Probing the regulation of TASK potassium channels by PI(4,5)P 2 with switchable phosphoinositide phosphatases

Non‐technical summary  The electrical activity of nerve cells is produced by the flux of ions through specialized membrane proteins called ion channels. Some ion channels can be regulated by the signalling lipid PIP 2 , a component of the channels’ membrane environment. Here we examine the relevance of PIP 2 for the regulation of one specific channel type, termed TASK. Many chemical transmitters in the brain change neural activity by shutting off TASK channels and it has been suggested that this results from reduction of PIP 2 . By using novel techniques to alter the concentration of PIP 2 in living cells, we find that the activity of TASK is independent of PIP 2 . Besides demonstrating that another signalling mechanism must control the activity of nerve cells via TASK inhibition, we delineate a general approach for clarifying the relevance of PIP 2 in many cell types and organs.