Abstract
Glucose transporter (GLUT) 4 is the insulin responsive glucose transporter in adipose tissue, skeletal muscle, and heart. Insulin elicits increased glucose uptake by recruiting GLUT4 from a specialized intracellular storage site to the cell surface. Expression of various proteins that colocalize with GLUT4 and/or are involved in insulin-stimulated GLUT4 translocation was examined in adipocytes as well as skeletal and cardiac muscles from GLUT4 null mice. Our data demonstrate that expression of insulin-regulated aminopeptidase (IRAP) is divergently regulated in GLUT4 null tissues, e.g., upregulated 1.6-fold in GLUT4 null adipocytes and downregulated in GLUT4 null skeletal muscle (40%) and heart (60%). IRAP exhibited abnormal subcellular distribution and impaired insulin-stimulated translocation in GLUT4-deficient tissues. We propose the compartment containing IRAP and proteins normally associated with GLUT4 vesicle traffics constitutively to the cell surface in GLUT4 null adipocytes and skeletal muscle.
Original language | English (US) |
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Pages (from-to) | 519-525 |
Number of pages | 7 |
Journal | Biochemical and Biophysical Research Communications |
Volume | 284 |
Issue number | 2 |
DOIs | |
State | Published - 2001 |
Keywords
- GLUT4 translocation
- Insulin action
- Insulin-regulated aminopeptidase
- Vesicle trafficking
ASJC Scopus subject areas
- Biophysics
- Biochemistry
- Molecular Biology
- Cell Biology