The exon-intron organization of the prohormone convertase PC2 gene from the insect Lucilia cuprina

Prohormone or proprotein convertases are members of the subtilisin family o f serine proteases. They are involved in the activation of precursor molecu les by endoproteolytic cleavage at basic amino acid residues. Among the dif ferent members of this prohormone convertase family, the prohormone convert ase 2 (PC2) is almost exclusively expressed in endocrine and neuroendocrine tissues and plays an important role in the endoproteolytic processing of p rohormones. Here we describe the exon-intron organization of the PC2 gene from the inse ct Lucilia cuprina by characterization of PCR-amplified genomic DNA fragmen ts. The insect PC2 gene contains 12 exons with an estimated size of over 14 .5 kb. The exon sizes range from 38 bp to >448 bp. All identified intron-exon boun daries are consistent with the GT-AG-rule. A comparison of the genomic structures of the thus far known prohormone con vertase genes with that of the insect PC2 gene revealed a conservation of t he positions of most introns interrupting the exons coding for the amino-te rminal and catalytic domains. This conservation is consistent with the sugg estion of a common evolutionary origin for the prohormone convertase gene f amily. (C) 1999 Elsevier Science B.V. All rights reserved.