Galactocerebroside mediated transmembrane Ca2+ signalling in U-87 MG cells: Possible involvement of phosphoinositides.
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Date
1996-03
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Abstract
Antibody to galactocerebroside (anti-GalC) has been shown to evoke a Ca2+
response in cultured glioma U-87 MG cells. The rise in [Ca2+]i was due to release of Ca2+ from
the intracellular stores and influx through the plasma membrane. The rise in [Ca2+]i was
markedly inhibited by neomycin sulphate and phorbol dibutyrate suggesting the involvement of
phosphoinositides in Ca2+ mobilization. The Ca2+ response induced by anti-GalC was rapidly
desensitized and repeated addition of anti-GalC did not elevate the [Ca2+]i . Heterologous
desensitization was observed with bradykinin and adenosine triphosphate. The intracellular Ca2+
store mobilized by anti-GalC appears to be the IP3 sensitive pool of endoplasmic reticulum. The
influx of Ca2+ is mediated by a channel. The Ca2+ influx was also prevented by pretreatment of
cells with neomycin sulphate or phorbol dibutyrate. We propose that galactocerebroside may be
associated with phospholipase C or other proteins linked to the phosphoinositide pathway of
transmembrane signalling and anti-GalC activates the breakdown of phosphoinositides and thus
mobilizes Ca2+ in U-87 MG cells.
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Galactocerebroside, transmembrane signalling, fura-2, intracellular calcium, glioma cells, anti-galactocerebroside
Citation
Mishra Sudha, Joshi Preeti G. Galactocerebroside mediated transmembrane Ca2+ signalling in U-87 MG cells: Possible involvement of phosphoinositides. Journal of Biosciences. 1996 Mar; 21(1): 1-12.