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Updated: Aug 24, 2026

Spectrophotometric Methods for the Study of Eukaryotic Glycogen Metabolism
Published on: August 19, 2021
Glucose starvation results in UDP-glucose deficiency and inactivation of glycogen synthase
Juan Carlos Higuita1, Monica Thelestam, Abram Katz
1Microbiology and Tumor Biology Center, Karolinska Institutet, Stockholm S-171 77, Sweden.
Abstract:
The effects of glucose starvation on glycogen synthase (GS) activity and protein expression were investigated. Fibroblasts were cultured in medium supplemented with either glucose or pyruvate. Pyruvate-cultured cells exhibited UDP-glucose contents that amounted to approximately 10% of those in cells cultured with glucose. GS activity, protein and mRNA amounts in pyruvate-cultured cells were decreased to approximately 35, 60, and 60%, respectively, of values in glucose-cultured cells. Incubation of extracts from glucose-cultured cells with radioactive UDP-glucose resulted in substantial binding of ligand to immunoprecipitated GS. However, binding in immunoprecipitates from pyruvate-cultured cells was decreased to approximately 25% of values in glucose-cultured cells. These data indicate that glucose starvation and the subsequent depletion of UDP-glucose result in: (1) inactivation of GS, owing to a decrease in its ability to bind UDP-glucose, and (2) decreased amount of GS protein, owing to a decrease in the levels of GS mRNA.
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