Mg2+ binding to open and closed states can activate BK channels provided that the voltage sensors are elevated
نویسندگان
چکیده
منابع مشابه
Mg2+ binding to open and closed states can activate BK channels provided that the voltage sensors are elevated
BK channels are activated by intracellular Ca(2+) and Mg(2+) as well as by depolarization. Such activation is possible because each of the four subunits has two high-affinity Ca(2+) sites, one low-affinity Mg(2+) site, and a voltage sensor. This study further investigates the mechanism of Mg(2+) activation by using single-channel recording to determine separately the action of Mg(2+) on the ope...
متن کاملMg2+ mediates interaction between the voltage sensor and cytosolic domain to activate BK channels.
The voltage-sensor domain (VSD) of voltage-dependent ion channels and enzymes is critical for cellular responses to membrane potential. The VSD can also be regulated by interaction with intracellular proteins and ligands, but how this occurs is poorly understood. Here, we show that the VSD of the BK-type K(+) channel is regulated by a state-dependent interaction with its own tethered cytosolic ...
متن کاملMg2+ Enhances Voltage Sensor/Gate Coupling in BK Channels
BK (Slo1) potassium channels are activated by millimolar intracellular Mg(2+) as well as micromolar Ca(2+) and membrane depolarization. Mg(2+) and Ca(2+) act in an approximately additive manner at different binding sites to shift the conductance-voltage (G(K)-V) relation, suggesting that these ligands might work through functionally similar but independent mechanisms. However, we find that the ...
متن کاملVoltage sensor conformations in the open and closed states in ROSETTA structural models of K(+) channels.
Voltage-gated ion channels control generation and propagation of action potentials in excitable cells. Significant progress has been made in understanding structure and function of the voltage-gated ion channels, highlighted by the high-resolution open-state structure of the voltage-gated potassium channel, K(v)1.2. However, because the structure of the closed state is unknown, the gating mecha...
متن کاملVoltage Sensor Movement and cAMP Binding Allosterically Regulate an Inherently Voltage-independent Closed−Open Transition in HCN Channels
The hyperpolarization-activated cyclic nucleotide-modulated cation (HCN) channels are regulated by both membrane voltage and the binding of cyclic nucleotides to a cytoplasmic, C-terminal cyclic nucleotide-binding domain (CNBD). Here we have addressed the mechanism of this dual regulation for HCN2 channels, which activate with slow kinetics that are strongly accelerated by cAMP, and HCN1 channe...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of General Physiology
سال: 2011
ISSN: 1540-7748,0022-1295
DOI: 10.1085/jgp.201110707