Maitotoxin, a potent, general activator of phosphoinositide breakdown

FEBS Letters

Gusovsky, Fabian¹  Daly, John W.¹  Yasumoto, Takeshi² 

[1] Laboratory of Bioorganic Chemistry, NIDDK, National Institutes of Health, Bethesda, MD 20892, USA;Faculty of Agriculture, Tohoku University, Sendai, Japan

关键词: Maitotoxin;    Phosphoinositide breakdown;    Ca2+ channel;   

DOI  :  10.1016/0014-5793(89)80151-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Maitotoxin (MTX), a potent marine toxin, elicits a calcium-dependent activation of cells that can be inhibited by calcium channel blockers like nifedipine. MTX also stimulates phosphoinositide breakdown in smooth muscle cells, NCB-20 cells and PC12 cells through a nifedipine-insensitive mechanism. We now report that MTX stimulates phosphoinositide breakdown in a wide variety of cells, and appears to repesent the first general activator of this second messenger-generating system. MTX-induced stimulation of phosphoinositide breakdown is dependent in every cell line on the presence of extracellular calcium. In differentiated HL60 cells, in which a chemotactic peptide (fMLP) activates phosphoinositide breakdown via a pertussis toxin-sensitive mechanism, MTX-induced stimulation is not affected by pertussis toxin treatment. A phorbol ester has no effect on the response to MTX. Thus, MTX stimulates phosphoinositide breakdown through a calcium-dependent mechanism that at least in three cell lines (PC12, NCB20 and HL60) is not mediated by a pathway that involves a pertussis toxin-sensitive guanine nucleotide-binding protein.

【 授权许可】

Unknown