[Store-operated cationic channels in human myeloid leukaemia K562 cells].
Using the whole-cell patch clamp technique, single channels operated by intracellular Ca(2+)-store depletion were first revealed in human myeloid leukaemia cells K562. A single store-operated channel could be detected in divalent-free extracellular solutions with Na+ as a permeant ion, and intracellular solutions with strong Ca(2+)-helating agent with some delay after whole-cell formation. Addition of inositol-1,4,5-triphosphate to the pipette solution resulted in a significant decrease of this latency. These channels had a conductance of 29 pS, and were inhibited by low concentration of external Ca2+. Our results enable us to assume that the revealed channels are calcium release-activated calcium channels, operated by Ca2+ depletion of endoplasmic reticulum.
Sergeev
Ia S
IaS
Institute of Cytology, RAS, St. Petersburg.
Glushankova
L N
LN
Neguliaev
Iu A
IuA
D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology; D015220:Calcium Channels / Q000737:chemistry / Q000378:metabolism*; D002412:Cations; D004721:Endoplasmic Reticulum / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D015544:Inositol 1,4,5-Trisphosphate; D020014:K562 Cells / Q000737:chemistry / Q000378:metabolism; D018408:Patch-Clamp Techniques; D012964:Sodium
D015220:Calcium Channels; D002412:Cations; D015544:Inositol 1,4,5-Trisphosphate; D012964:Sodium; D002118:Calcium