What question did this study set out to answer?

To examine the role and subcellular localization of Rab GTPases, particularly Rab4, in insulin- and okadaic acid-stimulated Glut 4 vesicle translocation in adipocytes.

September 1, 1993Journal of Biological ChemistryOpen Access

Insulin and okadaic acid induce Rab4 redistribution in adipocytes.

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Authors

MCMireille CormontInserm JTJean‐François TantiInserm AZAhmed ZahraouiInserm

Discussion

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Implication

In vitro experiment demonstrates Rab4 cycling from Glut 4 vesicles to cytosol in adipocytes, suggesting its role in insulin-stimulated glucose transport.

Key Points

To examine the role and subcellular localization of Rab GTPases, particularly Rab4, in insulin- and okadaic acid-stimulated Glut 4 vesicle translocation in adipocytes.
Subcellular fractionation of adipocytes to isolate low-density microsomal and cytosolic compartments following stimulation with insulin, okadaic acid, or phorbol ester.
Immunopurification of Glut 4-containing vesicles using specific antibodies to evaluate the physical association of Rab proteins with the vesicles.
Dose-response and reversibility assays measuring the redistribution of Rab4 and Glut 4 in response to varying insulin concentrations.
Insulin induced a 50% decrease in Rab4 content in the low-density microsomal fraction alongside Glut 4 departure, with superimposable dose responses showing half-maximal effects at 0.1 nM insulin.
Rab4 was tightly associated with immunopurified Glut 4 vesicles in basal conditions and shifted to the cytosol upon stimulation, a process reversed by insulin withdrawal.
Okadaic acid mirrored the insulin-induced redistribution of Rab4 to the cytosol, whereas the phorbol ester 12-O-tetradecanoylphorbol-13-acetate elicited no effect.

Cite This Study

Cormont et al. (1993) studied this question.

synapsesocial.com/papers/6a7718232ea07b97ffadffdb https://doi.org/10.1016/s0021-9258(19)36542-1

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Implication

In vitro experiment demonstrates Rab4 cycling from Glut 4 vesicles to cytosol in adipocytes, suggesting its role in insulin-stimulated glucose transport.

Insulin and okadaic acid induce Rab4 redistribution in adipocytes.

Discussion

Member takes

Implication

Key Points

Cite This Study

Insulin and okadaic acid induce Rab4 redistribution in adipocytes.

Discussion

Member takes

Implication

Key Points

Cite This Study

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