Skip to main content
. 2014 Dec 1;190(11):1229–1242. doi: 10.1164/rccm.201405-0872OC

Figure 5.

Figure 5.

Protein kinase A (PKA) inhibition prevents α1-antitrypsin (A1AT) activation of protein tyrosine phosphatase 1B (PTP1B)/protein phosphatase 2A (PP2A). A1AT did not alter PP2A B subunit (A) protein or (B) gene expression in A549 cells. (C) A1AT enhances PP2A activity primarily in the cytoplasm without altering translocation of the protein. (D) A1AT stimuli did not alter binding of the PP2A inhibitor, SET, to PP2A, demonstrated by IP of PP2AC and probing for SET and PP2AC. (E) Inhibition of PKA/cAMP activity alters A1AT’s ability to activate PP2A. Graphs represent mean ± SEM of three measurements. Representative immunoblots are shown demonstrating equal cellular protein content. *P < 0.05 for A1AT-treated versus albumin-treated A549 cells. **P < 0.05 for A1AT-treated versus A1AT+PKA inhibitor–treated A549 cells.