The polyphosphoinositide cycle exists in the nuclei of Swiss 3T3 cells under the control of a receptor (for IGF-I) in the plasma membrane, and stimulation of the cycle increases nuclear diacylglycerol and apparently induces translocation of protein kinase C to the nucleus.

摘要: Abstract When Swiss 3T3 cells are treated with Insulin-like Growth Factor I, a rapid decrease in the mass of polyphosphoinositol lipids (phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate) occurs within nuclei, concomitant increase nuclear diacylglycerol translocation protein kinase C to region. This is contrast effects regulatory peptide, bombesin, which causes similar inositol lipid changes plasma membrane, has no effect on inositide levels post-nuclear membranes. These results suggest existence discrete polyphosphoinositide signalling system entirely distinct from well-known membrane-located system, under control by cell surface-located receptors.