Acyl-coenzyme A dehydrogenases are localized on GLUT4-containing vesicles via association with insulin-regulated aminopeptidase in a manner dependent on its dileucine motif.
Insulin-regulated aminopeptidase (IRAP, also termed vp165) is known to be localized on the GLUT4-containing vesicles and to be recruited to the plasma membrane after stimulation with insulin. The cytoplasmic region of IRAP contains two dileucine motifs and acidic regions, one of which (amino acid residues 55-82) is reportedly involved in retention of GLUT4-containing vesicles. The region of IRAP fused with glutathione-S-transferase [GST-IRAP(55-82)] was incubated with lysates from 3T3-L1 adipocytes, leading to identification of long-chain, medium-chain, and short-chain acyl-coenzyme A dehydrogenases (ACDs) as the proteins associated with IRAP. The association was nearly abolished by mutation of the dileucine motif of IRAP. Immunoblotting of fractions prepared from sucrose gradient ultracentrifugation and vesicles immunopurified with anti-GLUT4 antibody revealed these ACDs to be localized on GLUT4-containing vesicles. Furthermore, 3-mercaptopropionic acid and hexanoyl-CoA, inhibitors of long-chain and medium-chain ACDs, respectively, induced dissociation of long-chain acyl-coenzyme A dehydrogenase and/or medium-chain acyl-coenzyme A dehydrogenase from IRAP in vitro as well as recruitment of GLUT4 to the plasma membrane and stimulation of glucose transport activity in permeabilized 3T3-L1 adipocytes. These findings suggest that ACDs are localized on GLUT4-containing vesicles via association with IRAP in a manner dependent on its dileucine motif and play a role in retention of GLUT4-containing vesicles to an intracellular compartment.
Katagiri
Hideki
H
Division of Molecular Metabolism and Diabetes, Department of Internal Medicine, Tohoku University Graduate School of Medicine, Sendai 980-8574, Japan. katagiri-tky@umin.ac.jp
Asano
Tomoichiro
T
Yamada
Tetsuya
T
Aoyama
Toshifumi
T
Fukushima
Yasushi
Y
Kikuchi
Masatoshi
M
Kodama
Tatsuhiko
T
Oka
Yoshitomo
Y
D015097:3-Mercaptopropionic Acid / Q000494:pharmacology; D016475:3T3 Cells; D000214:Acyl Coenzyme A / Q000494:pharmacology; D042964:Acyl-CoA Dehydrogenase; D017667:Adipocytes / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure; D000595:Amino Acid Sequence; D000626:Aminopeptidases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D002458:Cell Fractionation; D002463:Cell Membrane Permeability; D010122:Cystinyl Aminopeptidase; D004791:Enzyme Inhibitors / Q000494:pharmacology; D044943:Fatty Acid Desaturases / Q000032:analysis* / Q000378:metabolism; D015870:Gene Expression; D051275:Glucose Transporter Type 4; D005982:Glutathione Transferase / Q000235:genetics; D007163:Immunosorbent Techniques; D007930:Leucine / Q000737:chemistry*; D051379:Mice; D008861:Microsomes / Q000737:chemistry; D009004:Monosaccharide Transport Proteins / Q000032:analysis* / Q000378:metabolism; D009124:Muscle Proteins; D016296:Mutagenesis; D051381:Rats; D011993:Recombinant Fusion Proteins; D013329:Structure-Activity Relationship; D014162:Transfection; D014461:Ultracentrifugation
D000214:Acyl Coenzyme A; D004791:Enzyme Inhibitors; D051275:Glucose Transporter Type 4; D009004:Monosaccharide Transport Proteins; D009124:Muscle Proteins; D011993:Recombinant Fusion Proteins; C495693:Slc2a4 protein, mouse; C495694:Slc2a4 protein, rat; C044181:hexanoyl-coenzyme A; D015097:3-Mercaptopropionic Acid; D044943:Fatty Acid Desaturases; D042964:Acyl-CoA Dehydrogenase; D005982:Glutathione Transferase; D000626:Aminopeptidases; D010122:Cystinyl Aminopeptidase; C105964:leucyl-cystinyl aminopeptidase; D007930:Leucine