Cysteines control the N- and C-linker-dependent gating of KCNH1 potassium channels

► KCNH1 potassium channels are exceptionally sensitive to oxidative modification. ► Thiol-dependent modification of channel gating occurs in two different ways. ► C145/C214 in the N-linker are responsible for fast modification. ► C532/C562 in the C-linker are responsible for slow modification. ► Redox regulation determines information flow from the cytosolic termini to the channel's gate.