Ca2+-activated K+ channels in human leukemic Jurkat T cells

52Citations
Citations of this article
20Readers
Mendeley users who have this article in their library.

This article is free to access.

Abstract

Previous studies have demonstrated the presence of apamin-sensitive, small-conductance Ca2+-activated K+ currents in human leukemic Jurkat T cells. Using a combined cDNA and reverse transcriptase-polymerase chain reaction cloning strategy, we have isolated from Jurkat T cells a 2.5-kilobase cDNA, hSK2, encoding the human isoform of SK2 channels. Northern blot analysis reveals the presence of a 2.5-kilobase hSK2 transcript in Jurkat T cells. While present in various human tissues, including brain, heart, skeletal muscle, kidney, and liver, no hSK2 mRNA could be detected in resting and activated normal human T cells. The hSK2 gene is encoded by 8 exons and could be assigned to chromosome 5 (q21.2-q22.1). The protein encoded by hSK2 is 579 amino acids long and exhibits 97% identity with its rat counterpart rSK2. When expressed in Chinese hamster ovary cells, hSK2 produces Ca2+-activated K+ currents with a unitary conductance of 9.5 pS and a K0.5 for calcium of 0.7 μM; hSK2 currents are inhibited by apamin, scyllatoxin, and d-tubocurarine. Overexpression of the Src family tyrosine kinase p56lck in Jurkat cells, upregulates SK2 currents by 3-fold. While IKCa channels are transcriptionally induced upon activation of normal human T cells, our results show that in Jurkat cells SK2 channels are constitutively expressed and down-regulated following mitogenic stimulation.

References Powered by Scopus

Single-Step Method of RNA Isolation by Acid Guanidinium Thiocyanate-Phenol-Chloroform Extraction

66959Citations
N/AReaders
Get full text

Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches

15802Citations
N/AReaders
Get full text

An analysis of 5'-noncoding sequences from 699 vertebrate messenger rNAS

4698Citations
N/AReaders
Get full text

Cited by Powered by Scopus

Molecular background of leak K<sup>+</sup> currents: Two-pore domain potassium channels

703Citations
N/AReaders
Get full text

Molecular properties and physiological roles of ion channels in the immune system

218Citations
N/AReaders
Get full text

Modulators of small- and intermediate-conductance calcium-activated potassium channels and their therapeutic indications

184Citations
N/AReaders
Get full text

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Cite

CITATION STYLE

APA

Desai, R., Peretz, A., Idelson, H., Lazarovici, P., & Attali, B. (2000). Ca2+-activated K+ channels in human leukemic Jurkat T cells. Journal of Biological Chemistry, 275(51), 39954–39963. https://doi.org/10.1074/jbc.M001562200

Readers' Seniority

Tooltip

Professor / Associate Prof. 7

44%

PhD / Post grad / Masters / Doc 7

44%

Researcher 2

13%

Readers' Discipline

Tooltip

Agricultural and Biological Sciences 6

38%

Neuroscience 4

25%

Chemistry 3

19%

Medicine and Dentistry 3

19%

Article Metrics

Tooltip
Mentions
References: 2

Save time finding and organizing research with Mendeley

Sign up for free