Nck1 and Grb2 localization patterns can distinguish invadopodia from podosomes.
Invadopodia are matrix-degrading ventral cell surface structures formed in invasive carcinoma cells. Podosomes are matrix-degrading structures formed in normal cell types including macrophages, endothelial cells, and smooth muscle cells that are believed to be related to invadopodia in function. Both invadopodia and podosomes are enriched in proteins that regulate actin polymerization including proteins involved in N-WASp/WASp-dependent Arp2/3-complex activation. However, it is unclear whether invadopodia and podosomes use distinct mediators for N-WASp/WASp-dependent Arp2/3-complex activation. We investigated the localization patterns of the upstream N-WASp/WASp activators Nck1 and Grb2 in invadopodia of metastatic mammary carcinoma cells, podosomes formed in macrophages, and degradative structures formed in Src-transformed fibroblasts and PMA-stimulated endothelial cells. We provide evidence that Nck1 specifically localizes to invadopodia, but not to podosomes formed in macrophages or degradative structures formed in Src-transformed fibroblasts and PMA-stimulated endothelial cells. In contrast, Grb2 specifically localizes to degradative structures formed in Src-transformed fibroblasts and PMA-stimulated endothelial cells, but not invadopodia or podosomes formed in macrophages. These findings suggest that distinct upstream activators are responsible for N-WASp/WASp activation in invadopodia and podosomes, and that all these ventral cell surface degradative structures have distinguishing molecular as well as structural characteristics. These patterns of Nck1 and Grb2 localization, identified in our study, can be used to sub-classify ventral cell surface degradative structures.
Oser
Matthew
M
Department of Anatomy and Structural Biology, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY 10461, USA. matthew.oser@med.einstein.yu.edu
Dovas
Athanassios
A
Cox
Dianne
D
Condeelis
John
J
D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology; D022081:Cell Surface Extensions / Q000378:metabolism*; D003599:Cytoskeleton / Q000378:metabolism*; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism*; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D051380:GRB2 Adaptor Protein / Q000378:metabolism*; D006801:Humans; D008264:Macrophages / Q000166:cytology / Q000378:metabolism; D015513:Oncogene Proteins / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000031:analogs & derivatives / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal / Q000378:metabolism
D048868:Adaptor Proteins, Signal Transducing; D051380:GRB2 Adaptor Protein; C078332:Nck protein; D015513:Oncogene Proteins; C495771:WASL protein, human; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal; C016658:phorbolol myristate acetate; D013755:Tetradecanoylphorbol Acetate