FIG. 4.

Nuclear GSK3β can be redirected from the nucleus to the cytoplasm of differentiating mESCs by reactivation of AKT1. (A) Experimental scheme for panels B through E, where myr.AKT1-ER was activated in E14Tg2a mESCs by the addition of 4OHT (1 μM) for 24 h following 3 days of differentiation (−LIF) and relocalization of GSK3β to the nucleus. (B through D) After 4 days (4d), cells grown in the absence of LIF with or without 4OHT were probed as indicated. eGFP fluorescence (GFP) marks the positions of myr.AKT1-ER-expressing cells. (E) mESCs expressing myr.AKT1-ER were analyzed as for panel B except that LB was added 6 h before fixation.