Aging decreases phosphatidylinositol-4,5-bisphosphate level but has no effect on activities of phosphoinositide kinases
Zambrzycka, A.
Polish Journal of Pharmacology 56(5): 651-654
2004
ISSN/ISBN: 1230-6002 PMID: 15591657 Document Number: 573060
Phosphoinositides play an important role in cell signaling and cytoskeleton function. In this study, we investigate the effect of brain aging on phosphatidylinositol-4-monophosphate (PI(4)P) and phosphatidylinositol-4 5-bisphosphate (PI(4,5)P2) synthesis by PI 4-kinase (PI4K) and PI(4)P 5-kinase (PIP5K) in cortical synaptic plasma membranes in the presence of endogenous and exogenous substrates and gamma-(32P)ATP. Our data demonstrated that aging decreases PI(4,5)P2 formation by 40% in the presence of endogenous substrate, but had no effect on PI4K and PIP5K activities. One can hypothesize that aging decreases PI(4,5)P2 level probably by enhancement of polyphosphoinositides degradation. Alteration of PI(4,5)P2 concentration may disturb cellular signaling and cytoskeleton dynamics.