Kv2.1 and silent Kv subunits underlie the delayed rectifier K+ current in cultured small mouse DRG neurons
AUTOR(ES)
Bocksteins, Elke
FONTE
American Physiological Society
RESUMO
Silent voltage-gated K+ (Kv) subunits interact with Kv2 subunits and primarily modulate the voltage dependence of inactivation of these heterotetrameric channels. Both Kv2 and silent Kv subunits are expressed in the mammalian nervous system, but little is known about their expression and function in sensory neurons. This study reports the presence of Kv2.1, Kv2.2, and silent subunit Kv6.1, Kv8.1, Kv9.1, Kv9.2, and Kv9.3 mRNA in mouse dorsal root ganglia (DRG). Immunocytochemistry confirmed the protein expression of Kv2.x and Kv9.x subunits in cultured small DRG neurons. To investigate if Kv2 and silent Kv subunits are underlying the delayed rectifier K+ current (IK) in these neurons, Kv2-mediated currents were isolated by the extracellular application of rStromatoxin-1 (ScTx) or by the intracellular application of Kv2 antibodies. Both ScTx- and anti-Kv2.1-sensitive currents displayed two components in their voltage dependence of inactivation. Together, both components accounted for approximately two-thirds of IK. A comparison with results obtained in heterologous expression systems suggests that one component reflects homotetrameric Kv2.1 channels, whereas the other component represents heterotetrameric Kv2.1/silent Kv channels. These observations support a physiological role for silent Kv subunits in small DRG neurons.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2692416Documentos Relacionados
- Block by 4-aminopyridine of a Kv1.2 delayed rectifier K+ current expressed in Xenopus oocytes.
- Reduced Delayed-Rectifier K+ Current in the Learning Mutant rutabaga
- Cloning and expression of a Kv1.2 class delayed rectifier K+ channel from canine colonic smooth muscle.
- External blockade of the major cardiac delayed-rectifier K+ channel (Kv1.5) by polyunsaturated fatty acids.
- Multiple components of delayed rectifier K+ current in canine colonic smooth muscle.