Figure 5. Reversibility of the enhanced association of X11L with APP by withdrawal of osmotic stress.
(A) Time course of enhanced association of X11L with APP in cells treated with 0.5 M sorbitol. HEK293 cells (~2 × 105) were transiently transfected with 0.5 μg of pcDNA3.1-FLAG-X11L (+), and treated with (2, 5, 15, 45 and 120 min) 0.5 M sorbitol or left untreated (−). The cell lysates were incubated with GST-APPcyt, and lysates (input) and FLAG-X11L bound to GST-APPcyt (bound) were analyzed by immunoblotting with anti-FLAG M2 antibody.
(B) Effect of sorbitol withdrawal on the enhanced association of X11L with APP. HEK293 cells (~2 × 105) were transiently transfected with 0.5 μg of pcDNA3-HA-X11L (+), and treated with (+) or without (−) 0.5 M sorbitol for 45 min. The cells were then further cultured for 0, 15, 45, 120 and 240 min in the absence of sorbitol (restore). The cell lysates were incubated with GST-APPcyt, and HA-X11L bound to GST-APPcyt (bound) and the lysates (input) were analyzed by immunoblotting with anti-HA 12CA5 antibody.