Fig. 5. 14-3-3 and LKB1 cooperate to regulate QSK and SIK localization. Control (CT) HeLa cells that lack LKB1 expression or HeLa cells that stably express wild-type (WT) or kinase-inactive (KI) LKB1 were transfected with the indicated constructs encoding the expression of GFP-QSK (A, panels 1-9) or GFP-SIK (B, panels 1-9). Twenty-four hours post-transfection the cells were fixed in 3% (v/v) paraformaldehyde and GFP localization was visualized directly by observing GFP fluorescence. The cells were viewed using a Zeiss LSM 510 META or Leica Sp2 AOBS confocal microscope. The cells shown are representative images obtained in three separate experiments. The low level of cytoplasmic SIK (cyt) is indicated. Bars, 10 µm.