SK2 encodes the apamin‐sensitive Ca2+‐activated K+ channels in the human leukemic T cell line, Jurkat

FEBS Letters

Adelman, John P.¹  Grissmer, Stephan²  Jäger, Heike² 

[1] Vollum Institute, Oregon Health Sciences University, Portland, OR 97201-3098, USA;Department of Applied Physiology, University of Ulm, Albert-Einstein-Allee 11, D-89081 Ulm, Germany

关键词: Jurkat T lymphocyte;    Small conductance Ca2+-activated K+ channel;    Apamin;    Patch-clamp technique;    K(Ca) channel gene;    Molecular biology;   

DOI  :  10.1016/S0014-5793(00)01236-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

T cells express two different types of voltage-independent Ca²⁺-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, Ca²⁺-activated, apamin-sensitive, show an equivalent voltage-dependent Ba²⁺ 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.

【 授权许可】

Unknown