Fig. 8. MO25 isoforms stabilize the LKB1–STRADα complex. (A) 293 cells were transfected with 3 µg of the DNA construct encoding for expression of GST–LKB1, in the presence or absence of 3 µg of the Flag-STRADα construct and in the absence or presence of the indicated amounts of Myc-MO25α construct. Thirty-six hours post- transfection, GST–LKB1 was affinity purified from the cell lysates and immunoblotted with appropriate epitope antibodies to detect LKB1, STRADα and MO25α. Five micrograms of total cell lysates prior to affinity purification were also immunoblotted with the indicated antibodies (lower panels). (B) As above except that the MO25β construct was employed instead of the MO25α construct. Similar results were obtained in three separate experiments.