Sedimentation characteristics of vesicles associated with insulin-sensitive intracellular glucose transporter from rat adipocytes

Y, Shibata; Flanagan, J E; Smith, M M; Robinson, F W; Kôno, Tetsuro

doi:10.1016/0005-2736(87)90147-7

Cited by 12 publications

(2 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The slowly sedimenting fraction (22) was identical to what had previously been referred to as either the Golgi-rich fraction or the low density microsomal fraction. Briefly, the cells were washed and homogenized in STE buffer (250 mM sucrose, 10 mM Tris/HCl, 1 mM EDTA/Na, pH 7.4).The homogenate was centrifuged for 2 min at 3,000 ϫ g. The pellet (P-1) and the fat fraction were discarded, and the infranatant solution (S-1) was centrifuged for 15 min at 20,000 ϫ g. The supernatant (S-2) was further centrifuged as described below, and the pellet (P-2) was suspended in 0.5 ml of STE buffer and layered on top of a linear (15-32.5%, w/w) sucrose density gradient (approximately 1.4 ϫ 8.5 cm in size) and centrifuged for 40 min at 160,000 ϫ g; the sucrose solution was supplemented with 1 mM EDTA/Na and buffered with 10 mM Tris/HCl (pH 7.5).…”

Section: Measurement Of 3-o-methyl-d-glucose Uptake-supporting

confidence: 51%

A Synthetic Peptide Corresponding to the Rab4 Hypervariable Carboxyl-terminal Domain Inhibits Insulin Action on Glucose Transport in Rat Adipocytes

Shibata

Omata

Suzuki

et al. 1996

Journal of Biological Chemistry

View full text Add to dashboard Cite

The present study was conducted to examine the involvement of Rab4, a low molecular weight GTP-binding protein, in the action of insulin on glucose transport. A synthetic peptide corresponding to the Rab4 hypervariable carboxyl-terminal domain, Rab4-(191-210), was successfully transferred into rat adipocytes by electroporation and inhibited insulin-stimulated glucose transport by about 50% without affecting the basal transport activity. In contrast, synthetic peptides corresponding to the Rab3C and Rab3D carboxyl-terminal hypervariable domain had little effect on insulin action on glucose transport. The Rab4-(191-210) peptide also reduced insulin-induced GLUT4 translocation from the intracellular pool to the plasma membrane. Furthermore, the Rab4-(191-210) peptide reduced both insulin-induced glucose transport and GLUT4 translocation in the presence of a major histocompatibility complex class I antigen-derived peptide, D k -(62-85), which is a potent inhibitor of GLUT4 internalization, suggesting that the peptide inhibited exocytotic recruitment of GLUT4-containing vesicles. The Rab4-(191-210) peptide also inhibited GTP␥S-stimulated glucose transport. In addition, insulin-stimulated glucose transport was inhibited by the addition of anti-Rab4 antibody. These results suggest that Rab4 protein plays a crucial role in insulin action on GLUT4 translocation, especially in exocytotic recruitment by the hormone of the glucose transporter to the plasma membrane from the intracellular retention pool.Insulin stimulates glucose uptake in skeletal/cardiac muscles and adipocytes by promotion of translocation of glucose transporter isoform, GLUT4, from the intracellular pool to the plasma membrane (1-3). Although the precise mechanism(s) of insulin-induced GLUT4 redistribution is still unclear, several lines of evidence indicate that GTP-binding protein(s) is involved in the insulin action. Thus, nonhydrolyzable GTP analogues induce GLUT4 translocation (4, 5) and stimulate glucose transport (6, 7) in permeabilized adipocytes. Furthermore, by dissecting the recycling pathway of GLUT4 into exocytosis and endocytosis, we have demonstrated recently that GTP␥S 1 stimulates exocytotic fusion of GLUT4-containing vesicles, whereas the nucleotide inhibits endocytosis of the glucose transporter (8). Our previous study also indicated that the number of GLUT4 molecules in recycling pool is not large in the basal state and the rate-limiting step of insulin-induced redistribution of GLUT4 is the exocytotic recruitment from the intracellular retention pool to the plasma membrane (8).The Rab family proteins of Ras-related small GTP-binding proteins have been implicated in regulation of intracellular vesicular traffic (9). Given that exocytotic movement of vesicles is regulated by the Rab family protein(s), GTP␥S may promote exocytosis of GLUT4-containing vesicles by stimulation of the Rab protein(s) associated with the vesicles, although other candidates (e.g. trimeric GTP-binding proteins) cannot be ruled out. In this regard, Baldini et al....

show abstract

Section: Measurement Of 3-o-methyl-d-glucose Uptake-supporting

confidence: 51%

A Synthetic Peptide Corresponding to the Rab4 Hypervariable Carboxyl-terminal Domain Inhibits Insulin Action on Glucose Transport in Rat Adipocytes

