Skip to main content
. 2012 Jan 17;7(1):e30311. doi: 10.1371/journal.pone.0030311

Figure 3. Involvement of p-Akt in the proteasome mediated degradation of PDCD4 during serum deprival-readdition treatment.

Figure 3

(A) OVCA433 and SKOV3 were deprived from serum (SD) for 48 hours before serum was re-administrated for 1 h, 2 h, 6 h and 24 h. There was a dramatic increase of PDCD4 protein expression upon serum deprival treatment. PDCD4 rapidly disappeared after serum was re-administered. P-Akt and p-ERK were down-regulated when serum was withdrawn and gradually resumed after serum was added back. Total Akt and ERK were not affected during the treatment. (B) PDCD4 was elevated in serum deprived cells (SD) and depleted when serum was added back (SA, serum addition) for 2 and 4 hours. The administration of either proteasome inhibitor MG132 (S+MG132), or PI3K inhibitor LY294002 (S+LY294002) prevented the depletion of PDCD4. DMSO was also included as control (S+DMSO). Negative control (−ve) indicated for cells cultured with medium containing serum. (C) The expression of PTEN, p-Akt and p-ERK were altered in all PDCD4 over-expression stable clones, whereas the expressions of total Akt and ERK remained unchanged. Three independent experiments were performed. The quantification of the western blotting bands was presented in Data S2.