Cooperativity and cooperation in cyclic nucleotide-gated ion channels

CNG channels are highly sensitive to changes in cyclic nucleotide concentration. The variety of subfamilies that exist can coassemble to produce channels with a wide range of apparent affinities for cyclic nucleotide and with specificity for either cGMP or cAMP. Efforts to describe channel properties using physical models of channel function have resulted in increased understanding of how these channels work and how the different subfamilies relate to one another. As the number of subunits identified increases and our knowledge of channel function expands, we will be able to form a clearer picture of how these highly evolved cyclic nucleotide sensors perform their roles in a wide array of cell types.