An ion channel with a doorkeeper: The pH of calcium ions controls ion channel opening

(Johannes Gutenberg Universitaet Mainz) Ion channels are pores in the membrane of cells or cell organelles that allow ions to be transported across the membrane. Biochemists have now succeeded in imaging an important regulatory region of the human TRPML2 calcium ion channel at high resolution, an area of the channel shaped like a large ring on one side of the membrane. This ring acts like a doorman, deciding whether ions can move through the channel.