1. Nck adaptor proteins link Tks5 to invadopodia actin regulation and ECM degradation.
- Author
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Stylli SS, Stacey TT, Verhagen AM, Xu SS, Pass I, Courtneidge SA, and Lock P
- Subjects
- Adaptor Proteins, Signal Transducing antagonists & inhibitors, Adaptor Proteins, Signal Transducing genetics, Animals, Blotting, Western, Cell Surface Extensions ultrastructure, Fluorescent Antibody Technique, Humans, Immunoprecipitation, Mice, Neoplasms pathology, Oncogene Proteins antagonists & inhibitors, Oncogene Proteins genetics, Phosphate-Binding Proteins, Phosphoproteins antagonists & inhibitors, Phosphoproteins genetics, RNA, Small Interfering pharmacology, Transfection, Tumor Cells, Cultured, src Homology Domains, Actins metabolism, Adaptor Proteins, Signal Transducing metabolism, Cell Surface Extensions physiology, Extracellular Matrix metabolism, Neoplasms metabolism, Oncogene Proteins metabolism, Phosphoproteins metabolism
- Abstract
Invadopodia are actin-based projections enriched with proteases, which invasive cancer cells use to degrade the extracellular matrix (ECM). The Phox homology (PX)-Src homology (SH)3 domain adaptor protein Tks5 (also known as SH3PXD2A) cooperates with Src tyrosine kinase to promote invadopodia formation but the underlying pathway is not clear. Here we show that Src phosphorylates Tks5 at Y557, inducing it to associate directly with the SH3-SH2 domain adaptor proteins Nck1 and Nck2 in invadopodia. Tks5 mutants unable to bind Nck show reduced matrix degradation-promoting activity and recruit actin to invadopodia inefficiently. Conversely, Src- and Tks5-driven matrix proteolysis and actin assembly in invadopodia are enhanced by Nck1 or Nck2 overexpression and inhibited by Nck1 depletion. We show that clustering at the plasma membrane of the Tks5 inter-SH3 region containing Y557 triggers phosphorylation at this site, facilitating Nck recruitment and F-actin assembly. These results identify a Src-Tks5-Nck pathway in ECM-degrading invadopodia that shows parallels with pathways linking several mammalian and pathogen-derived proteins to local actin regulation.
- Published
- 2009
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