One step ahead: Role of filopodia in adhesion formation during cell migration of keratinocytes

The key feature for early migratory processes

“…For this reason we first analyzed stably adhered filopodial FXs in locomoting keratinocytes over time. As already shown before, 10 filopodial FX remained in place when overgrown by the lamellipodial leading edge to form classical FAs just by enlargement (Fig. 1A, Suppl.…”

“…9,10,28 Unfortunately, structural as well as functional analyses over the whole lifetime of lamellipodial structures of filopodial origin are rare. For this reason we first analyzed stably adhered filopodial FXs in locomoting keratinocytes over time.…”

“…Upon maturation this set of proteins changes for lamellipodial FXs 7,22,23 whereas filopodial FX protein composition seems to be rather complete and stable during maturation. 10 However, and palladin (Fig. 4E) transfected cells were fixed and additionally stained for actin.…”

“…Former results by Schäfer et al 10 argue for the formation of filopodial focal contacts upon filopodia binding to matrix molecules. Although the exact hierarchical recruitment of adhesion proteins still needs to be solved, latest findings now argue for a rather complete set of adhesion proteins already at these very early time points.…”

“…7 In addition, for cell types forming filopodia latest research has shown an important role of these finger-like extensions in cell spreading 8 and adhesion assembly during migration. 9,10 Here, nearly all lamellipodial focal adhesions (FAs) evolve from small focal complexes (FXs) originally assembled within filopodia and just increased in size when overgrown by the lamellipodial leading edge. Filopodia are dynamic structures that enclose a bundle of tightly packed actin fibers arising from the tip complex and cross-linked by fascin.…”