TRPC1 channels regulate directionality of migrating cells.

Cell migration depends on the generation of structural asymmetry and on different steps: protrusion and adhesion at the front and traction and detachment at the rear part of the cell. The activity of Ca(2+) channels coordinate these steps by arranging intracellular Ca(2+) signals along the axis of movement. Here, we investigated the role of the putative mechanosensitive canonical transient receptor potential channel 1 (TRPC1) in cell migration. We analyzed its function in transformed renal epithelial (Madin-Darby canine kidney-focus) cells with variation of TRPC1 expression. As shown by time lapse video microscopy, TRPC1 knockdown cells have partially lost their polarity and the ability to persistently migrate into a given direction. This failure is linked to the suppression of a local Ca(2+) gradient at the front of migrating TRPC1 knockdown cells, whereas TRPC1 overexpression leads to steeper Ca(2+) gradients. We propose that the Ca(2+) signaling events regulated by TRPC1 within the lamellipodium determine polarity and directed cell migration.