Spermine increases phosphatidylinositol 4,5-bisphosphate content in permeabilized and nonpermeabilized HL60 cells

The polyamine spermine (N,N' bis[3-aminopropyl]-1,4-butanediamine) activates phosphatidylinositol-4-phosphate 5-kinase (PtdIns(4)P5K) and phosphatidylinositol 4-kinase (PtdIns4K) in vitro. Spermine concentration increases that occur in proliferating cells were approximated in streptolysin O-permeabilized HL60 cells. When phospholipase C was activated by GTPgammaS to the presence of PITPalpha, 0.1-1.2 mM spermine evoked increases in PtdIns(4,5)P-2 contents in a dose-dependent manner to 110-170% of control and concomitantly decreased inositol phosphate formation by 10-50%. Sperm me-induced increases in PtdIns(4,5)P-2 content in permeabilized cells also occurred during GTPgammaS stimulation in the absence of PITPalpha, were augmented in the presence of PITPalpha, occurred in unstimulated cells and were additive to PtdIns(4,5)P-2 formation evoked by ARF1, another activator of phosphoinositide kinases. Slowly developing spermine-evoked increases in PtdIns(4,5)P-2 contents occurred in nonpermeabilized cells that were abolished in the presence of a spermine transport inhibitor. Data are consistent with spermine at physiological concentrations evoking a PITPalpha-dependent shift in formation of PtdIns(4,5)P-2 from compartments that contained an active phospholipase C to compartments that were separated from an active PLC and from PtdIns(4,5)P-2 formed by ARF1 (C) 2002 Elsevier Science B.V All rights reserved.