1. SNARE-mediated trafficking of α5β1 integrin is required for spreading in CHO cells
- Author
-
Michael Skalski and Marc G. Coppolino
- Subjects
Integrin ,Vesicular Transport Proteins ,Biophysics ,CHO Cells ,Biochemistry ,chemistry.chemical_compound ,Cricetulus ,Cell Movement ,Cricetinae ,Cell Adhesion ,Animals ,Cell adhesion ,Molecular Biology ,VAMP3 ,biology ,Chinese hamster ovary cell ,Cell Biology ,Adhesion ,Brefeldin A ,Fusion protein ,Cell biology ,Fibronectin ,Protein Transport ,chemistry ,biology.protein ,SNARE Proteins ,Integrin alpha5beta1 - Abstract
In this study, the role of SNARE-mediated membrane traffic in regulating integrin localization was examined and the requirement for SNARE function in cellular spreading was quantitatively assessed. Membrane traffic was inhibited with the VAMP-specific catalytic light chain from tetanus toxin (TeTx-LC), a dominant-negative form (E329Q) of N-ethylmaleimide-sensitive fusion protein (NSF), and brefeldin A (BfA). Inhibition of membrane traffic with either E329Q-NSF or TeTx-LC, but not BfA, significantly inhibited spreading of CHO cells on fibronectin. Spreading was rescued in TeTx-LC-expressing cells by co-transfection with a TeTx-resistant cellubrevin/VAMP3. E329Q-NSF, a general inhibitor of SNARE function, was a more potent inhibitor of cell spreading than TeTx-LC, suggesting that tetanus toxin-insensitive SNAREs contribute to adhesion. It was found that E329Q-NSF prevented trafficking of alpha5beta1 integrins from a central Rab11-containing compartment to sites of protrusion during cell adhesion, while TeTx-LC delayed this trafficking. These results are consistent with a model of cellular adhesion that implicates SNARE function as an important component of integrin trafficking during the process of cell spreading.
- Published
- 2005