Invadosomas

Cell Science at a Glance

3009
Podosomes and invadopodia (which can be subsumed under the umbrella term ‘invadosomes’) are cellular structures that establish close contact with the extracellular matrix (ECM). In contrast to similar structures such as focal adhesions, they are also able to degrade components of the ECM [for a comparison between podosomes and focal adhesions, see Block et al.(Block et al., 2008)]. Invadosomes are, therefore, thought to be key structures of cell invasion. Accordingly, much effort is currently focused on their potential roles in both physiological and pathological invasive processes, such as transendothelial diapedesis and inflammation, and atherosclerosis and metastasis. This poster article provides an introduction to the field, discusses currentlyinvestigated topics in invadosome regulation and points out future challenges for invadosome-related research.
Identification Podosomes and invadopodia share common features that can be used to distinguish them from other cell-matrix contacts or superficially similar structures. For example, both present as dot-like accumulations of filamentous actin (F-actin) at the substratecontacting side of thecell. Typical markers include actin-regulatory proteins such as the Arp2/3 complex, cortactin and WASP or N-WASP (Linder and Aepfelbacher, 2003; Buccione et al., 2004; Gimona and Buccione, 2006; Weaver, 2006; Linder, 2007; Buccione et al., 2009), which colocalize with the actinrich core of both structures. Moreover, many components of invadosomes are regulated by tyrosine kinase signaling, resultingin a high local enrichment of phosphotyrosine residues (Linder and Aepfelbacher, 2003; Luxenburg et al., 2006).

Invadosomes at a glance
Stefan Linder
Institut für Prophylaxe und Epidemiologie der Kreislaufkrankheiten, Ludwig-MaximiliansUniversität, Pettenkoferstr. 9, 80336 München, Germany Present address: Institut für Medizinische Mikrobiologie, Virologie und Hygiene, UniversitätsklinikumEppendorf, Campus Forschung, Martinistr. 52, 20246 Hamburg, Germany s.linder@uke.de
Journal of Cell Science 122, 3009-3013 Published by The Company of Biologists 2009 doi:10.1242/jcs.032631

This article is part of a Minifocus on invadopodia and podosomes. For further reading, please see related articles: ‘Matrix invasion by tumour cells: a focus on MT1-MMP trafficking to invadopodia’ by RenaudPoincloux et al. (J. Cell Sci. 122, 3015-3024), ‘Mechanisms for transcellular diapedesis: probing and pathfinding by ‘invadosome-like protrusions’’ by Christopher V. Carman (J. Cell Sci. 122, 3025-3035) and ‘Actin machinery and mechanosensitivity in invadopodia, podosomes and focal adhesions’ by Corinne Albiges-Rizo et al. (J. Cell Sci. 122, 3037-3049).

Journal of Cell Science

Invadosomes ata Glance
Stefan Linder
What are invadosomes?
Podosomes and invadopodia (subsumed under the umbrella term ‘invadosomes’) are cell-matrix contacts that establish close contact with the ECM. In contrast to similar structures, such as focal adhesions, they are also able to degrade ECM components. Therefore, invadosomes are thought to be key structures in both physiological and pathologicalprocesses that involve cell invasion. Podosomes Invadopodia Podosomes in a primary macrophage (left) and invadopodia in a melanoma cell (right). Note the two-part architecture of podosomes, which have a core structure (stained for F-actin, blue) and a surrounding ring structure (stained for vinculin, red). By contrast, invadopodia mostly comprise core structures [stained for F-actin (blue) and cortactin(red)]. Image credits: Vanessa van Vliet (left-hand image) and Roberto Buccione (right-hand image).
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Key features of invadosomes
Appearance Localization Composition Podosomes Dot-like On side of cell that is attached to substrate F-actin Actin regulators (cortactin, WASP or N-WASP, Arp2/3) Focal-adhesion proteins (e.g. vinculin, paxillin, talin, kindlin) Phosphotyrosine Monocytic...