Identification of an immediate early gene, pghs-B, whose protein product has prostaglandin synthase/cyclooxygenase activity.

We have characterized a growth factor-inducible gene, pghs-B, isolated by differential screening of a lambda complementary DNA library from RNA of serum-stimulated NIH 3T3 cells which encodes a 604-amino acid protein presenting high similarity with prostaglandin G/H synthase (PGHS). Induction of both pghs-B mRNA and protein is rapid and remains at high levels for several hours. The increase in pghs-B mRNA is mainly due to transcriptional activation of the gene. PGHS-B has been expressed in the baculovirus system and has been demonstrated to be involved in prostaglandin synthesis and to be inhibited by indomethacin, demonstrating that PGHS-B is indeed an enzyme related to PGHS. The pghs-B gene maps to the [1G-1H2] region of the murine genome.