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). Activated by cAMP, and at 10-100 times higher concentrations, also by cGMP. May mediate responses to sour stimuli. Belongs to the potassium channel HCN family. Note: This description may include information from UniProtKB.
Protein type: Membrane protein, integral; Membrane protein, multi-pass