimal deviation hepatoma 7288C. Immunological measurements in hepatoma tissue culture cells.
The mechanism of action of serum lipoproteins and 25-hydroxycholesterol on 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity in hepatoma tissue culture (HTC) cells was investigated using antiserum against purified rat liver HMG-CoA reductase (Heller, R. A., and Shrewsbury, M. A. (1976)J. Biol. Chem. 251, 3815-3822). This antiserum cross-reacted with solubilized and membrane-bound HMG-CoA reductase from HTC cells. The enzymes from rat liver and HTC cells appeared antigenically identical. The increase in HMG-CoA reductase activity of HTC cells grown in medium which lacked serum lipoproteins was shown to be due to an increase in immunoprecipitable enzyme. In contrast, the 25-hydroxycholesterol suppression of reductase activity leads to a reduction in the antigenicity of the enzyme rather than a decrease in its number of molecules.
D000429:Alcohol Oxidoreductases / Q000378:metabolism*; D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000201:enzymology*; D002460:Cell Line; D006888:Hydroxycholesterols / Q000494:pharmacology; D006903:Hydroxymethylglutaryl CoA Reductases / Q000276:immunology / Q000378:metabolism*; D007118:Immunoassay; D005779:Immunodiffusion; D007700:Kinetics; D008113:Liver Neoplasms / Q000201:enzymology; D008862:Microsomes, Liver / Q000201:enzymology; D051381:Rats
D006888:Hydroxycholesterols; D000429:Alcohol Oxidoreductases; D006903:Hydroxymethylglutaryl CoA Reductases