Full-length and truncated @entity2302 K+ channels are modulated by XXXX receptor activation and independently by PKC.

@entity36216 @entity1522 @entity36768 @entity1238 @entity19 @entity2302 @entity2733 @entity750 @entity141 @entity669 @entity4996 @entity10179
In T-cells, the Shaker-related gene, @entity2302 encodes the type n K+ channel, whereas the type l channel is a product of the Shaw. subfamily gene, @entity36216 . Both these genes are also expressed in the brain. We have used the @entity1238 oocyte heterologous expression system to study the modulatory effects of @entity750 ( @entity750 , @entity750 ) on both these cloned channels. In oocytes coexpressing the @entity19 @entity36768 receptor and @entity19 @entity2302 channel, addition of 100 nM @entity750 causes a complete and sustained suppression of @entity2302 currents in approximately 20 min. In contrast, @entity750 has no effect on @entity19 @entity36216 currents when coexpressed with @entity36768 receptor. The @entity750 -mediated suppression of @entity2302 currents proceeds via activation of a pertussis toxin-sensitive G protein and a subsequent rise in intracellular @entity141 , but @entity141 does not directly block the channel. @entity10179 ( @entity10179 ) C activation is not part of the pathway linking @entity36768 receptor to @entity2302 channels. However, @entity4996 independently suppress @entity2302 currents. Deletion of the first 146 @entity1522 from the @entity2733 -terminal, containing putative @entity669 kinase and PKA phosphorylation sites, does not alter the time course of @entity750 -mediated suppression of @entity2302 currents, indicating that these residues are not necessary for modulation. Treatment of oocytes with calmodulin or phosphatase inhibitors does not alter @entity750 -mediated modulation. Collectively, these experiments indicate that the @entity19 @entity2302 channel is capable of being modulated by @entity750 via @entity36768 receptor in a G protein and @entity141 -dependent manner, but the subsequent steps in the pathway remain elusive.(ABSTRACT TRUNCATED AT 250 WORDS)
