A Tbc1d1 Ser231Ala-knockin mutation partially impairs AICAR- but not exercise-induced muscle glucose uptake in mice

Research output: Contribution to journalJournal articleResearchpeer-review

  • Qiaoli Chen
  • Bingxian Xie
  • Sangsang Zhu
  • Ping Rong
  • Yang Sheng
  • Serge Ducommun
  • Liang Chen
  • Chao Quan
  • Min Li
  • Sakamoto, Kei
  • Carol MacKintosh
  • Shuai Chen
  • Hong Yu Wang

Aims/hypothesis: TBC1D1 (tre-2/USP6, BUB2, cdc16 domain family member 1) is a Rab GTPase-activating protein (RabGAP) that has been implicated in regulating GLUT4 trafficking. TBC1D1 can be phosphorylated by the AMP-activated protein kinase (AMPK) on Ser231, which consequently interacts with 14-3-3 proteins. Given the key role for AMPK in regulating insulin-independent muscle glucose uptake, we hypothesised that TBC1D1-Ser231 phosphorylation and/or 14-3-3 binding may mediate AMPK-governed glucose homeostasis. Methods: Whole-body glucose homeostasis and muscle glucose uptake were assayed in mice bearing a Tbc1d1Ser231Ala-knockin mutation or harbouring skeletal muscle-specific Ampkα1/α2 (also known as Prkaa1/2) double-knockout mutations in response to an AMPK-activating agent, 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside (AICAR). Exercise-induced muscle glucose uptake and exercise capacity were also determined in the Tbc1d1Ser231Ala-knockin mice. Results: Skeletal muscle-specific deletion of Ampkα1/a2 in mice prevented AICAR-induced hypoglycaemia and muscle glucose uptake. The Tbc1d1Ser231Ala-knockin mutation also attenuated the glucose-lowering effect of AICAR in mice. Glucose uptake and cell surface GLUT4 content were significantly lower in muscle isolated from the Tbc1d1Ser231Ala-knockin mice upon stimulation with a submaximal dose of AICAR. However, this Tbc1d1Ser231Ala-knockin mutation neither impaired exercise-induced muscle glucose uptake nor affected exercise capacity in mice. Conclusions/interpretation: TBC1D1-Ser231 phosphorylation and/or 14-3-3 binding partially mediates AMPK-governed glucose homeostasis and muscle glucose uptake in a context-dependent manner.

Original languageEnglish
JournalDiabetologia
Volume60
Issue number2
Pages (from-to)336-345
Number of pages10
ISSN0012-186X
DOIs
Publication statusPublished - 2017
Externally publishedYes

    Research areas

  • 14-3-3, AMPK, Glucose uptake, Phosphorylation, TBC1D1

ID: 238739930