Cryo-electron tomography and mathematical modelling reveal forces created by actin networks inside cells as they move and grip
Cells rely on a flexible skeleton of tiny actin filaments, prodding into the cellular floor like tent poles anchored in the living environment around them. Here they’re revealed – virtually sifted out like treasure trove from sand using a technique called electron cryotomography. The actin fibres in this human cell are highlighted in rainbow colours based on their orientation towards the floor. They form a dense stack alongside other fibres (brown) nestling below the cell’s organelles (grey) in cell regions called podosomes. With help from mathematical modelling, researchers find the complex mesh of fibres pulls together to store large amounts of elastic energy in the central core of bending actin fibres – like coiled springs they punch out, helping the cell to feel grip or destroy the surrounding environment. These models used may now be adapted to investigate forces in other cells, perhaps during development or during the spread of cancer.
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