Quantitative proteomics identifies a Dab2/integrin module regulating cell migration
ABSTRACT Clathrin-associated endocytic adapters recruit cargoes to coated pits as a first step in endocytosis. We developed an unbiased quantitative proteomics approach to identify and quantify glycoprotein cargoes for an endocytic adapter, Dab2. Surface levels of integrins beta1, alpha1, alpha2, and alpha3 but not alpha5 or alphav chains were specifically increased on Dab2-deficient HeLa cells. Dab2 colocalizes with integrin beta1 in coated pits that are dispersed over the cell surface, suggesting that it regulates bulk endocytosis of inactive integrins. Depletion of Dab2 inhibits cell migration and polarized movement of integrin beta1 and vinculin to the leading edge. By manipulating intracellular and surface integrin beta1 levels, we show that migration speed correlates with the intracellular integrin pool but not the surface level. Together, these results suggest that Dab2 internalizes integrins freely diffusing on the cell surface and that Dab2 regulates migration, perhaps by maintaining an internal pool of integrins that can be recycled to create new adhesions at the leading edge.
SourceAvailable from: Nigel B Jamieson[Show abstract] [Hide abstract]
ABSTRACT: The cell’s major fibronectin-binding integrin (α5β1) promotes survival and migration of tumor cells (Caswell et al., 2008 and Lee and Juliano, 2000), making this an important molecule for cell biologists interested in cancer progression. α5β1 integrin is continuously internalized, trafficked to recycling endosomes and then returned, or recycled, to the plasma membrane via both Rab11- and Arf6-dependent pathways (Caswell and Norman, 2006 and Pellinen and Ivaska, 2006). However, α5β1 integrins that are ligand-engaged do not reach recycling endosomes but are sent to lysosomes under control of Rab25 (Dozynkiewicz et al., 2012, Lobert et al., 2010 and Rainero and Norman, 2013). Moreover, Rab25 expression is associated with upregulation of a lysosomal protein called CLIC3, which prevents degradation of α5β1 and allows recycling from this compartment to the plasma membrane (Dozynkiewicz et al., 2012).Cell Reports 01/2015; 13. DOI:10.1016/j.celrep.2014.12.037 · 7.21 Impact Factor
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ABSTRACT: Crosstalk of different integrins, which bind to distinct types of extracellular matrix proteins, promotes specific functions. This crosstalk has not been investigated in depth. Previously, we demonstrated that integrin-syndecan crosstalk accelerated cell adhesion. Here, we evaluated the crosstalk of two different integrins using mixed peptide-polysaccharide (chitosan or alginate) matrices. Two different integrin binding peptides, FIB1 (integrin αvβ3), EF1zz (integrin α2β1), and 531 (integrin α3β1), were mixed in various molar ratios (9:1, 4:1, 1:1) and conjugated on a polysaccharide matrix. The mixture of FIB1/EF1zz- and FIB1/531-polysaccharide matrices did not show any difference in human dermal fibroblast (HDF) adhesion against the mono polysaccharide matrices. Interestingly, the EF1zz/531-polysaccharide matrix (molar ratio = 1:4) exhibited significantly decreased cell adhesion, but other EF1zz/531-polysaccharide matrices did not show any difference. When we examined the signal transduction of the EF1zz/531(1:4), Y397 phosphorylation of FAK significantly decreased but Y514 phosphorylation of Src did not exhibit any differences. Further investigation revealed that this suppression was mediated by PI3K signaling through the activation of integrin, and PKA signaling modulated suppression of HDF attachment. These findings suggest that a mixed peptide-polysaccharide matrix using receptor specific ligands can regulate cellular functions through receptor-specific crosstalk and is a useful approach to understand receptor specific crosstalk.Biomaterials 10/2014; 37. DOI:10.1016/j.biomaterials.2014.10.005 · 8.31 Impact Factor
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ABSTRACT: Directed cell migration is a fundamental process underlying diverse physiological and pathophysiological phenomena ranging from wound healing and induction of immune responses to cancer metastasis. Recent advances reveal that endocytic trafficking contributes to cell migration in multiple ways. (1) At the level of chemokines and chemokine receptors: internalization of chemokines by scavenger receptors is essential for shaping chemotactic gradients in tissue, whereas endocytosis of chemokine receptors and their subsequent recycling is key for maintaining a high responsiveness of migrating cells. (2) At the level of integrin trafficking and focal adhesion dynamics: endosomal pathways do not only modulate adhesion by delivering integrins to their site of action, but also by supplying factors for focal adhesion disassembly. (3) At the level of extracellular matrix reorganization: endosomal transport contributes to tumor cell migration not only by targeting integrins to invadosomes but also by delivering membrane type 1 matrix metalloprotease to the leading edge facilitating proteolysis-dependent chemotaxis. Consequently, numerous endocytic and endosomal factors have been shown to modulate cell migration. In fact key modulators of endocytic trafficking turn out to be also key regulators of cell migration. This review will highlight the recent progress in unraveling the contribution of cellular trafficking pathways to cell migration.Cellular and Molecular Life Sciences CMLS 02/2015; DOI:10.1007/s00018-015-1855-9 · 5.86 Impact Factor