Molecular cloning of rat renin cDNA and its gene.

Renin (EC 3.4.23.15) is an aspartyl protease that cleaves its only known substrate, angiotensinogen, to release the vasopressor hormone angiotensin. We have isolated full-length cDNAs for renin from a rat kidney cDNA library. The cDNAs are complementary to a 1434-nucleotide rat kidney mRNA that encodes preprorenin, the 402-amino acid precursor of renin. This rat cDNA was used to isolate the complete copy of a renin gene from a rat genomic library, and a comparison of this genomic clone with rat genomic DNA showed that renin is a single-copy gene in the rat. Rat renin is 85% identical to one mouse renin isozyme (renin-1) and 81% identical to the second mouse renin isozyme (renin-2), suggesting that the duplication of the mouse renin genes is a more recent event than the speciation of rats and mice. Analyses of rat, human, and mouse renin sequences revealed that the potential to form two-chain renin is apparently peculiar to mouse renin, and the expression of a tenth exon (which results in a three-amino acid insertion) is observed only in the human renin gene.