CLONED POTASSIUM CHANNELS FROM EUKARYOTES AND PROKARYOTES

Potassium channels contribute to the excitability of neurons and signa ling in the nervous system. They arise from multiple gene families inc luding one for voltage-gated potassium channels and one for inwardly r ectifying potassium channels. Features of potassium permeation, channe l gating and regulation, and subunit interaction have been analyzed. P otassium channels of similar design have been found in animals ranging from jellyfish to humans, as well as in plants, yeast, and bacteria. Structural similarities are evident for the pore-forming alpha subunit s and for the beta subunits, which could potentially regulate channel activity according to the level of energy and/or reducing power of the cell.