NUCLEAR TRANSLOCATION OF PHOSPHATIDYLINOSITOL 3-KINASE IN RAT PHEOCHROMOCYTOMA PC-12 CELLS AFTER TREATMENT WITH NERVE GROWTH-FACTOR

Immunocytochemical analysis of PI 3-kinase localization in PC 12 cells demonstrates that the enzyme translocates to the nucleus after cell t reatment with differentiating doses of NGF. The association of PI 3-ki nase to the nucleus occurs rapidly (within minutes) and increases with the time of exposure to NGF. We suggest that PI-3 kinase specific loc alization may determine the production of novel phosphoinositides in c ell compartments targeted to effect diverse cell responses. The nuclea r translocation is consistent with accumulating data on the existence of a nuclear inositol lipid cycle which could also include 3-phosphory lated inositides, participating to the modulation of the cell response to extracellular stimuli.