Extracellular engagement of ADAM12 induces clusters of invadopodia with localized ectodomain shedding activity.
Invadopodia are dynamic actin structures at the cell surface that degrade extracellular matrix and act as sites of signal transduction. The biogenesis of invadopodia, including the mechanisms regulating their formation, composition, and turnover is not entirely understood. Here, we demonstrate that antibody ligation of ADAM12, a transmembrane disintegrin and metalloprotease, resulted in the rapid accumulation of invadopodia with extracellular matrix-degrading capacity in epithelial cells expressing the αvβ3 integrin and active c-Src kinase. The induction of invadopodia clusters required an intact c-Src interaction site in the ADAM12 cytoplasmic domain, but was independent of the catalytic activity of ADAM12. Caveolin-1 and transmembrane protease MMP14/MT1-MMP were both present in the ADAM12-induced clusters of invadopodia, and cholesterol depletion prevented their formation, suggesting that lipid-raft microdomains are involved in the process. Importantly, our data demonstrate that ADAM12-mediated ectodomain shedding of epidermal growth factor receptor ligands can occur within these invadopodia. Such localized growth factor signalling offers an interesting novel biological concept highly relevant to the properties of carcinoma cells, which often show upregulated ADAM12 and β3 integrin expression, together with high levels of c-Src kinase activity.
Albrechtsen
Reidar
R
Department of Biomedical Sciences & Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Ole Maaløes Vej 5, 2200 Copenhagen, Denmark.
Stautz
Dorte
D
Sanjay
Archana
A
Kveiborg
Marie
M
Wewer
Ulla M
UM
D051722:ADAM Proteins / Q000235:genetics / Q000378:metabolism*; D000072199:ADAM12 Protein; D000199:Actins / Q000235:genetics / Q000378:metabolism*; D051242:Caveolin 1 / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D002462:Cell Membrane / Q000235:genetics / Q000378:metabolism*; D005109:Extracellular Matrix / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D039302:Integrin alphaVbeta3 / Q000235:genetics / Q000378:metabolism; D007668:Kidney / Q000166:cytology; D053511:Matrix Metalloproteinase 14 / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding / Q000235:genetics; D019030:Receptors, Vitronectin / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics; D014162:Transfection; D019061:src-Family Kinases / Q000235:genetics / Q000378:metabolism
D000199:Actins; D051242:Caveolin 1; D039302:Integrin alphaVbeta3; D008565:Membrane Proteins; D019030:Receptors, Vitronectin; D019061:src-Family Kinases; D051722:ADAM Proteins; D000072199:ADAM12 Protein; C000606480:ADAM12 protein, human; C507086:MMP14 protein, human; D053511:Matrix Metalloproteinase 14