STRUCTURE OF THE MURINE CD156 GENE, CHARACTERIZATION OF ITS PROMOTER,AND CHROMOSOMAL LOCATION

The murine cell surface antigen mCD156 is a glycoprotein that is expre ssed in monocytic cell limes and consists of a metalloprotease domain, a disintegrin domain, a cysteine-rich domain, and an epidermal growth factor-like domain in the extracellular region, The mCD156 gene is co mposed of 24 exons and 23 introns and spans approximately 14 kilobases , The first exon encodes most of the signal peptide sequence, and the transmembrane region is encoded by a single exon (19), In contrast, th e other regions are composed of multiple exons, Of these, exons 7-12 a nd 12-15 encode a metalloprotease domain and a disintegrin domain, res pectively, Sequence analysis of the 5'-flanking DNA revealed many pote ntial regulatory motifs, Chloramphenicol acetyltransferase analysis de monstrated that nucleotides at positions -183, -334, and -623 containe d cis-acting enhancing elements in a mouse monocytic cell line, aHINS- B3, Nucleotides at positions -183 and -390 contained elements responsi ble for lipopolysaccharide (LPS) inducibility, although several other 5'-flanking regions were also involved in LPS responsiveness, Regions -202, -507, and -659 play a role in interferon-gamma inducibility. Som e of the potential regulatory motifs and other unknown cis elements ma y be involved in the constitutive expression, and LPS and interferon-g amma inducibilities, The mCD156 gene was mapped to chromosome 7, regio n F3-F4.