Fig. 9. Association of NCS-1 and PI4Kß occurs in the cytosol and membrane fractions and is not influenced by Ca²⁺. In A, equal proportions of Triton X-100 extracts prepared from total rat brain postnuclear supernatant (S1), membrane (Mem) or cytosol (Cyt) were immunoprecipitated (IP) with anti-NCS-1 antibodies, or rabbit IgG (IgG). In B, equal amounts (600 µg proteins) of rat brain extracts (Con) or rat brain extracts supplemented with either 1 mM Ca²⁺ (+Ca) or 5 mM EGTA were immunoprecipitated (IP) with anti-NCS-1 antibodies or rabbit IgG (IgG). The immunoprecipitates were analyzed by western blotting using anti-PI4Kß or anti-NCS-1 antibodies.