Sommaire:

Actin, a major cytoskeletal biopolymer in eukaryotic cells, is crosslinked into networks of filaments and bundles. These networks are largely responsible for the maintenance of cellular shape, rigidity and mechanical stability. Other assemblies of actin are involved in a myriad of cellular processes, such as cell migration, division, intracellular transport and morphogenesis. In these processes, the spatial and temporal regulation of the network structure, their dynamics, and force generation due to myosin motors are crucial. Experimentally, one of the challenges is to measure force transmission across such networks, which is vital to properly understand function, failure and repair mechanisms beyond the linear regime. 

In this talk, I will focus on our recent work, where we have developed a FRET-based, reversible DNA force sensor to measure forces across the cytoskeletal network. Discussing the use of these DNA constructs as flexible crosslinkers across semiflexible actin, thereby reconstituting model networks of cytoskeletal structures in order to map force distributions and stress relaxations across the resulting network.  Where, the rheology and frequency response of these networks was probed via macro-rheology. I shall also describe how the DNA force sensor was characterized in solution and across actin networks through fluorescence lifetime imaging microscopy (FLIM) measurements. Bringing us to how we estimated the FRET efficiency of our DNA sensor and finally, testing of the DNA sensors for their function in living cells.

Pour plus d'informations, merci de contacter Walter J.-C.