ReviewKv2.1: A Voltage-Gated K+ Channel Critical to Dynamic Control of Neuronal Excitability
Section snippets
INTRODUCTION
Dynamic regulation of the intrinsic electrical excitability of neurons confers plasticity to neuronal function (Daoudal and Debanne, 2003). Neurons use a wide variety of mechanisms to precisely control electrical excitability. Voltage-dependent K+ (Kv) channels are especially diverse components of the channel repertoire that determine a neuron's intrinsic electrical excitability (Pongs, 1999). Neurons express a wide variety of Kv channels that can contribute to diverse aspects of neuronal
BIOSYNTHESIS, POST-TRANSLATIONAL MODIFICATIONS, AND INTRACELLULAR TRAFFICKING OF Kv2.1
Individual Kv channel Kv2.1 α subunit polypeptides have six transmembrane segments (termed S1–S6) and assemble post-translationally to form tetrameric complexes (Fig. 1). The ≈300 amino acid core domains containing the transmembrane S1–S6 segments present in each of the four α subunits co-assemble to form the major portions of both the voltage-sensing apparatus and ion-selective pore. Amino- and carboxyl-termini are cytoplasmic, such that all extracellular domains are found within the core
DYNAMIC MODULATION OF Kv2.1 IN NEURONAL ACTIVITY AND ITS ROLE IN NEURONAL SIGNALING
Persistent changes in intrinsic neuronal excitability in the face of sustained changes in synaptic input have been reported in different type of neurons. This phenomenon, a form of homeostatic plasticity (also as cellular or intrinsic plasticity), alters overall input–output function of a neuron and thus stabilize neuronal circuits by setting the optimal output level of each elements of the circuitry (Cantrell and Catterall, 2001, Daoudal and Debanne, 2003, Desai et al., 1999, Marder and Prinz,
POTENTIAL ROLES OF Kv2.1 IN NEURONS
Kv2.1, the major IK channel in cultured hippocampal neurons, is expressed at a very high level in virtually all brain neurons. This particular abundance presumably reflects a fundamental and general role for Kv2.1 in neurons. Kv2.1 has a single channel conductance of ∼10 pS when expressed in Xenopus oocytes (Chapman et al., 2001, Pascual et al., 1997, Taglialatela and Stefani, 1993). The activation and inactivation time constants are ∼10 ms (at 0 mV) and ∼3–5 s (at 10 mV in Xenopus oocytes),
Acknowledgement
Supported by NIH grant NS42225 (to JST).
References (62)
- et al.
Dynamic localization and clustering of dendritic Kv2.1 voltage-dependent potassium channels in developing hippocampal neurons
Neuroscience
(2001) - et al.
The K+ channel, Kv2.1, is apposed to astrocytic processes and is associated with inhibitory postsynaptic membranes in hippocampal and cortical principal neurons and inhibitory interneurons
Neuroscience
(1998) Reinsertion or degradation of AMPA receptors determined by activity-dependent endocytic sorting
Neuron
(2000)- et al.
Regulation of potassium channels by protein kinases
Curr Opin Neurobiol
(1996) - et al.
A novel targeting signal for proximal clustering of the Kv2.1 K+ channel in hippocampal neurons
Neuron
(2000) Potassium channels
FEBS Lett
(2003)- et al.
Subunit composition determines Kvl potassium channel surface expression
J Biol Chem
(2000) - et al.
Current compensation in neuronal homeostasis
Neuron
(2003) - et al.
Physical and genetic localization of a Shab subfamily potassium channel (KCNBl) gene to chromosomal region 20ql3.2
Genomics
(1995) - et al.
A novel primary culture system for biochemical analyses of neuronal proteins
J Neurosci Methods
(2005)