Poly-phosphoinositides

Muller, M., Schiller, J., Petkovic, M., Oehrl, W., Heinze, R., Wetzker, R., Arnold, K. and Arnhold, J., Limits for the detection of (poly-)phosphoinositides by matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDITOF MS), Chem Phys Lipids, 110 (2001) 151-164. 

In a study on human promyelocytic leukaemia HL-60 cells, quercetin reduced cellular groAvth dose-dependently, and abolished it at a concentration of 80 pM. This effect was attributed to the concomitant inhibition of membrane, but not cytosolic, PTK activity, determined on poly Glu-Tyr (4 1) as a substrate (IC50 = 20.1 pM), Inversely, quercetin inhibited cytosolic, but not membrane, PKC activity. As a possible result of the inhibition of phosphatidyl-inositol kinases, the production of phosphoinositides in intact HL-60 cells was greatly diminished by quercetin [46]. 

Apsel, B. etal. Targeted poly pharmacology discovery of dual inhibitors of tyrosine and phosphoinositide kinases. Nat. Chem. Biol. 4, 691-699 (2008). 

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