We also use TIRF microscopy to reveal structures close to the membrane within living cells. The  epithelial cell below  is expressing GFP-labelled myosin IIA which becomes localised within stress fibres and focal adhesions. The time course of fluorescence recovery after photobleaching the region encircled (FRAP) shows that myosin exchange within these structures occurs over several tens of seconds(measurement in collaboration with Dr M. Kriajevska).

Our particular focus is on the mechanism of interaction of S100A4 with one of its targets, non-muscle myosin IIA. We are correlating solution-based kinetic measurements of Ca²⁺ and myosin tail binding (Gingras et al, 2008) with events observed in living cells.