Aging decreases phosphatidylinositol-4,5-bisphosphate level but has no effect on activities of phosphoinositide kinases.
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)P(2)) 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-[(32)P]ATP. Our data demonstrated that aging decreases PI(4,5)P(2) 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)P(2) level probably by enhancement of polyphosphoinositides degradation. Alteration of PI(4,5)P(2) concentration may disturb cellular signaling and cytoskeleton dynamics.
Zambrzycka
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Department of Cellular Signaling, Medical Research Centre, Polish Academy of Sciences, Pawińskiego 5, PL 02-106 Warszawa, Poland. agatazambrzycka@hotmail.com
D019870:1-Phosphatidylinositol 4-Kinase / Q000378:metabolism*; D000375:Aging / Q000502:physiology*; D000818:Animals; D008297:Male; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
D019269:Phosphatidylinositol 4,5-Diphosphate; D019870:1-Phosphatidylinositol 4-Kinase