Characterization of a novel intracellular sphingolipid-gated Ca(2+)-permeable channel from rat basophilic leukemia cells

Sphingolipids stimulate the release of Ca2+ from intracellular stores. However, the mechanism by which this process occurs has not been characterized. Through single-channel recording from microsomes incorporated into planar lipid bilayers, we describe a novel channel that gates Ba2+ in response to...

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Bibliographic Details
Published inThe Journal of biological chemistry Vol. 269; no. 18; pp. 13088 - 13091
Main Authors Kindman, L A, Kim, S, McDonald, T V, Gardner, P
Format Journal Article
LanguageEnglish
Published United States American Society for Biochemistry and Molecular Biology 06.05.1994
Subjects
Animals
Calcium Channel Blockers - pharmacology
Calcium Channels - metabolism
Ion Channel Gating
Leukemia, Basophilic, Acute
Lipid Bilayers
Rats
Sphingolipids - metabolism
Tumor Cells, Cultured
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Summary:Sphingolipids stimulate the release of Ca2+ from intracellular stores. However, the mechanism by which this process occurs has not been characterized. Through single-channel recording from microsomes incorporated into planar lipid bilayers, we describe a novel channel that gates Ba2+ in response to sphingosylphosphorylcholine. The channel is both ligand-gated and voltage-modulated. Maximal open probability is observed between -10 and -20 mV and has a relatively high conductance (160 picosiemens with 53 mM Ba2+). We also observe that Ca2+ efflux from permeabilized rat basophilic leukemia cells is not antagonized by heparin, La3+, Ni2+, nifedipine, or omega-conotoxin GVIa. The sphingolipid-gated Ca(2+)-permeable channel is therefore a new member of the Ca(2+)-permeable, ligand-gated channel family.
Bibliography:ObjectType-Article-1
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ISSN:0021-9258
1083-351X
DOI:10.1016/S0021-9258(17)36802-3