23
Views
9
CrossRef citations to date
0
Altmetric
Original Article

Inhibition of endocytic transport by aluminum fluoride implicates GTPases as regulators of endocytosis

, , , , &
Pages 93-100 | Received 13 Aug 1993, Published online: 09 Jul 2009
 

Summary

It is now well established that GTP-binding proteins are important regulators of vesicular transport. Recent work has shown that multiple GTPases (both monomeric and heterotrimeric) are required for trafficking. In the present study we have used aluminum fluoride (AIF), a reagent that activates trimeric G proteins, as a tool to study the involvement of this family of GTPases in the regulation of endocytosis in intact cells. Our results indicate that AIF Inhibits fusion of early endosomes with an intracellular proteolytic compartment. Using the mixing of sequentially internalized ligands as a measure of endocytosis, we found that AIF inhibited endocytic transport as assessed by both biochemical and morphological methods. Taken together these results suggest that AIF affects membrane fusion, a common step in vesicular transport. To further examine the effects of AIF we tested this compound in a cell-free assay that reconstitutes fusion among endosomes. AIF affected endosomal fusion in a different way than did GTPgMS, an agent that activates both trimeric and small GTPases. Our results suggest that the coordinated activation of both classes of GTPases are required for efficient endocytic transport.

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.