Figure 4. Requirement for sPLA₂ catalytic activity.

Control BEAS-2B cells and those stably expressing wild-type enzymes (WT) or the catalytically inactive H48Q mutants of sPLA₂-V (A) or sPLA₂-X (B) were infected with Ad-mPGES-1 for 24 h. Then the cells were subjected to Northern-blotting to assess the expression of mPGES-1 and sPLA₂s. Equal loading of RNA in each lane was verified by ribosomal RNA (rRNA) stained with ethidium bromide. Bottom graphs indicate PLA₂ activity released into the supernatants, which confirmed that the H48Q mutants were catalytically inactive.