Inverse coupling in leak and voltage-activated K+ channel gates underlies distinct roles in electrical signaling.
Voltage-activated (Kv) and leak (K(2P)) K(+) channels have key, yet distinct, roles in electrical signaling in the nervous system. Here we examine how differences in the operation of the activation and slow inactivation pore gates of Kv and K(2P) channels underlie their unique roles in electrical signaling. We report that (i) leak K(+) channels possess a lower activation gate, (ii) the activation gate is an important determinant controlling the conformational stability of the K(+) channel pore, (iii) the lower activation and upper slow inactivation gates of leak channels cross-talk and (iv) unlike Kv channels, where the two gates are negatively coupled, these two gates are positively coupled in K(2P) channels. Our results demonstrate how basic thermodynamic properties of the K(+) channel pore, particularly conformational stability and coupling between gates, underlie the specialized roles of Kv and K(2P) channel families in electrical signaling.
Ben-Abu
Yuval
Y
Department of Life Sciences and the Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, P.O. Box 653, Beer Sheva 84105, Israel.
Zhou
Yufeng
Y
Zilberberg
Noam
N
Yifrach
Ofer
O
D000595:Amino Acid Sequence; D000818:Animals; D017124:Conserved Sequence; D029721:Drosophila Proteins / Q000737:chemistry / Q000502:physiology; D004355:Drug Stability; D004594:Electrophysiology; D015640:Ion Channel Gating / Q000502:physiology*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D024683:Potassium Channels, Tandem Pore Domain / Q000737:chemistry / Q000502:physiology*; D024642:Potassium Channels, Voltage-Gated / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000502:physiology*; D011199:Potentiometry; D011487:Protein Conformation; D016415:Sequence Alignment; D015398:Signal Transduction
D029721:Drosophila Proteins; D024683:Potassium Channels, Tandem Pore Domain; D024642:Potassium Channels, Voltage-Gated