Reply to Hernández—Glycolysis and gluconeogenesis: A teaching view

Open AccessPublished:December 07, 2020DOI:
      We thank Félix Hernández for his insightful and thoughtful comments as well as interest in our manuscript (
      • Shah A.M.
      • Wondisford F.E.
      Tracking the carbons supplying gluconeogenesis.
      ). Regarding suggestion 1, we omitted several glycolytic and gluconeogenic enzymes in the figure for simplicity. We specifically mentioned G6Pase and PEPCK as many investigators have studied these enzymes in particular when studying gluconeogenesis. Articles specifically referenced in our review article studied these two enzymes, and we wished to pictorially represent these enzymes. We further described each of these two enzymes’ specific functions in the text. Our manuscript does not go into the regulation of glycolysis or gluconeogenesis as our main intention was to show carbon flux. So we do not feel compelled to label the enzymes as suggested as that is not the intent of the picture.
      Regarding suggestions 2 and 3, we agree that there should be a single arrow between phosphoenolpyruvate to pyruvate and there should be a single arrow between pyruvate to oxaloacetate to best show carbon flux (Fig. 1).
      Figure thumbnail gr1
      Figure 1Glucose metabolism in the context of glycolysis and gluconeogenesis. α-KG, alpha-ketoglutarate; G6Pase, glucose-6-phosphatase; OAA, oxaloacetate; PEPCK, phosphoenolpyruvate carboxykinase.

      Conflict of interest

      The authors declare that they have no conflicts of interests with the contents of this article.


        • Shah A.M.
        • Wondisford F.E.
        Tracking the carbons supplying gluconeogenesis.
        J. Biol. Chem. 2020; 295: 14419-14429

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      • Glycolysis and gluconeogenesis: A teaching view
        Journal of Biological ChemistryVol. 296
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          I read with interest the recent review “Tracking the carbons supplying gluconeogenesis” by Ankit M. Shah and Fredric E. Wondisford (1). The figures are clear, and they are a good teaching source. Nevertheless, I note some potential teaching issues as well as offer additional suggestions. It is well known and it is explained to our students that there are three reactions of glycolysis that are essentially irreversible: hexokinase, phosphofrutokinase-1, and pyruvate kinase. Thus, I would like to observe in relation to Figure 1 that
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