The binding and degradation of insulin by brush-border membranes from rat kidney

1982 ◽  
Vol 10 (4) ◽  
pp. 220-220
Author(s):  
J. HYWEL THOMAS ◽  
PHILIP G. DAVEY ◽  
CHRISTOPHER D. G. JENKINS ◽  
DESPINA K. PAPACHRISTODOULOU
1983 ◽  
Vol 732 (2) ◽  
pp. 372-376 ◽  
Author(s):  
Gabriele Beyer ◽  
Folkert Bode ◽  
Karl Baumann

1999 ◽  
Vol 77 (1) ◽  
pp. 59-69 ◽  
Author(s):  
Diane Bilodeau ◽  
Sylvie Lamy ◽  
Richard R Desrosiers ◽  
Denis Gingras ◽  
Richard Béliveau

The Rho GDP dissociation inhibitor (GDI) is an ubiquitously expressed regulatory protein involved in the cycling of Rho proteins between membrane-bound and soluble forms. Here, we characterized the Rho solubilization activity of a glutathione S-transferase (GST) - GDI fusion protein in a cell-free system derived from rat kidney. Addition of GST-GDI to kidney brush border membranes resulted in the specific release of Cdc42 and RhoA from the membranes, while RhoB and Ras were not extracted. The release of Cdc42 and RhoA by GST-GDI was dose dependent and saturable with about 50% of both RhoA and Cdc42 extracted. The unextracted Rho proteins were tightly bound to membranes and could not be solubilized by repeated GST-GDI treatment. These results demonstrated that kidney brush border membranes contained two populations of RhoA and Cdc42. Furthermore, the GST-GDI solubilizing activity on membrane-bound Cdc42 and RhoA was abolished at physiological conditions of salt and temperature in all tissues examined. When using bead-immobilized GST-GDI, KCl did not reduced the binding of Rho proteins. However, washing brush border membranes with KCl prior treatment by GST-GDI inhibited the extraction of Rho proteins. Taken together, these results suggest that the binding of GDI to membrane-bound Cdc42 and RhoA occurs easily under physiological ionic strength conditions, but a complementary factor is required to extract these proteins from membranes. These observations suggest that the shuttling activity of GDI upon Rho proteins could be normally downregulated under physiological conditions.Key words: rhoGDI, rho proteins, ionic strength, kidney.


1980 ◽  
Vol 12 (1-2) ◽  
pp. 319-324 ◽  
Author(s):  
R. Kirsten ◽  
J. Assmutat ◽  
K. Nelson ◽  
U. Rüschendorf

1985 ◽  
Vol 8 (1) ◽  
pp. 19-29
Author(s):  
Jürg Biber ◽  
Vito Sealera ◽  
Heini Murer

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