PKA negatively regulates cell survival. (a and b) HUVECs transfected with GFP (–) or a dnPKA (+) were plated on (a) fibronectin-coated, (b) vitronectin-coated, or poly-L-lysine–coated plates in the absence or presence of anti-α5β1, anti-αvβ3, or anti-α2β1. After 24 hours, the percentage of annexin V–positive cells was determined. (c) HUVECs treated with culture medium or dibutyryl cAMP (250 μM) and HUVECs transfected with GFP or the catalytic subunit of PKA (PKA_cat) were plated on vitronectin-, or poly-L-lysine–coated plates. After 24 hours, the percentage of annexin V–positive cells was determined. (d) Expression of transgenes was detected by Western blotting cell lysates with anti-GFP or anti-V5.