Hyperpolarization-activated ion channel exhibiting weak selectivity for potassium over sodium ions . Contributes to the native pacemaker currents in heart (If) and in neurons (Ih). May mediate responses to sour stimuli.
Subcellular locations: Cell membrane
Detected in brain, in particular in amygdala and hippocampus, while expression in caudate nucleus, corpus callosum, substantia nigra, subthalamic nucleus and thalamus is very low or not detectable. Detected at very low levels in muscle and pancreas.