ATP-Regulated Ion Channels in the Plasma Membrane of a Characeae Alga, Nitellopsis obtusa.

Using the patch-clamp technique, we recorded single-channel currents across the excised patch of the plasma membrane of Nitellopsis. Both K(+) and Na(+) can pass this channel, but currents were not carried by Cl(-). Upon the addition of ATP or AMP to the cytoplasmic side, the frequency of channel opening decreased. This is the first report on an ATP-regulated channel in plant cells.