KV4.2 | Shal Related Potassium Channel Member 2
Shaker (KV1.1–KV1.8), Shab (KV2.1-KV2.2), Shaw (KV3.1–KV3.4), Shal (KV4.1–KV4.3), KQT like (KV7.1–KV7.5), Eag related (KV10.1-KV10.2), Erg related (KV11.1–KV11.3), Elk related (KV12.1)
Contains six transmembrane domains (S1–S6), four single subunits form a pore, homotetramers and heterotetramers are possible.
KV4.2 Background Information
KV4.2 is a voltage-gated potassium channel that mediates transmembrane potassium transport in excitable membranes, primarily in the brain. It mediates the major part of the dendritic A-type current ISA in brain neurons. ISA is triggered at membrane potentials that are below the threshold for action potentials. KV4.2 inactivates rapidly and recovers rapidly from inactivation. It regulates the firing of action potentials and plays a role in synaptic integration and plasticity. Potassium channels containing KV4.2 account for about 80% of the neuronal A-type potassium current. In contrast, the potassium channel responsible for the cardiac Ito current differs between species; it is mediated by KV4.2 in rodents. In human and other non-rodents KV4.3 may play an equivalent role.
Brain: in neurons, primarily detected on dendrites, dendritic spines and on the neuron cell body, but not on axons.
The channel regulates neuronal excitability in the brain. It prolongs the latency before the first spike in a series of action potentials, regulates the frequency of repetitive action potential firing, shortens the duration of action potentials and regulates the back-propagation of action potentials from the neuronal cell body to the dendrites.
Homotetramer or heterotetramer with KCND1 or KCND3. Associates with the regulatory subunits KCNIP1, KCNIP2, KCNIP3 and KCNIP4, DPP6, DPP10
DLG1, DLG4, NCS1/FREQ, FLNA, FLNC
Quinidine, phrixotoxin 1, arachidonic acid
Patch Clamp: whole cell
Reviews and Links
- Gutman et al. (2005) International Union of Pharmacology. LIII. Nomenclature and molecular relationships of voltage-gated potassium channels. Pharmacol Rev 57(4):473-508