PKA induced phosphorylation of TG2 at Ser
facilitates downregulation of PTEN in breast cancer cells. (A) MEF-7 and (B) T-47D breast cancer cells were transfected with various TG2 constructs. 48 h post-transfection, cells were serum starved and incubated with or without db-cAMP (100 μM) in the presence or absence of a PKA inhibitor H89 (100 nM). Cells were harvested and cell lysates were analyzed by western immunoblotting using protein and phospho-specific antibodies. Representative immunoblots of three different experiments are shown. Histograms showing relative quantification of protein/phospho-proteins are shown in right panel. (C) Histograms showing pNF-κB-MetLuc2-reporter gene activity in MCF-7 and T-47D cells transfected with TG2 and m-TG2 constructs. Data are represented as mean ± SEM, n = 3. * P < 0.05 (TG2 vs. vector control); ** P <0.01 (TG2 vs. vector control); # P < 0.05 (m-TG2 vs. TG2). WT, wild-type TG2; S216A, Ser216Ala-TG2 mutant.