A dual role of the N-terminal FQQI motif in GLUT4 trafficking
-
Ulrike Bernhardt
Abstract
In adipocytes, the glucose transporter GLUT4 recycles between intracellular storage vesicles and the plasma membrane. GLUT4 is internalized by a clathrin- and dynamin-dependent mechanism, and sorted into an insulin-sensitive storage compartment. Insulin stimulation leads to GLUT4 accumulation on the cell surface. The N-terminal F5QQI motif in GLUT4 has been shown previously to be required for sorting of the protein in the basal state. Here, we show that the FQQI motif is a binding site for the medium chain adaptin μ1, a subunit of the AP-1 adaptor complex that plays a role in post-Golgi/endosomal trafficking events. In order to investigate the role of AP-1 and AP-2 in GLUT4 trafficking, we generated 3T3-L1 adipocytes expressing HA-GLUT4-GFP and knocked down the AP-1 and AP-2 complex by RNAi, respectively. In AP-1 and AP-2 knockdown adipocytes, GLUT4 accumulates at the cell surface in the basal state, consistent with a role of AP-1 in post-endosomal sorting of GLUT4 to the insulin-sensitive storage compartment, and of AP-2 in clathrin-mediated endocytosis. Our data demonstrate a dual role of the F5QQI motif and support the conclusion that the AP complexes direct GLUT4 trafficking and endocytosis.
©2009 by Walter de Gruyter Berlin New York
Articles in the same Issue
- Review
- Dimeric/oligomeric DNA methyltransferases: an unfinished story
- Minireview
- Induced human pluripotent stem cells: promises and open questions
- Genes and Nucleic Acids
- Effect of a quaternary pentamine on RNA stabilization and enzymatic methylation
- Protein Structure and Function
- A soluble form of ammonia monooxygenase in Nitrosomonas europaea
- Metzincin's canonical methionine is responsible for the structural integrity of the zinc-binding site
- A dual role of the N-terminal FQQI motif in GLUT4 trafficking
- Molecular Medicine
- Peritumoral administration of GPI-anchored TIMP-1 inhibits colon carcinoma growth in Rag-2 γ chain-deficient mice
- Cell Biology and Signaling
- The effect of endogenous preproneuropeptide Y leucine 7 to proline 7 polymorphism on growth and apoptosis in primary cultured HUVECs
- Cross talk between kinin and angiotensin II receptors in mouse abdominal aorta
- Advanced glycation end product accumulation in rho0 cells without a functional respiratory chain
- Proteolysis
- Association between kallikrein-related peptidases (KLKs) and macroscopic indicators of semen analysis: their relation to sperm motility
- Catalytic properties of recombinant dipeptidyl carboxypeptidase from Escherichia coli: a comparative study with angiotensin I-converting enzyme
- Pharmacological inhibitors to identify roles of cathepsin K in cell-based studies: a comparison of available tools
Articles in the same Issue
- Review
- Dimeric/oligomeric DNA methyltransferases: an unfinished story
- Minireview
- Induced human pluripotent stem cells: promises and open questions
- Genes and Nucleic Acids
- Effect of a quaternary pentamine on RNA stabilization and enzymatic methylation
- Protein Structure and Function
- A soluble form of ammonia monooxygenase in Nitrosomonas europaea
- Metzincin's canonical methionine is responsible for the structural integrity of the zinc-binding site
- A dual role of the N-terminal FQQI motif in GLUT4 trafficking
- Molecular Medicine
- Peritumoral administration of GPI-anchored TIMP-1 inhibits colon carcinoma growth in Rag-2 γ chain-deficient mice
- Cell Biology and Signaling
- The effect of endogenous preproneuropeptide Y leucine 7 to proline 7 polymorphism on growth and apoptosis in primary cultured HUVECs
- Cross talk between kinin and angiotensin II receptors in mouse abdominal aorta
- Advanced glycation end product accumulation in rho0 cells without a functional respiratory chain
- Proteolysis
- Association between kallikrein-related peptidases (KLKs) and macroscopic indicators of semen analysis: their relation to sperm motility
- Catalytic properties of recombinant dipeptidyl carboxypeptidase from Escherichia coli: a comparative study with angiotensin I-converting enzyme
- Pharmacological inhibitors to identify roles of cathepsin K in cell-based studies: a comparison of available tools
