Fig. 6.

Cytosol-restricted constitutively active glycogen synthase kinase-3β (GSK-3β) enzyme enhances phosphorylated nucleophosmin (pNPM) threonine 95 (T95) phosphorylation in intact cells in the absence of stress. Primary murine proximal tubule epithelial cells (PTECs) were infected with lentiviral vector containing a flag-tagged cytosol-restricted NPM mutant (Flag-NPM-Amut) and either the constitutively active (GSK-3β-S9A) or constitutively inactive (GSK-3β-K85R) enzyme. After pretreatment with 4-benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione (TDZD-8; 2 or 10 μM), steady-state pNPM T95 content was assessed in immunoprecipitates (IP) harvested with a flag antibody. pNPM T95 specific antibody was used for immunoblot (IB) analysis.