{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,15]],"date-time":"2026-05-15T02:06:22Z","timestamp":1778810782527,"version":"3.51.4"},"reference-count":0,"publisher":"Rockefeller University Press","issue":"1","content-domain":{"domain":["rupress.org"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[1992,1,1]]},"abstract":"<jats:p>Using the patch-clamp technique, we have identified two types of Ca(2+)-activated K+ (K(Ca)) channels in the human leukemic T cell line. Jurkat. Substances that elevate the intracellular Ca2+ concentration ([Ca2+]i), such as ionomycin or the mitogenic lectin phytohemagglutinin (PHA), as well as whole-cell dialysis with pipette solutions containing elevated [Ca2+]i, activate a voltage-independent K+ conductance. Unlike the voltage-gated (type n) K+ channels in these cells, the majority of K(Ca) channels are insensitive to block by charybdotoxin (CTX) or 4-aminopyridine (4-AP), but are highly sensitive to block by apamin (Kd less than 1 nM). Channel activity is strongly dependent on [Ca2+]i, suggesting that multiple Ca2+ binding sites may be involved in channel opening. The Ca2+ concentration at which half of the channels are activated is 400 nM. These channels show little voltage dependence over a potential range of -100 to 0 mV and have a unitary conductance of 4-7 pS in symmetrical 170 mM K+. In the presence of 10 nM apamin, a less prevalent type of K(Ca) channel with a unitary conductance of 40-60 pS can be observed. These larger-conductance channels are sensitive to block by CTX. Pharmacological blockade of K(Ca) channels and voltage-gated type n channels inhibits oscillatory Ca2+ signaling triggered by PHA. These results suggest that K(Ca) channels play a supporting role during T cell activation by sustaining dynamic patterns of Ca2+ signaling.<\/jats:p>","DOI":"10.1085\/jgp.99.1.63","type":"journal-article","created":{"date-parts":[[2004,5,13]],"date-time":"2004-05-13T23:48:59Z","timestamp":1084492139000},"page":"63-84","update-policy":"https:\/\/doi.org\/10.1085\/jgp.crossmarkpolicy","source":"Crossref","is-referenced-by-count":88,"title":["Ca(2+)-activated K+ channels in human leukemic T cells."],"prefix":"10.1085","volume":"99","author":[{"given":"S","family":"Grissmer","sequence":"first","affiliation":[{"name":"Department of Physiology and Biophysics, University of California, Irvine 92717."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"R S","family":"Lewis","sequence":"additional","affiliation":[{"name":"Department of Physiology and Biophysics, University of California, Irvine 92717."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"M D","family":"Cahalan","sequence":"additional","affiliation":[{"name":"Department of Physiology and Biophysics, University of California, Irvine 92717."}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"291","published-online":{"date-parts":[[1992,1,1]]},"container-title":["The Journal of general physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/rupress.org\/jgp\/article-pdf\/99\/1\/63\/1814763\/63.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/rupress.org\/jgp\/article-pdf\/99\/1\/63\/1814763\/63.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,7,27]],"date-time":"2023-07-27T12:38:01Z","timestamp":1690461481000},"score":1,"resource":{"primary":{"URL":"https:\/\/rupress.org\/jgp\/article\/99\/1\/63\/27987\/Ca-2-activated-K-channels-in-human-leukemic-T"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1992,1,1]]},"references-count":0,"journal-issue":{"issue":"1","published-print":{"date-parts":[[1992,1,1]]}},"URL":"https:\/\/doi.org\/10.1085\/jgp.99.1.63","relation":{},"ISSN":["0022-1295","1540-7748"],"issn-type":[{"value":"0022-1295","type":"print"},{"value":"1540-7748","type":"electronic"}],"subject":[],"published":{"date-parts":[[1992,1,1]]}}}