Abstract
The ability of insulin to stimulate glucose uptake in skeletal muscle is important for whole-body glycemic control. Insulin-stimulated skeletal muscle glucose uptake is improved in the period after a single bout of exercise and accumulating evidence suggests that phosphorylation of TBC1D4 by the protein kinase AMPK is the primary mechanism responsible for this phenomenon. To investigate this, we generated a TBC1D4 knock-in mouse model with a serine-to-alanine point mutation at residue 711 that is phosphorylated in response to both insulin and AMPK activation. Female TBC1D4-S711A mice exhibited normal growth and eating behavior as well as intact wholebody glycemic control on chow and high-fat diets. Moreover, muscle contraction increased glucose uptake, glycogen utilization and AMPK activity similarly in wild-type and TBC1D4-S711A mice. In contrast, improvements in whole-body and muscle insulin sensitivity after exercise and contractions were only evident in wild-type mice and occurred concomitantly with enhanced phosphorylation of TBC1D4-S711. These results provide genetic evidence to support that TBC1D4-S711 serves as a major point of convergence for AMPK- and insulin-induced signaling that mediates the insulin-sensitizing effect of exercise and contractions on skeletal muscle glucose uptake.
Original language | English |
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Journal | Diabetes |
Volume | 72 |
Issue number | 7 |
Pages (from-to) | 857-871 |
Number of pages | 15 |
ISSN | 0012-1797 |
DOIs | |
Publication status | Published - 2023 |
Bibliographical note
© 2023 by the American Diabetes Association.Keywords
- Faculty of Science
- AS160
- AMPK
- Exercise
- Glucose uptake
- Insulin sensitivity