Cleavage of vesicle-associated membrane protein (VAMP)-2 and cellubrevin on GLUT4-containing vesicles inhibits the translocation of GLUT4 in 3T3-L1 adipocytes.
We have identified VAMP isoforms, VAMP-2 and cellubrevin, on GLUT4-containing vesicle membranes isolated from 3T3-Ll adipocytes. These proteins translocate from a low density microsomal fraction to the plasma membrane upon insulin stimulation in a fashion similar to GLUT4. VAMP-1 was not detected in this low density microsomal fraction nor on purified GLUT4-containing vesicles. In streptolysin-O permeabilized 3T3-L1 adipocytes, both VAMP-2 and cellubrevin were cleaved with botulinum neurotoxin isoform B, BoNTx/B. In addition, BoNTx/B partially inhibited insulin-stimulated GLUT4 translocation and glucose transport activity. We conclude that the synaptobrevin isoforms are important components of the insulin-dependent translocation of GLUT4 to the cell surface in adipocytes.
Tamori
Y
Y
The Second Department of Internal Medicine, Kobe University School of Medicine, Japan.
Hashiramoto
M
M
Araki
S
S
Kamata
Y
Y
Takahashi
M
M
Kozaki
S
S
Kasuga
M
M
D016475:3T3 Cells; D017667:Adipocytes / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies; D001692:Biological Transport / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D003847:Deoxyglucose / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D051275:Glucose Transporter Type 4; D007328:Insulin / Q000494:pharmacology; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D008861:Microsomes / Q000378:metabolism*; D008969:Molecular Sequence Data; D009004:Monosaccharide Transport Proteins / Q000096:biosynthesis / Q000378:metabolism*; D009124:Muscle Proteins; D009419:Nerve Tissue Proteins / Q000378:metabolism; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry / Q000276:immunology; D050683:R-SNARE Proteins; D051381:Rats; D013347:Subcellular Fractions / Q000378:metabolism; D013395:Sucrose / Q000378:metabolism; D051040:Vesicle-Associated Membrane Protein 3
D000906:Antibodies; D051275:Glucose Transporter Type 4; D007328:Insulin; D008565:Membrane Proteins; D009004:Monosaccharide Transport Proteins; D009124:Muscle Proteins; D009419:Nerve Tissue Proteins; D010446:Peptide Fragments; D050683:R-SNARE Proteins; C495693:Slc2a4 protein, mouse; C495694:Slc2a4 protein, rat; D051040:Vesicle-Associated Membrane Protein 3; D013395:Sucrose; D003847:Deoxyglucose; D005947:Glucose