2. A trans-membrane pore that presents a hydrophilic (dissolve in or mix with water) channel for ions to cross a lipid bilayer (layer two molecules thick) down their electrochemical gradients.
3. Protein expressed by virtually all living cells that creates a pathway for charged ions from dissolved salts, including sodium, potassium, calcium, and chloride ions, to pass through the otherwise impermeant lipid cell membrane.
Operation of cells in the nervous system, contraction of the heart and of skeletal muscle, and secretion in the pancreas are examples of physiological processes that require ion channels. In addition, ion channels in the membranes of intracellular organelles are important for regulating cytoplasmic calcium concentration and acidification of specific subcellular compartments
Ongoing basic research on ion channels seeks to understand the structural basis for permeability, ion selectivity, and gating at the molecular level.
Research efforts also attempt to answer questions about the cellular regulation of ion channel protein synthesis and about the subcellular distribution and ultimate degradation of channels.
In addition, compounds with greater specificity and potency for channels involved in pain sensation, cardiovascular disease, and other pathological conditions are potential sources for drug development.