The mouse NAD+-dependent 15-hydroxyprostaglandin dehydrogenase (15-PGDH) gene and its 5'-flanking region was cloned from a 129 mouse ES bacteriophage P1 genomic library. The gene contains 7 exons and 6 introns and is 11.3 kb in length. The transcription initiation site was mapped at 35 bases upstream from the ATG start codon. The nucleotide sequence of the 1.6 kb promoter region contains two TATA boxes and a number of potential regulatory elements including Sp1, CRE, GRE, AP1, AP2, NF-IL6 and estrogen receptor binding site. Studies of the promoter's activity showed that the first 400 nucleotides of 5'-flanking region efficiently drove the transcription of the luciferase reporter gene in U936 cells upon stimulation with a phorbol ester.