Annexin II is a thiazolidinedione-responsive gene involved in insulin-induced glucose transporter isoform 4 translocation in 3T3-L1 adipocytes.
The target genes of peroxisomal proliferator-activated receptor-gamma ligands that lead to insulin sensitization are not fully understood. In this study, we have found that the thiazolidinedione, troglitazone, increases expression of annexin II at both the mRNA and protein levels, raising the possibility that annexin II plays a role in insulin-stimulated glucose transporter isoform 4 (GLUT4) translocation and glucose transport. To assess this, we microinjected annexin II antibody or annexin II small interfering RNA into 3T3-L1 adipocytes and found that insulin-stimulated GLUT4 translocation was inhibited by 54 and 60%, respectively. Furthermore, microinjection of annexin II antibody inhibited constitutively active Galphaq (Q209L-Galphaq)-induced but not osmotic shock-induced GLUT4 translocation. When cells were cotransfected with wild-type annexin II, along with an enhanced green fluorescent protein-cmyc-GLUT4 construct, and the percentage of cells expressing cmyc-GLUT4 at the cell surface was measured by immunofluorescence microscopy, there was a marked increase in the ability of insulin to stimulate recruitment of cmyc-GLUT4 protein to the cell surface. In summary, our results show that annexin II is a newly described thiazolidinedione response gene involved in insulin-induced GLUT4 translocation in 3T3-L1 adipocytes.
Huang
Jie
J
Department of Medicine, Division of Endocrinology and Metabolism, University of California, San Diego 92093-0673, USA.
Hsia
Stanley H
SH
Imamura
Takeshi
T
Usui
Isao
I
Olefsky
Jerrold M
JM
D016475:3T3 Cells; D017667:Adipocytes / Q000187:drug effects* / Q000378:metabolism*; D000818:Animals; D017306:Annexin A2 / Q000187:drug effects / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D001692:Biological Transport / Q000187:drug effects / Q000502:physiology; D002839:Chromans / Q000494:pharmacology*; D005947:Glucose / Q000378:metabolism; D051275:Glucose Transporter Type 4; D007328:Insulin / Q000494:pharmacology*; D051379:Mice; D008856:Microscopy, Fluorescence; D009004:Monosaccharide Transport Proteins / Q000378:metabolism*; D009124:Muscle Proteins; D013347:Subcellular Fractions / Q000378:metabolism; D045162:Thiazolidinediones / Q000494:pharmacology*; D014018:Tissue Distribution; D000077288:Troglitazone
D017306:Annexin A2; D002839:Chromans; D051275:Glucose Transporter Type 4; D007328:Insulin; D009004:Monosaccharide Transport Proteins; D009124:Muscle Proteins; C495693:Slc2a4 protein, mouse; D045162:Thiazolidinediones; D000077288:Troglitazone; D005947:Glucose