Forms a receptor-activated non-selective calcium permeant cation channel. Acts as a cell-cell contact-dependent endothelial calcium entry channel. Probably operated by a phosphatidylinositol second messenger system activated by receptor tyrosine kinases or G-protein coupled receptors. Mediates cation entry, with an enhanced permeability to barium over calcium. May also be activated by intracellular calcium store depletion.
Membrane; Multi-pass membrane protein. Cell membrane; Multi-pass membrane protein. Enhanced insertion into the cell membrane after activation of the EGF receptor.
Strongly expressed in placenta. Expressed at lower levels in heart, pancreas, kidney and brain. Expressed in endothelial cells. Isoform alpha was found to be the predominant isoform. Isoform beta was not found in pancreas and brain.