Shibata

Omata

Suzuki

et al. 1996

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

“…Adipose cells were isolated from 50-56 male rats (170-200 g, CD strain, Charles River Breeding Laboratories) as described (17 (17). For the reasons noted by Shibata et al (19), the intracellular membranes correspond directly to the membranes erroneously named "low-density microsomes" (20). Membrane protein was assayed using bicinchoninic acid by a modification of the method of Smith et al (21) according to the manufacturer's instructions (Sigma).…”

Section: Methodsmentioning

confidence: 99%

Phosphorylation state of the GLUT4 isoform of the glucose transporter in subfractions of the rat adipose cell: effects of insulin, adenosine, and isoproterenol.

Nishimura

Saltis

Habberfield

et al. 1991

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

The acute effects of insulin, adenosine, and isoproterenol on the activity, subcellular distribution, and phosphorylation state of the GLUT4 glucose transporter isoform were investigated in rat adipocytes under conditions carefully controlled to monitor changes in cAMP-dependent protein kinase (A-kinase) activity. In contrast to GLUT1, which has not been shown to be phosphorylated even when cells are exposed to any of the above agents, GLUT4 was partially phosphorylated (0.1-0.2 mol/mol) when the activity of the A-kinase was suppressed, and remained unchanged in response to insulin. Isoproterenol elicited a 64% inhibition of insulinstimulated glucose transport activity in the absence, but not the presence, of adenosine receptor agonists. However, in either the presence or the absence of agonists, A-kinase was activated as assessed by examining the phosphorylation of the major adipocyte A-kinase substrate, perilipin. Similarly, under either condition, phosphorylation of GLUT4 was enhanced 1.4-fold in the intracellular membranes, but no significant change was observed in the plasma membrane. In the absence of adenosine receptor agonists, isoproterenol exerted a small (14%) but significant inhibition of the insulin-induced translocation of GLUT4 but had no effect on the translocation of GLUT1. Thus, changes in the phosphorylation state and/or subcellular distribution of GLUT4 cannot account for the inhibition of insulin-stimulated glucose activity induced by isoproterenol.Insulin stimulates glucose transport activity in rat adipose cells primarily by inducing the translocation of the transporter isoforms GLUT1 and GLUT4 from an intracellular location to the plasma membrane (1-4). GLUT1 is widely distributed whereas GLUT4, the predominant form in adipose cells (4-6), is found only in tissues where insulin regulates glucose transport activity (i.e., white and brown adipose tissue, heart, and skeletal muscle; for review see refs. 7 and 8). Hereafter, insulin-stimulated glucose transport activity will be abbreviated as transport activity. A second level of transport regulation is exerted by agents that modulate adenylyl cyclase and lipolysis (9-11). Lipolytic agents (isoproterenol, glucagon, and corticotropin) inhibit transport activity, but only in the absence of antilipolytic agents (adenosine, nicotinic acid, and prostaglandin E1). Further, Smith et al. (12) and Kuroda et al. (13) demonstrated that both the transport inhibition by lipolytic agents and the augmentation by antilipolytic agents did not result from changes in transporter location.An unresolved issue is whether the changes in transport activity mediated by these various agents are related to the changes in cAMP. Currently, two distinct mechanisms have been proposed. Kuroda et al. (13) demonstrated an apparent dissociation between isoproterenol-mediated stimulation of cAMP-dependent protein kinase (A-kinase) and inhibition of transport activity, suggesting that changes in A-kinasemediated phosphorylation are not responsible for transport inhibi...

show abstract

Inhibition of IRS-1 Phosphorylation and the Alterations of GLUT4 in Isolated Adipocytes from Cachectic Tumor-Bearing Rats

Yoshikawa

Noguchi

Satoh

1999

Biochemical and Biophysical Research Communications

View full text Add to dashboard Cite

Sedimentation characteristics of vesicles associated with insulin-sensitive intracellular glucose transporter from rat adipocytes

Cited by 12 publications

References 15 publications

A Synthetic Peptide Corresponding to the Rab4 Hypervariable Carboxyl-terminal Domain Inhibits Insulin Action on Glucose Transport in Rat Adipocytes

A Synthetic Peptide Corresponding to the Rab4 Hypervariable Carboxyl-terminal Domain Inhibits Insulin Action on Glucose Transport in Rat Adipocytes

Phosphorylation state of the GLUT4 isoform of the glucose transporter in subfractions of the rat adipose cell: effects of insulin, adenosine, and isoproterenol.

Inhibition of IRS-1 Phosphorylation and the Alterations of GLUT4 in Isolated Adipocytes from Cachectic Tumor-Bearing Rats

Contact Info

Product

Resources

About