Clathrin mediates integrin endocytosis for focal adhesion disassembly in migrating cells

• Published in: The Journal of cell biology Vol. 187; no. 5; pp. 733 - 747
• Main Authors: Ezratty, Ellen J, Bertaux, Claire, Marcantonio, Eugene E, Gundersen, Gregg G
• Format: Journal Article
• Language: English
• Published: United States The Rockefeller University Press 30-11-2009; Rockefeller University Press
• Subjects: Adaptor Proteins, Signal Transducing - antagonists & inhibitors; Adaptor Proteins, Vesicular Transport - antagonists & inhibitors; Animals; Cell adhesion & migration; Cell division; Cell lines; Cell Movement; Cell Polarity; Cells; Clathrin - physiology; Endocytosis; Experiments; Fibroblasts; Focal adhesions; Focal Adhesions - metabolism; Histograms; Integrins; Integrins - metabolism; Membrane Proteins - antagonists & inhibitors; Mice; Microtubules - physiology; Nerve Tissue Proteins - antagonists & inhibitors; NIH 3T3 Cells; Quantification; Regrowth; RNA Interference; Small interfering RNA
• ISSN: 0021-9525; 1540-8140
• DOI: 10.1083/jcb.200904054

Focal adhesion disassembly is regulated by microtubules (MTs) through an unknown mechanism that involves dynamin. To test whether endocytosis may be involved, we interfered with the function of clathrin or its adaptors autosomal recessive hypercholesteremia (ARH) and Dab2 (Disabled-2) and found that both treatments prevented MT-induced focal adhesion disassembly. Surface labeling experiments showed that integrin was endocytosed in an extracellular matrix-, clathrin-, and ARH- and Dab2-dependent manner before entering Rab5 endosomes. Clathrin colocalized with a subset of focal adhesions in an ARH- and Dab2-dependent fashion. Direct imaging showed that clathrin rapidly accumulated on focal adhesions during MT-stimulated disassembly and departed from focal adhesions with integrin upon their disassembly. In migrating cells, depletion of clathrin or Dab2 and ARH inhibited focal adhesion disassembly and decreased the rate of migration. These results show that focal adhesion disassembly occurs through a targeted mechanism involving MTs, clathrin, and specific clathrin adaptors and that direct endocytosis of integrins from focal adhesions mediates their disassembly in migrating cells.