Figure 3 |. Molecular organisation of IACs.

a - b | Lateral composite nanocluster organisation. In mature FAs, extensive granularity and occasional alignments of nanoclusters into linear chains along actin templates can be observed in certain cell types^203,204. For integrin α5β1, active and inactive integrin segregate into distinct nanoclusters⁶¹ suggesting that nanoclusters could function as discrete units. Single-molecule analysis of integrin motion provides a consistent picture whereby integrin can diffuse freely through IACs. Integrin is immobilised in distinct loci which are comparatively enriched in IACs. c | Multilaminar architecture of FA. Schematic diagram depicting vertical organisation of various IAC components that have been analysed by SRM studies^59,87,89,205. Integrins are depicted in clusters of inactive (bent-closed), active (extended-open), as well as in tilted orientation as inferred from fluorescence anisotropy measurements¹³⁷. d | Podosomes or invadopodia are arrays of typically centrally located IAC structures, consisting of actin-rich core that protrude against and degrade ECM, surrounded by ring-like plaques containing IAC components. e | Vertical organisation of podosome ring featuring polarised orientation of talin, and similar organisation of paxillin and vinculin as in FA. f | Comparison of SRM-based spatial organization with sub-networks of IAC components identified by proteomic analysis (Fig. 2d). A putative IAC compartment anchored by KANK proteins that may potentially interface with microtubules is also depicted.