These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Changes in the hepatic levels of messenger ribonucleic acid for malic enzyme during induction by thyroid hormone or diet.
    Author: Towle HC, Mariash CN, Oppenheimer JH.
    Journal: Biochemistry; 1980 Feb 05; 19(3):579-85. PubMed ID: 7356948.
    Abstract:
    Levels of hepatic messenger ribonucleic acid (mRNA) for malic enzyme [L-malate:NADP oxidoreductase (decarboxylating), EC 1.1.1.40] were quantitated in different dietary and hormonal states of the rat. Polysomal or total cellular poly(A)-containing RNA was translated in the rabbit reticulocyte lysate system, which had been treated to reduce endogenous mRNA activity. The relative level of incorporation of radiolabeled amino acid into malic enzyme was determined by immunoprecipitation with antibody to malic enzyme and formaldehyde-fixed Staphylococcus aureus (Cowens I strain) as an immunoadsorbent. The immunoprecipitated product comigrated with purified malic enzyme on sodium dodecyl sulfate--polyacrylamide gel electrophoresis. No malic enzyme was detected when nonspecific antisera or an excess of unlabeled malic enzyme was added during immunoprecipitation. The level of malic enzyme mRNA was found to markedly increase relative to euthyroid, chow-fed rats when the animal was either fed a high carbohydrate, fat-free diet or made hyperthyroid. Animals receiving both treatments had a further increase in mRNA activity to a level which was approximately 0.2% of the total incorporation of [3H]leucine. Levels of malic enzyme activity and the relative rate of synthesis were found to increase roughly in proportion to mRNA levels in these three states. Thus, the induction of malic enzyme by thyroid hormone or high carbohydrate, fat-free diet is due largely to an increase in the mRNA coding for this enzyme.
    [Abstract] [Full Text] [Related] [New Search]