Click here to close Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly. We suggest using a current version of Chrome, FireFox, or Safari.
XB-ART-21745
Biophys J 1994 Jan 01;661:179-90.
Show Gene links Show Anatomy links

Rescue of lethal subunits into functional K+ channels.

Taglialatela M , Payne JP , Drewe JA , Brown AM .


???displayArticle.abstract???
In a chimeric, voltage-dependent K+ channel (CHM), the valine at position 369 and the leucine at position 374 interact within the pore or P-region to regulate ion permeation and block. Here we show that the point mutation, CHM V369L, abolished channel function whereas previous experiments showed that CHM V369 and CHM V369I are functional. Coinjection of "lethal" CHM V369L cRNA with CHM L374V cRNA but not CHM cRNA generated functional heteromultimers. The whole-cell Rb+/K+ conductance ratio was 2.98 +/- 0.43 for CHM L374V and was reduced to 0.87 +/- 0.04 for the coexpressed CHM V369L and CHM L374V subunits. When single-channel currents were recorded, a single class of CHM V369L/CHM L374V heteromultimers was identified. This class was readily distinguishable from CHM L374V homomultimers by K+ conductance, gating, and blockade by internal tetraethylammonium. Coinjection experiments at various RNA ratios suggest that the CHM V369L/CHM L374V heteromultime, assuming it to be a tetramer, was composed of three CHM L374V subunits and one CHM V369L subunit. It appears that in the critical P-region of CHM position 369 may tolerate only one leucine.

???displayArticle.pubmedLink??? 8130337
???displayArticle.pmcLink??? PMC1275678
???displayArticle.link??? Biophys J
???displayArticle.grants??? [+]

Species referenced: Xenopus laevis

References [+] :
Armstrong, Interaction of tetraethylammonium ion derivatives with the potassium channels of giant axons. 1971, Pubmed