SNARE-mediated trafficking of alpha5beta1 integrin is required for spreading in CHO cells

Biochem Biophys Res Commun. 2005 Oct 7;335(4):1199-210. doi: 10.1016/j.bbrc.2005.07.195.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CHO Cells
  • Cell Adhesion / physiology*
  • Cell Movement / physiology*
  • Cricetinae
  • Cricetulus
  • Integrin alpha5beta1 / metabolism*
  • Protein Transport / physiology*
  • SNARE Proteins
  • Vesicular Transport Proteins / metabolism*

Substances

  • Integrin alpha5beta1
  • SNARE Proteins
  • Vesicular Transport Proteins