Functional Coupling of Ion Channels in the Process of Mechano-Dependent Activation in the Membrane of K562 Cells

Abstract

Mechanically gated cation channels that are activated upon deformation of the membrane are key participants in the transmission of mechanical signals from the cell surface to cytoplasmic structures. It has remained unclear how mechanically dependent reactions involving ion channels in native cells are realized. In this study, we analyzed the development of the activity of single channels in K562 human myeloid leukemia cells in response to the delivery of a mechanical stimulus, this being stretching of the membrane area. The registration of ion currents using the classic versions of the patch–clamp method allowed revealing the functional clustering and interaction of various types of channels in the plasma membrane during mechanotransduction. In K562 cells, coupled activation of mechanosensitive calcium-conducting channels and calcium-activated potassium channels was detected. Real-time recordings of currents demonstrate that the calcium influx from the extracellular medium into the cytoplasm through mechanically gated channels activates potassium channels that are colocalized with them, which do not have their own mechanosensitivity. In experiments on K562 cells and transformed 3T3-SV40 fibroblasts, the preservation of the functional conjugation of the channels during their mechanically gated activation after the action of the microfilament destructor cytochalasin D was shown. The results suggest that clusters including potassium SK channels and Piezo1/2 proteins forming stretch-activated cation channels function in the plasma membrane of K562 and 3T3-SV40 cells.