Involvement of protein kinase in Δ12‐prostaglandin J2‐induced expression of rat heme oxygenase‐1 gene

Abstract
We recently identified the cis-regulatory element and its specific nuclear binding factors for Δ12-prostaglandin (PG) J2-induced expression of the rat heme oxygenase, HO-1 [Koizumi, T., Odani, N., Okuyama, T., Ichikawa, A. and Negishi, M. (1995)J. Biol. Chem. 270, in press]. Here we further examined the molecular mechanism underlying the Δ12-PGJ2-induced HO-1 gene expression. Protein kinase inhibitors, 2-aminopurine and staurosporine, suppressed the Δ12-PGJ2-induced HO-1 mRNA and the nuclear protein binding to the Δ12-PGJ2-responsivecis-regulatory element in rat basophilic leukemia cells. Furthermore, the nuclear protein binding to the element was suppressed by in vitro phosphatase treatment of the nuclear proteins from Δ12-PGJ2-treated cells. These findings suggest that Δ12-PGJ2 induces the expression of the HO-1 gene through phosphorylation of the nuclear proteins which bind to the Δ12-PGJ2-responsive element