Mastoparan inhibits phosphoinositide hydrolysis via pertussis toxin‐intensive G‐protein in human astrocytoma cells

[摘要]

Mastoparan inhibited [³H]inositol phosphate accumulation induced by carbachol as well as cyclic AMP accumulation induced by isoproterenol in 1321N1 human astrocytoma cells. Mastoparan inhibited GTPγS-induced, but not Ca²⁺-induced, [³H]inositol phosphate accumulation in membrane preparations with an IC ₅₀ of approximately 10 μM. The inhibitory effect of mastoparan on carbachol-induced [³pH]inositol phosphate accumulation was resistant to pertussis toxin (IAP) treatment in intact cells. These results suggest that mastoparan inhibits phospholipase C in human astrocytoma cells via a GTP binding protein, which is not a substrate for IAP.

[学科分类] 生物化学/生物物理

[关键词] Mastoparan;Phospholipase C;GTP binding protein;Pertussis toxin;Inositol phosphate;IAP;islet activating protein (pertussis toxin);GTPγS;guanosine 5'-[γ-thio]triphosphate;G-protein;guanine nucleotide regulatory protein;cyclic AMP;adenosine 3';5'-mono-phosphate;DMEM;Dulbecco's modified Eagle's medium;EMEM;Eagle's minimum essential medium