Stimulation of phosphoinositides breakdown by the heat stable E. coli enterotoxin in rat intestinal epithelial cells

FEBS Letters

Ganguly, Uma¹  Banik, Napur¹ 

[1] National Institute of Cholera and Enteric Diseases, P-33 CIT Road, Scheme XM, Beliaghata, PO Box 177, Calcutta 700010, India

关键词: Heat stable enterotoxin;    Inositol lipid;    Inositol phosphate;    (Epithelial cell);   

DOI  :  10.1016/0014-5793(88)80083-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Rat intestinal epithelial cells were labelled with [³²P]P_i and extracted, and the phospholipids were analysed by thin-layer chromatography. ³²P-incorporation in phosphatidylinositol (PI) and phosphatidylinositol 4-phosphate (PIP) and phosphatidylinositol 4,5-phosphate (PIP₂) were measured in control and heat stable enterotoxin (ST)-treated cells. ST was found to induce rapid degradation of PIP and PIP₂. The degradation of inositol lipids was accompanied by an increase of water soluble inositol phosphate (IP₁, IP₂, IP₃) compounds. There was a two-fold increase of radioactivity in IP₂ and IP₃ but no significant change was observed in IP₁. Phospholipase C activity was increased tenfold with substrate PIP₂ in ST-pretreated cells. The present study indicates that ST triggers another second messenger system by increasing the PIP₂ hydrolysis with the enzyme phospholipase C.

【 授权许可】

Unknown