ELKIN1-dependent Ca++ flickers in melanoma cells depend on acto-myosin contractility

Melanoma cell migration is influenced by the expression of ELKIN1, an ion channel that supports mechanically-evoked currents when mechanical stimuli are applied to the cell-substrate interface, via the substrate. The deletion of ELKIN1 from melanoma cells impacts cell migration, cell invasion and cellular adaptation to changing gravitational loads. Here, we investigated whether ELKIN1 mediates calcium flickers at the cell-substrate interface as an indicator of channel activity, in the absence of externally applied forces. We found that calcium flickers can be detected in WM266/4 melanoma cells and that these flickers largely depended on ELKIN1 expression and acto-myosin contractility. Residual calcium flicker activity was detected in cells lacking ELKIN1, that was found to depend, in part, on TRPV4. However, this activity was not further blocked by inhibition of cellular contractility. These data suggest that ELKIN1 dependent signalling can be initiated by mechanical cues arising from cellular contractility.