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This Article Full Text Full Text (PDF) All Versions of this Article: 100/4/2125    most recent 90667.2008v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Pineda, R. H. Articles by Ribera, A. B. PubMed PubMed Citation Articles by Pineda, R. H. Articles by Ribera, A. B.

Kv1 Potassium Channel Complexes In Vivo Require Kvβ2 Subunits in Dorsal Spinal Neurons

¹Department of Physiology and Biophysics and ²Department of Pediatrics, University of Colorado Denver at Anschutz Medical Campus, Aurora, Colorado

Submitted 11 June 2008; accepted in final form 31 July 2008

Whereas Kvβ2 subunits modulate potassium current properties carried by Kv1 channel complexes in heterologous systems, little is known about the contributions of Kvβ2 subunits to native potassium channel function. Using antisense approaches and in situ recordings from Xenopus embryo spinal cord neurons, we tested the in vivo roles of Kvβ2 subunits in modulation of voltage-dependent potassium current (I_Kv). We focused on 1) two different populations of dorsal spinal neurons that express both Kvβ2 and Kv1 -subunit genes and 2) the 24- and 48-h developmental period, during which I_Kv undergoes developmental regulation. At both 24 and 48 h, antisense methods produced efficient knock-down of both Kvβ2 protein and I_Kv. At both times, dominant negative suppression of Kv1 channels also eliminated I_Kv, indicating that Kv1 channels require Kvβ2 subunits to function in dorsal spinal neurons. Even though Kv1 channels determined the I_Kv values of both dorsal neuron types, comparisons of their I_Kv properties revealed important differences at both developmental stages. The latter results support the notion that different Kv1 -subunits and/or posttranslational modifications underlie the I_Kv values of the two dorsal neuron types. Overall, the results demonstrate that Kvβ2 subunits function in vivo as obligatory subunits of Kv1 channels in at least two neuron types and two different developmental stages.