Referenced in: none

Automatically associated channels: SK2 , SK3

Title: SK2 encodes the apamin-sensitive Ca(2+)-activated K(+) channels in the human leukemic T cell line, Jurkat.

Authors: H Jäger, J P Adelman, S Grissmer

Journal, date & volume: FEBS Lett., 2000 Mar 10 , 469, 196-202

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/10713270

Abstract
T cells express two different types of voltage-independent Ca(2+)-activated K(+) channels with small (SK) and intermediate (IK) conductance that serve important roles in the activation of T lymphocytes. In contrast to the IK channels from T lymphocytes which are upregulated upon mitogen stimulation, SK channels of Jurkat T cells, a human leukemic T cell line, are constitutively expressed even in the absence of mitogenic stimulation. We have used patch-clamp recordings from transfected or injected mammalian cells to show that the cloned SK2 channel demonstrates the biophysical and pharmacological properties of the majority of K(Ca) channels in Jurkat T cells. The cloned and native channels are voltage-independent, Ca(2+)-activated, apamin-sensitive, show an equivalent voltage-dependent Ba(2+) block and possess a similar ion selectivity. In addition, we used the polymerase chain reaction to demonstrate the presence of SK2 mRNA in Jurkat T cells, whereas SK3 transcripts encoding the other cloned apamin-sensitive SK channel were not detected. These data suggest that the voltage-independent apamin-sensitive K(Ca) channel in Jurkat T cells represents the recently cloned SK2 channel.