Abstract
Most cells show a variety of reactions in response to external mechanical stimuli. Moreover internal forces are generated at various sites in the cell during cell-growth,-division, shape change, and migration, to modulate cell responses. Although cell mechanosensing is such a very important property of the cell, its mechanisms are largely unknown. The only identified cell mechanosensor at present is the SA channel with various types, among which a cation selective type is most popular. Activation of this channel increases intracellular Ca2+ level followed by activations of various signal cascades. However, it is controversial what forces are essential for SA channel activation, those in the membrane or in the cytoskeleton. I will show evidence that the SA channel in endothelial cells can be activated by the stress in the cytoskeleton, and discuss about the possibility that this activation mechanism gives the cell an ability of detecting force-direction.
